Current issue

• 2021 Vol.37 No.18 Published:25 June 2021

  The Effects of Intercropping on the Growth, Development, Physiology and Ecology of Dryland Crops: A Review Cui Aihua, Liu Shuai, Bai Zhigang, Hu Qixing, Sun Julong, Shen Jiaxing, Zhang Yunxi 2021, 37 (18):  1-5.  DOI: 10.11924/j.issn.1000-6850.casb2020-0493 Abstract + ( 538 )   HTML ( 15 )   PDF ( 1044KB )   ( 94 ) The aims of this study are to select suitable farming methods for dryland crops in the Yangtze River Basin, improve the yield and quality, obtain higher economic benefits and promote the sustainable development of dryland agriculture. The effects of intercropping on crop yield, quality, agronomic traits, ecological and photosynthetic characteristics, and nutrient uptake were reviewed both at home and abroad. The results show that the total yield (or income) of crops using an intercropping system is higher than that of any monoculture system. Intercropping significantly improves the quality of crops. Intercropping makes each crop complementary in space-time, water and fertilizer utilization. The total efficiency of radiation interception and utilization of intercropped dryland crops is not lower than that of monocultures of specific crops, and the soil water content and nutrient utilization rate of the intercropping system are higher than that of the monoculture system. Intercropping could lead the two crops to compete and improve the nutrient absorption, thus enhancing fertilizer use efficiency and reducing fertilizer loss rate. Intercropping system could use light, temperature and water intensively. Given the problems of dryland crop intercropping in the Yangtze River Basin, four research directions were pointed out.

  The Breeding of Corn Hybrid ‘Zhongkeyu 505’ and Its Implication for Commercial Breeding Fei Jifei, Sun Zhao, Wang Xingchuan, Gao Fei, Liu Qingpei, Wang Aifen, Yuan Zhiqiang, Chen Ruijie, Liu Dongsheng, Wang Yibo 2021, 37 (18):  6-13.  DOI: 10.11924/j.issn.1000-6850.casb2020-0841 Abstract + ( 1280 )   HTML ( 15 )   PDF ( 1153KB )   ( 178 ) The performance and characteristics of the new corn hybrid ‘Zhongkeyu 505’ are reported here to provide theoretical and practical information needed for large-scale commercialization of this hybrid. ‘Zhongkeyu 505’ was developed by crossing CT1668 as female parent and CT3354 as male parent. The yield performance, agronomic traits, drought resistance, high temperature tolerance, density tolerance, grain quality, and silage forage quality were analyzed based on the multi-year and multi-location data from national and provincial trials. The results showed that the yield of this hybrid increased by 3.4% and 8% respectively on average compared with that of the two check hybrid ‘Xianyu 335’ and ‘Zhengdan 958’. The ear characters such as ear length, ear diameter, kernel number per row, grain weight per ear and grain yield were better than those of the check hybrid. The drought tolerance reached the extremely strong standard, and the high-temperature tolerance reached the medium level equivalent to that of the check ‘Zhengdan 958’. The grain test weight was 746 g/L, the crude protein, crude fatty acid, crude starch, and lysine content reached 10.1%, 3.36%, 74.26%, and 0.3% respectively. The relative stalk feed quality was better than that of ‘Xianyu 335’ and ‘Zhengdan 958’. This hybrid is an excellent one of significant commercial value. In the process of commercial breeding of maize, special attention should be paid to the factors of the market safety evaluation of new varieties, seed production yield, stem rot, ear rot, Southern and Northern leaf blight, Southern rust, suitable planting density and lodging control etc., thus establishing a breeding method combining limited backcrossing with large population adversity screening.

