Soilless culture is considered to be an alternative to soilbased cultivation. It has been developed quickly because of rapid growth on biomass and high quality of crops. Hydroponics and aeroponics are both soilless culture, but with different techniques. Aeroponics is a newly soilless culture technique, in which the roots are suspended midair inside a chamber and are intermittently sprayed with a nutrient solution to supply the plants with mineral and water. Unlike hydroponics using water as a growing medium and relying on essential mineral to sustain plant growth, aeroponics is conducted without a growing medium. Thus, there are significant differences of root zone between aeroponic and hydroponic cultivation systems. However, little effort has been found in the literature evaluating the effect of the two soilless techniques on yield and quality of growing vegetable.
In this study, experiments were carried out to compare the biomass production and nutritional quality of lettuce between hydroponic and aeroponic cultivation systems under different nitrogen levels (2, 8 and 20 mmol/L NO₃^--N). 
Results showed that under the same nitrogen level, higher biomass, root growth, relative growth rate and photosynthetic rate were observed for lettuces grown in aeroponics than in hydroponics. Nitrate and glutathione contents were lower in aeroponics, while the ferric reducing/antioxidant power (FRAP) value and 1, 1-diphenyl-2-picrydrazyl (DPPH) radical scavenging rate were comparable to those in hydroponics. There were no differences in contents of soluble protein, soluble sugar and ascorbic acid, but the accumulations of soluble protein, soluble sugar, ascorbic acid and glutathione in aeroponics were markedly higher than those in hydroponics. Furthermore, the contents of nitrate and soluble protein of lettuces increased both in hydroponics and aeroponics, while the concentrations of soluble sugar, ascorbic acid and glutathione, FRAP value and DPPH radical scavenging rate decreased with increasing nitrogen level. Highest biomass, root morphological index, photosynthetic index, accumulations of soluble protein, soluble sugar, ascorbic acid and glutathione were observed under the nitrogen level of 8 mmol/L. 
In sum, aeroponics is beneficial for higher biomass, antioxidant accumulation and antioxidative activity, especially under the nitrogen level of 8 mmol/L.

Sweetpotato (Ipomoea batatas) is an important upland crop in China, which plays an important role in feed and industrial raw materials. The root tuber has rich nutrition, and the aerial part of stems and leaves also has extremely high nutritive value. Recently, research on sweetpotato for vegetable use increased gradually. With the rapid development of urbanization process, the cultivated area decreased gradually, along with the decline in quantity and quality of agricultural products. However, the increased space of balcony and roof accelerated the development of balcony agriculture and urban roof agriculture. Meanwhile, new devices for planting become popular in daily life in cities. Sweetpotatoes grow faster in summer, and can solve the problem of leaf vegetables in short supply. Moreover, people can plant organic sweetpotato for vegetable use at home in a convenient and safe way.
In this paper, three cultivation methods (soil cultivation, substrate cultivation and pipeline nutrient solution culture) and three cultivars (Pushu 53, Guangcaishu 5 and Fushu 18) of sweetpotato for vegetable use were selected for urban roof agriculture, to compare the impact of different cultivation methods on yield and quality of sweetpotato. In July 2014, stem cuttings from each of the three cultivars were planted under three cultivation methods in roof of Jixian Building in Zhejiang A & F University. Experiments were conducted in a randomized complete block design with three replications. Seedlings were examined and replanted in time after cutting to ensure a full stand of seedlings. Furthermore, control and prevention for pests should be conducted during the growth period, and sweetpotato tips (15 cm) were harvested after growth. The yield, water content, pigment content, soluble sugar content, soluble protein content, vitamin C content and nitrate content were determined in the lab.
The results showed that the pipeline nutrient solution culture had significant advantages compared with soil cultivation or substrate cultivation. The stem apex yield, chlorophyll b content, total chlorophyll content, carotenoid content and soluble sugar content of Pushu 53, Guangcaishu 5 and Fushu 18 were highest under the pipeline nutrient solution culture condition among all the treatments, while the nitrate content was the lowest. 
In conclusion, planting Fushu 18 using pipeline nutrient solution culture in urban roof agriculture will be a better choice, with higher biomass and guaranteed quality of sweetpotato for vegetable use.

Substantial amounts of heavy metals including cadmium have been released to the environment by geological activities or by anthropogenic impacts and industrialization, such as mining, smelting activities, sewage sluge, and the unreasonable utility of fertilizers and pesticides. Cadmium (Cd) is a toxic heavy metal with high mobility and can be readily absorbed into rice plants and transported to human bodies through the food chain. Selenium (Se) is an essential element for animals and human beings, which usually acts as a cofactor in antioxidant enzymes in human bodies. Though Se is not considered as an essential element for plants, there are lots of evidence suggesting its beneficial effects for plant growth and resistance to heavy metal stress. However, little effort has been found about the comparative study of Se effects with respect to different grain Cd-accumulative rice seedlings. Therefore, the aim of the present study is to explore the mitigation mechanisms of Se to Cd stress in different rice cultivars. 
In this research, a hydroponic experiment was conducted to study the alleviation role of Se in two hybrid rice variety (Yixiang 2115 with low grain Cd accumulation, Chuanguyou 2348 with high grain Cd accumulation) seedlings. Cd in the concentrations of 0, 0.1, 1 mmol/L with or without 3 μmol/L Se (Na₂SeO₃) solutions were treated on the two rice seedlings. The root and shoot biomasses, chlorophyll contents, Cd concentration and contents of mineral nutrient elements were measured. 
The results showed that, Se increased significantly the biomass and chlorophyll a content of the two rice seedlings under the Cd stress, but decreased the chlorophyll b content in Chuanguyou 2348, which had the high Cd content in grain. The contents of ascorbic acid and glutathione in the two rice seedlings also increased with the supplement of Se, but those were higher in Chuanguyou 2348 than in Yixiang 2115, showing the differences between the two varieties. Under the 1 mmol/L Cd stress, Se promoted the synthesis of ascorbic acid and reduced glutatione to alleviate Cd stress in Chuanguyou 2348, but accelerated the synthesis of phytochelatins in Yixiang 2115 to mitigate Cd stress. Se also mitigated the injuries of the Cd stress to roots, which kept root activity in higher level than those without Se supplementation. The Cd content in shoots of the two varieties increased sharply with the Cd concentration increasing in the nutrient solution. Se could inhibit the absorption of Cd in the two varieties directly. Se could decrease the contents of calcium (Ca) and zinc (Zn) in shoots of the two varieties under the Cd stresses, but induced different reactions on cuprum (Cu) and manganese (Mn) contents. To the roots, Se increased the Ca and Cu contents, but decreased the Zn and Mn contents in the two varieties under the Cd stress conditions.
It is concluded that, Se can mitigate inhibition of Cd stress to rice seedling growth by elevating seedling biomass, chlorophyll a content, changing the contents of ascorbic acid, glutathione and non-protein thiols, keeping higher root activity compared with only Cd treatment. Besides, Se can directly suppress Cd uptake in rice seedlings and mainly affects Cu and Mn concentrations in shoots between the two rice varieties.

Maca, Lepidium meyenii Walp. (Brassicaceae), has been domesticated as a medicinal crop at high altitude of the Peruvian Andes for two millennia. Its cultivars or landraces with different chemical profiles were bred and introduced out of Peru to various countries for industrial cultivation as driven by the increasing demand. Maca, which was approved on the China Inventory of New Resource Food in 2011, was also massively cultivated in multiple regions in China. The applied Maca cultivars differed among the producers, which may result in significant inconsistency of Maca quality. Thus, it is increasingly urgent to assess the quality of Maca roots with different cultivars and cultivation localities.
We simultaneously conducted both common garden and translocation experiments to address the contribution of both genetic and environmental variation to chemical similarity of Maca. Contents of mineral elements, amino acids, total alkaloid, and macamides were determined on five replicate samples of each Maca category using inductively coupled plasma mass spectrometer (ICP-MS), L8900 amino acid analyzer, UV-2700 spectrophotometer and ProStar 210 high performance liquid chromatograph. Both the chemical component contents and overall similarity coefficient were calculated and compared for the four parameters above using analysis of variance (ANOVA), principal component analysis (PCA), hierarchical clustering analysis (HCA) and cosine coefficient. Data analyses were conducted using SPSS version 22.0.
The results showed that the same cultivar from the translocation experiment (H₆, A₆) demonstrated remarkably greater chemical dissimilarity than the four cultivars (H₁, H₂, H₃, H₆) from the common garden experiment. The former experimental pair significantly differed in 11 components, while the latter four cultivars differed in five components. Although different groups of components differed to different extents between either cultivars or localities, the contents of mineral elements were prominently different between localities. Specifically, the total content and the contents of five of the total eight mineral elements were significantly different between the two studied localities. Meanwhile, Maca from Hongyuan of Sichuan Province (H₆) showed a significantly higher content of total alkaloids than that from Aba of Sichuan Province (A₆). Macamides did not differ either between localities or cultivars. A remarkable differentiation and the greater chemical dissimilarity between localities were also supported by the comparisons of the overall chemical similarity using PCA, HCA and cosine coefficient. 
In conclusion, the chemical quality of the analyzed Maca is mainly determined by the environmental difference, particularly the soils which may directly impact the contents of mineral elements in Maca roots. More attention should be laid on the selection of farm localities and the control of cultivation environments. Further investigations of genetic distances of Maca cultivars and their relationships with chemical similarity will help better understand the exact contribution of cultivars.

