Morphological traits played an important role in vegetative growth of cotton (Gossypium hirsutum L.), and also had an critical impact on reproductive growth. In this study, we dissected the genetic architecture of four morphological traits, including plant height (PLH), stem diameter (STD), stem first (STF) and stem node (STN). Thirty-nine lines and their 178 F1 hybrids of upland cotton grown in three environments were used for association mapping. The association mapping was conducted using mixed linear model approaches for analyzing full genetic model with genetic effects of additive, dominance, epistasis and their environment interaction. The results showed that 25 highly significant quantitative trait SSRs (QTSs) were detected and their total heritability was high for the four morphological traits studied (h2G+GE≈63.08%78.28%). It was revealed that additive, dominance and their environment interaction effects were important genetic recourses for morphological traits in cotton. This research provides new insights into cotton quantitative genetics and molecular breeding.

Dendrobium Candidum (Orchidaceae) is an aerophyte cultivated widely in Zhejiang Province as traditional Chinese herbal medicine. Two “myxomycete diseases”, which affected the growth of plants, were found in cultivated fields of D. candidum in Yueqing City of Zhejiang Province in 2011. Two “pathogens” were identified as Comatricha pulchella (C. Bab) Rostaf. and Fuligo septica (L.) Wigg. by morphological characters and molecular data, including light microscopy, scanning electron microscopy, spore germination and analysis of 18S rDNA sequences. Sporocarps of C. pulchella were stipitate and gregarious, with about 2.2 mm in total height and cylinder-shaped sporangia, intensively distributed on the plant stem and leaf surface; its dense capillitium arose from the entire columella and dark spores in mass (7.28.0 μm in diameter). Whereas, the sporocarp of F. septica was a large scale cushion-shaped or irregular type aethalium, with up to 15 cm in length and the colors of the outer peridium in the spore-bearing stage, which could cover the whole cluster of the plants. White, stipitate and young sporangia were observed on young leaves and stems of D. Candidum after 15 d of inoculation with C. pulchella, and the mature sporangia were observed after 20 d of inoculation. Whereas, no sporocarp was observed on young leaves and stems of D. Candidum, but yellowish sporocarps produced on the substrate near the root after 15 d of inoculation with F. septica; with development of the sporocarp, the color became opalescent, and large sporocarps were observed after 30 d of inoculation, which covered the basal part of stems. The artificial inoculation results showed that both the myxomycetes could not infect the living plants. To the best of our knowledge, the two species both were the new record in Zhejiang Province. The discovery of C. pulchella and F. septica enriches the fungal resources of Zhejiang Province and also provides fundamental materials to further study on geographical distribution and diversity of myxomycete in China.

Brassica oleracea var. italica is an important vegetable crop worldwide, and in China, Taizhou City of Zhejiang Province is one of the major broccoli production areas. Downy mildew and grey mold rot are two common fungal diseases caused by Hyaloperonospora parasitica and Botrytis cinerea, respectively. In recent years, broccoli production in Taizhou was frequently affected by these two fungal diseases, resulting in yield and quality loss. Broccoli germplasm resources resistance to disease is scarce; therefore, molecular breeding is regarded as an effective solution to solve the problem. This is critically important to isolate genes associated with disease resistance, which will act as potential target genes for broccoli breeding. Zinc finger proteins are kinds of important transcription factors in eukaryotic organisms, which involve in various biological activities, such as replication, transcription, translation, repair, metabolism and signaling. According to the number and order of cysteine and histidine residues, zinc finger proteins were classified into several different types, such as C2H2, C2C2, C2C2C2, C2HC and C3H. For example, C3H-type ones contain one to six typical motifs with three cysteine residues and one histidine residue. However, their functions are little known, and no gene has been reported in broccoli. In this study, a C3H-type zinc finger protein gene BoCCCH2 was isolated from broccoli, and later the expression patterns in different organs as well as leaves infected by H. parasitica and B. cinerea were studied. Results indicated that BoCCCH2 contained no intron, and the full length of coding sequence was 1 740 bp encoding 579 amino acids. The deduced protein sequence contained two ANK domains and two CCCH zinc finger structures, respectively, and the CCCH zinc finger types were C—X8—C—X5—C—X3—H and C—X5—C—X4—C—X3—H. Reverse transcription-polymerase chain reaction results showed that the BoCCCH2 was expressed in roots, leaves, stalks, young siliques, flower buds and flowers, with highest level in roots. Expression levels increased when challenged by both H. parasitica and B. cinerea. When infected by H. parasitica, expression levels increased after 24 h, and decreased after 72 h, while infected by B. cinerea, the highest level was detected after 6 h, and slowed down in 12 h. Homologous sequences were downloaded from NCBI (National Center for Biotechnology Information) website, including Citrus sinensis, Gossypium raimondii, Populus trichocarpa, Ricinus communis, Prunus persica, P. mume, Malus domestica, Fragaria vesca, Phaseolus vulgaris, Glycine soja, B. rapa, Camelina sativa, Capsella rubella, Arabidopsis thaliana and Eutrema salsugineum. Phylogenetic analysis results revealed that BoCCCH2 was grouped with homogeneous sequences from other Cruciferae plants with bootstrap confidence of 100%, and sequences from Leguminosae, Euphorbiaceae and Rosaceae were found on different clades. In conclusion, these results indicate that the BoCCCH2 might play an important role in defense responses challenged by either H. parasitica or B. cinerea. Cloning and expression analysis of BoCCCH2 provide evidence for further studies on gene function.