  Straw Fermentation Broth: Effects on Seed Germination and Seedling Growth Characteristics of Maize Sa Rula, Zhang Xueting, Yang Hengshan, Zhang Yun, Xu Yonghui 2021, 37 (18):  14-18.  DOI: 10.11924/j.issn.1000-6850.casb2020-0284 Abstract + ( 393 )   HTML ( 6 )   PDF ( 1083KB )   ( 64 ) To explore the effect of straw returning combined with composting agent on maize seedling, the natural fermentation of 40 g/L, 50 g/L, 60 g/L and 70 g/L corn straw soil extract and fermentation broth of decomposed agent were used as test materials. The seed germination rate, root length, root number, plant height, fresh weight, free proline and malondialdehyde content were measured by filter paper culture, pot culture and conventional methods. The results showed that the seed germination rate, root length, root number, root fresh weight, plant height and leaf fresh weight increased first and then decreased with the increase of fermentation broth concentration. The values of the above indexes of fermentation broth with the same-concentration decomposed agent were higher than that of natural fermentation broth, and the germination rate of 50 g/L natural fermentation and 60 g/L fermentation broth of decomposed agent was relatively high; the fermentation broth of composting agent significantly increased the root length of seedlings; 50 g/L fermentation broth of decomposed agent significantly increased the number of roots; all treatments had no significant effect on the fresh weight of root, leaf and plant height. The contents of free proline and malondialdehyde in roots and leaves of 50 g/L natural fermentation broth and 60 g/L composting agent fermentation broth were not significantly different from those in soil extract. In general, 50 g/L natural fermentation and 60 g/L fermentation broth of composting agent could significantly promote the growth of maize seedlings. The allelopathy of corn straw combined with composting agent fermentation could be weakened, and the amount of straw returned to the field should be appropriately increased when straw is returned to the field.

  Different Nitrogen Fertilizer Levels: Effects on the Grain Yield Trait and Soil Nutrient of Forage Rye in Tibet Zhang Guangyu, Shen Zhenxi, Zhong Zhiming, Cui Jianzhao, Zhaxi Dunzhu 2021, 37 (18):  19-24.  DOI: 10.11924/j.issn.1000-6850.casb2020-0288 Abstract + ( 388 )   HTML ( 8 )   PDF ( 1285KB )   ( 98 ) The aims are to investigate the effects of different nitrogen fertilizer levels on seed yield of ‘Dongmu 70’, determine the reasonable fertilizer addition rate for seed production of ‘Dongmu 70’ in the river valley of Tibet, and provide reference for rational fertilizer application in this area. In this study, ‘Dongmu 70’ was used as material, the seed yield and other related indexes were compared under different nitrogen fertilizer levels in 2018-2019. The results showed that nitrogen addition significantly increased soil organic matter, nitrogen and phosphorus. The increase of grain yield was the highest and the nitrogen use efficiency was also relatively high when nitrogen fertilizer level was 225.0 kg/hm2. Therefore, higher nitrogen addition rate is needed to achieve higher grain yield of ‘Dongmu 70’. Increasing nitrogen addition level could increase the panicle number, grain number per panicle and grain yield of ‘Dongmu 70’ and soil organic matter, nitrogen and phosphorus content in the river valley of Tibet.

  Different Components of MS Medium: Effects on the Growth of Potato Virus-free Test-tube Seedlings Jia Xiaoxia, Qi Enfang, Liu Shi, Huang Wei, Lv Heping, Wen Guohong, Ma Sheng 2021, 37 (18):  25-30.  DOI: 10.11924/j.issn.1000-6850.casb2020-0422 Abstract + ( 381 )   HTML ( 5 )   PDF ( 1381KB )   ( 47 ) To explore high-efficiency and low-cost media for rapid propagation of virus-free potato seedlings, ‘Longshu 7’ and ‘Longshu 20’ were used as test materials, the plant height, stem diameter, the number of leaves, fresh/dry weight of stems and leaves, and chlorophyll content of test-tube seedlings on different media were determined. The results showed that compared with MS medium with organic removal, both varieties grew normally on the medium lacking calcium, but the plant height of ‘Longshu 20’ was significantly lower than that of the control. When only lacking trace elements or lacking calcium salt and trace elements at the same time, there was no significant difference between ‘Longshu 7’ and the control, but the plant height of ‘Longshu 20’ was significantly lower than that of the control. The lack of iron made the new bud of ‘Longshu 7’ lose green and the growth was hindered, but it had no adverse effect on ‘Longshu 20’, and the lack of iron and calcium salt at the same time was beneficial to the growth of ‘Longshu 20’. When cultured on the medium containing only MS macro elements, the stems and leaves of the two varieties appeared yellowish at the early stage, but with the extension of the cultivation time, the yellowness gradually disappeared, and the indexes of ‘Longshu 7’ were significantly higher than those of the control. Therefore, different varieties have different requirements for nutrient elements, and ‘Longshu 7’ and ‘Longshu 20’ can be efficiently and rapidly propagated on MS medium containing only macro elements and macro elements + trace elements, respectively.