Loquat, Eriobotrya japonica (Thunb.) Lindl., is indigenous in southeast of China, which belongs to the family Rosaceae and subfamily Maloideae. Based on the color of fruit flesh, loquat can be sorted into red- and white-flesh cultivars. Zhejiang Province is the major producing area of loquat in China, with an area of about 1.2×10⁴ hm²; the annual production of loquat is about 6.5×10⁴ t, with a value of about 2.5 billion Chinese Yuan. Therefore, germplasm resources of loquat are abundant in Zhejiang Province. However, there are two whiteflesh loquat germplasms (Ruantiao white-flesh loquat from Huangyan, white-flesh loquat from Lanxi) which are different in leaf morphology and fruit shape from two producing areas of Zhejiang Province. Controversy on whether the two varieties are synonyms has existed for a long time, and no conclusive evidence was presented yet. 
In this paper, morphological characteristics of the two varieties were examined, and their ploidy and stomata were analyzed, and their genetic relationships were identified using simple sequence repeat (SSR) marker. 
Results showed that the single fruit mass of Ruantiao white-flesh loquat from Huangyan area was 1.38 times heavier than that of whiteflesh loquat from Lanxi area. However, the number of seeds, pericarp thickness, fruit hardness of whiteflesh fruit from Lanxi were 1.36, 1.096 and 1.22 times higher than those of Ruantiao white-flesh loquat from Huangyan, respectively. Flow cytometry analysis indicated that the two varieties were both diploid. Stomatal density of whiteflesh loquat from Lanxi was significantly higher than Ruantiao white-flesh loquat from Huangyan, while conversely, the stomatal area from Lanxi was significantly smaller than that from Huangyan. The cluster analysis using SSR marker showed that the genetic similarity coefficient (GS) of the loquat from Huangyan was 0.40, and 0.45 from Lanxi, indicating these two kinds of white-flesh loquats had a distant genetic relationship. The difference of the two varieties in maturation periods was mainly affected by variety characteristics and different geographical regions. 
In conclusion, the two experimental materials have a distant genetic relationship and belong to different germplasms. The creation of the novel germplasm has positive significance in enriching market supply and industrial development of white-flesh loquat.

Much research has been done on the high economic benefit, stable yield and superior seed quality of monocropping vegetable soybean. But with the arrival of the food crisis, intercropping is more and more popular. Whether vegetable soybean can maintain the excellent qualities mentioned above still needs more research. 　　We explored the effects of maize-soybean strip intercropping on seed quality of vegetable soybean with field experiment. Maize (Zhenghong 505) was planted two lines in narrow row while vegetable soybean was also sowed two lines in wide row at the same time (May 5th, 2015). Three vegetable soybean varieties were adapted in this experiment: Zhexiandou 4, Qingsu 5 and Shenxian 6. At the beginning of R6, samples were taken to determine the agronomic characters and nutrition quality of vegetable soybean. The seed agronomic characters include the fresh mass per 100-pod, fresh mass per 100-pod seeds， fresh mass per 100-seed mass, flat pods number per plant, one-pod number per plant, two-pod number per plant, three-pod number per plant and two-pod rate per plant. The nutrition quality contained protein, free amino acid, crude fat, soluble sugar, starch， and moisture. 　　As the results showed, the agronomic characters of intercropping vegetable soybean decreased compared with those of monocropping, but 100-seed mass increased. The content of protein and soluble sugar of intercropping vegetable soybean seeds was higher than those in monoculture. What’s more, the free amino acid of Zhexiandou 4, Shenxian 6 was higher than that in monoculture, but Qingsu 5 was lower. Comparing these three vegetable soybeans, we concluded that as for appearance quality Qingsu 5 was the best, and Zhexiandou 4 took the second, Shenxian 6 was poor. However with regard to nutrition, Shenxian 6 was the best, Qingsu 5 was the last. 　　As the interactive analysis showed, both appearance and nutrition quality of vegetable quality was mainly determined by cropping pattern. But there were some difference among different varieties. Correlation analysis suggested that fresh mass per 100-seed mass was significantly negatively correlated with crude fat, and it was the same as fresh mass per 100-seed mass and moisture. Fresh mass per 100-pod seeds was significantly positively correlated with sweet amino acid and free amino acid. 　　In summary,when the appearance quality is good, the nutrition quality will be poor. So it is necessary to coordinate appearance quality and nutrition quality. Because the appearance quality of vegetable soybean is affected by cropping pattern and the nutrition are affected by pattern and variety, we should screen out well adaptability and good quality varieties. At the same time, we must focus on techniques including line spacing, crop allocation, density, fertilization management and harvest time. So that we can achieve high quality and high yield vegetable soybean in intercropping pattern.

Nitrogen is the most important mineral nutrient taken up from the soil by plants. In cereal crops, accumulation and utilization of nitrogen are essential physiological processes that determine grain yield and quality. However, low nitrogen fertilizer efficiency and much nitrogen loss directly and indirectly led to a series of environment problems. The nitrogen fertilizer efficiency of rice cultivars is significantly different. Thus, exploring and exploiting low-nitrogen tolerant rice germplasm resources, and cultivating genetically modified rice cultivars with high nitrogen fertilizer efficiency is an ideal way to solve this problem. Previous studies were carried out on low nitrogen tolerance, and a number of useful low nitrogen tolerant germplasm resources were identified. However, there are few studies about screening and comprehensive evaluation of low nitrogen tolerance of Zhejiang photosensitive japonica rice cultivars. 　　To understand the difference of low nitrogen tolerance in Zhejiang photosensitive japonica rice varieties, 14 Zhejiang photosensitive japonica rice cultivars were used to analyze the morphological traits at the seedling stage, the tiller number at the tillering stage and the yield-related traits at the maturity stage under low nitrogen treatment in the nutrient solution and field test. Fuzzy membership function, principal component analysis and cluster analysis were used to comprehensively evaluate low nitrogen tolerance. 　　The results showed that low nitrogen stress had a significant impact on the morphological and yield indexes of rice cultivars. Seedling height, shoot dry mass, tiller number, plant height, effective panicle number and yield per plant were reduced by 15.61%, 36.92%, 38.88%, 5.98%, 12.98% and 29.44%, respectively; root tips number, root length, root dry mass, root to shoot ratio, panicle length, seed set rate and 1 000-grain mass were increased by 2.68%, 1.83%, 8.31%, 74.78%, 0.05%, 1.18% and 0.26%, respectively. Based on the coefficients of variation of relative value, total of 6 indexes including root tips number, shoot dry mass, root dry mass, root to shoot ratio, effective panicle number and yield per plant were selected as indexes for screening and evaluating low nitrogen tolerance. And then we used fuzzy membership function, principal component analysis and cluster analysis to comprehensive evaluate low nitrogen tolerance, the coincidences rates of the results reached 80%. This study showed that Zhejing 88, Xianghu 301 and Xiushui 42 were low nitrogen resistant cultivars; Hu 251, Zhehu 3 and Ainuo 21 were sensitive cultivars. 　　According to the results, root tips number, root dry mass, shoot dry mass and root to shoot ratio at the seedling stage, effective panicle number and yield per plant at the maturity stage were selected as indexes for screening and evaluating low nitrogen tolerance of the tested cultivars.

Continuous cropping obstacle caused by intensive cropping of potato has seriously affected its healthy development of industrialization. Autotoxicity was confirmed to be one of the mechanisms causing continuous cropping obstacle; therefore it will be significance to study the autotoxicity of potato for sustainable agriculture production. The growth of plants can be inhibited by autotoxicity through regulating the permeability of cell membrane, affecting the function and enzymatic activities, and even the photosynthesis system. It was so difficult to eliminate the continuous cropping obstacle by agronomic measures, thus it become necessary to solve the problem of continuous cropping obstacle and to reveal the mechanism of autotoxicity for potato.
In this paper, a pot experiment was conducted to investigate effects of water extracts from different organs (root, stem and leaf) of potato on its growth and development. The potatoes were collected from tuber of mature potato in the field, and matrix culture method was adopted to conduct the experiments. Morphological characteristics of root system (root length, root surface area and root volume), and physiological parameters (catalase, peroxidase and malondiadehyde) were used as indicators to study the autotoxicity effect. 
The results showed that: Water extracts from different organs of potato exhibited obvious inhibitory effect on the growth of potato, and the extracts from stem and leaves had significant inhibitory effect on the height of potato (P<0.05), with the alleopathic response index (RI) value of -0.11. The root extracts significantly inhibited the number of branches and stem diameter, with the RI value of -0.11 and -0.13, respectively. Meanwhile, the damage of root system caused by the root extracts was also worst, with the RI value of -0.25 for the root surface area, -0.32 for the root tip number, and -0.32 for the branch number, respectively. The chlorophyll contents of potato leaf, activities of peroxidase and catalase all decreased under the treatments of water extracts from different organs of potato; however, the MDA content was increased, and the allelopathic effect of root extracts was the strongest, with the RI value of -0.10. The soluble sugar content was significantly increased by the root extracts, while reduced by the stem and leaf extracts, with the RI value of -0.11 and -0.02, respectively. On the contrary, the soluble protein content was increased by the stem and leaf extracts, while reduced by the root extracts, with the RI value of -0.06. 
In conclusion, the autotoxicity effect is observed in different organs of potato, but the adaptation to allelochemicals is distinct among the different organs of potato, and the inhibitory effect by root extracts is strongest.