Allelopathy played an important role in interspecific relationships of plants. Effects of aqueous extract from Caragana intermedia root on seed germination and seedling growth of plant species in desert steppe were investigated, to reveal the function of C. intermedia in artificial compound system and vegetation succession. Seven common species were selected, including Sophora alopecuroides, Astragalus adsurgens, Melilotus officinalis, Elymus dahuricus, Sorghum sudanense, Caragana korshinskii and Caragana microphylla. Laboratory bioassays were conducted, and gas chromatography-mass spectrometry (GC-MS) was used to analyze the compounds in the aqueous extract from C. intermedia root. The results showed that allelopathic effects were observed for aqueous extract from C. intermedia root, but showed distinct influences on different species. Seed germination and seedling growth of five species (S. alopecuroides, M. officinalis, S. sudanense, C. korshinskii and C. microphylla) were inhibited by aqueous extract at some certain concentrations; however, those of A. adsurgens and E. dahuricus were promoted. In addition, the aqueous extract from C. intermedia root had inhibition effect on seed germination of S. alopecuroides, S. sudanense and C. microphylla, whereas it had promotion effect on seedling growth at the same concentration. Twenty-one compounds were identified from the aqueous extract, including eight kinds of compounds such as alcohol, ketone, ether, ester, terpenes, organic acid, alkyl halide and nitrogen compounds. In sum, the aqueous extract from C. intermedia root has distinct allelopathic effects on different species in laboratory bioassays. Nevertheless, under the field condition, whether C. intermedia had allelopathic effects, and whether the action concentration could impose an allelopathic effect on seed germination and plant growth required further study.

Hemocytes are the main executor of cellular immune system, which play an important role in defense against pathogen invasion. The immune defense mechanism has been concerned by many scholars. Many studies showed that hemocytes would contact pathogen through hemolymph circulation when encounter with invasion of pathogen, and pathogen would be devoured, formed nodules and agglutinated into tumor or be coated. However, in the immune response, pathogens would produce toxins to cause damage, resulting in variation on morphology, quantity and proportion of the hemocytes. Therefore, studying the immune function and mechanism of the hemocytes will provide theoretical reference for biological control of the pests. Heterolocha jinyinhuaphaga Chu was a newly discovered defoliator of honeysuckle, which was observed three generations per year in Anhui Province recently. The pest caused production reduction and even death of honeysuckle in a large scale, and brought great economic losses. Several studies have investigated the biological characteristics of the pest and its control measures, the immunity response of hemocytes has not been reported yet. In the preliminary study, six types of hemocytes including prohemocytes, plasmatocytes, granulocytes, spherulocytes, oenocytoids and cystocytes were found in H. jinyinhuaphaga Chu larva. In this study, the hemocytes of H. jinyinhuaphaga Chu infected by Escherichia coli were investigated, and the variation of morphology, total number and proportion of hemocytes in H. jinyinhuaphaga Chu larva at different time was observed, to understand the hemocyte types involved in the immunity response, to explore the mechanism of hemocyte immunity function and to provide scientific reference for developing effective microbial insecticides. The results showed that deformation, disruption, nucleus shift and vacuole were found in the hemocytes of H. jinyinhuaphaga Chu larva after infected by E. coli at different dosages. In each time period, the total number of hemocytes was significantly higher than control, and increased rapidly over time. The peak was observed at 12 h, and started to decrease in 24 h. The proportion of prohemocytes decreased significantly at 3 h, and declined over time, until the lowest level was observed at 12 h, and started to increase at 24 h. But the proportion of plasmatocytes, granulocytes, spherulocytes, oenocytoids and cystocytes relatively increased, and reached the highest level at 12 h, then began to decrease at 24 h. Significant difference was observed among the proportions of the plasmatocytes, granulocytes and cystocytes （P<0.05） at each time period, but not for the spherulocytes and oenocytoids （P<0.05）. In conclusion, infection by E. coli can cause hemocyte immune response in H. jinyinhuaphaga Chu, and the plasmatocytes, granulocytes and cystocytes are the main hemocytes involved in the immune response.

