The complementary deoxyribonucleic acid（cDNA）of Bombyx mandarina serine proteaselike protein gene was cloned by reverse transcriptionpolymerase chain reaction （RT-PCR）. The results showed that the cDNA with 938 bp in length contained an open reading frame （ORF） of 912 bp which encoded 303 amino acid residues. The encoded amino acid sequence had a high identity to the reported sequence of serine proteaselike protein from other insects and shared the typical structural features of serine protease family. The serine proteaselike protein gene was only expressed in haemolymph of B. mandarina by RT-PCR and Northern blot analysis. These results provide a molecular basis for further studying the function of this gene in B. mandarina.

Huanglongbing (HLB) is a destructive disease that represents a major threat to the world citrus industry. It was first reported from Chaoshan area of Guangdong Province in the early 20th century, and is now known to occur in next to 40 different Asian, African, Oceanian, South and North American countries and areas. Its pathogen is a phloemlimited, noncultured, Gramnegative bacterium which belongs to the genus Candidatus Liberibacter. Three species, i.e., Ca. L. asiaticus, Ca. L. americanus, and Ca. L. africanus with Ca. L. africanus subsp. capensis are currently known. So far, the pathogen of HLB disease discovered in China is only Ca. L. asiaticus, which distributes widely in almost all major citrus growing areas such as Guangdong, Guangxi, Fujian, Yunnan, Zhejiang and so on. This pathogen can be transmitted by grafting and Diaphorina citri and infect almost all fruit trees of Citrus, Fortunella and Poncirus, causing different characteristic symptoms including asymmetric blotchy mottle, vein yellowing or nutrition deficiency on leaves, and “red nose”, “greening” or deformed shape on fruits. While the infected Murraya exotica usually show no symptoms. Based on the above mentioned facts, it is referred that genetic diversity might exist in populations of Ca. L. asiaticus. The gene sequences of 16S rDNA, 16S-23S rDNA ITS and 23S rDNA of Ca. L. asiaticus have been confirmed to have a high degree of conservation and are not suitable for genetic diversity analysis. The omp gene, an outer membrane protein gene of Gramnegative bacterium, has been demonstrated as a potential candidate gene used for research on the genetic diversity. In this study, genetic variations of omp genes of 18 Ca. L. asiaticus isolates from China and other countries were analyzed aiming to understand the genetic diversity in populations of Ca. L. asiaticus and the effect of geographical source and host species. First, omp genes of Ca. L. asiaticus isolates from seven different geographical regions and 11 different host species in Taizhou of Zhejiang were amplified with special primers OMP5 (5′-GATGATAGGTGCATAAAAGTACAGAAG-3′) and OMP3 (5′-AATACCCTTATGGGATACAAAAA-3′). Then, the PCR products were subjected to digestion with restriction enzymes AluⅠ, ApoⅠ, HinfⅠ, RsaⅠ, SspⅠand TaqⅠrespectively, and were separated using agarose gel electrophoresis. To further characterize the omp gene of Ca. L. asiaticus, the PCR products were cloned and sequenced. The sequences of omp genes were submitted to GenBank (JQ928882-JQ928889), and were aligned with software DNAMAN and NCBI Blast. Finally, the phylogenetic tree of Ca. L. asiaticus was constructed by neighbor-joining method using MEGA 5.05. The results showed that the omp genes of Ca. L. asiaticus isolates from different geographical regions yielded different DNA fingerprints, but those from different host species in Taizhou area didn’t. Digestion with RsaⅠ yielded two distinct RFLP patterns, in which the pattern of isolate from Guangdong was different from those of others. Two distinct RFLP patterns were also obtained with HinfⅠdigestion, and the isolate from Jiangxi had a unique pattern. However, AluⅠ, ApoⅠ, SspⅠand TaqⅠdidn’t reveal genetic variation of these eight isolates. Sequence analysis revealed that the omp gene sequences of Ca. L. asiaticus isolates from different host species in Taizhou area were completely identical, while molecular variations existed within both nucleotide sequences and amino acid sequences of those from different geographical regions. Nucleotide sequences exhibited more than 99.9% identity among these Ca. L. asiaticus isolates, about 73% identity with those of Ca. L. africanus isolates, and nearly 69% identity with those of Ca. L. solanacearum isolates. Amino acid sequences of Ca. L. asiaticus isolates had over 99.8% identity with each other, about 59% identity with those of Ca. L. africanus isolates, and about 55% identity with those of Ca. L. solanacearum isolates. All Ca. L. asiaticus isolates exhibited extremely close genetic relationship and were clustered into one group in the phylogenetic tree, while Ca. L. africanus isolate and Ca. L. solanacearum isolate were clustered into other groups respectively. In conclusion, genetic diversity exists in populations of Ca. L. asiaticus, which are mainly affected by geographical origins, while not or little affected by host species. Thoroughly understanding the genetic diversity has an important significance to promote the research on strain differentiation and pathogenic variation, make clear the evolutionary trend of HLB pathogen and epidemic characteristics of HLB disease, and provide guidance to establish more scientific and effective control and prevention measures in future.

