 摘要： [Objectives] This study was conducted to improve crop yield and select excellent wheat varieties. [Methods] Wheat seedlings were treated with different concentrations of NaCl solution, and the activities of superoxide dismutase (SOD) and peroxidase (POD) and the content changes of malondialdehyde (MDA) in the leaves of seedlings were determined. A control group (distilled water) and three treatment groups (NaCl concentrations of 1, 2 and 3 mmol/L) were set up. When the wheat seedlings grew to two leaves and one heart, they should be treated with different concentrations of NaCl solution (the wheat seedlings grew uniformly, and 20 ml of each NaCl concentration was used for treatment of wheat). When the wheat seedlings grew to four leaves and one heart under stress, samples were taken separately, once every 2 d, for three times, with 5 g of leaves each time. The SOD and POD activities and MDA content of seedlings in the control group and treatment groups were determined, and related protein sequences were analyzed by bioinformatics, including signal peptide prediction, transmembrane domain prediction, phosphorylation prediction and protein structure prediction. [Results] Under NaCl stress, the growth rates of seedling length and root length of wheat decreased obviously, and SOD and POD in leaves decreased, while the MDA content in leaves after treatment increased compared with the control group. SOD had no signal peptide, while POD had signal peptides and a transmembrane region. SOD and POD were different in terms of secondary and tertiary structures and the number of phosphorylation sites. [Conclusions] These results lays a solid theoretical foundation and application prospect for the study on salt tolerance mechanism of wheat seedlings in the later stage. 

 摘要： [Objectives] This study was conducted to solve the problems of long breeding cycle and low induction rate of double-haploid plants of asparagus. [Methods] Based on the achievements and practice of breeding research, an all-male asparagus breeding technology system was constructed. [Results] The technology system includes such six techniques as collection and identification of germplasm resources, tetraploid plant induction, anther culture, artificial hybridization of double-haploid plants, offspring screening and tissue culture and rapid propagation of parents. [Conclusions] The construction of this system lays a foundation for breeding new all-male asparagus varieties with excellent quality. 

 摘要： [Objectives] This study was conducted to find out the best sowing date and sowing rate of rice. [Methods] Based on the technique of dry seedling raising in aperture disk, the effects of sowing date and sowing rate on rice yield were studied. [Results] Sowing date and sowing rate per hole had obvious effects on tillering dynamics, growth process, number of panicles per unit area, number of filled grains per panicle and rice yield of rice developed from dry-raised seedlings. The comprehensive analysis showed that the highest yield was 10 285.5 kg/hm2 with the sowing date of May 20 and sowing rate of 5 grains/hole. [Conclusions] This study provides theoretical support and data support for the popularization and application of rice developed from seedlings dry raised in aperture disk. 

 摘要： [Objectives] This study was conducted to solve the problem of lacking excellent germplasm resources in asparagus cultivation in China. [Methods] Twenty asparagus germplasm resources were introduced from home and abroad, and evaluated and screened from biological traits, yield, quality, disease resistance and stress resistance. [Results] Six excellent asparagus cultivars were screened out. Four cultivars, Jinguan, Feicuimingzhu, Jiyulvlu3 and Potron, performed well in agronomic traits, yield, commodity quality and disease resistance, and these four varieties had strong resistance to stem wilt, so they are suitable for planting in North China. JX1502 and Jersey knight showed strong salt tolerance, and exhibited a high yield in saline-alkali soil with a soil salt content of 0.56%. indicating that they are suitable for cultivation in coastal saline-alkali areas in China. [Conclusions] This study provides a theoretical basis for the development of asparagus industry in Hebei Province.