The goal of traditional irrigation is to provide proper moisture for crops and to get the highest yield per unit area. However, on background of water deficits and associated economics in the arid desert regions of Northern Xinjiang, relations between water input and crop yield have become a hot topic. In this study, insufficient irrigation test was carried out in the northern region, and the yields of alfalfa, Sudan grass and silage corn were analyzed under different soil water conditions, and the water production function model of these artificial grasslands was determined; meanwhile, the water sensitivity index or coefficient for alfalfa, Sudan grass and silage corn in each growth stage was calculated by using Jensen model, Stewart model and Jensen model, respectively. The test results showed that the models had a high precision, and the average relative errors for alfalfa, Sudan grass and silage corn were 6.51%, 9.24% and 9.25%, respectively. The research results can provide theoretical and technical support for the rational development of limited water and soil resources in Altay grassland and pasture of Xinjiang.

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.

Chilled pork is an important food in China due to its high nutritional value and excellent taste. However, the major problem associated with chilled pork is its susceptibility to contamination by pathogenic bacteria in the process of slaughtering, processing and transportation. Chitosan has been found to be a biocompatible, nonantigenic, biodegradable, nontoxic and biofunctional natural compound. And it was reported to have strong antimicrobial and antifungal activities, against a range of foodborne filamentous fungi, yeast, and bacteria. So chitosan makes it a potential natural source of food preservative or coating material. Food irradiation technology, as a kind of cold sterilization technology, has advantages of no residue, excellent sterilization effect and so on. Nowadays gamma irradiation is one of the most commonly used irradiation methods in China, due to its strong penetrating power, perfect technique and equipment protection, and excellent sterilization effect. Till now, the single effect of chitosan and gamma irradiation on chilled pork has been reported, but the combined effect of both chitosan and gamma ray on quality of chilled fresh pork has not been documented. This study was to explore a new way on shelf-life extension of chilled pork. Chilled fresh pork was soaked in 0%, 1% and 1.5% chitosan solution, was vacuum-packed in polythene bags individually and then was subjected to 0, 3, 5 and 7 kGy doses of irradiation using 60Co gamma ray. Water content, pH value, chromaticity, lipid oxidation index of thiobarbituric acid (TBA) value, and total viable counts were measured at regular time. Plate count method was used to measure samples for the total number of colonies. Significance between treatments was determined by multi-factor analysis of variance (MANOVA) using SPSS 16.0. Results indicated that in the storage period, the range of water content was 69.88% 75.22% on the whole, and the pH value finally had a certain degree of rise, but the chitosan solution and irradiation treatment played a role in controlling pH rise. In terms of total viable counts, with the increase of irradiation dose and concentration of chitosan solution, the total colony number of samples declined. Chitosan combined with gamma ray treatment groups performed better in controlling the total number of colonies than the single application of gamma ray irradiation treatment groups and chitosan solution treatment groups. The TBA value of groups treated by chitosan solution at low doses was lower than the groups without chitosan solution treatment. In terms of color evaluation, at the first day after irradiation, a* value of the irradiation treatment groups was higher than that of treatment groups without irradiation, but b* value was the opposite. The a* value of all treatment groups increased with the irradiation dose at the first day, while the b* value of all treatment groups increased with the extension of storage time. In conclusion, compared with the single application of gamma irradiation treatment groups and chitosan solution treatment groups, though the chitosan-gamma ray combined skill has not shown obvious advantages in controlling water content and preventing color change and fat oxidation, it does better in controlling the rise of pH to some degree, and especially in controlling the total number of colonies, which is one of the most important factors influencing the shelf-life of food.