Gluconobacter oxydans is widely used in industrial application for its dehydrogenase system locating on cell membrane. These dehydrogenases have a character to oxidize sugars and sugar alcohols incompletely. There are two potential pathways known for glucose oxidization in G. oxydans: More than 90% of glucose is transformed into gluconate in the periplasmic space; only a minority of glucose (about 5%) is phosphorylated and taken into functional central metabolic pathways such as Entner-Doudoroff pathway (EDP) and pentose phosphate pathway (PPP) in the cytoplasmic compartment. In previous study, the Embden-Meyerhof-Parnas pathway (EMP) was found inactive in G. oxydans due to its lack of phosphofructokinase. In this study, a G. oxydans strain named DHA3-9 was screened which produced dihydroxyacetone (DHA) during glucose degradation. But DHA was not a product in EDP or PPP. A mutant strain of G. oxydans DHA3-9 lacking of glucose dehydrogenase in cell membrane was constructed to study the possibility of other pathway of glucose metabolism in G. oxydans. A mgdh genedisrupted mutant of G. oxydans DHA3-9 was constructed by the way of homologous recombination and its characteristic changes of the cells growth on glucose, glucose degradation, gluconate transformation, intermediate products and growth inhibition on acetate were studied. The results indicated that the growth of mutant strain on glucose showed an obvious delay and pH dropped much slower than that of wild type. The mutant lost most of its ability of glucose degradation and produced little gluconate. Instead, DHA formation of the mutant was recorded four times as that of wild type. Pyruvate and acetate were detected in the products of mutant whereas none of such products were found in wild type culture. Under the condition with glucose as the sole carbon source, 50 mmol/L acetate completely inhibited the growth of mutant, whereas this effect was remarkably low on wild type. These results prove that in G. oxydans DHA3-9 mutant strain, glucose is utilized in cytoplasmic compartment primarily through EMP and acetate can be produced by activities of pyruvate decarboxylase and acetaldehyde dehydrogenase.

Sclerotinia sclerotiorum (Lib.) de Bary is one of the most important necrotrophic fungal pathogens. It has a very wide host range, reportedly infecting over 400 species of plants worldwide. S. sclerotiorum causes white mould (stem rot) disease of many important crops, especially oil crops such as rape, soybean, peanut and sunflower. However, so far, the molecular mechanism of pathogenicity of this pathogen has not been fully understood. It is clear that cell wall degrading enzymes (CWDEs) and oxalic acid (OA) are the important pathogenicity factors of S. sclerotiorum. During infection, the pathogen secretes CWDEs to degrade components of host plant cell wall and thus facilitates its infection. OA is of concern as another essential pathogenicity factor. The known roles of OA in pathogenicity include lowering extracellular pH value and thus increasing activity of CWDEs, altering redox status to regulate accumulation of reactive oxygen species (ROS) and programmed cell death (PCD), and having direct toxicity to plant cells. Additionally, OA is thought to be able to chelate calcium in cell wall and thus enhances its degradation by some CWDEs secreted by the pathogen. However, the effect of OA on Ca2+ concentration of the whole cells and Ca2+ signaling pathways remains unclear, which is examined in this study. The dye Fluo4 interacts with Ca2+ inside living cells and can be detected with the green fluorescence by confocal laserscanning microscope. Employing Fluo4 as an indicator of Ca2+ concentration inside cells, the effect of OA on Ca2+ concentration was analyzed. Infiltration of 1 mmol/L OA only weakly lowered the Ca2+ concentration inside leaf cells of Arabidopsis. However, 10 mmol/L OA rapidly and dramatically reduced it. The fluorescent signal was almost undetectable since 10 min post this treatment. This result reveals that the effect of OA on Ca2+ concentration inside plant cells is dependent on their concentrations. Additionally, the effect of OA on gene expression of Ca2+ signaling pathways was examined using realtime quantitative reverse transcriptasepolymerase chain reaction (qRTPCR). The genes under investigation included CRT gene family, which play roles in regulation of Ca2+ homeostasis and signaling and disease resistance, two CDPKs, which are Ca2+ sensors, and CAMTA3, a calmodulinbinding transcriptional factor involved in regulation of plant disease resistance. Expression results showed that the tested genes responded differently to OA treatment. Generally speaking, the expression of two CDPKs and CAMTA3 altered more strongly but in contrast direction in response to OA in comparison with CRT family genes. In addition, these genes were expressed differently in response to OA of different concentrations. The expression level of these genes was much higher in response to OA of higher concentration. In response to 1 mmol/L OA, the expression of three CRT genes and CDPK1 was continuously upregulated by about 10 times for CRT3 and 130 times for CDPK1 at 24 h post treatment (hpt), and the expression of CAMTA3 gene was continuously downregulated to be almost undetectable at 24 hpt, while the expression of CDPK2 gene was significantly upregulated at 6 hpt and then slightly reduced at 24 hpt. In summary, the data of this study reveal that 10 mmol/L OA, which is typically secreted by S. sclerotiorum during infection, rapidly and dramatically reduces Ca2+ concentration inside plant cells. OA may target Ca2+ signaling pathway at some key components such as CRTs, CDPKs and CAMTA3 during plant and S. sclerotiorum interactions.

