Current issue

• 2021 Vol.37 No.12 Published:25 April 2021

  Breeding of Rice Line ‘Heidaxiang1’: Combinning Molecular Marker Identification with Field Trait Selection Li Rongtian, Ma Tengxu, Wang Haoran, Liu Changhua 2021, 37 (12):  1-9.  DOI: 10.11924/j.issn.1000-6850.casb2020-0760 Abstract + ( 501 )   HTML ( 9 )   PDF ( 1598KB )   ( 34 ) The purpose of this study is to cultivate new rice varieties with characteristics of high yield, good quality and middle maturing date, which are urgently needed in good taste rice production in Heilongjiang Province. Rice varieties meeting requirements of the breeding objectives were bred with the combination of molecular marker and field trait selection from generations of ‘Jijing88’× the introgression line ‘Daohuaxiang2(hd2hd4)’. ‘Jijing88’ had the traits of erected plant type, lodging resistance, high yield, Hd2Hd2Hd4Hd4 genotype of heading date and late maturing, and the introgression line ‘Daohuaxiang2(hd2hd4)’ possessed the characteristics of fragrance, good palatability, hd2hd2hd4hd4 genotype and early maturing. A new rice line, which was hd2hd2Hd4Hd4fgrfgr genotype, with 13 leaves of main stem, erected stem-leaf, lodging resistance, high yield, fragrance and good palatability, was bred based on offspring materials of the combination of ‘Jijing 88’בDaohuaxiang2(hd2hd4)’. It was named ‘Heidaxiang1’. The rice ‘Heidaxiang1’ with better agronomic characteristics could be used for good taste rice production in the lower limit of the first accumulated temperate region of Heilongjiang Province.

  Foliar Spraying of Microelements: Effect on Grain Yield and Trace Element Contents of Wheat Seed Xu Yafang, Wang Yun, Ren Shuaishuai, Qin Shiyu, Zhao Peng 2021, 37 (12):  10-17.  DOI: 10.11924/j.issn.1000-6850.casb2020-0417 Abstract + ( 362 )   HTML ( 5 )   PDF ( 1186KB )   ( 55 ) The absorption and utilization of trace elements in winter wheat were studied by spraying different concentrations of trace elements at different stages of wheat growth. A field experiment was designed with 1-fold (B1), 50-fold (B2), 100-fold (B3) and 500-fold (B4) at seedling stage (A1), seedling stage + elongation stage (A2), seedling stage + elongation stage + flowering stage (A3), elongation stage (A4), elongation stage + flowering stage (A5) and flowering stage (A6) by foliar spraying of trace elements (equal amount of water as the control). The yield and trace elements concentration in grains were determined. The yield variation ranged from 3741 to 6204 kg/hm2 under different treatments. The optimal yield was increased by 39.52% compared with that of the control under A4B4 treatment. The variation range of Zn was 31.07-44.68 mg/kg with the highest Zn concentration under A3B1 treatment. Copper (Cu) ranged from 1.75 to 28.67 mg/kg with the highest Cu concentration under A1B1 treatment. The variation range of iron (Fe) was 73.62-203.99 mg/kg with the highest Fe concentration under A3B1 treatment. The variation range of manganese (Mn) was 36.48-55.56 mg/kg with the highest Mn concentration under A6B4 treatment. The contents of Zn, Cu, Fe and Mn were increased by 37.86%, 1650%, 148% and 26.82% respectively compared with those of the control. Application of high concentration of trace elements at elongation stage is the most beneficial to increase the yield. Different spraying stages and concentrations affect the utilization efficiency of trace elements.

  Calculation and Spatio-temporal Difference Analysis of Peanut Green Total Factor Productivity in Hebei Province Yin Mingzhe, Li Yifan, Lu Lingyuan, Xing Jiaxuan, Tao Peijun, Cui Yongfu 2021, 37 (12):  18-23.  DOI: 10.11924/j.issn.1000-6850.casb2020-0206 Abstract + ( 305 )   HTML ( 5 )   PDF ( 1494KB )   ( 32 ) The peanut is the third largest crop in Hebei Province, in order to promote the green, sustainable and stable development of the peanut industry in Hebei Province, relevant research has been carried out. Based on the 2012-2017 panel data of peanut production in cities and counties of Hebei Province, the Green Factor Productivity (GTFP) of peanut in Hebei Province was calculated by Malmquist index method, a non-parameter DEA model, and a GIS thematic map was made for analysis. The results showed that: during the studied period, the peanut green total factor productivity in Hebei Province presented an increasing trend, technical progress played a very good promoting role, but technical efficiency was the opposite; from the spatial change pattern, the annual change of green total factor productivity in the eastern part of Hebei Province is obvious, and there was an obvious spatial concentration phenomenon. The western mountainous areas were at relative disadvantage because of peanut production, the annual variation of its efficiency value was obvious and its stability was insufficient. In summary, the growth rate of green total factor productivity of peanut production in Hebei Province is slow. In order to break this trend, we must focus on adjusting the relationship between input and output, and realizing the dual drive of technological progress and technological efficiency to increase peanut production.