Shine Muscat (Vitis labruscana Bailey ×V. vinifera L. Shine Muscat) is a diploid table grape cultivar resulted from cross breeding of ‘Akitsu21’ [‘Steuben’ (V. labruscana) × ‘Muscat of Alexandria’ ( V. vinifera)] with ‘Hakunan’ (V. vinifera) released by National Institute of Fruit Tree Science (NIFTS) in Japan. It has a large berry size, bright yellowgreen pericarp, crispy and juicy flesh, musky flavor, high soluble solid content and low acidity. Fruit ripening of Shine Muscat was in middle to late August with a long shelf life. The average mass is 10.0 g and 12.4 g for seeded and seedless fruit production, respectively. The seedless berries can be commercially produced by applying gibberellin A3 (GA3) to flower and fruit clusters in full bloom and 10 to 15 days after full bloom, respectively. Under natural conditions, however, the berries of Shine Muscat are smaller, and grape clusters are relatively sparse. Besides, Shine Muscat grape has the problem of rusty spot incidence, which occurs at the maturation stage just before harvest. Tiny reddishbrown blotches appear on the surface of berries and considerably affected its production quality and commodity value. 
In this study, 3yearold Shine Muscat trees were selected as the material, and the effects of different concentrations and collocations of GA3 and N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) treatments on fruit setting and fruit quality of Shine Muscat grape were studied. 
The results showed that co-treatment with GA3 and CPPU could significantly improve the fruit setting rate, fruit cluster density, yield stability of Shine Muscat grape; meanwhile, it could also improve the percentage of seedless fruit. The combined use of GA3 and CPPU could remarkably increase single fruit mass, spike mass, total soluble solid content (TSS) and fruit hardness. Higher concentration of CPPU in the early stage would result in higher fruit hollow rate. On the contrary, lower concentration of CPPU in the early stage had no significant effect on fruit enlargement. Meanwhile, higher concentration of CPPU in the later stage would decrease the content of fruit soluble solids. 
In sum, comprehensive consideration for the fruit cluster compactness, fruit size, sugar degree, aroma component and cost saving, the better cotreatments in production are as follows: 1) 25 mg/L GA3+10 mg/L CPPU for one time at 5 days after full bloom, or 2) 25 mg/L GA3+5 mg/L CPPU at 1-3 days right after full bloom, and 25 mg/L GA3 at 10-15 days after full bloom (treatment Ⅴ), or 3) 25 mg/L GA3+5 mg/L CPPU at 1-3 days right after full bloom, and 25 mg/L GA3+5 mg/L CPPU at 10-15 days after full bloom (treatment Ⅸ). The results will provide technical support on solving the key problems during cultivation of the new cultivar Shine Muscat grape

Blueberry (Vaccinium spp.) is well known for its rich anthocyanins and other bioactive compounds, which helps preventing from cardiovascular disease and other chronic illnesses. Over the past decades, blueberry has been cultured in many areas of China, thus became the fastestgrowing species in fruit production, potentially making China one of the largest blueberryproducing countries in the world. However, blueberry growth and production were severely affected by drought events in areas of Yangtze River. Vaccinium plants preferred acidic soils and spontaneously formed mutualistic symbiotic associations mainly with soil fungi of the phylum Ascomycota, called ‘ericoid mycorrhizae’. However, some reports have indicated that the absence of ericoid mycorrhizal fungi inoculum may allow Vaccinium plants to associate with arbuscular mycorrhizal (AM) fungi, and AM fungi inoculation significantly enhanced growth of Vaccinium plants. Southern highbush blueberry (Vaccinium corymbosum) has short or even rare root hairs in field systems, and depends on fungi for optimal growth. Meanwhile, few reports were about the effects of AM fungi on osmotic adjustment and reactive oxygen metabolism of southern highbush blueberry. The purpose of this study is to evaluate the effects of Glomus mosseae, G. versiforme, G. intraradices and G. etunicatum on the southern highbush blueberry seedlings under drought stress conditions, and antioxidant and osmotic adjustment matters, mineral nutrition in blueberry plants and enzymatic activities in rhizosphere soil were investigated. Two soil water regimes (wellwatered ［WW］ and drought stress ［DS］) and five AM fungi inoculations (four Glomus and non-AM fungi inoculation ［CK］) were arranged in a complete randomized block design. Each treatment (one plant per pot) was performed in three replicates. Water treatments began after 134 days (July 31, 2014) adaption of greenhouse conditions, and WW pots were maintained, but DS pots were cut off for 20 days of water supply and resumed on August 20. Meanwhile, the leaves of blueberry cultivar Misty plants were collected for determination of physiological index on 13 d drought, 20 d drought and 2 d rewatering, respectively. The results showed that the leaf relative water content (RWC) and chlorophyll contents decreased in DS treatments, while the soluble sugar content, superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents increased, but had no significant effects on mycorrhizal colonization. Under the DS conditions, leaf RWC, chlorophyll, soluble sugar contents and SOD activity were significantly higher in AM fungiinoculated plants, especially in G. mosseaeinoculated plants than in non-AM fungi inoculated plants, while the leaf MDA content was lower. In addition, AM fungi, especially G. mosseae, increased phosphorus (P) and potassium (K) contents in the leaves, stems and roots, as well as acid phosphatase (ACP), catalase (CAT) and urease activities in rhizosphere soil of blueberry plants, in comparison with the nonAM fungiinoculated treatment (CK).  These results indicate that the drought tolerance of blueberry cultivar Misty is enhanced with AM fungi inoculation through increase of antioxidant enzyme and osmotic adjustment, and the soil environment is improved, accompanied by P and K uptake increases by plants. In addition, G. mosseae is the most beneficial Glomus among the four AM fungi to improve the resistance of blueberry cultivar Misty plants against DS.

Lily has high ornamental and economic value. However, the reproduction rate of traditional propagation method was low, and was easily infected, causing degradation of bulbs and associated problems. Application of tissue culture techniques can greatly improve the reproduction coefficient in the production process, but the weakness of plantlets and low survival rate in the transplanting process have become a prominent problem during the commercial process of lily bulbs. Hence, to cultivate strong seedling and increase survival rate, we could promote the formation and enlargement of bulbs by in vitro culture. This study aimed to explore the influence of sucrose and photoperiod on the enlargement of in vitro bulblet of Lilium sargentiae and their interaction effect, and to explain their action mechanism in the process of in vitro bulblet enlargement. Sterile buds induced by bulblet scales of L. sargentiae as explants were selected as materials. The experiments were conducted under three different concentrations of sucrose (30, 60 and 90 g/L) and five different photoperiods (0, 8, 12, 16 and 24 h/d). The morphological index, endogenous sugar and related enzymatic activity changes were measured in formation and enlargement of in vitro bulblet. The results showed that: 1) The optimal condition for bulblet enlargement was sucrose concentration of 60 g/L and photoperiod of 8 h/d. At a certain concentration of sucrose, there was no significant difference between the photoperiods of 8 h/d and 0 h/d. 2) Under the sucrose concentration of 30 g/L and different lighting conditions, the trend was W type for sucrose content, and M type for both fructose and glucose contents; under the sucrose concentrations of 60 and 90 g/L, the trend of sucrose content was fall rise fall, while the trend of fructose and glucose contents was rise fall rise, opposite to that of sucrose content. 3) Among treatments with different sucrose concentrations, the change trend of sucrose phosphate synthase activity was basically the same with that of the sucrose content, but the change trends of the sucrose synthase activity and sucrose content were opposite. In conclusion, 60 g/L sucrose in complete darkness can promote bulblet enlargement in production. The sucrose synthase is involved in decomposition process of sucrose, while the sucrose phosphate synthase is involved in the accumulation process of sucrose. Sucrose not only plays a physiological role, but also may play a sugar signal role in the bulblet enlargement process, both of which are strictly regulated by sugar concentration. Sucrose concentration and photoperiod have interaction effect on the induction and enlargement of in vitro bulblets, but the effect of sucrose is greater. Thus, sucrose is a major factor for the formation and enlargement of in vitro bulblets.

The effect of abscisic acid (ABA) on wound-healing capability and related enzyme activities were investigated in postharvest cherry tomato fruits treated by ABA and fluridone (FLD, an inhibitor of ABA). 　　After wounding at equator with a sterilized scalpel, fruits were immersed in 1.0 mmol/L ABA, 0.1 mmol/L FLD and deionized water (control, CK) under vacuum (0.07 MPa, 5 min), respectively. Treated fruits were allowed to wound-heal at 20 ℃ and 90% relative humidity in dark. Fruit weight loss, autofluorescence intensity, phenylalanine ammonia-lyase (PAL) and peroxidase (POD) activities were determined in wound tissues every day. 　　The results indicated that ABA content decreased within the first two days followed by a slight increase in the control, but maintained at high levels in ABA group and low levels in FLD group. Fruit weight loss increased gradually in all groups during storage. However, the weight loss was more and faster in FLD group, but less and slower in ABA group in contrast to the control. The intensity of autofluorescence increased during wound-healing. Compared with the control, ABA group exhibited an increase in the intensity of autofluorescence especially after 3 d of storage while FLD group depicted a reduced intensity. PAL activity increased after wounding, reached the maximum at the third day and then decreased, while POD activity decreased after wounding and then increased in all groups during wound-healing. PAL and POD activities were enhanced by ABA application while inhibited by FLD treatment compared with the control. 　　In conclusion, ABA promotes wound-healing process in postharvest tomato fruits. This study provides theoretical basis for the research of wound-healing mechanism in postharvest fruit and vegetable.

