Heavy metal pollution in farmland soil is serious in China and poses a threat to the safety in agricultural production. Based on the integrated technology of “source controlling, process blocking, end remediation and safety production”, this paper concluded the current technologies and problems for “phytoremediation coupled with agro-production” of moderate and mild heavy metal polluted farmlands in China by literature review. For the sources controlling, the advantages and merits of the source apportionment methods and the field monitoring of heavy metal pollution sources were analyzed, and the application for the source identification methods and reduction technologies of pollution sources were clarified. Regarding the contaminated soil, we summarized the current applications of deactivators/activators and estimated the phytoextraction rate of heavy metals from the aboveground of accumulators/hyperaccumulators. The feasibility of the safety production technologies for heavy metal polluted farmlands was analyzed, which was based on planting low heavy metal accumulation varieties and changing crop systems. Finally, the related issues that need to be further studied on safety utilization of heavy metal polluted farmland soil were put forward.

To explore the physiological effects of silicon on tomato seedlings under different low phosphorus conditions, we performed this study using ‘Zhongza 9’ tomato cultivar as the experimental material, with seven combination treatments of two silicon levels (0 and 1.5 mmol/L K₂SiO₃?nH₂O) and four phosphorus levels (0.66, 0.44, 0.22 and 0 mmol/L NaH₂PO₄) under hydroponic cultivation, and investigated the effects of silicon on the plant dry mass, leaf relative water content, root morphological parameters, chlorophyll contents, membrane lipid peroxidation, plasma membrane integrity, reactive oxygen species levels, antioxidant enzyme activities, silicon and phosphorus contents of tomato seedlings exposed to different phosphorus supply levels. The results showed that, compared with the control treatment (0.66 mmol/L NaH₂PO₄), the leaf chlorophyll content and total root length were significantly reduced under the low phosphorus condition, while the membrane lipid damage was intensified and the phosphorus content in plant was declined, which led to the growth inhibition of tomato seedlings. Addition of exogenous silicon significantly alleviated the inhibitory effects of low phosphorus stress on the seedling growth, and the stressed-plants were maintained with higher leaf relative water contents, chlorophyll contents and better root growth. Besides, the corresponding malondialdehyde (MDA) content, content and H₂O₂ level in leaves and roots were decreased due to the enhancement of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities, and the assimilation of phosphorus in plants was promoted. Interestingly, there was the most significant facilitation of silicon on the growth of tomato seedlings when subjected to mildly low phosphorus stress. In general, exogenous silicon could promote the tolerance of tomato seedlings to phosphorus-deficiency, through improving the root growth and leaf water status, as well as inducing the enhancement of plant antioxidation capacity, and the silicon-mediated regulatory effect was more pronounced for mildly low phosphorus stress. These results are helpful for further understanding the synergistic effects of silicon and phosphorus elements, and will provide a theory basis for illuminating the physiological mechanism of silicon-mediated alleviation of tomato seedlings under the low phosphorus stress.

In order to research the formation mechanism of Pleurotus pulmonarius fruit body with essential low temperature treatment, the mycelial growth at different temperatures were studied. The mycelia were cultivated at 20, 22, 24, 26, 28, 30 ℃, respectively, and then they were cultivated at 4, 8, 12 ℃ and 25 ℃ (CK) for 3-24 h after the mycelia fully lasted 30 d, and the activities of five extracellular enzymes, including carboxymethyl cellulase, filter paper cellulase, hemicellulase, amylase and laccase were tested. At the same time, the economical characters of P. pulmonarius were analyzed at different cultivation temperatures (8, 12, 16, 20 ℃） and time (6, 9, 12, 15, 18 h) in summer. The results showed that P. pulmonarius grew fast and had the strongest mycelium growth at 26 ℃. The mycelial growth became weaker with the increase of cultivation temperature. At the same low temperature, the activities of the five extracellular enzymes first increased, peaked at 9-18 h, and then decreased on the whole. At the same time, the activities of carboxymethyl cellulase, filter paper cellulase, hemicellulase and amylase were stronger at 4, 8 and 12 ℃ than at 25 ℃ (CK), but the laccase activity was lower than CK, and the lower cultivation temperature, the lower laccase activity. The cultivation experiment showed that the average yield of one fungus bag exceeded 100 g at 8 ℃ for 9-15 h or 16 ℃ for 12 h. The speed of mushroom bud formation and fruit body uniformity were excellent at 16 ℃ for 12 h. In conclusion, the activities of five extracellular enzymes are regulated by low temperature treatment, and then the degradation of macromolecule nutrients in the matrix and nutrient absorption of mycelia are adjusted. The above results are of great significance for the further study on the formation mechanism of P. pulmonarius fruit body and the guidance of the production in summer.