Wetlands are important ecosystems with various functions in Northwest of China. Though Ningxia Plain locates in arid region, wetlands are widely distributed in the region because of the Yellow River, where the wetlands are typical as oasis wetlands. There are four different types of wetlands, including rivers, lakes, marshes and constructed wetlands. A variety of ecological services are widely provided for people living in the developing countries. Therefore, evaluation on ecosystem services plays an important role in management and conservation of wetlands. The aim of this study is to better understand the economic value and service value of wetland, which could offer a basis on decision making for sustainable development. Field investigation and laboratory analysis, combining remote sensing (RS) and geographic information system (GIS) technology and statistical data were used to assess the ecological service value of the wetland in Yellow River valleys of Ningxia Plain, including eight final services, such as material production, water supply, water quality purification, climate regulation, carbon sequestration and oxygen release, soil conservation, scientific research and entertainment, and four middle services, such as water storage, net primary productivity, nutrient cycling and wild life habitat. Mathematic and economic methods were applied, including market value method, carbon tax rate method, shadow project method, development phase coefficient, travel cost method and result parameter method. In order to avoid repeated calculation, wetland ecosystem services were divided into ultimate services and were further used as the gross value of ecosystem services for the wetland. The results showed that in 2014, the total ecosystem service value of wetlands in Ningxia Plain was about 228.22×108 Yuan RMB, accounting for 15% of gross domestic product in Ningxia Plain area, and the middle service value was 125.69×108 Yuan RMB. The order of final service value for different wetland types was as follows: river (136.82 ×108 Yuan RMB) > marsh (36.80 ×108 Yuan RMB) > lake (32.56×108 Yuan RMB)> constructed wetland (22.04×108 Yuan RMB). The ecosystem service function value of the rivers, lakes, marshes and constructed wetland were 19.85×104, 11.07×104, 11.02×104 and 12.42×104 Yuan RMB/hm2 respectively, and the ecological service value per unit area of the river is the highest. The service value of wetland in the unit area was about 15.27×104 Yuan RMB/hm2, and the order of final service value was as follows: leisure tourism > water supply > carbon sequestration and oxygen release > climate regulation > soil conservation > material production > water quality purification > scientific research. The spatial distribution of ecosystem service value showed significant variation in Ningxia Plain wetland, in which the highest service value of river, lake and marsh wetlands was in Pingluo County, and the highest service value of constructed wetland was in Helan County, and the lower service value was observed in Xixia and Jinfeng Districts of Yinchuan.