Pine wood nematode (PWN) is a destructive disease to pines. For the research on its pathogenic mechanism, the theory which is about the complex infection of PWN and the bacterium carried by it is recognized. Bursaphelenchus mucronatus is considered as a related species of Bursaphelenchus xylophilus, which may be differentiation with the homologous species in different environments. In early studies, B. mucronatus was served as contrast species to B. xylophilus due to the weak or lacking pathogenicity. But recently, many reports have pointed out that it has the strong pathogenicity and can cause the widespread death of pines, which referred to Pinus thunbergii, P. yunnanensis, P. taiwanensis, P. densata, etc. The large numbers of P. yunnanensis were dead in Sichuan in recent years. However, no systematic study was conducted on the pathogenicity of the bacterium carried by B. mucronatus. This study has the aim of evaluating the effects of the bacterium carried by B. mucronatus on wilting ratio and phenylpropanoid metabolism of pine needles, and further exploring the effect of bacterium in the pathogenic process of B. mucronatus. Two-year-old P. yunnanensis seedlings, B. mucronatus isolated from PWN disease district in Sichuan, the bacterium carried by B. mucronatus and its metabolite as the materials, the wilting ratio was calculated, and the total phenol content, phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD) activities were determined by the inoculation of burette to branch phloem of P. yunnanensis in laboratory, which represented the pathogenicity of the bacterium and its metabolite on P. yunnanensis. The results showed that Pectobacterium cypripedii and its non-protein metabolite had strongest effect on P. yunnanensis in 26 species of bacteria isolated from the surface of nematodes, and the wilting degree and wilting ratio were significantly high in these two treatments. They caused the accumulation of total phenol content and the changes of PAL, PPO and POD activities, the PPO and POD activities of which increased from 12 h to 24 h and declined after 24 h, and PAL activities declined during 12-48 h. Moreover, in above each index, significant correlation with wilting ratio was observed, but among the indexes in phenylpropanoid metabolism, only PAL and PPO activities were found to have a significant correlation. It is concluded that P. cypripedii and its nonprotein metabolite can continuously decrease the phenolic antioxidants, which makes the metabolism to be disordered and induce cell toxicity of the needles through affecting the phenylpropanoid metabolism. And then, the needles display lesion, fading, browning, drying and even death. The above results reveal that the occurrence and development of PWN disease is closely related to the abnormal changes of the phenylpropanoid metabolism in host.

Tibetan annual wild barley is an ancestor of cultivated barley and rich in genetic diversity. Moreover, some wild barley accessions show high tolerance to poor soil. In this research, 82 wild barley accessions and 16 cultivated barley genotypes were firstly used in a hydroponic experiment, in order to compare their tolerance to low nitrogen (N). The results showed that there was a significant difference among genotypes in their low N tolerance, with the wild barley having wider variation than the cultivated barley. On the basis of the results obtained in the first experiment, two low-N tolerant wild genotypes (XZ113 and XZ149), one moderately tolerant wild genotype (XZ125) and one cultivated barley genotype (ZD9) were selected and used in the second experiment, to determine their growth and physiological performance under different N levels. The analysis of N-uptake dynamics showed that ZD9 and XZ113 had similar maximum uptake velocity (Vmax), and ZD9 had the smaller MichaelisMenten constant (Km), similar to that of XZ149. Among the four barley genotypes, XZ113 had higher photosynthetic rate and ZD9 had higher nitrate reductase activity. The current results indicate that Tibetan wild barley has different mechanisms underlying low N tolerance from those in cultivated barley, and may provide the elite germplasm with low N tolerance or high N use efficiency for modern barley breeding.