  Nitrogen Nutrition Index of Cotton: Estimation Based on Leaf SPAD Ha Faduman, Ma Lulu, Yin Caixia, Su Wei, Li Dongmei, Ding Yiren, Lv Xin, Zhang Ze 2021, 37 (18):  31-37.  DOI: 10.11924/j.issn.1000-6850.casb2020-0499 Abstract + ( 459 )   HTML ( 8 )   PDF ( 1242KB )   ( 51 ) To explore the effects of different nitrogen application treatments on the SPAD value, biomass and nitrogen nutrition index (NNI) of cotton leaves, through a 2-year field experiment, 5 nitrogen application levels (0, 120, 240, 360, 480 kg/hm2) were set to study the SPAD value of cotton leaves, the law of nitrogen absorption and distribution, and the change of biomass. The results showed that the SPAD value of cotton leaves increased with the increase of nitrogen application rate, and reached the maximum value under N4 treatment. The dilution model of cotton nitrogen concentration was established: Nc=3.02Wmax-0.24. The analysis showed that there was a positive correlation between SPAD and NNI of cotton leaves, and the correlation coefficient R2 was 0.05-0.74. It is proved that the simulation performance of the model at different growth stages of cotton is relatively good, and the correlation coefficient could reach the maximum at 97 days after seedling emergence. There is a significant positive correlation between the SPAD value of cotton leaves and the critical nitrogen concentration, which can be used as an index for cotton nitrogen nutrition diagnosis.

  Comparative Study on Physiological Characteristics of Three Sophora japonica ‘Jinhuai’ Varieties Qin Fang, Shi Yancai, Qin Huizhen, Zou Rong, Jiang Yunsheng, Xiong Zhongchen 2021, 37 (18):  38-43.  DOI: 10.11924/j.issn.1000-6850.casb2020-0230 Abstract + ( 316 )   HTML ( 7 )   PDF ( 1259KB )   ( 75 ) To explore the resistance ability of different varieties of Sophora japonica ‘Jinhuai’, and provide a theoretical basis for the variety selection and cultivation physiology research, taking three S. japonica ‘Jinhuai’ (‘Jinhuai J1’, ‘Jinguai J2’and ‘Jinhuai J3’) as the research objects, we investigated the photosynthetic indexes, MDA and PRO content, activities of SOD, POD and CAT in the leaves. The results showed that the variation trend of light response curves of the three S. japonica ‘Jinhuai’ varieties were basically the same, but after 800 μmol/(m2·s) of photosynthetic active radiation (PAR), the net photosynthetic rate of ‘Jinhuai J2’ was significantly higher than that of ‘Jinhuai J1’ and ‘Jinhuai J3’. The light saturation point, net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration efficiency, proline content, catalase activity, superoxide dismutase activity and peroxidase of the three varieties showed the same regularity, and the order from high to low was ‘Jinhuai J2’, ‘Jinhuai J1’, ‘Jinhuai J3’. The order of MDA content from high to low was ‘Jinhuai J3’, ‘Jinhuai J1’, Jinhuai J2. Considering that ‘Jinhuai J2’ has strong adaptability to water shortage and drought condition, and has strong stress resistance, it can be the first choice for planting.