  Differences of Accumulation and Distribution of Nitrogen, Phosphorus and Potassium in Rapeseed Under Two Soil Salt Concentration Levels Liu Jingyi, Zuo Qingsong, Wang Long, You Jingjing, Zheng Jingdong, Chen Jiaxuan, Yang Guang, Leng Suohu 2021, 37 (12):  24-30.  DOI: 10.11924/j.issn.1000-6850.casb2020-0139 Abstract + ( 501 )   HTML ( 10 )   PDF ( 1264KB )   ( 73 ) To study the effects of different salt concentrations on the accumulation and distribution of nitrogen (N), phosphorus (P) and potassium (K), three rapeseed varieties (Brassica napus L.) were cultivated under low salt concentration and high salt concentration, respectively. Dry matter was weighed and N, P and K contents were tested at maturity. Results show that with the increase of soil salt concentration, the dry matter accumulation of whole plant and different organs decrease significantly. The range of total N and P accumulation is 141.39-193.14 kg/hm2 and 21.95-36.24 kg/hm2, respectively. Among different organs, the average decreasing range of N and P accumulation in root are the largest, and the average decreasing range of K accumulation in grains is the largest. At maturity, nitrogen and phosphorus are mainly distributed in seeds, and the range of distribution proportion of N and P vary from 63.15% to 67.73% and 75.23% to 81.56% respectively. Potassium is mainly distributed in stems, and its variation is from 45.59% to 49.67%. Studying the agronomic characters and physiological indexes of rapeseed in different saline soil at maturity could clarify the influence mechanism of salt on rapeseed growth and nutrients absorption characteristics.

  Effect of Substrate Modified by the Reuse of Agricultural and Forestry Organic Waste on Seeding Growth: Meta-analysis Xia Siyao, Wang Chong, Liu Mengli 2021, 37 (12):  31-38.  DOI: 10.11924/j.issn.1000-6850.casb2020-0267 Abstract + ( 387 )   HTML ( 4 )   PDF ( 1779KB )   ( 43 ) The effects of adding organic waste from agriculture and forestry on seedling growth were quantitatively evaluated by the Meta-analysis based on 64 literature. The results show that the organic waste from forestry could significantly improve the total porosity (+10%), aeration porosity (+20%), total N content (+103.29%), alkali hydrolyzed nitrogen content (+59.59%) and available potassium content (+114.5%) in the substrates, and increase root activity and shoot biomass by 28.01% and 35.50% respectively. Organic waste after biological treatment could significantly increase the nutrient content of substrate, thus enhance the root activity, chlorophyll concentration and shoot biomass in the seedlings by 43.5%, 18.52% and 26.54% respectively. In conclusion, adding forest waste or organic waste after biological treatment into the matrix could significantly promote the growth of seedlings and realize the resource utilization of waste.

  Comparative Study on Salt Tolerance of Apocynum venetum Under Different Salt Stresses Wang Pengshan, Jia Lin, Zhang Jinlong, Ci Huacong, Liu Luyao, Li Zhiming 2021, 37 (12):  39-44.  DOI: 10.11924/j.issn.1000-6850.casb2020-0391 Abstract + ( 330 )   HTML ( 5 )   PDF ( 1327KB )   ( 35 ) Apocynum venetum, as an important salt-tolerant plant, has great application potential of soil ecological remediation and plant introduction & improvement in saline land. This study compared the salt-tolerance of Apocynum venetum seeds during germination and analyzed the difference in seed germination under different concentrations of salt stress. In the experiment, Apocynum venetum seeds were used as materials, and different concentration gradients of NaCl, Na2SO4, and NaHCO3 were set for salt stress during the seed germination stage. The results showed that with the increase of salt concentration, the germination rate, germination potential and germination index of Apocynum venetum seeds decreased. The inhibitory effect of low concentration salt stress on the germination of Apocynum venetum was not significant, but the high concentration salt stress had a significant inhibitory effect. As the salt concentration increased, the initial germination time was postponed, NaCl had the most obvious delay effect on the initial germination time of Apocynum venetum seeds, followed by NaHCO3, and Na2SO4 had the least effect. Apocynum venetum seed germination was more sensitive to NaCl,NaCl had the strongest inhibitory effect. At the same time, the delay effect of NaCl on the germination speed of seeds was higher than that of the other two salts. The suitable concentration range, half-lethal concentration and fatal concentration of Na2SO4 were higher than that of NaHCO3 and NaCl. The fatal concentration of Na2SO4 could be 7.81%. Compared with Na+~Cl- type saline soil, Apocynum venetum is more suitable for Na +~SO42- type saline soil.