In order to reveal the reasons for the low fruit setting rate of sweet cherry in Hangzhou area, taking three representative four-year-old sweet cherry cultivars with a certain fruit setting rate but instability and different chilling requirement in Hangzhou and Tai’an areas as the experimental materials, we studied and compared the development of female and male gametophytes, quality of floral organ and pollen in the same cultivar. The result revealed that there was a high proportion of empty pollen sac in the male gametophyte, which could result in less pollen quantity. In addition, the degradation and various abnormal types of male gametophyte led to its abortion. There was also a high proportion of ovule without embryo sac, which could cause female gametophyte abortion during the development of female gametophyte. The pollen quality was poorer in Hangzhou than in Tai’an. It is suggested that the abnormal development of male and female gametophytes could be the main reasons for very low fruit setting rate of sweet cherry in Hangzhou area.

The taxonomic identification and antimicrobial effect of a strain called F11 which has inhibitory effect on strawberry gray mold was studied. In order to improve the fermentation efficiency of the strain, the fermentation formula and conditions were optimized by orthogonal experiment and single factor test. The results showed that the strain F11 could inhibit the growth and reproduction of 12 common pathogens with high inhibition rate reaching 79.88% or more, which showed that this strain possessed broad-spectrum and high-efficiency antimicrobial effect, and that it would be a hidden promising resource for biological control agent to resist plant diseases. The strain F11 was identified as Bacillus amyloliquefaciens by observation of colony morphology, physiological and biochemical tests, 16S rRNA and gyrB gene sequencing. The fermentation medium of strain F11 was optimized from L₁₆ (4³×2⁶) orthogonal test: 3.00 g/L beef extract, 10.00 g/L peptone, 5.00 g/L NaCl, 3.00 g/L glucose, 2.00 g/L MgCl₂. Furthermore, the single factor test further showed that based on the optimized medium, the suitable initial pH of strain F11 culture was 7.0, and the befitting temperature was 30 ℃, and the proper oscillation rate was 150 r/min, which the number of viable cells were 4.67×10⁹ CFU/mL.

Taking advantage of TaqMan^? array microfluidic card technology, 24 primer-and-probe sets of real-time fluorescence quantitative polymerase chain reaction (RT-PCR) for identification of 24 different animal species (categories) were assembled in one array to achieve simultaneous detection of multiple animal-derived components. The repeatability, specificity and sensitivity of the method were verified. Coefficient of variation (CV) value was used to indicate the repeatability in one array card when detecting the same component (species). Among 66 CV values, 11 CV values were less than 1%; 15 CV values were more than 2%; and the remaining 40 CV values were between 1% and 2%; but none of them was higher than 3%. P value showed the repeatability among different array cards when detecting the same component. Among the 22 P values of the 22 animal-derived components, only one was less than 0.05, which indicated the significant difference of the CV values of the components between the cards. But none of the resting 21 components showed significant inter-plate differences. Therefore, the vast majority of the components tested in this study showed good repeatability both in-card and inter-card. No false positive results were found in TaqMan array tests, but false negative results were appeared in two component detection. The sensitivity of TaqMan array assay was not higher than that of the individual RT-PCR assay. Ten of the 22 components decreased to 10% of the originals in detection sensitivities; another one component even decreased to 1%. And the remaining 11 components were consistent with that of the individual RT-PCR. However, in general, TaqMan array approach can meet the needs of authenticity identification in terms of repeatability, specificity and sensitivity, which offers promise for rapid and simultaneous identification of multiple animal-derived components.