 摘要： The giant panda (Ailuropoda melanoleuca), as a rare and endangered wild animal in China, has attracted wide attention from all walks of life. In this study, the changes of disturbances in the habitat of giant panda population in the Qionglai Mountains of Sichuan Province were studied and analyzed by comparing the data of two giant panda surveys in Qionglai Mountains and combining with the remote sensing (ES) data of related areas. The results showed that the number of general disturbances in the habitat of giant pandas in Qionglai Mountains greatly reduced in 10 years, and the types of disturbances also changed greatly. The logging disturbance which was most distributed in the third survey almost disappeared in the fourth survey, and the grazing disturbance in the habitat became the disturbance type with the highest encounter rate. The density of human activities in the whole mountain system greatly decreased, but the scope was slightly expanded. Baoxing and Lushan were areas with high density of giant panda activities, and the number of various human activities was relatively large. In the two surveys, the avoidance effect of giant pandas on logging, grazing, roads, hunting and other disturbances showed significant differences. The activity density of local small populations of giant pandas in Qionglai Mountains changed. 

 摘要： [Objectives] Straw-preserved frozen semen from native and imported pig breeds and its conception performance were studied to provide a scientific basis for further optimizing pig breeding strategy. [Methods] This study was conducted to systematically evaluate straw-preserved frozen semen produced by the Guizhou Testing Center for Livestock and Poultry Germplasm from 2018 to 2023. We analyzed 206 samples from native Guizhou pig breeds, including Kele, Zongdi Hua, and Nuogu pigs, as well as 363 samples from imported and bred pig breeds, such as Duroc, Large Yorkshire, Landrace, Topigs, and French Yorkshire, among others. Additionally, we assessed the conception performance of more than 300 heads across 10 batches, comprising both native and imported and bred pig breeds, following deep insemination. [Results]  Significant differences were identified in sperm motility and abnormal sperm percentage (ABSP) among native breeds (P<0.05), as well as in number of progressively motile sperm (NPMS) and ABSP among imported and bred breeds (P<0.05). The average semen dose for both native and imported/bred pigs was 0.47 ml, with a standard deviation of 0.01 ml. Sperm motility ranged from 41.5 % to 58 % in native breeds and 50.4 % to 61.7 % in imported and bred breeds. The NPMS ranged from 144 to 177 million in native breeds and 149 to 177 million in imported and bred breeds. ABSPs remained within acceptable limits, ranging from 6.6 % to 16.8 % for native breeds and 6.1 % to 18.1 % for imported and bred breeds. The imported and bred pigs outperformed the native breeds in terms of sperm motility (50.42 % to 69.58 % vs. 41.63 % to 48.37 %), farrowing rate (71.13 % to 86.70 % vs. 57.15 % to 74.35 %), and litter size (7.74 to 10.30 vs. 6.39 to 7.45). [Conclusions] These findings suggest that long-term selective breeding and domestication of native Guizhou pigs are necessary to enhance their reproductive performance.

 摘要： [Objectives] This study was conducted to analyze the effects of continuous application of biogas slurry for many years on soil ecosystem restoration of rare earth tailings by planting Pennisetum × sinese, in order to provide basis for scientific application of biogas slurry. [Methods] The fields with different years of continuous application of biogas slurry in Dingnan Rare Earth Tailings Ecological Restoration Demonstration Park were selected as the research object, and the differences in soil physical and chemical properties and microbial community structure after application of biogas slurry for different years (0, 3 and 5 years) were studied. [Results] The bulk density of soil with continuous application of biogas slurry showed a downward trend, while the maximum water holding capacity, capillary water holding capacity, porosity, aeration, pH, organic matter, nitrogen, phosphorus and potassium, alkali-hydrolyzable nitrogen and available phosphorus showed an upward trend. Moreover, the effects achieved by application for 5 years were better than those by application for 3 years. Continuous application of biogas slurry could significantly improve the activity of soil urease, acid phosphatase, sucrase and cellulase, and it effects increased with the application year increasing. Continuous application of biogas slurry could significantly improve the abundance of dominant bacteria in soil, and with the increase of application years, the abundances of dominant bacteria also increased. [Conclusions] Continuous application of biogas slurry effectively improved soil physical and chemical properties and soil fertility in rare earth tailings areas where Pennisetum × sinese was planted to restore rare earth tailings. This study provides a theoretical support for establishing key ecological restoration technoiques. 