“Alexander” grape (Vitis vinifera cv. Muscat of Alexandria) belongs to Euro-Asian species and performed excellent in the southern China such as Zhejiang Province. However, as its high fruit setting and compact fruit spikes, fruit thinning in time was very necessary. Currently, elongating clusters of grape using gibberellin (GA₃) is usually used in Euro-American species; however, the effects of clusters elongation on fruit quality and simplified degree of fruit thinning have not been reported. In addition, the concentration of GA₃ used for clusters elongating have great differences according to sensitive degree of cultivars. 　　We explored the effects of GA₃ treatment on simplification of fruit thinning and fruit quality in this study, in order to provide the theoretical basis and technical support for industrial development of “Alexander” grape. 　　Six-year-old “Mascat of Alexandria” trees were used in this study. Clusters were sprayed with different concentrations (1, 2, 3, 4, and 5 mg/L) of GA₃ when their length reached 2.71—8.68 cm about 15 days before full-bloom stage of “Alexander” grape in order to explore the effects of GA₃ treatment on simplification of fruit thinning and fruit quality. Fruits were picked when the total soluble solid (TSS) content reached 17% and were sampled when they reached commercial maturity. The length of the clusters and quality indexes were determined at harvest. 　　The results showed that the treatment effect of 3 mg/L GA₃ solution was the best when the new shoot length reached 15—20 cm, the leaf number was 6—7 pieces and the average length of the clusters was 3.53 cm. Compared with the control (0 mg/L GA₃ treatment), 3 mg/L GA₃ treatment can elongate clusters by 50%, obtain loose fruit spikes but not too loosen as well as better fruit setting. The average fruit spike mass reached the maximum value after 3 mg/L treatment, and can reduce workload of fruit thinning by 38%. Compared with the control, treatment with different concentrations of GA₃ solution all enhanced the content of TSS, glucose, fructose, tartaric acid, malic acid, and linalool. Moreover, 3 mg/L GA₃ treatment greatly increased the contents of total phenols and nerol. 　　3 mg/L GA₃ treatment can obtain better fruit quality and effectively lower work load of fruit thinning. It is suggested to spray “Alexander” grape clusters with 3 mg/L GA₃ solution about 15 days before full-bloom stage in the production, in order to reduce labor cost and improve labor efficiency.

Compared with tea, tea flower has similar composition and biological activities. Tea flower is rich in polysaccharide, which is regarded as “natural moisturizing factor”. Because of the effect of moisturizing and bacteriostasis, it can be used for improving the moisturizing properties of cosmetic products. The polyphenols and flavonoids from the tea flower have antibacterial, anti-allergic, UV resistant function and can inhibit oxidase lipid peroxidation. They also can inhibit the formation of free radicals and melanin. The saponin from the tea flower has strong effect of emulsification, dispersion, solubility, foaming, cleaning and many other kinds of active function on surface. In addition, tea flower has special honey fragrance, so that it can be used as natural spice products. 　　Tea flower can be used in daily chemical products industry. Three factors and three levels orthogonal analysis was used to select the formula of tea flower soap. The three independent variables are the types of soap material, tea flower powder additive amount, tea flower petal additive amount. And the quality of tea flower soap was valued from skin care, sensory indexes. The results showed that the best components in soap were weakly-alkaline soap material and 2% tea flower powder, which make the soap white with a little yellow and have tea flower fragrance. The skin test on the dorsum of hand showed that the usage of tea flower soap can decrease oil contents 49% and pigment contents 20%, while increasing water contents in dermal layer 51%, elasticity 36% and collagen protein contents 9%. By expanding experiment, it was found that the tea flower extracts can further improve the performance of product. 　　This study developed natural tea flower soap with strong ability of cleaning and protecting skin. It also provides scientific theoretical basis for tea flower’s application in daily chemical products and a new way for the comprehensive utilization of Camellia resources.

Tobacco (Nicotianat abacum L.) is a worldwide economic crop, and tobacco industry is an important resource of tax revenue in China. Style, quality and economic characteristics of tobacco are the focuses of attention for both tobacco breeders and companies. 　　Most tobacco economic characteristics are quantitative traits, affected by variety, environment, variety-by-environment interaction and other unknown ecological factors. It is very crucial to clearly understand the contribution rates of these factors to the economic characteristics of tobacco, so as to screen appropriate varieties for specific tobacco producing regions. 　　A regional variety trial with random complete block design was conducted in multiple locations in 2014. Totally, 14 Fen-flavor tobacco varieties and 11 testing locations in 4 Fen-flavor tobacco producing regions were arranged with 3 blocks in each location. Six main economic traits, the average price, the grade index, the superior tobacco rate, the grain per 667m², the output value per 667 m² and the yield, were investigated. Analysis of variance and stability were performed based on a mixed linear model including variety effects, location effects, variety-by-location interaction effects and block effects. QTModel and SAS software were employed for the analysis. 　　Variance analysis results showed that variety effects, location effects and variety-by-location interaction effects were significant for all six economic traits. Wherein, location effects had the highest contribution, accounting for 60%—90% of total variation of each economic trait, and nearly 90% variance of the average price came from location effects. In addition, variety related effects explained 8.9%—42.7% of the total variance for each economic trait. In terms of the contribution rate of location effect, the order of traits from high to low contribution was the average price, the grade index, the superior tobacco rate, the output value per 667 m², the yield and the grain per 667m². The block effects were only significant for the average price, the grain per 667 m² and the grade index and it only contributed at most 4% to the total variation. 　　In adaptability evaluation, according to the results of multiple comparisons for comprehensive and each economic trait, the varieties marked by “a” were selected as appropriate ones for the region, and within them those with trait mean equal to or larger than that of all appropriate ones were selected as the most appropriate varieties. If more significant differences between varieties were detected, the varieties whose trait mean was larger than the total average would be regarded as the appropriate ones. As a result, the most appropriate varieties were PVH1452, Yunyan208, Yunyan105 for the region of Yunnan Plateau Basin; Yunyan116, Yunyan119 for the region of Yunnan Low Latitude Valley; Yunyan208, Yunyan105, Yunyan110, Yunyan119 for the region of Wumeng Mountain; Yunyan208, Yunyan97 for the region of West Fujian Wuyishan. 　　Results on variety stability showed that, location effects were the main sources of total variation, and as high as 70%—99% of the total variation could be explained by location effects. It suggested that Fen-flavor tobacco's economic characteristics are not stable across different planting areas.

Forchlorfenuron, 1-(2-chloro-4-pyridyl)-3-phenyl, is a multipurpose plant growth regulator. The previous reports showed forchlorfenuron was a relatively safe and low toxic pesticide without teratogenic and mutagenic effect on human and animals. However, recent researches showed excessive exposure of forchlorfenuron could cause the disorder of protein metabolism, mild emphysema. Therefore, residue detection of forchlorfenuron in fruits and vegetables is imperative. 　　High performance liquid chromatography (HPLC) analysis is a common detection method. The suitable conditions for the extraction and purification of sample play an important role prior to HPLC analysis. 　　In this study, the extraction efficiency of forchlorfenuron residues in loquat was compared using matrix dispersive solid phase extraction and QuEChERS (quick, easy, cheap, effective, rugged, safe). 　　The results showed QuEChERS was more suitable pretreatment method for the determination of forchlorfenuron residues in loquat, because it had obviously higher average recoveries than matrix dispersive solid phase extraction. Effects of different extraction and purification conditions on QuEChERS were further studied. The optimal conditions obtained were that 8.0 g of loquat samples were extracted with 16 mL of acetonitrile for 20 min, and then salted out for dehydration by m (anhydrous magnesium sulfate)∶m(sodium chloride)=3∶2, and ultimately purified by m (primary secondary amine (PSA))∶m (C₁8)=1∶1 for 3 min. The forchlorfenuron residues in loquat could be completely separated from impurities under these optimal conditions, and furthermore, the spiked recoveries of forchlorfenuron in loquat were 80%—100%, with coefficient of variation （CV） of 3.1%—4.8%. 　　It was concluded that this method could effectively extract and purify forchlorfenuron residues in loquat.