First, a hydroponic experiment was conducted to compare the difference in low potassium (K) tolerance among 99 Tibetan annual wild barley genotypes. The wild barleys that were examined showed a significant difference in low K tolerance, with XZ107, XZ153 and XZ159 being high tolerant, and XZ141 being high sensitive. Second, these four wild barley genotypes as well as two cultivated barley cultivars were used to investigate the genotypic difference in K use efficiency (KUE), net photosynthesis and expression of HvHAK1. The results showed that the values of these parameters were larger in low K tolerant genotypes than in sensitive ones. In addition, the association analysis using DArT markers indicated that tissue K concentration was controlled by multiple genes. The current results also showed that Tibetan annual wild barley may provide elite germplasm or genes for genetic improvement of KUE in barley and other crops, and relative tissue biomass as well as KUE under low K relative to normal K level can be used as the reliable index for evaluating low K tolerance in barley.

“Yinhong” grape (Vitis vinifera×Vitis labrusca) cultivar has many excellent characteristics, such as strong resistance, high branching rate and extensive management. The maturation of this cultivar is mainly in the middle of August, and it is one of the most promising popularized varieties after “Kyoho” and “Fujiminori” in Zhejiang Province. In recent years, with the development and promotion of protected cultivation technology, the grape picking tourism industry was booming, which undoubtedly had wider requirement for the maturity of grape. However, there exists excessive load to adjust maturity and delay picking in sightseeing orchard in production, and the effect of excessive load on adjusting maturity is not clear yet, and especially its effect on grape quality after delaying picking had not been reported. Therefore, the aim of this research is to study the effect of different load levels on berry maturity and quality. Three-year-old “Yinhong” trees were used in experiment. Three fruit load levels were designed including 2 kg/m2 (1 250 kg/667 m2), 3 kg/m2 (1 875 kg/667 m2), 4 kg/m2 (2 500 kg/667 m2) by cluster and fruit thinning. Fruit was picked when berry seed was brown and fruit mass did not increase. The quality indexes such as fruit mass, color, hardness, fruit total soluble solids (TSS), titration acid (TA) were determined at harvest. The results showed that the growing curves of different fruit loads were the same pattern, showing a double “S” curve. With the growing of the fruit, fruit diameter of 2 kg/m2 load level was highest from hardcore to maturity period, but there was no significant difference among three levels. According to the standard of harvest, both load levels of 3 and 4 kg/m2 could delay fruit ripening, and especially 4 kg/m2 could effectively delay fruit maturity by 42 days compared to 2 kg/m2. The TSS content decreased after delaying picking a week, and could not reach 17% at last for 4 kg/m2. The TA content of 2 kg/m2 load level was highest. With delaying the picking of grapes, TA content was decreased after maturity. Fruit of 4 kg/m2 load level had lower hardness compared with other two levels at maturity and was no significant change with delaying picking. The fruit masses of 3 and 4 kg/m2 load levels were lower than 2 kg/m2, but there were no significant difference among them. Color index of red grape of 4 kg/m2 load level was significantly lower than others. Anthocyanin content of 4 kg/m2 was reduced by 42% compared with 2 kg/m2. The quality indexes of 3 kg/m2 load level had large fluctuation, but the mean content was between 2 and 4 kg/m2 load levels. The data in spring of 2013 showed that the 2 kg/m2 load level had higher germination rate and was easy to produce double buds than 3 and 4 kg/m2, however, there was no significant difference between latter two levels. The load level of 4 kg/m2 reduced the flower number by 20.1% and flower length by 19.76%, compared with 2 kg/m2 load level. In conclusion, 3 and 4 kg/m2 load levels can delay fruit maturity, however the fruit quality of 4 kg/m2 load level is bad, such as soft fruit, low TSS and anthocyanin contents. After maturity, the flavor quality of 4 kg/m2 load level decrease quickly with delaying picking. Meanwhile, the flower quality is poor in the following year. The fruit mass, hardness and anthocyanin content in the 3 kg/m2 load level are also lower than 2 kg/m2. So higher fruit load had negative effect on fruit quality and vine potential, and it is not suggested to use in production unless it is necessary. Therefore, 2 kg/m2 load level of “Yinhong” grape is recommended in the production.