In order to strengthen the ecological management and promote the rational utilization of land in nature reserve, this study used spatial analysis methods of minimum cumulative resistance model and geographic information system (GIS) and resistance evaluation index system, which included four factors of topography, ecological environment, human disturbance and eco-functional zone, to evaluate the land ecological suitability of Wanfo Mountain Nature Reserve in Hunan Province and gave some corresponding regulatory advices according to the spatial coupling relationship. The result showed that according to the ecological suitability of land, Wanfo Mountain Nature Reserve can be divided into four levels. The suitable area of grade Ⅰ was 4 036.04 hm², where we should give priority to ecological protection and control all construction activities. The suitable area of grade Ⅱ was 3 828.51 hm², where we should protect the landscape types such as rivers and ecological gardens and improve the function of the ecosystem. The suitable area of grade Ⅲ was 1 426.77 hm², where we should take the ecological security as the bottom line, develop ecological agriculture and carry out the project of returning farmland to forest actively. The suitable area of grade Ⅳ was 692.11 hm², where we should adhere to the principle of environmental protection and environmental construction, and focus on ecological construction.

To select suitable halophytes for best desalting effect of Populus euphratica seedlings, taking one-year P. euphratica seedlings as the experimental materials, and Suaeda glauca (Bunge)Bunge (T₁), Salicornia europaea L. (T₂) and Halocnemum strobilaceum (Pall.) M. Bieb.(T₃) of the common halophytes in Xinjiang as the associated plants, the seedlings of three P. euphratica and one associated plant were cultivated in pots treated with NaC1 solutions of 5 g/L (B) and 11 g/L (C) and three replications, and a parallel treatment and three block treatments were set as the controls (CK₀: 0 g/L NaCl+P. euphratica; CK₁: 0 g/L NaCl+S. glauca; CK₂: 0 g/L NaCl+S. europaea; CK₃: 0 g/L NaCl+H. strobilaceum), and then the physiological indexes of P. euphratica seedlings were determinated to explore the rule of desalting effect on it. The results showed that the associated halophytes had obvious desalting effect on soil (P＜0.05). Under the condition of 5 g/L NaC1 (B), the desalination rate of T₁, T₂ and T₃ was 26.8%, 22.0% and 14.2%, respectively. Under the condition of 11 g/L NaC1 (C), the desalination rate of T₁, T₂ and T₃ was 14.9%, 23.1% and 19.7%, respectively. The contents of proline (Pro) and malondialdehyde (MDA) in P. euphratica seedlings increased on the whole as compared with the controls, but the increase was not obvious. Under the same B salt concentration, the changes of Pro and MDA contents under the different treatments were as follows: T₃＞T₂＞CK₀＞T₁＞CK₃＞CK₂＞CK₁, and T₃＞CK₀＞CK₃＞T₂＞T₁＞CK₂＞CK₁, respectively. Under the same C salt concentration, the changes of Pro and MDA contents under the different treatments were as follows: T₃＞T₁＞T₂＞CK₀＞CK₃＞CK₂＞CK₁, and T₃＞T₁＞T₂＞CK₀＞CK₃＞CK₂＞CK₁, respectively. Antioxidant activities of the superoxide dismutase (SOD) and peroxidase (POD) were linearly opposite to MDA content. In a word, based on the physiological and ecological indicators, the three associated halophytes produce a significant desalting effect in the 30 d. Under the condition of 5 g/L NaC1, the desalting effect of S. glauca on P. euphratica seedlings is the best; under the condition of 11 g/L NaC1, the desalting effect of S. europaea is the best.