  Effects of Different Fertilization Treatments on the Quality of Toona sinensis in Lead-Cadmium Contaminated Soil Huang Yifang, Zhao Jiaojiao, Ai Jianguo 2021, 37 (18):  44-50.  DOI: 10.11924/j.issn.1000-6850.casb2020-0503 Abstract + ( 290 )   HTML ( 6 )   PDF ( 1239KB )   ( 74 ) This experiment mainly studies the effects of different fertilization treatments on the quality of Toona sinensis in lead-cadmium contaminated soil, aiming to provide a theoretical basis for further explore the cultivation technology of pollution-free vegetables. With Toona sinensis (A. Juss.) Roem. as the test material and the heavy metal lead-cadmium combined contaminated soil and background soil as the cultivation substrate, the effects of non-fertilization (CK), single application of inorganic fertilizer (NPK), single application of organic fertilizer (WM) and combination of organic and inorganic fertilizer (1/2NPK+1/2WM) on the nutritional quality and safety quality of Toona sinensis were studied. The top buds of Toona sinensis were collected before the leaves fell, and the contents of soluble sugar, soluble protein, vitamin C, trace elements, minerals, nitrate and heavy metals were measured by conventional methods. The results showed that the soluble protein content of NPK, WM and 1/2NPK+1/2WM treated with heavy metal lead and cadmium was 4.28, 4.59 and 5.40 mg/g, respectively, which were higher than that of CK of 3.56 mg/g with significant difference (P<0.05). Under background soil condition, the contents of soluble protein under four fertilization treatments in soil matrix were 3.23, 4.62, 5.38 and 5.85 mg/g, respectively, with significant differences (P<0.05). The Vc content of the three fertilization treatments under heavy metal lead and cadmium polluted substrate was 83.36, 117.57 and 112.33 mg/100 g, respectively, which were significantly higher than that of CK (P<0.05). The Vc content in the leaves under four fertilization treatments in the background soil matrix was 51.33, 56.06, 74.03 and 65.03 mg/100 g, respectively, and that of WM and 1/2NPK+1/2WM treatments were significantly higher than that of CK (P<0.05). Whether in the background soil or in the soil contaminated by heavy metals such as lead and cadmium, WM and 1/2NPK+1/2WM could significantly improve the soluble sugar content and the content of total Fe and total Mn in Toona sinensis leaves (P<0.05), while WM treatment could also significantly increase the content of total Cu and total Zn in Toona sinensis leaves (P<0.05). Among the treatments in the two different cultivation substrates, the Pb content of Toona sinensis leaves was the lowest in CK, and that of the other treatments were significantly higher (P<0.05), while the Cd content was the lowest in NPK. The following conclusions could be drawn from this experiment: in the two kinds of cultivation matrix, 1/2NPK+1/2WM could significantly improve the soluble protein, vitamin C, soluble sugar content, beneficial microelements of Toona sinensis leaves, to some extent, it could reduce nitrate and heavy metal lead and cadmium content, so as to improve the quality of the leaves. Under the same fertilizer treatment, soluble protein, soluble sugar content, total content of Fe, Mn, Cu in leaves were much lower in heavy metal lead-cadmium contaminated soil than that in background soil, but the vitamin C content, total zinc content and nitrate content were higher in leaves in polluted soil, indicating that heavy metal pollution could significantly reduce the quality of Toona sinensisleaves.

  1-Methylcyclopropene: Effect on the Postharvest Softening of ‘Hongxin’ Guava Fruits Chen Hongbin, Wang Huiling, Jiang Xuanjing, Cai Yingqing, Zhang Chaokun 2021, 37 (18):  51-56.  DOI: 10.11924/j.issn.1000-6850.casb2020-0203 Abstract + ( 400 )   HTML ( 4 )   PDF ( 1272KB )   ( 141 ) To study the mechanism of 1-methylcyclopropene (1-MCP) regulating the softening of postharvest guava fruit from the perspective of cell wall metabolism, 1 μL/L 1-MCP was used to treat ‘Hongxin’ guava fruit. By measuring the changes of fruit firmness, cell wall metabolism-related substances and the related enzyme activities, the inhibition effects of 1-MCP treatment on the softening of guava fruits under room temperature (25±1℃) were studied. The results showed that the firmness of guava fruit treated with 1 μL/L 1-MCP was 0.51 times higher than that of the control group, and it effectively inhibited the activities of polygalacturonase, pectinesterase, cellulase, β-glucosaccharase, α-amylase and β-amylase, retarded the increase of soluble pectin and glucose contents, and delayed the decrease of protopectin, cellulose and starch contents during postharvest storage period. Therefore, 1 μL/L 1-MCP treatment could effectively delay the softening process of harvested ‘Hongxin’ guava and prolong the preservation period.

