Eucalyptus, as one of the most important components of the forestry resources, was originated in Australia, and then was cultivated worldwide including China. Prior to the early twentieth century, with the increasing introduction of this tree species, Eucalyptus dieback, caused by Cylindrocladium scoparium (teleomorph: Calonectria morganii), was frequently affected in almost regions of China. Also it has historically been an important disease of Eucalyptus, which was defined as a key national plant quarantine disease in China, on January 5, 1996. In Southern China, this disease affected Eucalyptus throughout its range of cultivation and caused severe yield loss and tree mortality. Cylindrocladium scoparium, especially in late infection, can cause a large damage to the growth of Eucalyptus, as well as dieback, even all branches withered severely. Even in early infection, it can easily lead to reddish-brown spots, wilting leafs, and droping branches. However, thus far, it is still a great constraint to the cultivation and production expansion of Eucalyptus in many provinces of China, such as Sichuan, Fujian, and Guangxi. Therefore, to establish a rapid and effective detection technology has an important significance for control and prevention of Eucalyptus dieback. A total of 19 isolates of fungus, including C. scoparium were obtained from diseased Eucalyptus in Sichuan Province, and three isolates (C. scoparium and Cylindrocladium ilicicola) were purchased from Chinese academy of Forestry. Based on its conserved domain beta-tubulin gene, two pairs of specific primers BT-S-1/BT-A-1 and universal primers BT-T1-S/BT-CYLTUBIR-A were severally designed by the aid of the software Premier 5.0, and then were synthesized respectively, and the specificities and sensitivities of these two pairs were tested with the method of universal polymerase chain reaction (PCR)
and nested-PCR. Meanwhile, the field tests were conducted. The results showed that a band of 500 bp with the universal primers BT-T1-S/BT-CYLTUBIR-A was amplified among these isolates, while only a band of 148 bp was amplified by these six isolates of C. scoparium, and the nested-PCR with these two pairs of primers also amplified the band of 148 bp. The difference was that the sensitivity of nested-PCR was 5 fg/μL, which was significantly 103 times higher than universal PCR detection. The field tests showed that nested-PCR was much more accurate and sensitive than universal PCR. In conclusion, the detection technique of nested-PCR of C. scoparium was proved to be rapid and specific in monitoring of C. scoparium and it has a great significance for the prevention and control of Eucalyptus dieback. Furthermore, the result of the nested-PCR can play an effective role in the early diagnosis of Eucalyptus dieback and also provide a new basis for the detection of other diseases.

The disruption of natural flow regimes in river systems poses many challenges to riparian ecosystems and their native species. The construction of the Three Gorges Dam has altered the flow regimes of the upper Yangtze River and created a riparian zone with a vertical gap of 30 m. Because of the anti-seasonal change of the water level caused by annual water regulation, plants grown on the riparian zone of the Three Gorges Reservoir Area (TGRA) may suffer from submergence, and often display dynamic change characteristics. Such water level change is likely to disturb the normal ecophysiological rhythm of the native tree species of the riparian zone. These hydrological changes highlight the importance of screening suitable tree species for reforestation in the TGRA and similar environments. Thus, the native tree species Metasequoia glyptostroboides, will most likely to experience continuous submergence or inundation. Current research on M. glyptostroboides seedlings is more focused on genetic structure, membrane composition, chemical property, growth and photosynthesis, and the like. However, the eco-physiological implications of submersion on M. glyptostroboides seedlings are not well known, especially under the condition of full-submersion. The aim of this study was to investigate the responding characteristics of the M. glyptostroboides seedlings to the water level change in the TGRA, and provide theoretical basis for species selection for revegetation in the riparian zone of the TGRA. Measured indexes included protective enzymes such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (ASP) and catalase (CAT), osmotic adjustment substances such as soluble protein and free proline, and membrane lipid peroxidation such as malondialdehyde (MDA), as well as photosynthetic characteristics and biomass accumulation of the two-year old M. glyptostroboides seedlings to submergence, upon mimicking the water level change in the riparian zone of the TGRA. Based on soil moisture change pattern in the TGRA, water treatments including control (CK), half-submersion (HS), and full-submersion (FS) were applied. The activities of SOD, POD, ASP, CAT and content of free proline of M. glyptostroboides seedlings in HS and FS group were higher than that in CK after submersion. Under submersion, MDA content in HS and FS group increased as compared with that in CK. The net photosynthetic rate of M. glyptostroboides seedlings in HS was significantly higher than that in CK. Root-shoot ratio in FS was significantly higher than that in CK, but no significant difference was detected between FS and HS. Leaves of M. glyptostroboides seedlings in FS were leaf bud, and survival rates were 100%. The results indicated that antioxidant enzymes, osmotic adjustment substances and photosystem Ⅱ have a positive response during submersion, M. glyptostroboides seedlings show strong adaptability to the submersion. Thus, M. glyptostroboides should be considered as one of the potential species for revegetation in the TGRA.