  Research Progress and Prospect of Spatial Interpolation Method for Cultivated Land Quality Ren Yanmin, Gao Yunbing, Liu Yu 2021, 37 (12):  45-50.  DOI: 10.11924/j.issn.1000-6850.casb2020-0404 Abstract + ( 208 )   HTML ( 7 )   PDF ( 1182KB )   ( 47 ) Constructing an efficient and standardized spatial interpolation method is an important issue for building the big data platform for cultivated land quality and serving macroscopic decision-making, and is conducive to quickly and accurately obtain the distribution map of cultivated land quality indicators of counties and even the whole country. Through literature and research review, this study summarized the current concept and process of spatial interpolation method, and clarified its precision influencing factors and application status in monitoring and evaluation of cultivated land quality. Combined with the actual application requirements of the big data platform for cultivated land quality, four in-depth research directions were put forward, including regional interpolation, geographic barriers interpolation, auxiliary variables interpolation, and module design of interpolation. The research results could provide method reference for the standardized processing of cultivated land quality data.

  The Impact of Climate Change on China’s Grain Production Chen Yuanyuan 2021, 37 (12):  51-57.  DOI: 10.11924/j.issn.1000-6850.casb2020-0402 Abstract + ( 767 )   HTML ( 15 )   PDF ( 1093KB )   ( 148 ) The impact of climate change on grain production in China has been highly concerned, and a lot of researches have been formed. However, the evaluation results of the impact are somewhat controversial. By studying 100 relevant high-quality literature at home and abroad since the beginning of the 21st century, the impacts of climate change on China’s grain production were summarized and discussed. The results show that: (1) since 1961, climate change has influenced China’s grain production mainly by affecting the crop growth, changing the cropping structure, and causing the intensification of agricultural diseases and pests and meteorological disasters, the impact is both positive and negative, but the overall effect is negative, and the negative effect is mainly caused by the temperature increase; (2) the impact of climate change on grain production varies in different regions, in the high latitudes such as China’s northeast region and northwest oasis, the increase of temperature has improved the regional heat condition and also the grain production; in the North China Plain, the rice planting areas in south China, the southwest China and the dry farming areas in northwest China, the increase of temperature has shortened the crop growth period, and combined with the change of precipitation, the climate change has led to the decline of grain production; (3) without considering the fertilizer effect of CO2, future climate change is likely to cause the decrease of grain production, and the decrease of wheat production might be more than that of rice and maize production; considering the fertilizer effect of CO2, the negative effect of climate change would be weakened, and the impact of climate change on rice production in northeast China and wheat production in North China Plain might be positive.

  Response of Woody Plants to Climate Warming During Phenological Period in No. 8 Division of Xinjiang Production and Construction Corps Li Hongying, Wang Xiaotian, Zheng Xiaoqian, Xu Haoyi, Xiang Dao, Zhu Jiangli 2021, 37 (12):  58-63.  DOI: 10.11924/j.issn.1000-6850.casb20200100019 Abstract + ( 296 )   HTML ( 4 )   PDF ( 1300KB )   ( 39 ) To grasp the indicative climatic characteristics of plant phenology, based on the natural phenology and meteorological observation data of No.8 Division of Xinjiang Production and Construction Corps, we studied the woody plants in this area from 1980 to 2018 using linear regression, correlation analysis and Mann-Kendall mutation test. Spring phenology characteristics of Salix matsudana, elm and Populus japonica and their response to temperature changes were explored. The results showed that the spring phenology of Salix matsudana, elm and Populus sylvestris had an obvious advancing trend. The initial stage of leaf and the flowering period of Salix matsudana were earlier by 2.9 days and 2.7 days every 10 years on average, after the mutation in 2004, they were earlier by 4-5 days on average. The two periods of the elm were earlier by 5.6 days and 1.3 days every 10 years on average. After the mutation in 2004, they were earlier by 9 days and 5 days. On average, the initial stage of leaf of Populus japonica was earlier by 2.7 days every 10 years, and it was earlier by 4 days after the mutation in 2004. The average temperature from March to April was significantly and negatively related with the spring phenology of Salix matsudana, elm, and Populus sylvestris. The temperature had the most significant effect on the woody phenology during the one or two months (March and April) before the phenology. When the average temperature in the research area increased from March to April by 1℃, the beginning stage of leaf and the flowering period of Salix matsudana were earlier by 1.8 days, respectively, and those of elm were earlier by 2.9 and 1.8 days, and the beginning stage of leaf of Populus sylvestris was earlier by 1.9 days. In summary, the advancing of spring phenological period of woody plants under climate warming in the research area has become a reality, which has good effect on agricultural time forecasting for local agricultural production. The results could provide references for local ecosystem protection, agricultural structure adjustment, and tourism industry development.