  Plant Response to Waterlogging Stress: Research Progress Nie Gongping, Chen Minmin, Yang Liuyan, Cai Youming, Xu Feng, Zhang Yongchun 2021, 37 (18):  57-64.  DOI: 10.11924/j.issn.1000-6850.casb2020-0403 Abstract + ( 452 )   HTML ( 12 )   PDF ( 1118KB )   ( 1609 ) Waterlogging stress is an important factor that affects the distribution, growth and development of plants. The research on plant waterlogging tolerance is critical to improving plant tolerance in order to cope with the increasingly severe extreme weather and the large-scale production management. In order to carry out researches on plant waterlogging tolerance and explore the regulation mechanism of different plants in response to waterlogging stress, we summarized the effects of waterlogging stress on plant growth, the regulation mechanism of plant in response to waterlogging stress, and analyzed the effects of waterlogging stress on plant phenotypic traits, biomass, photosynthesis, reactive oxygen species accumulation, sugar content as well as biological membrane in detail. In addition, the regulation mechanism of ethylene signal molecule, reactive oxygen species scavenging mechanism, osmotic regulation, morphological regulation, molecular and metabolic regulation of plant in response to waterlogging stress were also analyzed. Finally, it is proposed that further in-depth study should be focus on the development of exogenous regulatory substances to improve plant waterlogging tolerance.

  Effects of Biochar and Organic Manure Combined Application on Soil Enzyme Activities and Microbial Community Component in Upland Red Soil Shen Fangfang, Zhang Zhe, Yuan Yinghong, 2021, 37 (18):  65-74.  DOI: 10.11924/j.issn.1000-6850.casb2020-0502 Abstract + ( 316 )   HTML ( 5 )   PDF ( 1354KB )   ( 532 ) To investigate the effects of biochar and organic manure combined application on soil nutrients in dry land can provide a theoretical foundation for soil improvement. Taking the upland red soil derived from Quaternary red clay in the mid-subtropical zone as the material, we added different biochar-organic manure compost into upland red soil during indoor culture experiment to explore the variation of soil microbial biomass carbon and nitrogen (MBC, MBN), enzyme activities (urease, sucrase and catalase) and microbial community component. Five treatments were set up, which were control (CK, 0 g/kg), rice straw biochar-organic manure compost (RM, 50 g/kg), corn straw biochar-organic manure compost (CM, 50 g/kg), wheat straw biochar-manure compost (WM, 50 g/kg) and manure compost (M, 40 g/kg). To eliminate errors as much as possible, test data were normalized, that was the measured value minus CK value then was divided by the amount of C and N added in each treatment. The results showed that RM, CM and WM treatment significantly reduced soil MBC, MBN, urease activity and total PLFAs, and the most significance was observed in WM treatment with the decrease rates of 33.89%, 69.03%, 47.62% and 23.30% of those of M treatment. RM treatment significantly increased soil sucrase and catalase activities, with the increase rates of 91.49% and 28.94% of those of M treatment. Compared with manure compost alone, biochar-organic manure compost reduced the total soil PLFAs (-16.89%), fungal abundance (-38.17%), fungi to bacteria ratio (F/B, -40.63%), gram-negative to gram-positive bacteria ratio (G-/G+, -4.3%), while increased the relative abundance of soil bacteria (+5.18%), Shannon-Wiener index (+0.38%) of soil microorganisms and soil bacterial pressure index (BSI, +11%). Principal component analysis showed that biochar-organic manure compost had a certain effect on soil microbial community component with the most obvious effect in RM treatment. In summary, the application of different materials’ biochar-organic manure compost could cause great difference in soil microbial biomass, enzyme activities and microbial community component. Our results indicate that the effect of rice straw biochar-organic manure compost treatment is the most significant, which could provide certain references for reducing greenhouse gas emission.