Due to the climatic feature of low light, small temperature difference and high humidity, transplanting rice was the major pattern in rice production in Sichuan Basin. As the rural labor force was decreased and the new types of rural management body were developing rapidly, the development of direct-seeded rice has becoming increasingly concerned. With the further development of direct seeding technology,direct seeding technique of rice has been successfully applied in 12 provinces and cities in China, which showed a significant role in improving the production and efficiency. In terms of the particular climate, topographic condition, and the hybrid rice in Sichuan Province, there were few studies on direct-seeded rice. Many researches had been done on the growth and development in direct-seeded rice under mechanical dry direct seeding and precision hill-direct-seeding, but the nitrogen management in those studies was according to the high-yield cultivation management of transplanting rice, and whether the nitrogen fertilizer management of transplanting rice was appropriate for direct-seeded rice was undefined. Seeding rate could immediate affect the population quality of rice plants and grain yield. The former researches often used the conventional rice as material but not the hybrid rice, so, further studies on the effects of seeding rate and nitrogen management on the dry matter production characteristic, nitrogen absorption and utilization law in direct-seeded hybrid rice were necessary.
Hybrid rice 446A/518 was used to investigate the effects of seeding rate and nitrogen fertilizer management on the photosynthetic productivity, dry matter accumulation and translocation, nitrogen absorption and utilization under manual wet direct-seeding,
and the correlation among the three which are photosynthesis index, grain yield and nitrogen utilization efficiency of rice plants were also taken to analyze. The results indicated that increasing the seeding rate would enhance the leaf area index during jointing stage and promote the nitrogen accumulation, nitrogen use efficiency (NUE) for biomass production and NUE for grain production. However, the leaf area index (LAI), SPAD value, photosynthetic rate, dry matter accumulation and translocation, partial factor productivity of applied nitrogen and NUE firstly increased and then decreased with the increasing of seeding rate. From the views of nitrogen management, the nitrogen fertilization for heading sprouting of 40% (N2) would obtain the highest LAI during jointing stage. Adding the nitrogen fertilization for heading sprouting was beneficial to increase LAI after heading stage and promote photosynthetic rate, dry matter accumulation and nitrogen accumulation, enhance substance accumulation and turn-over capacity and nitrogen-absorption and nitrogen utilization efficiency under the seeding rates of 15.0 or 22.5 kg/hm2. Moreover, when the seeding rate was added up to 30.0 kg/hm2, through antedisplacement of nitrogen would avail the nutrient absorbability of rice and promote substance accumulation and turn-over capacity and improve the NUE. Correlation analysis indicated that both the photosynthetic efficiency and LAI during heading stage were significantly correlated with grain yield, nitrogen-absorbing ability and nitrogen-utilizing efficiency of rice plants. In summary, when the seeding rate was 22.5 kg/hm2 and the ratio of nitrogen application at transplanting stage, tillering stage and booting stage were 40%, 10%, and 50%, respectively, it would lead to gain the relatively high grain yield and higher photosynthetic efficiency, dry matter production capacity and nitrogen utilization efficiency.