  Salt-stress (NaHCO3) Revealed by RNA-seq: Effect on Gene Expression in Lilium pumilum Bulb Li Guanrong, He Hao, Zhu Guoqing, Chen Shiya, Xu Yang, Jin Shumei 2021, 37 (12):  64-71.  DOI: 10.11924/j.issn.1000-6850.casb2020-0400 Abstract + ( 292 )   HTML ( 5 )   PDF ( 2749KB )   ( 29 ) The aim of this study is to reveal the gene expression of Lilium pumilum under saline-alkali stress, and to provide a theoretical basis for rational utilization of saline-alkali land and large-scale planting of Lilium pumilum. Using the bulb of annual Lilium pumilum as material, treated with 20 mmol/L NaHCO3 for 24 h, the transcriptome was sequenced by Illumina HiSeqTM2000 sequencing platform. A total of 56828 mRNA annotation information was measured, among which 55433 Unigenes were annotated to NR database, 26973 Unigenes were annotated to KOG database, 23610 Unigenes were annotated to GO database, and 13142 Unigenes were annotated to five categories of KEGG database. 390 differentially expressed genes were identified. 9 genes closely related to saline-alkali stress were selected for qPCR verification, and the expression results of the 9 genes were basically consistent with the results of transcriptome. Through the transcriptome comparison data of Lilium pumilum under carbonate (NaHCO3) stress, many gene expression pathways and expression differences were provided, which could lay a theoretical basis for rational utilization of saline-alkali land and large-scale planting of Lilium pumilum.

  Test-tube Seedlings of Atractylodes lancea (Thunb.) DC: ISSR and MSAP Analysis Zhang Chengcai, Xiang Zengxu 2021, 37 (12):  72-78.  DOI: 10.11924/j.issn.1000-6850.casb2020-0128 Abstract + ( 226 )   HTML ( 5 )   PDF ( 1317KB )   ( 30 ) The purpose of this study is to explore the genetic stability and DNA methylation changes of test tube plantlets of Atractylodes lancea (Thunb.) DC in long-term subculture, so as to ensure the quality of plantlets produced in factory. We established an efficient in vitro rapid propagation system for long-term subculture with young terminal buds of Atractylodes lancea and analyzed the test tube plantlets with different subculture times by ISSR and MSAP. The results showed that 10 samples with different generations had low genetic diversity and high genetic stability. Among them, the genetic similarity coefficient between the first generation and the tenth generation samples was the lowest, and the genetic relationship was far away. From the fourth generation of subculture, the bands of different primer amplification patterns changed in individual loci, and the change was more obvious with the increase of subculture times. After long-term subculture, the methylation level of test tube plantlet of A. lancea decreased, and the demethylation mode and methylation mode coexisted, but the demethylation mode was the main mode. The mutation phenomenon after long-term subculture might be caused by different culture conditions and culture time, resulting in gene reactivation and expression or inhibition, and demethylation mode was higher than methylation mode. The results of this study provide a theoretical basis for germplasm conservation and industrial production of A. lancea.