A field experiment was conducted to assess the effects of side-deep placement of fertilizer on the rice (early rice and single cropping late rice) yield, apparent nitrogen use efficiency (ANUE) and ammonia volatilization (AV). Five treatments were conducted: 1) no nitrogen fertilizer (N₀); 2) conventional fertilizer (CF); 3) side-deep placement of compound fertilizers (90%CFD); 4) broadcast application of slow-release fertilizer (80%CRF); 5) side-deep placement of slow-release fertilizer (80%CRFD). Results showed that the 90%CFD, 80%CRF and 80%CRFD reduced application rate of N fertilizer by 10% and 20%, but could maintain the grain yields of early rice and single cropping late rice as compared with the CF. The grain yield of single cropping late rice was significantly higher in the 80%CRFD than in the 80%CRF. The AV amounts ranged from 12.45 to 18.50 kg/hm² and 18.75 to 26.23 kg/hm² in the three treatments (90%CFD, 80%CRF and 80%CRFD) during the growth period of early rice and single cropping late rice, respectively, and all of those were significantly lower as compared with the CF treatment. The AV rates in the 90%CFD, 80%CRF and 80%CRFD treatments were 9.3%-12.6% and 10.4%-12.9% during the growth period of early rice and single cropping late rice, respectively. Compared with the CF, the three treatments (90%CFD, 80%CRF and 80%CRFD) decreased the AV rates by 2.0-5.3 and 2.4-4.9 percentage points in the early rice and single cropping late rice, respectively. The AV rate was lower in the 80%CRFD than in the 80%CRF in both of the early rice and single cropping late rice. The ANUEs in the three treatments (90%CFD, 80%CRF and 80%CRFD) were 35.6%-46.9% in the early rice, and they were 4.0-15.3 percentage points higher than in the CF. In the single cropping late rice, the ANUE increased in the side-deep placement treatments of fertilizer (90%CFD and 80%CRFD) as compared with the CF, but there was no significant differences between the 80%CRF and CF treatments. It is concluded that the 90%CFD, 80%CRF and 80%CRFD are the recommended fertilizer management in the early rice, and the 90%CFD and 80%CRFD are the recommended fertilization patterns in the single cropping late rice.

A field experiment with four typical fertilization models such as conventional fertilization (CF), conventional recommended fertilization (CRF), optimized soil testing for formulated fertilization (TF) and application of organic manure as a partial replacement for chemical fertilizers based on optimized soil testing for formulated fertilization (TFM) was conducted. The responses of single crop rice yield and runoff losses of nitrogen and phosphorus from paddy fields to different fertilization models were investigated. The results showed that the grain yield of the three improved fertilization models increased by 2.80%-3.63% compared with the conventional fertilization, and nitrogen and phosphorus contents in various parts of rice plants kept at the similar levels. The cumulative total nitrogen runoff losses of CRF, TF and TFM treatments decreased by 2.75%, 14.15% and 33.28%, respectively, and the cumulative total phosphorus runoff losses decreased by 19.02%, 21.31% and 29.51%, respectively. In general, three improved fertilization models can meet nitrogen and phosphorus needs of rice plants, increase grain yield, and control the runoff losses of nitrogen and phosphorus effectively, among which TFM is the best.

Eighty 200-day-old Shaoxing ducks were randomly divided into two groups, including the ground group (control group) and the caged stress group (treatment group). Then the tissue damage degree of the duodenum and antioxidant indicators were determinated, and the relative expression levels of endoplasmic reticulum stress gene, inflammation-related gene and apoptotic gene mRNA were detected by real-time fluorescence polymerase chain reaction (RT-PCR) at 1, 2, 4, 7 and 10 d after cage rearing, which providing theoretical basis for the large-scale breeding of laying ducks and the scientific prevention for caged stress disease. The results showed that: 1) With the increase of caged stress time, the damage degree of the duodenum in the treatment group gradually increased, mainly manifested by inflammatory cell infiltration and intestinal gland epithelial cell shedding. 2) During the progress of caged stress, the duodenal malondialdehyde (MDA) content, total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), activities in the treatment group showed fluctuating changes, while the catalase (CAT) activity increased significantly at the 7th day after cage rearing (P＜0.05). 3) RT-PCR results showed that compared with the control group, the endoplasmic reticulum stress-related genes glucose regulated protein 78 (GRP78)and CCAAT/enhancer-binding protein-homologous protein (CHOP) mRNA expression levels showed fluctuating changes, and increased significantly in the Shaoxing ducks at the 2nd and 10th day after cage rearing (P＜0.05). In addition, the expression level of apoptosis-related gene Bcl-2 associated X protein (Bax) mRNA increased significantly at the 7th and 10th day after cage rearing (P＜0.05), while the expression of cysteinecontaining aspartate-specific proteases-3 (Caspase3) mRNA expression level was not significantly different from the control group (P＞0.05). At the same time, the cyclooxygenase-2 (COX-2) mRNA expression level was significantly up-regulated and increased significantly at the 10th day after cage rearing (P＜0.05), while the expression level of inducible nitric oxide (iNOS) showed a trend of decreasing first and then increasing. The above results indicate that the stress of caged rearing causes different degrees of tissue damage on Shaoxing duck duodenum, which enhances the body’s antioxidant capacity. At the same time, the up-regulation of endoplasmic reticulum stress intensity eventually leads to apoptosis and inflammation.