Nitrogen is a major limiting factor on plant growth and yield formation, and a moderate amount of nitrogen fertilizers can increase crop yields every year. The tolerance to low N-fertilized level is different among maize cultivars, meanwhile the response of different maize cultivars are also significantly different under different N-fertilized levels. What’s more, different maize cultivars have significant difference in the dry matter production and nitrogen utilization efficiency. Related researches indicate that dry matter and nitrogen accumulation of low nitrogen tolerant maize cultivars were remarkable higher than that of low nitrogen sensitive maize cultivars, besides, low nitrogen tolerant maize cultivars had larger green leaf areas to increase the nitrogen absorption in the late growth stage, and the difference of those in two types maize cultivars is mainly performed after the silking stage. A split plot experiment using the screened maize cultivars Zhenghong 311 with low nitrogen tolerance and Xianyu 508 with low nitrogen sensitivity as materials was conducted to investigate the difference of growth and development, dry matter and nitrogen accumulation and allocation in different low nitrogen tolerant maize cultivars under six nitrogen levels, and the different maize cultivars (Zhenghong 311 and Xianyu 508) were used as main plot and nitrogen fertilization rate (0N-0 kg/hm2, 90N-90 kg/hm2, 180N-180 kg/hm2, 270N-270 kg/hm2, 360N-360 kg/hm2 and 450N-450 kg/hm2, 50% base fertilizer and 50% panicle fertilizer) were used as sub-plot. The aims were to provide the theoretical and practical data for the reasonable nitrogen management of different low nitrogen tolerant maize cultivars in hilly areas. The results showed that the accumulation and allocation of dry matter and nitrogen in stem-sheath and leaf of low nitrogen tolerant Zhenghong 311 were higher than that of low nitrogen sensitivity Xianyu 508 in all stages, while the dry matter and nitrogen allocation ratio of panicle in Xianyu 508 were higher. Compared with low nitrogen sensitive cultivar, low nitrogen tolerant cultivar increased the accumulation and allocation ratio of dry matter and nitrogen in leaf, and reduced that in panicle. The higher dry matter and nitrogen accumulation and allocation ratio of vegetative organs in low nitrogen tolerant cultivar were beneficial to keep higher nutrition absorption and dry matter productivity, and the yield of Zhenghong 311 was significantly higher than Xianyu 508 because the Zhenghong 311 delayed the senescence of leaf and prolonged the time of high photosynthesis rate under low nitrogen tolerant stress. Nitrogen fertilization significantly increased plant height, stem diameter, leaf area, dry matter accumulation, nitrogen absorption, yield and yield component, while the effect of nitrogen fertilization on the allocation ratio in dry matter and nitrogen were slight. Excessive nitrogen was not conducive to the growth and development of maize, meanwhile it reduced the harvest index that go against the increase of yield. It is concluded that the low nitrogen tolerant cultivar Zhenghong 311 has higher dry matter and nitrogen accumulation to keep higher yield under low nitrogen levels, while the low nitrogen sensitive cultivar Xianyu 508 needs higher nitrogen fertilizer to get higher yield. Therefore, we can reduce nitrogen fertilization for low nitrogen tolerant cultivar Zhenghong 311 or plant it in poor soil of hilly region to make good use of the yield advantage under low nitrogen environment. On the contrary, the nitrogen fertilization of the low nitrogen sensitive cultivar Xianyu 508 should be increased or planted in a fertile region to guarantee its high stable yield.

The experiment was designed in three-factor split plot by using Fyou 498 as material. Comparing meteorological characteristics of the two seedbed, effects of Heng Aoda and nutrient soil and different seedling ages with 20, 30 and 40 d on seedling quality and transplanting quality of hybrid indica rice were studied. The main results were as follows: 1) The temperature, relative humidity and light intensity of greenhouse seedbed were similar to these of field seedbed, and diurnal variation in temperature, relative humidity and light intensity of greenhouse seedbed lagged behind these of field seedbed. Light intensity of greenhouse seedbed was lower than field seedbed and temperature of greenhouse seedbed was higher than field seedbed. 2) The seedling growth in greenhouse was two segments with fast early and slow rear, and its rate of empty hills and rate of float hills were 4.29% and 2.73% lower than these of field seedbed when transplanted, respectively. The seedling in greenhouse had a better transplanting quality, and the number of plants per hill was 22.22% higher than that in field seedbed. 3) The seedling with 30 d seedling age was suitable for planting mechanization for the lowest rate of empty hills and the highest number of plants per hill. However, the seedling with 40 d seedling age had poor transplanting quality for the highest rate of empty hills, the highest rate of injury hills, the highest rate of float hills and the lowest number of plants per hill. The seedling in greenhouse could be suitable for long seedling age by properly controlling seedling growth with temperature, relative humidity and light intensity regulation to increase scope of seedling age for planting mechanization. 4) The nutrient soil seeding had better transplanting quality than Heng Aoda seeding with high rate of empty hills and high rate of float hills, but substrate seeding had small injury for its loose property on planting mechanization. Thus, the substrate was considered to support seeding in greenhouse for low rate of injury hills by further research. 5) The temperature, relative humidity and light intensity had an impact on seedling quality and transplanting quality including a great effect of temperature on leaf area, leaf age and dry mass, and accumulated temperature was significantly correlated with the leaf age. The temperature, relative humidity and light intensity had an impact on rate of float hills and number of plants per hill and was not significantly correlated with the rate of empty hills and rate of injury hills.