  Chlorella vulgar HDA04: Establishment of Growth Conditions Huang Mengmeng, He Jianbo, Shi Huiling, Ling Hongzhi, Ge Jingping 2021, 37 (12):  79-85.  DOI: 10.11924/j.issn.1000-6850.casb2020-0338 Abstract + ( 428 )   HTML ( 6 )   PDF ( 1433KB )   ( 28 ) To study the effects of antibiotic types and concentrations on biomass and relative oil content of Chlorella, and to optimize the contents of peptone and NaCl in culture medium, Chlorella vulgar HDA04 was used as the test algae strain, different concentrations of antibiotics were added into the culture medium. The biomass and oil content were detected and the medium composition was optimized. The results showed that three antibiotics (kanamycin, tetracycline and penicillin) were added to the initial BG11 medium, penicillin had the best optimization effect on Chlorella vulgar HDA04. When the concentration of penicillin, sodium chloride and peptone was 1.0 mg/L, 8 g/L and 1.5 g/L, respectively, the biomass and relative oil content of C. vulgar HDA04 reached the highest, and the highest biomass was 4.26±0.35 g/L, and the highest relative oil content was 27.04±1.13, which was 111% and 692.3% higher than control group (initial BG11 culture medium), respectively. Optimizing the culture conditions of Chlorella vulgar HDA04 lays a theoretical basis for biodiesel production by Chlorella vulgar, which has great significance to the exploration of microalgae in the alpine saline lake area.

  Detection Technology of Sedative Residues in Aquatic Products: Research Progress Li Qin, Mu Shuhe, Han Gang, Liu Huan, Wu Lidong, Xu Yuyan, Li Jincheng 2021, 37 (12):  86-91.  DOI: 10.11924/j.issn.1000-6850.casb2020-0064 Abstract + ( 248 )   HTML ( 3 )   PDF ( 1106KB )   ( 51 ) China's fresh aquatic products market is growing rapidly, but the geographical difference between production and sales is obvious, and long-distance transportation demand is significant. The sedative can inhibit the body's metabolism and slow down the stress response of fresh aquatic products. Sedatives have been used in the transportation, breeding and surgery of aquatic products to increase the survival rate of aquatic products. However, the residual problems that may be caused by the widespread use of sedatives in aquatic products have attracted the attention of researchers at home and abroad. In this paper, the research progress of the detection technology of sedative residues in aquatic products was summarized, in order to provide reference for the follow-up research. This paper introduced the types and usage regulations of sedatives in aquatic products, and analyzed the research progress of sedatives in aquatic products in the past 10 years. The progress of sample preparation methods, HPLC detection methods, HPLC-MS/MS, and GC-MS/MS in the detection of sedative residues in aquatic products were reviewed, and the application prospects of the technologies were discussed. On the basis of the current study, more in-depth research should be carried out on the new simple and efficient sample preparation methods in the future to provide technical support for the supervision of sedatives in aquatic products.

  Virulence Factors of Pathogenic Fusarium oxysporum: Research Progress Li Ying, Du Chunmei 2021, 37 (12):  92-97.  DOI: 10.11924/j.issn.1000-6850.casb2020-0389 Abstract + ( 491 )   HTML ( 9 )   PDF ( 1194KB )   ( 70 ) Plant wilt disease triggered by pathogenic Fusarium oxysporum infecting plant is a devastating soil borne fungal disease that is widespread in the world, and the fungi are currently ranked as the fifth most phytopathogenic fungi in the world. Because the pathogen is transmitted through the soil, its pathogenic mechanism has not been fully defined, and a full understanding of the pathogenic mechanism of F. oxysporum is a prerequisite for combating this disease. To better explore and implement the effective control strategies and thus limit host plant infection, this review concludes the pathogenesis of F. oxysporum, summarizes the contribution of cell wall degrading enzymes, toxins, signaling pathways (MAPK pathways) in virulence factors to the pathogenic process, and analyzes the regulatory mechanisms of virulence genes and transcription factors during infection. It is hoped to provide targets and rationale for controlling wilt diseases caused by F. oxysporum.