Yunyan87 was a flue-cured tobacco variety with largest-scale cultivation in China. To further improve the yield and quality of Yunyan87, two new mutant strains named T24 and Aoyeyan were developed from the natural mutants of Yunyan87 using selection breeding method. The characteristics and DNA fingerprint of the two new mutant strains were identified to provide basis for variety application, identification and protection. The field tests were performed to identify the botanic characters, agronomic characteristics, yield and quality of T24 and Aoyeyan in Tongren City of Guizhou Province from 2011 to 2013, using the leading flue-cured tobacco cultivars Yunyan87 and K326 as control varieties. Furthermore, simple sequence repeat (SSR) molecular marker technology was used to establish the DNA fingerprint maps of T24, Aoyeyan and their genetically related varieties Yunyan87, K326, Yunyan97 and four new mutant lines and strains (M97-1, Pianpianhuang, 09-1, Ketianyan), altogether nine accessions. The results were as follows: 1) The botanic characteristics, plant shape and growth duration in field of T24 and Aoyeyan were similar with Yunyan87, but their effective leaf numbers, leaf length and width, stem circumference, plant height all exceeded Yunyan87. The yields of T24 and Aoyeyan were 2 247.38 and 2 195.62 kg/hm2, with production value of 53 657.56 and 52 586.47 Yuan RMB/hm2, and the rates of superior and middle grade leaves were 90.59% and 90.38%, respectively, which all exceeded control varieties。 The contents of reducing sugar, total sugar, starch, total plant nicotine of T24 and Aoyeyan were all up to the high quality standard of flue-cured tobacco leaves. The sensory taste score of T24 was 80.0, higher than Yunyan87 and K326, with scores of 76.3 and 77.7, respectively. The sensory taste score of Aoyeyan was 75.3. 2) Four SSR primers, i.e. PT20213, PT30028, PT30224 and PT30399 were selected from 14 core primers, which gave stable and polymorphic amplification profiles and had efficient identification ability to tobacco varieties. Eighteen polymorphic DNA fragments of all nine varieties including T24, Aoyeyan, Yunyan87, K326, Yunyan97, M97-1, Pianpianhuang, 09-1, Ketianyan were amplified, among which seven specific bands were selected to encode the fingerprint database. Fingerprint map of the nine varieties were drawn according to the fingerprint database. Each variety had a distinctive fingerprint map, therefore could be identified each other by at least three SSR primers, and the identification process of the nine varieties was established. In conclusion, the yield and quality of T24 are higher than Yunyan87, so T24 has a great application potential. The distinctive fingerprint map of the tested varieties can provide basis for the variety identification and protection.

Illumination enables plants to assimilate carbon by photosynthesis. Under the extended photoperiod, plants could continue to grow through uninterrupted carbohydrate production, leading to increase of dry mass accumulation. Physiological responses under these driven-changes have been fully studied for photosynthesis, such as carbon (C) and nitrogen (N) balance, and N utilization. The purposes of most studies were to understand the mechanism of plant growth in the extended photoperiod, for application in culture of tree seedling. However, the application was limited by lack of evidence for the establishment of inherent nutrient reserve, acting as the most determinative factor for an acceptable seedling quality. High-valued ornamental tree seedlings usually own a naturally slowly growing rate. Hence, they are usually suggested to be cultured under the extended photoperiod so as to stimulate their growth to meet the standard morphologies for selling. However, this manipulation may be fatal for the survival of these slowly growing ornamental tree seedlings, because quite little attention has been paid to their inherent nutrient reserve, and their quality would have been impaired at the end of nursery culture. Recently, research on one typical ornamental tree seedling of Buddhist pine (Podocarpus macrophyllus ［Thunb.］ D. Don) found coexistence of nutrient dilution with dry mass accumulation under the extended photoperiod. However, results and conclusions therein were limited by the unique tree species in the experiment. Meanwhile, the evidence for effects of nutrient leaching on nutrient utilization remained insufficient. Therefore, the application of extended photoperiod on culture of slowly growing ornamental seedlings remains debatable. In the present study, seedlings of Buddhist pine and Japanese maple (Acer palmatum Thunb.) were raised in an extended photoperiod (EP) treatment of 18-hour light per day, while the natural photoperiod was employed as a control, in a practical greenhouse at Flower Research and Development Center, Zhejiang Academy of Agricultural Sciences in Xiaoshan District of Hangzhou City, China. The experiment commenced at 17 June 2014 and ended until the termination on 17 December 2014. In the last month before the experiment terminated, leachates were collected to determine the nutrient contents once a week. The results indicated that compared to the control, seedling height increased by 17% (P=0.004 8) and 20% (P=0.023 0), but new root number decreased by 31% (P=0.044 2) and 21% (P=0.026 5) for Buddhist pine and Japanese maple seedlings under the EP, respectively. However, both root-collar diameter (RCD) and root length did not respond at all; additionally, whole-plant biomass accumulation (P=0.005 5) and nutrient contents of N (P=0.018 3), P (P=0.012 5) and K (P=0.001 4) in Japanese maple seedlings were all promoted in the longer photoperiod, whilst the contents of P and K did not show any significant response in Buddhist pine seedlings. At the end of experiment, the concentrations of N, P and K were determined to be （1.57±0.14）%, （0.93±0.25）% and （1.21±0.15）% in Buddhist pine seedlings, which were higher than those in Japanese maple seedlings by 8% (P=0.045 8), 87% (P<0.000 1) and 110% (P<0.000 1), respectively. In conclusion, for slowly growing ornamental seedlings, such as Buddhist pine and Japanese maple, an extended photoperiod can effectively promote biomass accumulation, height growth and nutrient uptake efficiency, but has no influence on the growth of RCD and root length, also invalid effect is found on nutrient leaching. The seedlings cultured in the extended photoperiod tend to present a morphological feature of “big head but light feet”, and have potential risks on within-body nutrient dilution.

Water is a main limiting factor in arid and semi-arid areas, so the core technical problem for afforestation is how to ensure and maintain basic water demand for normal growth and development of trees. Investigation on the actual transpiration water consumption of main afforestation tree species can provide important guidance and theoretical basis for density control, water use, forest stability, woodland water balance and environmental capacity estimation of water resources of artificial vegetation. In this paper, four arbor species Populus szechuanica var. tibetica, Populus alba, Salix paraplesia var. subintegra and Ulmus pumila of three years old were selected in semi-arid valley of Lhasa, water consumptions of which were measured by pot seedling weight method, and net photosynthetic rate (Pn), transpiration rate (Tr) and water use efficiency (WUE) of them were investigated by Li-6400 photosynthetic system measuring method under different drought stresses. The stress treatments included normal water supply (90%95% of field moisture capacity, CK), light drought stress (70%75% of field moisture capacity, LS), moderate drought stress (50%55% of field moisture capacity, MS) and heavy drought stress (30%35% of field moisture capacity, HS) on potted experiments. The results showed that: 1) Under the normal water supply, the day water consumptions of P. szechuanica var. tibetica, P. alba, S. paraplesia var. subintegra and U. pumila seedlings were 1 096.5, 1 363.8, 915.1 and 702.9 g/m2, respectively. The water consumption of native trees (P. szechuanica var. tibetica and S. paraplesia var. subintegra) was significantly lower than that of P. alba. Under the light drought stress, the day-and-night and day water consumptions of S. paraplesia var. subintegra and U. pumila increased significantly compared to the control, wherein, the former increasing by 38.1% and 40.8%, and the latter increasing by 30.1% and 28.7%, respectively; and the remaining two species declined at different degrees. The water consumption of the four kinds of seedlings declined under the moderate drought stress, and it was minimal under the heavy drought stress. For example, the day-and-night water consumption of P. szechuanica var. tibetica and P. alba under the heavy drought stress was only 25.0% and 19.3% under the normal supply. 2) Under the normal water supply, the diurnal variation of water consumption rate (WCR) of P. szechuanica var. tibetica and S. paraplesia var. subintegra was bimodal curve, with the two peaks at 12:00—14:00 and 16:00—18:00; the other two species was a single peak curve, with the peak at 12:00—14:00. Under the light drought stress, the WCR diurnal variation of P. alba was bimodal curve, the first peak of which was at 12:00—14:00, and the remaining three species were observed a single peak, the peak of P. szechuanica var. tibetica in which was at 12:00—14:00, and the other two species were at 14:00—16:00. Under the moderate drought stress, the WCR diurnal variation of all tree species showed a single peak curve, the peak of P. szechuanica var. tibetica and P. alba in which was at 12:00—14:00, and the other two species appeared at 14:00—16:00. The curves of all species were single peak under the heavy drought stress, all peaks of which appeared at 14:00—16:00. 3) The Pn and Tr of P. szechuanica var. tibetica and P. alba declined gradually with the increase of drought stress. The Pn and Tr of S. paraplesia var. subintegra were largest under the light drought stress, while they decreased gradually with the increase of drought stress. The Pn and Tr of U. pumila were relatively low, and the maximum values were observed under the moderate drought stress, and its Pn and Tr were significantly lower than any other treatment under the heavy drought stress. 4) The WUE of P. szechuanica var. tibetica under the moderate and heavy drought stresses was higher than the other two stress conditions. The WUE of P. alba was relatively low under the ea