 摘要： [Objectives] This study was conducted to reveal the migration and distribution law of soil available nutrients in soil layer under moistube irrigation and screen out suitable fertilization modes for facility cucumber planting. [Methods] The experiment adopted the moistube irrigation mode and randomized block design. Seven treatments were set up as following: inorganic fertilizer (T1), medium-concentration inorganic fertilizer (T2), high-concentration inorganic fertilizer (T3), low-concentration inorganic fertilizer + low-concentration biological organic fertilizer (T4), low-concentration inorganic fertilizer + medium-concentration biological organic fertilizer (T5), low-concentration inorganic fertilizer + high-concentration biological organic fertilizer (T6) and no fertilizer control (CK). Nitrate nitrogen, available phosphorus and available potassium in soil and fruit yield and quality were determined. [Results] Under the moistube irrigation mode, the application of soluble bio-organic fertilizer combined with inorganic fertilizer could significantly increase the contents of available nutrients in the 0-40 cm soil layer available for cucumber utilization, and promote the absorption of available nutrients by cucumber plants. It reduced the contents of nitrate nitrogen and available potassium in the soil layer of 40-60 cm, but had no significant effect on the content of available phosphorus in the soil layer of 40-60 cm. Compared with the CK treatment, the cucumber yield, vitamin C content, soluble sugar content and soluble protein content of treatment T6 increased by 69.27%, 29.68%, 55.91% and 32.5%, respectively. Compared with treatment T3 (high-concentration inorganic fertilizer), treatment T6 showed no significant difference in yield, but its nitrate content decreased by 15.97%. Soluble bio-organic fertilizer combined with inorganic fertilizer could be well combined with moistube irrigation, which could not only achieve high yield, but also reduce the risk of environmental pollution caused by fertilization, thus achieving the purpose of saving water and fertilizers and protecting the ecological environment. Considering the yield and quality of cucumber fruit, treatment T6 was a more suitable fertilization model for cucumber planting in moistube irrigation facilities. [Conclusions] This study provides a scientific basis for the popularization of moistube irrigation techniques and efficient utilization of fertilizers. 

 摘要： Carbendazim belongs to the benzimidazole fungicides, which can be used for control lots of fungi pathogens. High-performance liquid chromatography is frequently used for the analysis of carbendazim in all kinds of samples. In most occasions, the developed methods were applied for the simultaneous detection of a huge number of pesticides. Thus, an analytical method via UPLC-FLD was developed, and the sample preparation process was optimized by studying the effect of extraction solvent, approach, time and purification absorbent on the recovery rate of carbendazim. The results showed the optimized method for analysis was ultrasonication-assisted extraction with acetonitrile for 1 min, and subsequent purification by C18. In this occasion, the established analytical method of carbendazim in tomato samples displayed good linearity, accuracy and precision.

 摘要： [Objectives] This study was conducted to evaluate the residual status and dietary intake risk of clothianidin in Chinese chives. [Methods] From various markets in Tangshan City, 147 batches of Chinese chive samples were randomly collected for the detection of clothianidin pesticide residue, and the dietary risk of the detected samples was evaluated by using SiO-6512 automatic pretreatment equipment extraction and LCMS-8050 high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). [Results] Among the 147 batches of Chinese chivesamples, clothianidin was detected in 46 batches, with a detection rate of 31.29%; and the residual level ranged from 0.0120 to 3.516 mg/kg, with an average value of 0.274 mg/kg. The results of dietary risk assessment showed that the index of food safety (IFS) of clothianidin in Chinese chives ranged from 0.000 004 5 to 0.004 605 5, with an average value of 0.000 220 9. The average IFS values for minors, adults, the elderly and the entire population were, respectively, 0.000 358 9, 0.000 210 7, 0.000 102 6 and 0.000 211 3, which were far less than 1, indicating that it had no impact on human health. [Conclusions] This study provides reference for establishing the residue limit standard of clothianidin in Chinese chives.