Rice is one of the most important staple food crop in China and other Asian countries. Breeding high yielding varieties and improving resource-use efficiency are eternal themes in the areas of both rice research and rice production. In recent years, many super hybrid rice varieties with high yield potential have been widely grown by rice farmers in China, but the rule of nutrient uptake and accumulation is not fully clear. This paper attempted to ascertain the characteristics and genetic differences of grain yield performance and nitrogen (N), phosphorus (P), potassium (K) uptake and accumulation of super hybrid rice under different ecological conditions. The field experiments with 8 representative super hybrid rice varieties (i.e., Liangyoupeijiu, Zhongzheyou 1, Zhunliangyou 527, Y-liangyou 1, Ⅱ-you 084, Ⅱ-youhang 1, Neiliangyou 6 and D-you 527) were conducted in Guidong County, Changsha City and Nanxian County of Hunan Province in China from 2007 to 2009, of which a common hybrid rice variety Shanyou 63 and a super inbred rice variety Shengtai 1 were taken as the control. The varieties were arranged in a randomized block design with 3 replications. Germinated seeds were sown at the rate of 15 g/m2 on 1520th May in Guiding and on 1520th April in Changsha and Nanxian. Twenty five-days old seedling were transplanted with 2 seedlings per hill and a hill spacing is 23.33 cm×23.33 cm. Crop management followed high yielding cultivation practices. The results showed that there were significantly genetic and regional differences in grain yield and nitrogen， phosphorus, potassium (NPK) uptake and accumulation. Averaged across 3 locations and 2 years, grain yields of super hybrid rice varieties were 9.3210.25 t/hm2, which were 5.1%15.6% and 8.9%19.7% higher than those of Shanyou 63 and Shengtai 1, respectively. Guidong had the highest average grain yield of 11.45 t/hm2, which was 38.1% and 30.0% higher than that in Changsha and Nanxian, respectively. The high grain yield in Guiding was attributed to high panicle number and filled grain percentage. In addition, there was significant difference in grain yield among years. The highest average grain yield of 10.01 t/hm2 was obtained in 2009 and the lowest one of 8.29 t/hm2 was recorded in 2007, of which the former was resulted from high panicle number and the latter was cased by small panicle size. Nutrient requirement for producing 1 000 kg grains of super hybrid rice appeared as N 18.4819.85 kg, P 3.754.63 kg and K 15.9017.40 kg. There were no significant differences in the NPK requirements between super hybrid rice and the control except for that Shengtai 1 showed significantly less N requirement. Nutrient uptake rate of super hybrid rice appeared as N 177.69189.09 kg/hm2, P 36.9439.80 kg/hm2 and K 153.38165.39 kg/hm2, of which 61.2%65.3% of N and 67.6%74.4% of P accumulated in rice grains and 86.9%89.6% of K accumulated in rice straw. Compared with super hybrid and common hybrid rice, inbred rice Shengtai 1 showed significantly less NK uptake rates but similar P uptake rate. Percentage of N uptake rate to the total was about 20% until to mid-tillering stage (20 d after transplanting), 25%30% from mid-tillering stage to panicle initiation stage, 30%40% from panicle initiation stage to heading stage and about 20% after heading, and the percentage of P was 15%,20%30%,40%45% and 10%20%, respectively, and the percentage of K was 15%20%, 25%35%, 30%40% and 15%20%, respectively. There were no significant differences in NPK accumulation rates at each growth stage between hybrid rice and inbred rice. As above,super hybrid rice displayed significantly higher yield potential but lower nutrient requirements for NPK than those of common hybrid rice and inbred rice. It is concluded that high grain yield can be achieved with high nutrient-use efficiency in super hybrid rice.