Organic carbon is the basis of soil system, which plays an important role in the soil quality and regulating the supply of nutrients. Physical, chemical and biological properties and productivity of soil were all closely related to the content and character of organic carbon. Therefore, the maintenance of organic carbon in soils is emphasized by various soil researchers and land managers. Appropriate organic carbon contents in soils could increase cation exchange capacity (CEC), moisture storage, mineral nutrients, and food source for soil organisms, and improve soil structure and aggregate stability. As an important component in carbon pool of terrestrial ecosystem, soil organic carbon plays an important role in regulating greenhouse effect and global warming. Organic carbon contents in soils depended on the factors such as climate condition, soil type, mineralization process, and land use type and management. For a given soil, the maximum amount of organic carbon generally accumulated in the topsoil under long-term undisturbed vegetation, typically grassland or forest. Loss of organic carbon is generally regarded as undesirable, though some reports pointed out that low soil carbon contents can reduce application rates of pesticides in soil due to lower sorption. It is well known that various kinds of soil management can cause changes in organic carbon concentrations, and the carbon contents of cropped and tilled soils are usually lower than those of undisturbed grassland or forest. The decline of organic carbon contents was often caused by top soil erosion and breakdown of stabilized soil. To understand the sequestering carbon potential of tea garden soil and its accumulation characteristic on different fractions of organic carbon, soil profile samples were collected from nine tea gardens and three uplands in northwest Zhejiang. Samples from nine tea gardens were divided into three groups (quaternary red clay, yellow-red soil and yellowish red soil), each group corresponding to three tea plantation ages (510 years, 1520 years, and > 30 years). The contents of total organic carbon, light-fraction organic carbon, particulate organic carbon, microbial biomass carbon and water soluble organic carbon in the soil samples were analyzed, and compared with those local upland soils with similar utilization time. The results showed that different fractions of organic carbon in the tea garden soils had surface accumulation pattern, and the proportion of the light-fraction and particulate organic carbons in the total organic carbon decreased faster with depth than the content of total organic carbon itself. Furthermore, different fractions of organic carbon in the surface soil and storages of total organic carbon in the whole soil profile increased with the age of tea plantation; the water-stable aggregates with size >2 mm increased obviously in the surface soil. Meanwhile, the organic carbon accumulated in the surface soil tended to distribute in the water-stable aggregates of > 2 mm, especially for the light-fraction organic carbon. Increase rate of the light-fraction and particulate organic carbons was greater than that of the total organic carbon with aging of tea plantation, suggesting that the light-fraction and particulate organic carbons with higher activity were the main forms accumulated, and the organic carbon accumulated in the soils was mainly distributed in the surface layer. It is concluded that the accumulation rate of organic carbon in the tea garden soil is significantly higher than that in the upland soil. Therefore, the tea garden soil has a greater potential of sequestering carbon than the upland.

Since the first artificial hybrid was created in 1719, significant developments such as transgenic approach have been seen in the methods for crop breeding in recent hundreds of years. A lot of breeding-related data have been collected up to now. The big data technology was developed recently and has been successfully used in economics, IT (information technology) and other fields. With the increasing expansion of data in crops breeding, it becomes extremely necessary for breeders to take advantage of existing data in terms of efficient breeding technology, especially for the information generated from next-generation sequencing which could newly reach terabytes of data in a sequencing platform in one hour. In this study, we proposed a conceptual framework for big data-based crop breeding approach after we analyzed the genetic information flow of crop breeding program using an innovation tool, TRIZ
(theory of inventive problem solving). The expected new breeding technique tends to collect all breeding-related data (including data from phenotype, environments, references to molecular markers and sequences) for target crops and set up an automatic approach to collect breeding-related trait data. The technique will include a computer system to analyze the data and a human machine interface for users (breeders). We believe that big data has the potential to revolutionize the breeding of crops and the big data-based breeding approach is our future of crop breeding programs.

Due to the salinity-alkalinity stresses in agricultural environment, the production, quality and economic benefit of crops are seriously restricted. Salinity-alkalinity stresses not only decreased crop yields and affected crop quality, but also severely restricted sustainable and efficient crop production development. Therefore, it is of great significance to increase the crop resistance to salinity-alkalinity stresses for high-efficient and high-yield agriculture. γ-aminobutyric acid (GABA) is a non-protein amino acid, commonly exist in plant and animal tissues, which can indirectly affect plant growth and development under stress. However, there are few studies about the effect of exogenous GABA on seed germination under salinity-alkalinity stress. Thus, the experiment was carried out to screen the optimal concentration of GABA to improve the salt resistance of melon seeds. Salt-sensitive variety of melon (Cucumis melo L.) seeds (cv “Yipintianxia 208”), which is sensitive to salinity-alkalinity stresses, was chosen as experiment material. The effects of different concentrations (0, 5, 10, and 50 mmol/L) of exogenous GABA on germination index, radicle antioxidant enzyme activities, and GABA metabolism of melon seeds under 50 mmol/L salinity-alkalinity stress conditions (NaCl∶Na2SO4∶ NaHCO3∶Na2CO3 as molar volume ratio 1∶9∶9∶1) were studied. There were five treatments in this experiment (i) CK: Purified water presoaking and pre-germination; (ii) T1: Purified water presoaking and pre-germination under 50 mmol/L salinity-alkalinity stress; (iii) T2: 5 mmol/L GABA presoaking and pre-germination under 50 mmol/L salinity-alkalinity stress; (iv) T3: 10 mmol/L GABA presoaking and pre-germination under 50 mmol/L salinity-alkalinity stress; (v) T4: 50 mmol/L GABA presoaking and pre-germination under 50 mmol/L salinity-alkalinity stress. The results showed that salinity-alkalinity stresses significantly inhibited seeds germination and the growth of radicles and embryos of melon. Soaking seeds in different concentrations of GABA partly decreased the stress-induced inhibition on seeds germination of melon. Compared with the melon seeds in the treatment of salinity-alkalinity stress without GABA, a presoaking concentration of 5 mmol/L GABA improved superoxide dismutase (SOD) activity, and presoaking with 10 mmol/L GABA improved soluble protein content, endogenous GABA content and glutamate decarboxylase (GAD) activity in the radicles; presoaking with 50 mmol/L GABA improved seed germination rates, germination potential, vigor index, fresh mass, lengths of radicles and embryos, and peroxidase (POD), catalase (CAT) and GABA transaminase (GABA-T) activities and decreased malondialdehyde (MDA) content. It was concluded that 50 mmol/L GABA presoaking significantly alleviate the inhibition of melon seeds under salinity-alkalinity stress, and improved the salt tolerance of melon seeds.

In addition to the genetic cultivar characteristic and cultivation strategy, the environmental condition is considered as another important factor affecting grain yield in rice. Previous studies were carried out on yield formation of rice under the low temperature and weak sunshine condition, however, the ecological adaptability such as yield formation, nitrogen accumulation and utilization of different thermos-photoperiod sensitive rice cultivars to the low temperature and weak sunshine is still obscure, as well as the response mechanism. The main objective of this study was to determine the ecological adaptability of different rice cultivars under the low temperature and weak sunshine condition in the middle and late growth duration. Field experiments were conducted in 2013 and 2014 in Guiyang which was regarded as the representative eco-site with low temperature and weak sunshine, 35 rice genotypes including released cultivars and potential rice combinations were used as tested materials, and two ecology-adaptive cultivars (Zhuyou606 and Qianyou108) and two ecology-sensitive cultivars (Y Liangyou2 and Y Liangyou302) were selected out as the tested materials to study the differences in grain yield and yield formation, nitrogen accumulation and distribution, root characteristics. The results showed that: When values were averaged across cultivars and years, compared with ecology-adaptive cultivars, ecology-sensitive cultivars obtained a lower grain yield by 13.8%, which was mainly caused by a 9.9% lower filled grain ratio and 15.5% lower 1 000-grain mass. In comparison with ecology-adaptive cultivars, ecology-sensitive cultivars achieved 18.8%, 10.8%, 14.5% lower nitrogen accumulation amount at the mid-tillering (critical stage of productive tillering), heading, maturity stage, respectively, resulting in 17.9% lower nitrogen recovery efficiency (RE). Furthermore, a higher nitrogen accumulation amount in stem-leaves at heading stage and a lower nitrogen accumulation amount in stem-leaves at maturity stage were found in ecology-sensitive cultivars, relative to ecology-adaptive cultivars, and the nitrogen translocation amount from stems and leaves to panicle achieved 3.41 kg/667m2, which was 24.6% lower than that in ecology-adaptive cultivars,the nitrogen translocation ratio from stems and leaves to panicle achieved 38.55%,which was 19.4% lower than that in ecology-adaptive cultivars. The root bleeding intensity of ecology-adaptive cultivars achieved 20.2 kg/(h·667m2) at heading stage and 4.55 kg/(h·667 m2) at maturity stage, which were 8.8% and 21.6% lower than that in ecology-adaptive cultivars, respectively. Accordingto the results, a strategy to increase the grain yield of ecology-adaptive cultivars is suggested: keeping a higher filled grain ratio and a higher 1 000-grain mass, which is able to be accomplished by increasing nitrogen accumulation during the growth period from heading to maturity. Moreover, these methods such as cultivating strong roots and improving root activity are helpful to increase the amount of nitrogen absorption.