  Endophytic Bacteria YN2014042: Colonization and Growth Promoting Effect on Tobacco and Maize Yang Zhenfu, He Pengfei, Wu Yiyin, He Pengbo, Kong Baohua, Zhao Chongjun, Liu Jianjin, He Yueqiu 2021, 37 (12):  98-105.  DOI: 10.11924/j.issn.1000-6850.casb2020-0247 Abstract + ( 243 )   HTML ( 7 )   PDF ( 1806KB )   ( 69 ) To utilize endophytic Bacillus amyloliquefaciens YN2014042 (YN42) isolated from tobacco, the colonization and growth promotion of YN42 were studied. We successfully obtained a stable GFP tagged strain YN42-GFP by using natural transformation with pHAPII plasmid introduced into YN42. Inhibition activity showed that the strain YN42-GFP exhibited the comparable ability as the wild type strain YN42 to inhibit13 pathogenic fungi such as Phytophthora parasitica var. nicotianae and Fusarium graminearum. When YN42-GFP was irrigated to tobacco and maize seedlings with 1.00×10 7 CFU/g, its colony number was respectively 1.89 × 10 6 CFU/g, 1.07×104 CFU/g and 0.93×103 CFU/g of tobacco root, stem and leaf tissues on the 50th day, and the colony number was 6.67×103CFU/g of maize leaf on the 25th day after inoculation, indicating that YN42 could colonize stably in both its indigenous host and non-host plants. When wild type of YN42 was added to tobacco seedling substrate with 1.00×107 CFU/g, the plant type height and fresh weight of aerial parts of 45-day-old tobacco seedling increased by 450.58% and 756.52%, respectively. When maize was drenched with 1.00×107 CFU/g, the plant type height and fresh weight of aerial parts of 30-day-old maize seedling increased by 19.37% and 61.42%, respectively. In conclusion, YN42 not only have a significant inhibitory effect on a variety of plant pathogens but also could colonize well in tobacco and maize, and promote the growth of tobacco and maize. YN42 has a good application prospect in agricultural production.

  High-efficiency Compound Formula Fungicides: Control Efficacy on Sugarcane Brown Stripe Disease Zhang Hanshu, Wang Xiaoyan, Cang Xiaoyan, Shan Hongli, Zhang Rongyue, Wang Changmi, Chen Jie, Duan Tingying, Huang Pizhong, Zhou You, Huang Yingkun 2021, 37 (12):  106-111.  DOI: 10.11924/j.issn.1000-6850.casb2020-0421 Abstract + ( 269 )   HTML ( 10 )   PDF ( 1207KB )   ( 43 ) To screen high-efficiency compound formula fungicides and study their precise application technology for controlling sugarcane brown stripe disease, carbendazim, benomyl, chlorothalonil, azoxystrobin, pyraclostrobin and difenoconazole·azoxystrobin were selected for the field efficacy test. The results show that three formula fungicides: (1500 g of 50% carbendazim WP + 1500 g of 75% chlorothalonil WP + 2400 g KH2PO4 + 300 mL agricultural synergist)/hm2, (1500 g of 50% benomyl WP + 1500 g of 75% chlorothalonil WP + 2400 g KH2PO4 + 300 mL agricultural synergist)/hm2, and (600 mL of 25% pyraclostrobin SC + 2400 g KH2PO4 + 300 mL agricultural synergist)/hm2 have good control efficacy against sugarcane brown stripe disease, the disease indexes are all below 14.02 and the control effects are all above 84.41%. This study indicates that these three formula fungicides are the ideal high-efficiency compound formula fungicides for controlling brown stripe disease, which can be sprayed onto the leaves by artificial and unmanned aerial vehicle in July and August, with twice in succession spaced 7 to 10 days apart.

  Effect of Chlorella on the Quality and Bacterial Community Structure of GIFT Tilapia Culture Water Qin Lu, Chen Xi, Qiu Liping, Fan Limin, Song Chao, Zheng Yao, Meng Shunlong, Chen Jiazhang 2021, 37 (12):  112-120.  DOI: 10.11924/j.issn.1000-6850.casb2020-0287 Abstract + ( 428 )   HTML ( 5 )   PDF ( 2597KB )   ( 55 ) By adding Chlorella to tilapia aquaculture water, this study aims to explore the optimal concentration of Chlorella for the degradation of N and P and the regulation of microbial community in aquaculture water. Control group (NC), low concentration group (LC), middle concentration group (MC) and high concentration group (HC) were set to explore the effects of different concentrations of Chlorella on reducing the concentration of N and P in tilapia aquaculture water. The 16S rRNA high-throughput sequencing technology was used to analyze bacteria community structure changes of aquaculture water body. Compared with other treatment groups, N and P nutrition of water body in HC group decreased, and the degradation rate of nitrogen in three forms was NH4 +-N>NO3--N>NO2--N. Compared with NC group, the microbial diversity of MC and HC group decreased. The relative abundance of Proteobacteria in each treatment group increased, while that of Bacteroidetes decreased, and the relative abundance of Bacteroidetes in HC group was the highest, the community richness was significantly correlated with the content of NH4+-N. In summary, Chlorella can absorb N and P nutrition from aquaculture water, regulate aquaculture water microbial community structure, and improve aquaculture water quality. The study could provide a theoretical basis for aquaculture production practice.