Plant root system is plastic and dynamic, allowing plants to respond to their different environments in order to optimize acquisition of important soil resources. A number of root architecture parameters are known to be correlated with improved crop performance. Therefore, quantitative analysis of root architecture parameters, or the spatial configuration and distribution of root system in soil, will help to promote our understanding for root structure, function and their interactions with the soil in rhizosphere zone. The overall objective of the present work is to reconstruct 3D (three-dimensional) root architecture in situ non-destructively and to measure quantitatively geometric parameters of root system. The maize roots were used as research object, and the crosssection images of maize roots were performed on a whole-body magnetic resonance (MR) imaging system with a static magnetic field of 3.0 Tesla. The MR method was found to be very effective for capturing root slice images dynamically without any contact or perturbation of plant root system or growth medium. Based on the root slice image data for maize root architectures obtained by this nondestructive approach, 3D root architecture parameters were measured. Root slice images were generated using a fast spin echo sequence with effective echo time of 10.2 ms, repetition time of 1 800 ms, slice thickness of 2 mm, and imaging matrix of 512×512 pixels. Although MR imaging is closely related to the water content of material, volumetric water contents of rhizosphere in the range of 5%20% have not significant impact on the quality of root slice images. The reconstruction process consisted of the following steps: image format conversion, filtering, roots target extraction, root data encapsulation, model reconstruction. Radiant DICOM viewer and Matlab r2009b were employed to preprocess the original slice images, including: 1) gray level transformation of the original gray level images; 2) contourlet transform filtering for noise reduction and image quality enhancement; 3) segmentation through Otsu threshold segmentation algorithm. A procedure to obtain root architecture system of maize was developed by computer image graphics technology. The root model was reconstructed with improved volume rendering algorithm in the environment of Visualization Toolkit 5.4. In order to verify the reliability of the reconstructed model, the obtained root architecture models were converted to STL (standard template library) format, and then were transformed to a 3D solid object. Then they were imported into a computer aideddesign software Pro/E to calculate their geometric parameters. Similarly, actual geometric parameters of the samples were measured manually by a vernier caliper and water displacement method. By comparing the reconstruction model of root architecture with the physical object, it was found that the obtained models were well consistent with real samples, showing very good agreement in shape, volume and other morphological parameters, and the errors among them were less than 3%. In sum, the presented methodology can avoid making great efforts in experimental measurements and consequently development of the root architecture models, and decrease the error generated from manual data extraction. This work is expected to be a useful contribution for modeling and simulation of root architecture system in situ non-destructively. Therefore, this approach provides a novel technique for the study of plant root growth and its adaptive changes to various environmental conditions.

Potato is the fourth major food crops in the world after rice, wheat and maize, and it can also be used as important vegetables, feed and industrial raw materials. Potatoes with short growth cycle, strong adaptability, high yield, wide range of uses and long industrial chain have a huge potential of valueadded processing. It is known as one of the top ten popular healthy and nutritious foods, as well as one of the economic crops with best developmental prospect in the world in the 21st century. However, some external defects on potatoes seriously affect their qualities. The traditional classification method has low efficiency and poor objectivity, costs big labor intensity, and is difficult to identify shortcomings through it. In order to realize the accurate and fast classification of potatoes in the process of actual processing, various potatoes with external defects were detected in spectral region of 400-1 000 nm using hyperspectral image technology, and an online nondestructive testing method was established by principal component analysis of characteristic wavelengths and image subtraction algorithm. Six defective potato types (mechanical damage, hole, scab, surface bruise, sprout, green skin, normal) and one qualified potato type were used as the research objects in this study, and their hyperspectral images were obtained, respectively. Then the reflectance spectrums of interest regions of potato in these hyperspectral images were extracted and analyzed. Principal component analysis was used for spectral data dimension reduction. Five feature wavelengths (478, 670, 723, 819 and 973 nm) were selected according to the local extrema of weight coefficient curve of the second principal component image of all the potato types. After that, principal component analysis was conducted again based on the five selected characteristic wavelengths, then elected the principal component images where the differences of grey value between the defective area and the surrounding area on potatoes were most obvious. Furthermore, in order to eliminate the impact of grey value of potato images in the background and improve the contrast between defective area and surrounding area, image subtraction algorithm was put forward. Using the subtraction method based on the principal component image and the reference image can effectively eliminate the influence of background region and the reflect light of potato surface. Potato external defects were identified through image processing methods, such as threshold segmentation, corrosion, expansion and connectivity analysis. The result showed that the recognition rate of all the seven potato types achieved 82.50% using principal component analysis method of the characteristic wavelengths, however, it was found up to 96.43% using image subtraction algorithm combined with principal component analysis method, indicating that the latter can more accurately identify the defective area. In sum, this image processing method based on hyperspectral image can effectively identify the external defects on potatoes, which can realize the accurate and fast classification of potatoes in the process of actual processing and has a great application prospect in the future.