Tobacco (Nicotiana tabacum L.) is an important commercial crop planted in China. Generally, tobacco stalks were burnt in the field after harvest, causing severe air pollution. The utilization of tobacco stalk has become an increasingly challenging issue in tobacco production, whereas conversion of tobacco stalk into biochar may provide a feasible approach. Biochar is a carbonaceous solid pyrolyzed from residual of agricultural and forest biomass. It can be used as soil amendment due to its favorable properties, such as high pH value, cation exchange capacity, oxygen-containing function groups, as well as microporous structures. Previous studies have demonstrated that biochar can be used for remediation of soils contaminated with organic and inorganic pollutants. Moreover, biochar has the potential of enhancing long-term sequestration on soil organic carbon, improving soil structure and water retention ability, promoting bioavailability and retention of the nutrients, and ultimately promoting plant growth and increasing crop yield. The environmental behavior and impacts of biochar mainly depend on its physical and chemical properties, while pyrolysis temperature is the main factor affecting the physicochemical characteristic. To understand the influence of pyrolysis temperature on the physicochemical properties of biochars, the tobacco stalk was pyrolyzed at 350, 400, 450, 500, 550 and 600 ℃, then the properties of biochars such as yield rate, pH value, electrical conductivity and specific surface area were determined. The composition and structure characteristics of biochars were investigated by scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray spectrometry, X-ray diffraction and 13C-nuclear magnetic resonance analyses. The results showed that the yield rate, contents of O and H as well as the H/C, O/C, (O+N)/C ratios of the biochars decreased with the rise of pyrolysis temperature. However, the pH value, electrical conductivity, specific surface area and total carbon contents of biochars increased as the pyrolysis temperature increased. The yield rate and pH value of biochar tended to be stable above 500 ℃, and the specific surface area and pH value peaked at 450 ℃. With the rise of pyrolysis temperature, the content of mineral elements and surface crystal increased, whereas the content of oxygen-containing functional groups decreased. Concentrations of K, Al and Ca were 28.4635.47, 10.7435.86 and 13.1524.95 g/kg, respectively. The stability and aromaticity of biochar increased but its polarity decreased with the rise of pyrolysis temperature. Overall, the tobacco stalk biochar pyrolyzed at 450 ℃ could achieve the optimal benefits for agricultural production and environmental protection. The results can provide useful theoretical guidance and technological support for the recycle and utilization of tobacco stalk, and the application of tobacco stalk biochar in agricultural production and environmental protection.

Due to large biomass, submergence tolerance, rapid growth, well-developed root system and strong adaptability, willow (Salix matsudana) trees were not only widely used in ecological restoration of the heavy metal pollution, organic pollution and eutrophication, but also used as source of biomass energy. To expand the range of application and improve the economic value, it is necessary to enhance the biomass and nutrient accumulation of willow. Phyto-microbial remediation technology was widely used in recent years for it was environmentally friendly, low cost and high efficiency in restoration. With assistance of microbe, the efficiency of phytoremediation was significantly enhanced. Endophytic bacterium, a kind of microbe colonized in plant tissue without causing pathogenicity, could produce plant hormones like gibberellin and indole acetic acid (IAA) to promote plant growth. In this study, willow trees were inoculated by eight endophytic bacteria (SaMR12, SaZR4, SaMR10, SaNR1, SaCS20, SM03, SM05 and LM02) derived from hyperaccumulator Sedum alfredii, and the plant growth and accumulation of nitrogen and phosphorus were investigated. In hydroponics experiment, the willow cuttings were grown in 2.5 L Hoagland’s solution with physiology upward until root length was above 1 cm. And propagation of endophytic bacteria suspension was added to the vessel with final density of 1×108 CFU/mL. The bacterial solution was replaced after 3 days. The treatment without bacterial inoculation was used as a control. The willows were observed and determined after 2 months of culture. The chlorophyll contents, root morphology, shoot and root biomass, nitrogen and phosphorus accumulation showed significantly different among different endophytic bacteria treatments. Chlorophyll content was significantly increased by 15% and 14% with inoculation of SaMR12 and SaMR10 endophytic strains as compared with the control. After inoculation with LM02, SaNR1 and SaMR12, the root morphology was significantly improved. The total root length was increased by 163%, 136% and 66%, respectively. Root surface area was increased by 54%, 12% and 17%, and the number of root tips was increased by 54%, 44% and 48%, respectively. With the inoculation of LM02, SaMR12 and SaMR10, the total biomass of willow was increased by 234%, 43% and 54%, respectively. The accumulation of nitrogen and phosphorus nutrients was also significantly promoted. Shoot nitrogen accumulation was increased by 176%, 26% and 41%, and shoot phosphorus accumulation was increased by 109%, 12% and 30%, respectively, as compared with the control. The root nitrogen accumulation was increased by 8.3 times, 2.4 times and 3.4 times, and the root phosphorus accumulation was increased by 4.8 times, 2.1 times and 2.8 times, respectively, with the inoculation of LM02, SaMR12 and SaMR10. Meanwhile, the concentrations of nitrogen and phosphorus in eutrophic water were significantly decreased. It is concluded that LM02, SaMR10 and SaMR12 are more efficient in promotion of plant growth than other endophytic bacteria. These strains also show the enhancement of willow growth for bio-energy and improvement of phytoremediation efficiency, which have a broad application prospect.