  Evaluation and Source Analysis of Soil Potential Toxic Elements Pollution in Tea Garden in Yibin City Cheng Qiangqiang, Wang Zhe, Yi Facheng, Sun Qing, Zhang Yiping, Jiang Hu, Wang Chengxia 2021, 37 (18):  75-84.  DOI: 10.11924/j.issn.1000-6850.casb2020-0387 Abstract + ( 425 )   HTML ( 7 )   PDF ( 1704KB )   ( 39 ) To reveal the current status and source of PTEs pollution in tea garden soil in Pingshan County, Yibin City, through the collection and detection of samples, the pollution assessment of 7 potentially toxic elements (PTEs) (Cd, As, Cr, Cu, Pb, Zn, Ni) was carried out by using the Nemerow index, geo-accumulation index and potential ecological risk index, and the source analysis was conducted by multivariate statistics and spatial analysis. The results showed that among the concentrations of the 7 PTEs, only Cd exceeded the screening value of agricultural land in the tea garden soil. Compared with the soil background value in Sichuan Province, the Cd over-standard rate was 88.45 times, and the average value of Nemerow pollution index, geo-accumulated pollution index and comprehensive potential ecological pollution risk index was 7.65, 3.38 and 1262.06 respectively, indicating that tea garden soil was seriously polluted, and the potentially ecological risk was high. Multivariate statistics and pollution spatial analysis showed that the enrichment of Cd, Cr, Ni and Zn might be caused by pyrite mining; Pb was mainly caused by the large-scale use of coal in the mining and smelting of pyrite. In addition to burning coal, As was also related to the use of fertilizers; the early generation of the paper mills along the Xiaolongxi caused Cu enrichment in the river and acidification of the surrounding soil in the study area. The spatial distribution characteristics of PTEs pollution indicated that Cd was the main source of risk, which had a controlling effect on PTEs pollution in tea garden soil in Yibin.

  Research Progress of Three Lipid Transporter Families in Plants Jiang Xue, Song Xingshun, Meng Wei 2021, 37 (18):  85-94.  DOI: 10.11924/j.issn.1000-6850.casb2020-0738 Abstract + ( 750 )   HTML ( 13 )   PDF ( 1401KB )   ( 134 ) Lipid is one of the most essential substances in an organism. Lipid trafficking is an important process within lipid metabolism. There are three types of protein families involved in lipid trafficking in plant:lipid transfer proteins (LTPs), ATP-binding cassette (ABC) transporters and acyl-coenzyme A (CoA)-binding proteins (ACBPs). Due to the differences in subcellular localization, these three protein families function differently in lipid metabolism. Recent findings show that aside from conserved lipid transport ability, these proteins are also involved in development and stress responses to a different extent. To further understand the functional mechanism of lipid trafficking in development and stress responses, the structure, classification and subcellular localization of these proteins in different plant species were summarized and the function of lipid trafficking in development and stress responses was emphasized. Although much evidence show that these proteins involved in development and stress responses, a few of them indicate that lipid trafficking plays important roles in it, and most of the relevant findings focus on the studies of ACBPs.

  nsLTPs Genes Involved in Plant Response to Stress: Research Progress Ma Yue, Yu Bing 2021, 37 (18):  95-101.  DOI: 10.11924/j.issn.1000-6850.casb2020-0806 Abstract + ( 286 )   HTML ( 8 )   PDF ( 1325KB )   ( 54 ) Genes encoding non-specific lipid transfer proteins, nsLTPs, play an important role in plant response to biotic and abiotic stress and in plant growth and development. In order to investigate the molecular mechanisms of plant nsLTPs genes in response to biotic and abiotic stress, this paper summarized the structural features and classification of non-specific lipid transfer proteins nsLTPs, analyzed the subcellular localization of nsLTPs, and focused on summarizing the relevant research progress of nsLTPs genes in plant stress response, and proposed the molecular regulatory pathways of nsLTPs genes involved in plant stress in different plant species, which could provide a theoretical basis for improving the regulatory mechanism of nsLTPs genes in plant stress response.

  Endophytic Fungi from Panax notoginseng (Burk.) F.H.Chen: Isolation and Identification Li Weijiao, Ren Ke, Pu Shibiao 2021, 37 (18):  102-108.  DOI: 10.11924/j.issn.1000-6850.casb2020-0054 Abstract + ( 356 )   HTML ( 6 )   PDF ( 1977KB )   ( 102 ) Panax notoginseng (Burk.) F.H. Chen is a perennial herbaceous medicinal plant of ginseng in Acanthopanax family. The study aims to isolate endophytic fungus strains which can produce the same or similar biological active substances as the host plant from the medicinal plant. P. notoginseng was used as material. The endophytic fungi strains of P. notoginseng was isolated and purified, and then the endophytic fungi strains were identified based on the traditional morphological characteristics and ITS sequence. A total of 24 strains of endophytic fungi were isolated from cultivated P. notoginseng, and they were identified as 12 genera (species). The types and numbers of endophytic fungi in different organs and tissues of cultivated P. notoginseng were quite different, the roots and leaves had the most, and the stems had less. Among them, 11 species and 6 genera were isolated from leaves, 1 species and 1 genus from stems, 12 species and 5 genera from roots. The statistical results showed that Penicillium commune and Colletotrichum gloeosporioides were the dominant species isolated from leaves, accounting for 27.28% of the isolates from leaves; the dominant strains isolated from the fibrous roots were Chaetomidium arxii, accounting for 72.73% of the isolated root strains. The cultivated P. notoginseng endophytic fungi have rich biodiversity, thus the experimental results could provide a material basis and experimental parameters for further exploring the relationship between cultivated P. notoginseng endophytic fungi and physiological active substances.