Tomato is one of the main vegetables cultivated in greenhouse for its rich nutrition and good taste. In recent years, the occurrence of tomato disease brought a big threat to the yield and quality of tomato. Therefore, it is becoming more important to forecast and prevent the disease occurrence. In greenhouse, environmental factors, such as temperature and humidity, have great effect on occurrence of grey mould disease. Environmental factors are interactional in greenhouse, and the relationships between these factors and disease occurrence are complex, nonlinear and not easy to articulate. The traditional methods of mathematical statistics have some limitations in modeling the effects of environmental factors on the disease occurrence. Radical basis function (RBF) neural network is an ideal tool that could be applied to predict the grey mould disease from greenhouse tomato. It has fine characteristics of approximation performance and the global optimum which can overcome the limitations. It is difficult to build up the prediction model with all the involved factors, so the most correlated factors with the disease occurrence should be determined as predictors. A good prediction can strengthen foresight for preventing and treating diseases, which will provide scientific basis to formulate the most reasonable scheme for control diseases. In this paper, we used a neural network toolbox provided by Matlab to establish the RBF neural networks. The data of grey mould disease from greenhouse tomato and corresponding environmental data used in the experiments had been collected from one of the greenhouses in Xintiandi demonstration garden (Yangling, shaanxi Province) during the dates from 2009-04-01 to 2010-05-18. There were 102 sets of sample data in all, among which 90 sets were used to train the neural network models, and the other 12 sets were used to test. The RBF network consisted of input layer, hidden layer and output layer. Grey mould disease grade of tomato was target output, which was expressed by four node vectors to represent four grades. Input vectors had been pretreated with the normalization function “premnmx”. Mean temperature, minimum temperature and mean relative humidity were selected as input vectors. The highest accuracy and the lowest mean square error from all the variable combination were obtained while the input layer was made up of the three variables. The newrb function was used to establish the RBF neural network model. The spread value was set at 1.0 and the maximum number of neurons was 20. Through cycle test, training accuracy was the highest when spread value was 1.3, which could reach 0.966 7. The curve showed that the predicted output was similar to the expected output. The results of fitting testing of experimental data from other 12 samples with the obtained model showed that the predicted values of 10 samples about grey mould disease grade were the same with their actual values, while one grade higher than actual value could be seen in other two samples. The prediction accuracy was 0.833 3 and mean square error was 0.082 1, respectively. It is concluded that the RBF neural network may be considered as an effective method for forecasting disease grade in greenhouse. And also, the performance of the experiments could be improved if there were more sample data.

Chemical fertilizer application efficiency is an important influence factor in agricultural production. Low chemical fertilizer application efficiency not only lead to cotton production cost increase and constrain cotton per unit area yield, but also may cause agricultural non-point source pollution, because excessive use of chemical fertilizers damage inevitably the environment and resources which are vital for agricultural development. Therefore, our aim is first to systematically evaluate chemical fertilizer application efficiency by cotton farmers. And second, with the purpose to figure out the essential ways to raise production efficiency of agricultural internal system, we assess the active results of different kinds of influence factors of technical efficiency. Furthermore, we hope the results can help to increase agricultural economic benefits of farmers and agricultural scientific and technical level, and ultimately prompt the sustainable development of agriculture. By using the field survey data which were obtained from 203 peasant households in Shache County, a first agricultural county in Xinjiang with favorable cotton plant conditions, an evaluation model with stochastic frontier approach (SFA) was constructed to analyze the chemical fertilizer application efficiency by cotton farmers and then tried to estimate cotton production technical efficiency and chemical fertilizer application efficiency of different groups of cotton farmers to some extent. After that, a double logarithmic model, built by SPSS 17.0 statistical software, was used to assess the relationship between chemical fertilizer application efficiency and thirteen influence factors, and further to find the major reason why the chemical fertilizer application efficiency in Shache County’s cotton production was rather lower. The result showed that the chemical fertilizer application efficiency in cotton production of Shache County was merely 0.459 8, which was much lower than appropriate result, indicating that, under the current technical stage, only a small amount of chemical fertilizers used was absorbed by cotton plants. To be more specific, the more obvious influence factor for chemical fertilizer application efficiency was farmers’ education level, followed by farmers’ perception to chemical fertilizer utilization rate, agricultural technology training, and soil quality change, the proportion of farmers who carry out agricultural production and the application of organic fertilizers. While on the other side, the factors which had lower influence on chemical fertilizer application efficiency were plant scale, chemical fertilizer price change and working hours on farmland. Another point which was worthy mentioning was that only the soil quality change had negative influence on chemical fertilizer application efficiency. In the end, on the basis of empirical analysis in the study, a number of countermeasures (e.g. improving farmers’ educational level, enforcing agricultural technology extension, prompting agricultural production and operation in moderate scale and controlling chemical fertilizer price) were proposed to increase the chemical fertilizer application efficiency and reduce the possibility of agriculture nonpoint pollution.