Light condition is one of the important factors affecting plant growth. During plant growth, light deficiency will result in the decrease in carbon fixation, photosynthetic efficiency, and leaf senescence acceleration, and thus decrease yield evidently. Besides yield, light also affect the rice qualities through influencing the seed compositions such as protein. Many studies have been carried out to evaluate the effect of light on protein synthesis. For example, previous studies have been certified that the protein accumulation is increased during the seed filling stage, as well as amino acids. The enzymes of glutamine synthetase (GS), glutamic oxalo-acetic transaminase (GOT), and glutamate pyruvate transaminase (GPT) are considered as the key enzymes regulating the synthesis of protein. Almost 95% of N was absorbed through GS/glutamate synthetase (GOGAT) cycle in plants and converted into glutamic acid (Glu) and glutamine (Gln). The Glu and Gln are then converted into other amino acids which provide the precursor materials for protein synthesis through the transamination reactions of GOT and GPT. However, researches about the effect of the activities of GS, GOT and GPT on amino acid and protein synthesis of rice are limited, especially under stress conditions such as low light. Based on previous studies, we carried out this experiment to evaluate the effect of low light on key enzyme activities of nitrogen metabolism and protein accumulation during the seed filling stage. The aims of this study were to study the dynamic changes of GS, GOT and GPT under different low light conditions during the seed filling stage, and evaluate the relationships between the activities of enzymes and protein accumulation. The experiment was initiated at Sichuan Agricultural University, Ya’an, China, in 2013. Four cultivars including japonica cultivars Akitakomachi and Koshihikari, indica cultivar IR72, and hybrid indica cultivar Gangyou 527 were selected as the materials. All the cultivars were managed routinely till the flowering stage, then 25% shading (A1) and 50% shading (A2), were set respectively as the treatments till maturity by using shade net, and natural condition was set as CK. Each treatment plot was repeated 3 times and the rice panicles which grown uniformly were marked for further sample collection. After 10 days of treatments, the seed samples were collected per 7-day period till maturity and stored in freezer at -80 ℃. After harvest, the samples were used to measure GS, GOT and GPT activities, as well as soluble protein, total protein and amino acid contents. Results showed that the GS activities were significantly decreased by 2001%-3052% at A2 than A1 (1161%-1936%) compared with CK, whereas, the activities of GOT and GPT increased significantly at A2 (GOT increased by 2607%-3682% and GPT increased by 2607%-6107%) than A1(GOT increased by 1402%-2302% GPT increased by 1181%-3383%) compared with CK In consistent with GOT and GPT, patterns of soluble protein, total protein, as well as amino acids were also significantly increased under low light conditions especially at A2 (compared with CK, soluble protein increased by 3119%-7051%, total protein increased by 1602%-2889%, and amino acids increased by 1604%-2248% at A2). The correlation analysis showed that GS activity was negatively correlated to soluble protein, total protein and amino acids under low light conditions, however, GOT and GPT showed positive correlations with soluble protein, total protein and amino acids. Based on the results, we speculated that the synthesis of protein of rice grain was more significantly affected by GOT and GPT which tended to increase the accumulation of both protein and amino acids, compared with GS. In addition, in consistent with previous studies, the low light conditions were beneficial for protein and amino acid synthesis of rice grain during the seed filling stage.

Rice is one of the most important crops in the world, especially in Asia, where more than 90% of the world’s rice is grown and consumed. In recent years, with the increase of living quality, the requirement for rice improvement is not only limited to yield, but also to its quality. During rice development, genetic and environmental factors significantly affect both of the yield and quality. Among the environmental factors, fertilizer management and planting density are considered as the main factors affecting rice growth and development. Data from the previous studies on the impact of nitrogen application rate and planting density on rice yield and quality have been inconsistent due to the differences in regional ecological conditions. Therefore, it is necessary to continue exploring the influence of nitrogen application rate and planting density on rice yield and quality. Chengdu plain, the main rice cropping region in the southwest of China, has the unique light, heat and water resources. In order to promote the planting of a japonica rice variety (identified in our previous research) in this area, we investigated how nitrogen (N) application rate and planting density and their interactions affect grain yield and quality. Data from this study would provide information for japonica rice cultivation in the area for high yield and good quality. To investigate the effect of nitrogen application rate and planting density on rice grain yield and quality characteristics, we used japonica rice cultivar D46 as the test material in this study. Split plot experiments with N application rate (N 150, 225 and 300 kg/hm2) as main plot and planting density (20×104, 26.67×104 and 40×104 seedlings/hm2) as sub-plot were carried out. The experiment was conducted on sandy loam in 2013 at the experimental farm of Sichuan Agricultural University in Wenjiang, China. The results showed that both N application rate and planting density had significant effects on the yield of the japonica rice cultivar D46 (P<0.05). The combination of N application rate of 225 kg/hm2 and planting density of 26.67×104 seedlings/hm2 led to the highest yield (7.58×103 kg/hm2), and which was significantly higher than other treatments (P<0.05). Dry matter accumulation tended to increase with the increase of N application rate during the whole growth period, whereas, for planting density, it reached the maximum at 26.67×104 seedlings/hm2 rather than at 20×104 and 40×104 seedlings/hm2. Furthermore, N application rate and planting density were shown to have different degrees of influence on the rice quality. The processing quality, chalky rate and protein content increased as the N application increased from 150 to 225 kg/hm2 and then declined with any further increases in N supply. In contrast, increasing planting density was not conducive to improving rice quality. Based on the results, and considering the importance of improving both rice yield and quality, the optimal combination of N application rate and planting density for japonica rice cultivar D46 in the planting area of Chengdu plain is N 225 kg/hm2 and 26.67×104 seedlings/hm2, respectively.

As the fourth major food crop, potato growing area increased year by year, which was an important mainstay industry in some provinces of China. In recent years, continuous cropping became common in potato growing areas. However, continuous cropping obstacle is one of the main factors limiting potato industry, which can lead to yield and quality losses, diseases spreading, and unbalanced soil ecology system. Therefore, it is an urgent task to explore effective ways to reduce the continuous cropping obstacle of potato and improve the yield and quality. Crop rotation is an effective practice to overcome the continuous cropping obstacle. Many scientific researchers have demonstrated that the crop rotation can relieve soil sickness by improving soil quality, ecological microclimate and crop productivity. Therefore, the crop rotation practice can partly eliminate the continuous cropping obstacle, but the selection of appropriate companion crops is the key. In this study, maize was selected as a rotation successive crop, which is widely planted in mountainous area of southwest China. A short term (2 years) pot experiment with potato-maize rotation, maize-potato rotation compared with potato successive cropping was conducted to study the changes in soil nutrients and enzyme activities of rhizosphere soils. Meanwhile, the effects of potato-maize rotation on rhizosphere soil nutrient and enzyme activity were also discussed. The results showed that, in mature period, rhizosphere soil nutrient contents of potato continuous cropping were decreased compared with those before seeding.
Only total phosphorus of the rhizosphere soils in potato-maize crop rotation were increased by 3.32%, respectively. Total nitrogen, total phosphorus, and available phosphorus, total potassium and available potassium compared with those before seeding, maize-potato crop rotation were increased by 6.84%, 32.67%, 4.13%, 3.77% and 10.81%, respectively.
The total nitrogen, alkali-hydrolyzable nitrogen in maize-potato rotation and the alkaline hydrolysis nitrogen in potato-maize rotation were decreased in the mature period, which were still higher than those in the potato continuous cropping. It was showed that soil nutrients, especially the available nutrients were over used in potato continuous cropping, compared with those in the rotation cropping. Polyphenol oxidase activity had a significant difference in tuber bulking. For other soil enzyme activities of rhizosphere, in the mature stage of the maize-potato crop rotation, the activities of rhizosphere soil urease, catalase, invertase were increased by 5.71%, 2.19% and 4.85%, respectively, and also increased by 52.07%, 32.23% and 11.62% in potato-maize rotation, which were significantly higher than those in the potato continuous cropping system. In summary, potato-maize crop rotation system can effectively relieve the potato continuous cropping obstacle by improving soil enzyme activities, and accelerating physiological and biochemical reactions of rhizosphere soils. Furthermore, the rotation system can relieve the potato continuous cropping obstacle effectively, and provide a theoretical basis for solving the problem of potato continuous cropping obstacle.