  Chinese Herbal Complex in Combination with Microbial Bacteriocide: Effect on Farm-scaled Culture of Eriocheir Sinensis Huang Xiaodong, Gu Ying, Zhang Jiang, Zhou Huihua, Gai Chunlei, Chen Baiyao, Cao Haipeng, An Jiang 2021, 37 (12):  121-125.  DOI: 10.11924/j.issn.1000-6850.casb2020-0277 Abstract + ( 276 )   HTML ( 4 )   PDF ( 1147KB )   ( 47 ) The study aims to assess the effect of Chinese herbal complex in combination with microbial bacteriocide on the farm-scaled culture of Eriocheir sinensis. Using water quality, cumulative death count and farming performance as evaluation indexes, the application effect of Chinese herbal complex (10 g/kg feed, twice per day) and microbial bacteriocide (3.75 kg/hm 2, once every 10 days) in combination on the aquaculture of E. sinensis was observed for 130 days. In comparison with the traditional culture of E. sinensis, the combination of Chinese herbal complex and microbial bacteriocide could significantly improve the aquaculture water quality with the reduction of ammonia, nitrite and increase dissolved oxygen in aquaculture water, greatly decrease the cumulative death counts of crabs for 130 days by 91.3%, and remarkably enhance the yield and output value per hectare by 40.9% and 61.9%, respectively. This study confirms the significant effect of the combination of Chinese herbal complex and microbial bacteriocide on the farm-scaled culture of E. sinensis, and can provide a scientific basis for the development of high-efficient culture techniques of E. sinensis.

  Extraction and Separation of Schisandrin B and Its Compound Preservative Xiao Qinjian, Zhang Xiaohu, Gao Mengdie, Zhang Junwei 2021, 37 (12):  126-135.  DOI: 10.11924/j.issn.1000-6850.casb2020-0221 Abstract + ( 230 )   HTML ( 3 )   PDF ( 2241KB )   ( 28 ) Taking schisandra chinensis as the research object, the extraction and purification of schisandrin B and its antibacterial effect were studied. The compound preservative was prepared from schisandrin B, shellac wax, ascorbic acid and calcium chloride to prolong the storage period of green asparagus. The effect of different concentrations of schisandrin B, shellac wax, ascorbic acid and calcium chloride on the preservation freshness of green asparagus were investigated by using decay rate, total chlorophyll content, weight loss rate and crude fiber content as indicators. On the basis of single factor experiment, response surface methodology was used to optimize the extraction process parameters of schisandrin B, and the response value was the extraction rate of schisandrin B. The results showed that the optimum extraction parameters were: the ratio of solid to liquid was 1:12, the extraction temperature was 82℃, 87% ethanol was elected, and the extraction time was 1.7h. The yield of schisandrin B was 2.501mg/g. After the extraction of schisandrin B was purified by DM-130 macroporous resin, the antibacterial effect of three kinds of bacteria was tested, and the sequence of antibacterial effect was obtained as: Staphylococcus aureus > Escherichia coli > Salmonella paratyphi B. The preservative was compounded with shellac wax, ascorbic acid and calcium chloride for 11 days at 25℃ and 65% RH. The optimal preservative formula was 2.5% schisandrin B + 0.75% shellac wax + 2% ascorbic acid + 1% calcium chloride. The results can be used as a technical reference for using schisandrin B to preserve fruits and vegetables.

  Proanthocyanidin Extraction Process from Brown Cotton Fiber: Optimized by Response Surface Method Xie Yongfei, Zhao Gang, Sun Na, Lv Yinping, Wu Yong, Shen Meichen, Lv Wenben, Gao Junshan 2021, 37 (12):  136-143.  DOI: 10.11924/j.issn.1000-6850.casb2020-0379 Abstract + ( 291 )   HTML ( 5 )   PDF ( 1596KB )   ( 27 ) To improve the yield of proanthocyanidin from brown cotton fiber, and optimize the extraction process, the brown cotton fibers were used as materials to study the effect of methanol concentration, solid-liquid ratio, ultrasonic time and temperature on the extraction efficiency of proanthocyanidin, and to obtain the optimized extraction conditions. Proanthocyanidin was extracted by ultrasonic combined with methanol-n-butanol hydrochloride, the extraction process was optimized by response surface methodology. The results showed that the optimum parameters were methanol concentration of 83%, solid-liquid ratio of 1:60, ultrasonic temperature of 42℃, ultrasonic time of 18 min, and the extraction rate was (7.16±0.03)%. The extraction yield of proanthocyanidin by the optimized method was improved by about 4% compared with that of the general method. The extraction process optimized by response surface methodology has high extraction efficiency, and the experimental operation is simple and fast, which can be used to extract proanthocyanidin in batches. The study lays a foundation for the research on biological activities and the development of products of proanthocyanidin.