The semi-arid area in middle of Ningxia has suffered from dry climate, which causes intensive evaporation of soil and low yield of potato. Therefore, a field study was conducted to determine the effects of super absorbent dosage on water status of dryland soil, growth and yield of potato, and water use efficiency (WUE), by comparing two different types of super absorbents (Wote and Microbe). Two super absorbents were diluted in ratio of 1∶100 before bunch planting at different application rates. Two super absorbents in different dosage in the experiments were set as follows: Wote super absorbent of 30 kg/hm2 (M2), Wote super absorbent of 60 kg/hm2 (M4), Wote super absorbent of 90 kg/hm2 (M6), Microbe super absorbent of 30 kg/hm2 (N2), Microbe super absorbent of 60 kg/hm2 (N4), and Microbe super absorbent of 90 kg/hm2 (N6). The treatment with no super absorbent applying was marked as the control. The results showed that, the application of Wote or Microbe super absorbent had greatly improved the water storage of soil layers at 0100 cm from early florescence stage to maturity stage of potato, and the effects increased along with the applying dosage. The M4 and M6 treatments had better effect on water conservation, and water storage of soil layers at 0100 cm were 55.1% and 62.1% higher than that of the control, respectively. The soil water contents of Microbe super absorbent treatments were significantly higher than that of the control in the early stage of potato. However, the Wote super absorbent treatments significantly improved soil water content at expansion-maturity stage. The application of Microbe super absorbent significantly promoted the growth in the early florescence stage of potato, with plant height, stem diameter and biomass of potato significantly higher than the control. In contrast, the application of Wote super absorbent significantly promoted the growth at expansion-maturity stage of potato, with plant height, stem diameter and biomass of potato significantly higher than the control. Higher yield and WUE were also achieved by the application of Wote and Microbe super absorbents, with optimum dosage of 90 kg/hm2 for Wote super absorbent, and the yield and WUE of potato were increased by 41.4% and 86.5%, comparing with the control, respectively. Meanwhile, the commodity rate was the highest (87.5%) with optimum dosage of 60 kg/hm2 for Wote super absorbent. In conclusion, the soil super absorbents could not only improve the water status of soil and WUE, but also promote the growth and yield of potato. The potato yield, WUE and commodity rate were the highest in the treatments of Wote super absorbent of 6090 kg/hm2.

Previous studies in our laboratory demonstrated that a marine Bacillus megaterium could inhibit the growth of Aspergillus flavus and turn off the biosynthesis of aflatoxin B1. In order to investigate the mechanisms of inhibition by B. megaterium on A. flavus growth and aflatoxin production in peanuts and to evaluate the possible application of B. megaterium as a biocontrol agent, genes expression analysis using whole A. flavus genome gene chip when A. flavus was co-cultured with B. megaterium in peanuts were performed. The aim of this research was to study the inhibitory effect of B. megaterium on aflatoxin biosynthetic pathway genes expression in A. flavus. The effects of B. megaterium on aflatoxin biosynthesis and genes expression in A. flavus were tested in two types of peanut varieties, UF 715133-1 and Jinhua 1012 by the aid of high performance liquid chromatography (HPLC), gene chip and quantitative real-time polymerase chain reaction (qRT-PCR). UF 715133-1 is a kind of peanut that could resist to A. flavus invasion, while Jinhua 1012 is susceptible to the infection of A. flavus. The results showed that though more than 85% of aflatoxin B1 was inhibited by the treatment of B. megaterium in UF 715133-1 and Jinhua 1012, no important aflatoxin biosynthetic pathway gene was differentially expressed. Peanuts unsuitable for the growth of B. megaterium was the main reason for B. megaterium unthoroughly inhibit the biosynthesis of aflatoxin like in minimal medium (MM) or potato dextrose broth (PDB). Furthermore, the experimental condition (28 ℃, relative humidity 85%), which is the optimal condition for aflatoxin biosynthesis, wasn’t suitable for the growth of B. megaterium neither. So we inferred that B. megaterium inhibited aflatoxin biosynthesis by inhibiting the growth of A. flavus in peanuts, and the secondary metabolites in B. megaterium accounted for the inhibition. Furthermore, the results showed some coding protease genes were highly downregulated, such as short-chain dehydrogenase, and non-ribosomal peptide synthetase, which may relate to aflatoxin biosynthesis. In conclusion, this strain of marine B. megaterium isolated from the Yellow Sea of East China could significantly inhibit the aflatoxin biosynthesis in peanuts through inhibiting genes expression in A. flavus. While the role of most highly downregulated genes in aflatoxin biosynthesis hasn’t been clarified, the mechanism remains to be further studied.