In order to understand the effects of different culture patterns on the nutritional components of fish body, young fish Alosa sapidissima cultured in outdoor and shaded ponds were analyzed by biochemical analysis method, and the nutritive quality was analyzed and compared. The results showed that the body water content of shaded pond group (69.22%) was significantly lower than that of the outdoor pond group (70.68%) (P＜0.05), while the body crude fat content of shaded pond group (10.79%) was significantly higher than that of the outdoor pond group (7.48%) (P＜0.05). No significant differences in the contents of crude protein and ash in body were found between the two groups (P＞0.05). A total of 18 kinds of amino acids were found, and there were no significant differences in the contents of 11 kinds of amino acids (threonine, glycine, valine, methionine, tyrosine, phenylalanine, histidine, arginine, proline, tryptophane, cystine) between the two groups (P＞0.05), while in other seven kinds of amino acids (aspartate, serine, glutamic acid, alanine, isoleucine, leucine, lysine), the contents of outdoor pond group were significantly higher than those in shaded pond group (P＜0.05). The percentage contents of total amino acid (TAA), non-essential amino acid (NEAA) and delicious amino acid (DAA) in dry body of outdoor pond group were significantly higher than those of shaded pond group (P＜0.05), while there were no significant differences in the percentage contents of essential amino acid (EAA) and half-essential amino acid (HEAA) in dry body between the two groups (P＞0.05). There were no significant differences in the ratios of EAA/TAA, EAA/NEAA and DAA/TAA, and the body essential amino acid indexes (EAAI) of shaded pond group and outdoor pond group were 76.49 and 76.46, respectively. The total content of saturated fatty acid (SFA) of outdoor pond group (35.91%) was significantly higher than that of shaded pond group (27.70%) (P＜0.05), while the total content of poly-unsaturated fatty acid (PUFA) of outdoor pond group (13.66%) was significantly lower than that of shaded pond group (21.35%) (P＜0.05). There were no significant differences in the total contents of mono-unsaturated fatty acid (MUFA) and eicosapentaenoic acid+docosahexaenoic acid (EPA+DHA) between the two groups. The results indicated that the body protein quality of young fish A. sapidissima cultured in the outdoor pond was slightly better than that of young fish cultured in the shaded pond, but the body fatty acid quality of young fish A. sapidissima cultured in the shaded pond was much better. So, we suggest the composition of fatty acids in formulated feed should be optimized to increase the content of PUFA, especially the content of EPA and DHA.

This study mainly compared the virulence genes and drug resistance characteristics of Escherichia coli in laying ducks under the two different breeding modes: net bed with pool and net bed dry-system. Six farms including three net beds with pool and three net bed dry-systems were selected in Wenzhou, Zhejiang Province, and ten laying ducks were collected from each farm. The cotton swabs were used to collect microorganisms in the rectum forthe isolation of E. coli. The VITEK 2 COMPACT analysis system was used to identify the isolates and analyze the drug resistance profile. The virulence genes, drug-resistant genes and class Ⅰ integron genes were amplified by polymerase chain reaction. The results showed that the isolation rate of E. coli in laying ducks was 100%. The detection rates of virulence genes eae, ipa H, invE, aggR and pic of E. coli in the net bed dry-system were higher than those in the net bed with pool. For the drug-resistant phenotype, the proportion of strains with ≥3 resistance in E. coli in the net bed dry-system was 23.33%, while the proportion of strains with ≥3 in the net bed with pool was 10.00%. Similarly, the detection rates of the drug-resistant genes and the class Ⅰ integron genes in the net bed dry-system were also higher than those in the net bed with pool. Four of the 10 strains of class Ⅰ integron-positive E. coli carried the gene cassette insert, one of which derived from the E. coli class Ⅰ integron gene cassette of laying duck in the net bed with pool was dfrA12-aadA2, and the other three strains derived from the E. coli class Ⅰ integron gene cassette of laying duck in the net bed dry-system were dfrA1-aadA1. The above results indicate that the virulence gene carrying rate and drug resistance of E. coli in the intestinal tract of laying duck in the net bed dry-system are higher than those in the net bed with pool. It is suggested tha the changes of breeding mode may have some effect on the drug resistance characteristics of bacteria in waterfowls.