Environmental perception has been drowning more and more attention all over the world. Farmers’ accurate perception is the premise of reasonable environmental behavior. It is significant to study farmers’ perception and adaptation to ecological-environment changes. Some international relevant researches find that the farmers can change land use patterns and life strategies to reduce the impact of climatic fluctuation on crop yield and agricultural income. Some domestic relevant researches find that the farmers in different areas have different perceptions of ecological-environment changes. The farmers of same life strategies express strong space hierarchy for different ecological-environment problems. They pay close attention to the ecological-environment problems which are closely related to their subsistence activities. Farmers’ perceptions and memories of extreme climate changes are associated with the time series of events. Farmers are the main parts of economic activities and they are also the basic decision-making unit in ecotone. Farmers rely on grassland resource and cultivated land resource more and more, and the way that farmers use grassland resource and economic management behaviors has become primary and the most immediate factors which influence the region ecological-environment changes. Therefore, this study researched environmental effect caused by the ways of production and lifestyles of ecologicalenvironment changes. The main aim is to research formation mechanism of farmer behavior caused by environmental effects. It will provide the scientific basis to eliminate the ecosystem excessive interference. Farmers’ perception and adaptation measures were studied using stratified random sampling survey, participatory rural appraisal and investigation of plots. First, the natural, social and economic statistical data from county government departments were collected. Second, five unincorporated villages, 121 farmer samples were investigated, and 109 valid questionnaires were obtained. The following items were investigated: 1) basic family details; 2) farmers’ perception of ecological-environment changes; 3) farmers’ cognition of factors which caused ecological-environment changes; 4) farmers’ measures to extreme climate events; 5) farmers’ ecological attention to ecological-environment changes; and 6) farmers’ protection degree of ecological-environment changes. Third, the farmer households were classified three types according to the percentage of nonagricultural income, i.e. pure agricultural households, agriculture-dependent households and off-farm dependent households. The results showed that: 1) the farmers’ livelihood diversification was low, and the livelihood diversification index of the farmers was 1.49. The livelihood diversification index of pure agricultural households, agriculture-dependent households and off-farm dependent households was 0.51, 0.52 and 0.54 respectively. 2) Farmers perceived that the ecological-environment of study area became well. The perception index of environmental change declined from agriculture-dependent households to off-farm dependent households. Farmers’ cognition of climate change conformed to the tendency of climatic index nearly 50 years. 3) Famers’ awareness of environment enhanced. They were sensitive to the environment changes. Pure agricultural households paid attention to all kinds of extreme climate events, and agriculture-dependent households and off-farm dependent households concerned more about drought. They took a variety of measures to adapt to ecological-environment changes, the main measures of which were to buy foods and fodder grass. When farmers encountered the extreme climate events, they took appropriate afterwards emergency measures, which basically was the passive adaptation. 4) Through increasing the input to the grassland, reducing cultivated land and grazing without permission, farmers maintained the stability of their own household agri-ecosystems. It is concluded that establishing the stabilizing mechanism between household ecosystem and ecosystem can eliminate excessive interference caused gradually by human activities. It is beneficial to ecological construction, resource utilization and wild plants and animals preservation. But farmers’ behaviors of different life strategies have some kinds of effects on ecological environment. It is necessary to solve the ecological-environment degradation problem in ecotone based on farmers’ life strategies.