  Farmers’ Willingness to Planting Miscellanous Grain Crops and Its Influencing Factors—Based on the Survey Data of 337 Households in Hebei Province Liu Meng, Zhao Yu, Liu Fei, Zhao Wenqing, Li Shunguo, Liu Jianjun 2021, 37 (12):  144-150.  DOI: 10.11924/j.issn.1000-6850.casb20200300165 Abstract + ( 393 )   HTML ( 2 )   PDF ( 1284KB )   ( 63 ) Farmers’ miscellaneous grain production is related to the food source of the whole miscellaneous grain industry. At present, farmers are the main body of miscellaneous grain production, and their planting behavior could affect the supply of miscellaneous grain. In order to analyze current farmers’ willingness to grow miscellaneous grain and its influencing factors, we carried out the study by using the statistical software SPSS and logistic model regression analysis method based on the survey data of 337 miscellaneous grain growers in Hebei Province. The results show that 81.9% of the farmers are willing to grow miscellaneous grain. The age factor of farmers reaches an extremely significant level of 0.01, the education level of farmers and the yield of miscellaneous grain reach a significant level of 0.05, and the seed cost and the availability of orders reach a significant level of 0.10. Finally, the study proposes that it is necessary to carry out research and development and promotion of varieties, technologies, machinery, etc., encourage young and educated technicians to engage in miscellaneous grain production, strengthen technical training, and improve the subsidy system of operating entities and the order system of enterprise farmers.

  The Sustainable Development of Leisure Agriculture in Jiangsu Province Based on SWOT-PEST Analysis Jia Xinping, Tang Ling, Mei Xueying, Luo Hairong, Jia Junli, Yi Neng, Liu Huazhou 2021, 37 (12):  151-157.  DOI: 10.11924/j.issn.1000-6850.casb2020-0395 Abstract + ( 328 )   HTML ( 5 )   PDF ( 1189KB )   ( 79 ) Taking leisure agriculture in Jiangsu Province as an example, we analyzed the development environment of leisure agriculture and the formulation of development strategy. The research results are expected to provide theoretical support and scientific basis for the development of leisure agriculture in Jiangsu Province and the whole country. In this study, we used the SWOT-PEST method to analyze the advantages, disadvantages, opportunities and challenges of leisure agriculture in Jiangsu Province from four aspects of politics, economy, society and technology. In 2019, the leisure agriculture of Jiangsu Province received more than 230 million tourists, the comprehensive income was over 68 billion yuan, and the total number of leisure agriculture brands ranks in the forefront of the country. These results show that diverse agricultural resources, obvious geographical advantages, strong economic strength, increased leisure time, and extensive application of information technology are the advantages and opportunities. However, there are some problems such as uneven regional development, lack of science planning, and shortage of professionals. The development of leisure agriculture in Jiangsu Province is also facing the threat of intensified market competition, ecological environment threat, lack of innovation and creativity and so on. In view of the problems existing in the development of leisure agriculture in Jiangsu Province, the SWOT-PEST analysis matrix is constructed in this study, and we put forward four sustainable development strategies: development strategy, reverse strategy, diversification strategy and defensive strategy.

  The Research Status of Melatonin Affecting Leaf Senescence— Based on Bibliometric Analysis Jiang Lu, Liu Yang, He Hui, Qu Ying, Zhang Lu 2021, 37 (12):  158-164.  DOI: 10.11924/j.issn.1000-6850.casb2020-0163 Abstract + ( 256 )   HTML ( 3 )   PDF ( 2972KB )   ( 47 ) In order to grasp the development context and current status of the research on melatonin affecting leaf senescence, we collected published literature in the Web of Science (WOS) and CNKI, analyzed the annual literature number, most related journals, research subject direction, national or regional density distribution, cooperation between authors or between institutions, funding agencies and research hotspots in this field, and displayed them by using information visualization software VOSviewer based on bibliometric. The results showed that there were 7 Chinese literature and 145 English literature, so the visualization of Chinese literature was roughly analyzed. At present, melatonin has attracted more attention to the leaf visible damage, changes in leaf photosynthesis and physiological regulation under oxidative stress. In future, we should focus on the biochemical and molecular mechanism underlying the effects of melatonin on alleviating leaf senescence and the metabolic regulation of melatonin in plants.