Jasmine-scented tea is a mainstream product of scented tea, which is very popular in Chinese northern tea market. Until nowadays, tea quality evaluation still mainly depends on the sensory assessment, which is potentially affected by individual preference and physical and mental conditions of tasters. It is necessary to search for objective and quantifiable methods for quality evaluation and discrimination. Factor analysis and discriminant analysis are statistical methods widely used in natural science, medicine, economics, sociology and many other fields. There have been some researches about application of these two methods in evaluating tea quality or discriminating the locality, variety and grade of tea. In this paper, factor analysis and discriminant analysis were used for quality evaluation and price discrimination of jasmine-scented tea. Compared with the sensory evaluation, extraction is an usual method to get tea liquor for tea quality research, which is considered to be a time and energy consuming method. In the present paper, brewing method for sensory analysis was introduced in the price discrimination study, aiming at simplifying the method for preparing tea liquor. One hundred and twelve samples of jasmine-scented tea with price ranging from 28 to 3 000 Yuan RMB per kilogram were purchased from tea market or supplied by tea companies of Wuyutai, Zhangyiyuan, Yuanchanghou and Jinghua. The tea liquor was prepared by brewing and extracting methods respectively. Brewing method for sensory analysis, 3.0 g jasmine-scented tea was infused with 150 mL freshly boiled water for 5 min and then filtered while hot. The concentrations (mg/mL) of 13 main chemical components were measured. Total extracting method, the tea liquor was prepared according to the method of China national standard GB/T 8312—2002. Extracting 3.0 g jasmine-scented tea powder with 450 mL boiled water for 45 min in boiling water bath and shaking it in every 10 min. The liquor was pressure filtered while hot and diluted with distilled water to 500 mL when cooled. The contents (%) of 13 main chemical components were measured. Concentrations and contents of polyphenols, amino acids and water soluble extract were determined by the methods of China national standard GB/T 8313—2002, GB/T 8314—2002 and GB/T 8305—1987, respectively. While concentrations and contents of caffeine, gallic acid (GA) and the composition of catechins including gallocatechin (GC), epigallocatechin (EGC), catechin (C), epicatechin (EC), epigallocatechin gallate (EGCG), gallocatechin gallate (GCG), epicatechin gallate (ECG), catechin gallate (CG) were determined by high performance liquid chromatography (HPLC). Factor analysis and discriminant analysis were carried out based on the 32 variables using SPSS 16.0 for Windows. The models for quality evaluation and price discrimination of jasmine-scented tea samples were established by factor and discriminant analysis based on the data obtained from brewing and extracting methods. For brewing and extracting methods, 5 factors with cumulative variance of 91.825% and 93.858% were obtained along with factor analysis, and 5 factor score functions and 1 comprehensive evaluation function were obtained. Three Bayes discrimination functions were obtained along with discriminant analysis. For the two methods, recognition accuracy of back substitution was 85.7% and 83.9%, respectively; meanwhile the recognition accuracy of the cross-validation was 84.8% and 81.3%, respectively. On the whole, the discrimination results are satisfactory and the brewing method for sensory analysis is better.