The regulation of dormancy is very essential in the production of potato. To satisfy the demand of different sowing dates and to keep high rate of emergence and growth potential in seed potato, it always requires prolonging or shortening the dormancy stage to guarantee the field emergence. Meanwhile, when potatoes are treated as food, the dormancy period should be prolonged as long as possible to keep the potatoes fresh. Physical and plant growth regulator treatments are two main methods that regulate the dormancy in potato. The physical treatment requires high cost of labor and material resources, while the plant growth regulator treatment has advantages of convenience and cost saving over the physical treatment. The conventional plant growth regulators were used to adjust the plant dormancy including
sprouting inhibitors chlorpropham (CIPC), abscisic acid (ABA), and sprouting promoter gibberellin A3 (GA3). There were numerous reports about the regulating effects of these regulators, but only a few investigations have been done to compare the regulating effects of these regulators on potato. To comprehensively study the effects of different growth regulators on the germination and main carbon-nitrogen metabolites contents of potato during storage, a laboratory experiment was conducted from May to August in 2014. The potato cultivar “Chuanyu-117” was used in this research. Potato tubers were dipped in aqueous solutions of CIPC, ABA and GA3 with efficacious concentrations for 30 minutes, respectively. The results indicated that GA3 could release potato dormancy in advance, and the intensity and amplitude of tubers dormancy, when treated with GA3, reduced by 17 days and 11 days, respectively, the length/diameter ratio of bud was much higher than that of control (CK), showing that GA3 could accelerate potato tubers germination and bud growth. Whereas, ABA significantly prolonged the dormancy, the dormancy amplitude reduced by 11 days but the dormancy intensity increased by 6 days, and the length/diameter ratio of bud was lower than that of CK, which showed that ABA could accelerate the speed, vigor and uniformity of bud growth after germination. The CIPC had a more obviously suppressive effect with a 70-day interval between the beginning of treatment and germination, and the germination period was also expanded to at least 40 days in contrast with CK. The change regulations of carbon-nitrogen metabolites contents in different treatments were the same, but the degrees of changes were quite different. The starch contents of potatoes treated with GA3, ABA and CIPC for 12 weeks reduced by 13.36%, 11.30% and 5.93%, respectively; while the soluble sugar contents reduced by 48.3%, 58.9% and 56.1%, respectively, when compared with those of the beginning of treatments. Both of the soluble protein content and the crude protein content showed a high-low trend line. The soluble protein content of GA3, ABA and CIPC treatment at the previous time of storage increased by 25.73%, 39.68% and 31.32%, respectively, and then reduced by 19.17%, 33.22% and 17.74% at later storage period, respectively. The crude protein content of GA3, ABA, and CIPC treatments increased by 4.77%, 12.67% and 12.65% at the previous time of storage, respectively, and then reduced by 11.37%, 18.02% and 8.71% at later storage period, respectively. The C/N ratio of the sprouting promoter treatment was higher than those of the sprouting inhibitor treatments, and all of them showed a downward tendency. In conclusion, GA3 could release the dormancy of potato in advance, the bud grew faster and the carbon-nitrogen metabolism activity was strong. Whereas, CIPC could prolong the dormancy period and inhibit the bud growth, the carbon-nitrogen metabolism activity of potato tuber was weak and the nutrient consumption was also less. ABA also prolonged the dormancy period but enhanced the germination uniformity and bud growth and the carbon-ni

In recent years, southern rice black-streaked dwarf virus (SRBSDV) has spread rapidly in Southern China and caused a serious viral dwarf disease. The white-backed planthopper (WBPH) Sogatella furcifera is a main vector for SRBSDD transmission. Use of disease resistant cultivars and insect vector control are the most economical and environmentally friendly strategy for arboviral disease control. This research focused on the resistance to SRBSDD among different rice varieties. The relationship between density of insect vectors and occurrence degree of SRBSDD was examined, and the effectiveness of disease management with controlling WBPH was measured, to build a predictive model for the occurrence of disease and damage degree of SRBSDD. In this study, we investigated the population dynamics of WBPH on 17 rice varieties in Hangzhou, China and created a predictive model for SRBSDD. The results showed that the population densities of WBPH and the disease indexes of SRBSDD on different rice varieties were significantly different, which were highest on the four rice varieties, including Yueyou 9113, Tianyouhuazhan, Y-Liangyou 2 and New-Liangyou 6. Statistical analysis demonstrated that the disease index of SRBSDD was significantly positively correlated with the population density of WBPH. For example, the disease index of SRBSDD at heading stage (Y1) was significantly positively correlated with the population density of WBPH in early August (X2) or early September (X4). The predictive model for SRBSDD was Y1=-7.962+0.110X2+2.505X4 (r=0.808, P＜0.000 6). The results confirmed the critical role of WBPH in primary infection during seedling stage to early growth stage and in secondary infection of SRBSDV, which affected the occurrence degree of SRBSDD significantly. Meanwhile, we compared the population density of WBPH and control effectiveness of SRBSDD after different pesticide treatments. The seed treatment of imidacloprid FS and the foliar application of Virtako WG 40% (chlorantraniliprole 20%+thiamethoxam 20%) decreased spread of SRBSDV by 61.7% and 73.2% respectively. The control effectiveness and disease indexes of SRBSDD showed a significant positive relationship with the population density and control effectiveness of WBPH. In conclusion, it is possible to predict the occurrence degree of SRBSDD, based on the population density of WBPH at early growth phase of rice. Using seed treatments and foliar applications of pesticides at seedling stage or early growth phase of rice is an effective way to control the disease by decreasing the major primary infection source of SRBSDV.

Tillering and earing is a key factor for yield formation in rice and one of remarkable features of high-yield colony, characterized by effective panicles per unit area. Transplanting seedling age is an important factor that may greatly affect tillering and panicle formation. Related researches have showed that by extending the transplanting seedling ages, the seedling quality would become worse; the tillering growth rate would slow down; the percentage of effective panicles would reduce; the numbers of effective panicle per plant and grains per panicle would decrease, resulting in obvious reduction of grain yield. Due to the special landscape of the hilly areas in China, the long transplanting seedling age still existed in those areas. To investigate the effect of different seedlings per hole and water-nitrogen managements on tillering and panicle formation pattern under long seedling age, F you 498 was used as test material in this experiment. A three-factor split plot was conducted with transplanting seedling ages as the main plot; the water-nitrogen management patterns as the secondary plot and seedlings per hole as the third plot. The aim was to provide the theoretical and practical data for improving the grain yield of long transplanting seedling age in hilly areas. The results showed that the tillering capacity of the older-age seedlings was stronger, and the number of leaf positions of tillers and panicles were increased. And the tillering ability of different water-nitrogen management patterns was controlled alternate irrigation pattern > dry cultivation pattern > submerged irrigation pattern under 65 d seedling age. Meanwhile, single seedling in a hole had higher percentage of emerging and earbearing tiller than double seedlings in a hole at older seedling age. At 65 d seedling age, the contribution for yield was the primary tiller > secondary tiller > main stem > third tiller; and the grain number per panicle and thousand-grain mass were primary tiller > secondary tiller > main stem, while the seed setting rate was primary tiller >main stem > secondary tiller. The superior leaf positions of emerging tiller of older seedling age were the first to ninth leaf for primary tiller, the first to second and seventh to eighth leaf for secondary tiller; the superior leaf positions of earbearing were the second, seventh to ninth leaf for primary tiller, and the first to third and seventh to eighth leaf for secondary tiller; the superior leaf positions of yield contribution were the sixth to ninth leaf for primary tiller, the first, second and seventh leaf for secondary tiller. It is concluded that the superior leaf positions of older seedling age rice are the first to second and seventh to ninth leaf, of which the total contribution to the yield reaches 68.95%. With the extension of seedling age, the yield obviously decreased; however, applying to single seedling per hole in combination with controlled alternate irrigation pattern can improve the yield of long-age seedlings effectively.

In order to reduce artificial inputs and improve the efficiency of crop production, the slow- and controlled-release nitrogen (N) fertilizer has become a research focus. However, relatively little work has been done on slow- and controlled-release N fertilizer in machine-transplanted rice. Few studies were reported on whether slow- and controlled-release N fertilizer can improve machine-transplanted rice yield and simplify the fertilization technique. Therefore, different slow- and controlled-release N fertilizers and varieties under machine-transplanted rice were set in this paper, to explore effects of slow- and controlled-release N fertilizer on N utilization characteristics and yield in machine-transplanted rice. Two-factor split-plot design was used to explore the slow- and controlled-release N fertilizer to improve N utilization efficiency and yield increasing mechanism in machine-transplanted rice. Early-maturing indica rice Zhongjiazao 17 and medium-late indica hybrid rice Chuanguyou 7329 were used as trial varieties. The main plot treatments were variety types. The subplot treatments were the coated slow- and controlled-release N fertilizer with nitrification inhibitor applied before transplanting (N1), sulfur-coated slow- and controlled-release N fertilizer applied before transplanting (N2), two resin-coated slow- and controlled-release N fertilizer applied before transplanting (N3, N4), single basal application of urea (N5), and the urea application proportion of base, tillering and spike fertilizers was 5∶3∶2 (N6). The results showed significant interactions between variety types and slow- and controlled-release N fertilizers application on biomass, N accumulation, translocation and grain yield at main growth stages. The N apparent use-efficiency was much improved when resin-coated slow- and controlled-release N fertilizer was applied. Besides, N accumulation of panicle, partial factor productivity of applied N, N agronomic efficiency, N apparent use efficiency and yield were increased by 51.83%, 18.71%, 57.97% and 5.54% compared to N6, respectively. Resin-coated slow- and controlled-release N fertilizer was the best among the slow- and controlled-release N fertilizers tested in machine-transplanted rice, which had a significant effect on N accumulation and use efficiency in medium-late indica hybrid rice. However, sulfur-coated slow- and controlled-release N fertilizer and coated slow- and controlled-release N fertilizer with nitrification inhibitor were lower than conventional fertilization in increasing yield and synergism, but they were effective for translocation of vegetative organs and N transportation efficiency. In addition, long growth period of late maturity hybrid rice Chuanguyou 7329 formed sufficient panicles and structure optimization of high quality group, and the rice could fully carry out construction of source-sink and accumulation of dry matter at full heading stage. And from full heading stage to mature stage, dry matter accumulation was improved steadily, and nitrogen accumulation increased N translocation of vegetative organs during grain filling. Ultimately, the late hybrid rice was significantly higher than early-maturing rice in N accumulation, translocation and yield at different growth stages. However, the efficiency of N utilization in Chuanguyou 7329 was low because of its low efficiency of the stem and leaf translocation. In conclusion, under the experimental condition, resin-coated N fertilizer in combination with medium-late indica hybrid rice is the optimal treatment for high yield and high N use efficiency.