In natural aquatic system, salinity can largely influence growth, breeding, and even fishes survival. In general, euryhaline fishes often possess strong osmotic adjustment capacity. The gill filaments play an important role in the maintenance of blood ion and acid-base balance in seawater-acclimated fishes, especially if there is a sudden change in water salinity. Seawater-acclimated fishes drink seawater to counter osmotic loss of water, and secrete excess Na+ and Cl- across the gill filaments. When there is a change between freshwater and seawater, euryhaline fishes must transform their gill filaments from an ionabsorbing epithelium to an ionsecreting epithelium, or vice versa. Associated with this transformation is change of Na+/K+-ATPase activity, Na+/K+-ATPase gene expression and structural change of the gill. Euryhaline teleost fishes, such as killifish Fundulus heteroclitus and Mozambique tilapia Oreochromis mossambicus, have been used as model animals for the study of osmo- and ion-regulation in teleost fish. However, there are little accumulating researches and available literature on juvenile Mugil cephalus. Thus, the objective of the present study is to explore the response and adjustment mechanisms of juvenile M. cephalus to salinity stress. The present study examined the effects of low salinity stress (salinity 15, 10, 5, 0, and salinity 20 as control) on Na+-K+-ATPase activities, expression of Na+-K+-ATPase β-subunit mRNA and structural changes in the gill filaments of juvenile M. cephalus during the experimental period of 20 days. The results showed that no fish mortality occurred for all experimental groups during the study period. The Na+-K+-ATPase activities in the gill filament tissue were significantly lower in the control group than in the treatment groups. At the low salinity groups (0 and 5), the Na+-K+-ATPase activities showed rising trends by high and low amplitude during the early and later experimental period, respectively, and the activities at salinity 10 and 15 groups attained the maximum value in 15 days, and then slightly decreased. The expression of Na+-K+-ATPase β-subunit mRNA changed according with the Na+-K+-ATPase activity. It showed rising trend with the decrease of salinity. There were significant differences in Na+-K+-ATPases and their β-subunit mRNA expressions between the control group and salinity 0 group from day 5 to day 20, as well as between the control group and salinity 5 group from day 10 to day 20 (P<0.05). The highest expression of Na+-K+-ATPase β-subunit mRNA at the salinity 0, 5 groups was 4.10 and 2.51 times higher than that at the control group respectively, suggesting that the Na+-K+-ATPase β-subunit mRNA played an important role in the process of regulation. With the decrease of salinity, the gill lamellae gradually became wide, and the distance between them as well as the number and size of chloride cells showed decreasing trend, while the size of pavement cells and the number of mucous cells consistently increased. In conclusion, the structure and physiological functions of the gill of juvenile M. cephalus adapt themselves to the salinity change.

Seedling transplanting plays an important role in urban greening and forest plantation. However, this job is still relying on manual labor in China. There are many disadvantages such as heavy labor intensity，high cost and low survival rate of seedlings in this situation. Thus it is necessary to design a machine that can replace artificial seedling transplant. First, a simple, convenient and reliable portable tree transplanting machine was designed, which mainly included damping handle, gasoline engine, deceleration strip, eccentric vibration device, vibration shovel and so on. When this machine was used to transplant trees, the eccentric block was driven by the gasoline engine through the deceleration strip. Combining this with a vertical vibration and a torsion vibration in a horizontal direction and users’ depression, the tree transplanting machine can excavate seedling easily. Furthermore, the format of the vibration shovel was suitable to some different trees whose diameter ranged from 100 mm to 200 mm. Second, in order to increase the machine’s working performance, a response surface method was considered to optimize the working parameter of the portable tree transplanting machine. According to the Box-Behnken principles of experimental design, the operating parameters such as eccentric block roller speed, eccentric block mass and linear eccentricity were selected as independent variables, which would influence the time of machine digging down 200 mm. Meanwhile, the software of Design-Expert 7.0.0 was taken to analyze the experimental data, and the quadratic regression mathematical model was established which can expound the relationship between the three operating parameters and response value. The analysis of variance and significance test of the regression coefficients showed that the quadratic regression mathematical model was consistent with the actual situation and also could predict the test results accurately. Lastly, in line with the optimization of the quadratic regression mathematical model, the optimum operating parameter was determined. In order to verify the correctness of the optimum operating parameter, the actual test was taken by the prototype. The results showed that the three operating parameters all strongly influenced extremely the time of digging down 200 mm and the descending order was eccentric block mass, linear eccentricity and eccentric block roller speed. In addition, the interaction of the eccentric block mass and linear eccentricity also influenced extremely the time of digging down 200 mm. Meanwhile, the mathematical model between these three operating parameters and the time of digging down 200 mm was established. The optimal working parameters were eccentric block roller speed of 1 500 r/min, eccentric block mass of 85.47 g, linear eccentricity of 94.67 mm, then the time of digging down 200 mm was 22.07 s, Which is basically matched with the actual result (19.66 s). And the average relative error between the optimization and trials is 10.90%. In conclusion, the optimization experiment improves the machine’s operating performance and also provides a preferable reference for the design of the tree transplanting machine.