e increasing market demand. The production of matrine by microbial fermentation, however, would be an alternative for the production obtained from plants, and must have more advantages over the extracting from plants, with less labor and time consumed. However, there are no many reports concerning microbes with capacity to produce matrine. Hence, it is very necessary to obtain matrine-producing microorganisms for establishing the bio-production by microbial fermentation. The study presented hereby was carried out to isolate and identify the fungus with the ability to synthesize matrine from petroleum-contaminated soil samples. The fungal isolate with the capability to synthesize matrine was classified by morphological and molecular biological methods. The fungal isolates were firstly obtained from samples of oil-contaminated soil in North Shaanxi, China, through spread-plate technique and plate streaking. The chemical compositions in fermentation broth of the obtained fungus were detected by thin-layer chromatography and gas chromatograph-mass spectrometer. Subsequently, the isolate was observed under the light microscope and the classification of the isolate was performed preliminarily according to the morphological characteristics. The internal transcribed sequence (ITS) of the isolated fungus was amplified and sequenced. Homology comparison was then conducted and the phylogenetic tree was established based on the sequences of other strains from previous reports. Finally, the matrine-producing fungus was classified according to the combined results of both morphology observation and phylogenetic analysis. The experimental results showed that a fungal strain was isolated from the samples of petroleum-contaminated soil. The results of both thin-layer chromatography and gas chromatograph-mass spectrometer indicated that the fungus had the capacity to produce matrine. The morphological observation showed that the colony of this fungus was white villous, circular, abaxially cream to reddish brown, with mycelia scattered. The hyphae was colorless, smooth and septate. The sporangiophores were conical, mostly solitary, showing to grow directly from the hyphae. The conidia were colorless, smooth, showing clusters or chains, with long spindle shaped, pointed at both ends and there was no chlamydospore observed. These morphological characteristics of this fungal strain were highly similar to that of Acremonium sp. and Simplicillium sp. reported previously. The results of the fungal homology comparison showed that the fungus was more closely related to Acremonium sp. with 99% homology and the phylogenetic analysis indicated that there was no significant difference in genetic distance between this strain and Acremonium. Integrating these above results, the fungus should belong to Acremonium, with the name of Acremonium sp. P0997 in this study. As there are not so many reports about Acremonium sp. to produce matrine, our study has provided much information about this species with the capacity to produce matrine. These results would contribute to establishing matrine production by microbes. Therefore, this study concerning for Acremonium sp. with the capacity to synthesize matrine has a promising application prospect for matrine production by microbes. Further researches are ongoing about the metabolites of the genus in our laboratory. The study would provide an important scientific basis for establishing matrine production by microorganisms.

In recent years, the mechanism of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxicity has been a focal point in research. Generally it enriched in adipose tissue, and gradually amplified through food chains. It is seriously interfered with the normal function of the endocrine system of the organism, and displayed a wide spectrum of toxic effects, including dermal toxicity, reproductive toxicity, immunotoxicity and hepatotoxicity. The current research about the toxic mechanism of TCDD was mainly focused on the oxidative stress reaction, which was considered to be playing an important role in TCDD toxic research. Normally, the production and elimination of activated oxygen through the antioxidant system was in a balanceable and dynamic state. The antioxidant system could prevent excessive reactive oxygen species causing oxidative stress, keep the body balance, maintain the normal structure and function of cells. TCDD combined with aromatic hydrocarbon receptor and entered the nucleus, which changed the mRNA transcription of target gene, caused adverse change in the activity of enzymes and proteins, produced a series of oxidative stress reaction. Chinese medicinal herbs had been widely used in animal disease prevention due to their characteristics of rich bioactive components, free pollution, low side effects and immune enhancement. Many studies had reported that natural antioxidants were efficacious in preventing oxidative stress-related liver pathologies due to particular interactions and synergisms. Glycyrrhiza glabra extracts (GGE) was one of the common traditional Chinese herbal medicine, it could adjust the immunity, and had anti-tumor, anti-virus, antioxidant effects and so on. Although numerous studies had reported its beneficial effects on mammals, there was a lack of reports on its function in aquatic animals. The aim of this study was to evaluate the hepatoprotective and antioxidant effects of GGE on the TCDD-induced liver injury in Jian carp (Cyprinus carpio var. Jian). Jian carp were fed with diet containing 3 doses of GGE (0.1, 0.5 and 1.0 g/kg diet) for 60 days before a single intraperitoneal injection of TCDD (0.6 μg/kg), 72 h after TCDD injection, blood and liver samples were taken for biochemical analysis. The results showed that GGE at 1.0 g/kg diet for 60 days prior to TCDD intoxication significantly reduced the elevated activities of ALT, AST, LDH, AKP and increased the reduced levels of total protein (TP), albumin (Alb) in the serum, markedly inhibited the reduction of the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), total antioxidant capacity (T-AOC), and reduced the malondialdehyde (MDA) formation in liver tissue. Meanwhile, histopathological observation also showed that GGE can significantly relieve TCDD induced liver injury. It is concluded that GGE exhibited protective effect against TCDD-induced hepatotoxicity in fish, which is likely related to its antioxidant activity, and it is suggested that GGE may potentially be used as a hepatoprotective agent for fish liver injury.