  A Strain of Bacillus velezensis: Isolation and Identification Miao Furong, Chen Xinzhu, Qiu Hualing, Liu Jing 2021, 37 (18):  109-116.  DOI: 10.11924/j.issn.1000-6850.casb2020-0460 Abstract + ( 482 )   HTML ( 10 )   PDF ( 1813KB )   ( 75 ) In order to obtain strains which can decomposing tea residue in high-temperature and with high efficiency, we used the high temperature special habitat separation method, and isolated 5 bacteria strains that could decompose tea residues. Among them, the protease and cellulase produced by the Fb strain had the highest activity. After studying the morphology, physiological and biochemical characteristics and growth characteristics of the Fb strain, the 16S rDNA gene sequence and the gyrB gene sequence of the strain were cloned, and the phylogenetic analysis was carried out. The results showed that Fb belonged to Bacillus velezensis, which could tolerate the high temperature of 55℃. The optimal growth condition of the strain was: the filling volume of 30 mL, the rotation speed of the shaking table of 120 r/min, the incubation temperature of 42-45℃, the initial pH of 5.0-7.0, the incubation time of 16 h, and the salinity of 1.0%-6.0%. For the first time, Bacillus velezensis is isolated and screened out of tea residue, and the study could provide a theoretical basis for the development and research of tea residue.

  Pesticide Residues Biodegradation: Research Progress Wang Yan, Peng Qiang, Zhao Xiaoming, Yin Heng 2021, 37 (18):  117-124.  DOI: 10.11924/j.issn.1000-6850.casb2020-0384 Abstract + ( 528 )   HTML ( 21 )   PDF ( 1394KB )   ( 100 ) In order to promote the degradation of pesticides and reduce pesticide residues in crops, we summarized the methods of pesticide degradation, including photolysis, chemical degradation and biodegradation, analyzed the advantages and disadvantages of various pesticide degradation methods, concluded the way and mechanisms of the exogenous substances (pesticide safety agent, brassinolide, melatonin) in promoting the degradation of pesticides in crops. And then we pointed out the effect of oligosaccharides on reducing pesticide residues in crops and its possible mechanism, as well as some problems and suggestions in the research of promoting the degradation of pesticides in crops. We expected this paper could play a positive role in reducing pesticide residues in crops and have a guiding role in agriculture.

  Research Progress on Soybean Pest Thrips nigropilosus Zhao Yijin, Gao Yu, Wang Di, Xu Jiajia, Shi Shusen 2021, 37 (18):  125-130.  DOI: 10.11924/j.issn.1000-6850.casb2020-0114 Abstract + ( 310 )   HTML ( 4 )   PDF ( 1276KB )   ( 54 ) In order to study Thrips nigropilosus in soybean, we summarized the research progress on the distribution and host, morphological characteristics, damage characteristics, occurrence regularity, living habits, relationship between occurrence and ecological factors, as well as the integrated management of the T. nigropilosus. T. nigropilosus mainly damages many cash crops, such as cultivated soybean, chrysanthemum, tobacco and so on. It has many times of outbreak at home and abroad and caused damage to crops, and there is still a certain risk in the future. It is suggested that the occurrence regularity, basic bio-ecological characteristics, forecasting technology and green control technology of T. nigropilosus needs to be explored in depth under the new climate condition and planting system.