Bacterial sepsis is a serious infection for fish. In the past years, the feeding cost of Megalobrama amblycephala had been seriously affected by bacterial sepsis. However, bacterial sepsis does not extensively occur during the feeding processes of Megalobrama terminalis. Therefore, M. terminalis which is highly resisted to bacterial sepsis is increasingly favored by farmers.
To study the pathogen resistance mechanism of different varieties of Megalobrama fish in response to Aeromonas hydrophila, we used label-free based proteomics technology to study the proteome change of the livers of M. terminalis and M. amblycephala infected with A. hydrophila at 0 h, 3 h, 10 h and 24 h.
After identification and relative quantification, 49 and 29 proteins changed at different post-infection time points in M. terminalis and M. amblycephala, respectively. The differentially expressed proteins were deeply analyzed by gene ontology annotation and bioinformatics, and we found that, by comparing with M. amblycephala, the percentage of differentially expressed redox proteins in M. terminalis increased from 7% to 13%, and β-globin was up-regulated (1.66, 3.44 and 1.93 times increased at 3 time points). Furthermore, we found that M. terminalis may specifically induce synergistic pathogen resistance mechanism including the regulation of pentose phosphate pathway, metabolism of fatty acids, leucine metabolism pathway and over-expression of β-globin to resist the invasion of pathogens.
In summary, we studied four different stages of Megalobrama liver proteome expression after A. hydrophila infection, and found different pathogen resistance signal response pathway between two fish species, which indicates the resistance mechanism of different fish species after A. hydrophila infection. The result is of great benefit to further deeply reveal the molecular mechanisms of fish pathogen interactions and the breeding of pathogen-resistant Megalobrama fish varieties.

China is the largest country of vegetable production in the world, and more than 60% vegetable varieties are planted by seedling transplanting, which mainly depends on manual work. However, there are some shortcomings in the traditional manual transplanting, such as high labor intensity, low productivity, poor quality and high cost. It is necessary to do some researches on the vegetable transplanters to adapt to the requirements of the mechanization of agricultural production. Currently, the domestic vegetable transplanters are mainly clip-chain transplanter, seedling guide tube transplanter, nacelle-type transplanter and flexible disc transplanter. The transplanters can meet the basic seedling transplanting requirements, but still stays in the semi-mechanization level. The research work of the vegetable transplanter is mainly focused on the design and optimization of the seedling picking and transplanting mechanism. However, automatic vegetable transplanter needs integrated knowledge and technology, the research on which should also combine the structural design with the physical and mechanical properties of vegetable seedling pot. Thus, it will be helpful for further optimal design of the key components of automatic vegetable transplanter, such as the picking seedling mechanism and the transplanting mechanism. Tomato seedlings with the age of 23 d were used as experiment objects. The physical and mechanical properties of the tomato seedling pot have been tested and analyzed, which were directly related to the transplanting machine design. Tablet compression of seedling pot has been done with a universal testing machine Instron 5543 and P100 flat probe. In the experiment, the regular pressure-deformation was analyzed and the clamping force characteristics of pot during seedling picking were determined. Pot puncture test using a universal testing machine Instron 5543 and P5 cylinder probe has been done to analyze the puncture characteristics of seedling pot during seedling picking. At the same time, to analyze the creep characteristics of seedling pot, creep test has been done using a universal testing machine Instron 5543 and P100 flat probe and combined with the describe of Burgers model. Then a scatter platform with 500 mm height was built and pots were scattered from the platform. The scattering rate of seedling was obtained and the scattering characteristics during transplanting were analyzed. Testing results show that the relationship between the capacity of resistance for compression and deformation was non-linear. The capacity of resistance for compression on yield point was 3.15 N when the deformation of the pot was 5.64 mm, so the picking seedling force should exceed the calculated yield point in the design of picking seedling machinery. In the puncturing process, the relationship between puncturing force and displacement was approximately linear at the displacement of 0 to 13.5 mm, and then it remained constant in the displacement range of 13.5 mm to 19.5 mm , while it increased significantly when the puncturing displacement was greater than 19.5 mm. Seedling pot creep property conformed to the creep law of Burgers model, and the average creep value was 0.398 9 mm in the condition of loading force of 5 N with 120 s retention time. In the scattering process, the tests showed the average scattering rate of seedling was 22.73%, and the seedling pots kept intact after falling, which met the requirements of mechanical planting. The research results on the physical and mechanical properties of vegetable seedling pot will provide important data for the design on the key components of automatic vegetable transplanters.