  Pathogenic Mechanism and Control Method of Potato Scab: Research Progress Yang Bing, Ping Yuan, Du Chunmei 2021, 37 (18):  131-137.  DOI: 10.11924/j.issn.1000-6850.casb2020-0454 Abstract + ( 714 )   HTML ( 22 )   PDF ( 1149KB )   ( 1374 ) Potato scab caused by the pathogenic Streptomyces scabies is a soil-borne bacterial disease that exists worldwide, and it is difficult to control. In order to formulate more effective control strategies and develop new types of agents to control potato scab more effectively, the effects of virogen thaxtomins produced by S. scabie and plant hormones (cytokinins, auxins and ethylene) on the pathogenic process of S. scabies were concluded, the main chemical agents, agricultural techniques and microbial source preparations used for controlling potato scab disease were summarized, and the advantages and disadvantages of various control methods were analyzed. It was pointed out that to dive deeper into the pathogenic mechanism of potato scab was of great significance to develop new control agents against potato scab, and the development and application of compound microbial inoculants should be an important direction to control potato scab in the future. It is believed that the combination of chemical control, agricultural measures and compound microbial agents can prevent and control the occurrence and damage of potato scab, which is of great significance to the sustainable development of the potato industry.

  Biocontrol Bacteria Against Ditylenchus destructor: Screening and Identification Zhang Niu, Wang Dong, Zhao Yuanzheng, Xiang Peng, Qiu Tingyan, Zhao Xin, Gao Tengda, Gao Zhichao, Zhou Hongyou 2021, 37 (18):  138-146.  DOI: 10.11924/j.issn.1000-6850.casb2020-0605 Abstract + ( 393 )   HTML ( 7 )   PDF ( 4595KB )   ( 36 ) The objective is to develop bioagent resources with high nematicidal activity to control Ditylenchus destructor. Fermentation broths of 34 bacterial strains were used to test their contact activities against D. destructor by direct contact method. The classification status of biocontrol bacteria were identified based on colony phenotype, physiological and biochemical characteristics and 16S rDNA gene sequence. The results showed that 9 biocontrol bacteria with high contact activity were screened and could lead to D. destructor with 72.36%-82.59% corrected mortality after being treated with their fermentation broths for 48 h. Strains Chi9-7, Nong3-5, Nong5-6 and b1-3 were identified as Bacillus subtilis. b5-4 was B. velezensis, and Chi9-2, Xia4-11, Gu4-7 and Z-1 were B. amyloliquefaciens. In this study, 9 Bacillus strains with obvious nematicidal effect were screened and identified, which could provide novel biocontrol resources for the development of microbial nematicides and lay a foundation for the effective control of D. destructor.

  Wood Vinegar: Acute and Chronic Effects on the Growth and Reproduction of Myzus persicae Yu Huiling, Ye Lefu, Wang Xue, Xu Zhen, Feng Xinyu, Ma Tianyuan, Fu Xue 2021, 37 (18):  147-152.  DOI: 10.11924/j.issn.1000-6850.casb2020-0593 Abstract + ( 377 )   HTML ( 4 )   PDF ( 1092KB )   ( 45 ) To determine the short-term and long-term effects of wood vinegar on peach aphid, the aphid was treated with 100 times diluted wood vinegar solution on Chinese cabbage, and the reproduction and development data of the peach aphid were measured. The results showed that wood vinegar treatment significantly shortened the reproductive period of peach aphid, and the reproductive period of F1 generation was 37% longer than that of F0 generation. Compared with the control group, the total aphid individuals produced in F0 generation and F1 generation were decreased by 62% and 66%, respectively. The survival rate of F1 and F2 generation in treatment group was 23% and 24% lower than that of control group, but there was no significant difference between F1 and F2 generation. The lifespan of F1 generation was reduced by 25%, while the difference of F2 generation was not significant. This study proved that wood vinegar could shorten the reproduction period, prolong the duration of the nymph aphid, shorten the life span of the peach aphid, and reduce the survival rate of the progeny. In conclusion, wood vinegar has certain inhibitory effect on the growth and reproduction of peach aphid, but this inhibitory effect will gradually weaken with the increase of application frequency, that is, the short-term and long-term effects of wood vinegar are different, so wood vinegar has the development value as a biological pesticide.

  Insecticide Controlling Sweet Poato Weevil: Selection and Field Efficacy Xu Jin, Su Zhiping, Su Huirong, Zhu Hongbo, Cheng Shengyong, Wu Zhengwei 2021, 37 (18):  153-158.  DOI: 10.11924/j.issn.1000-6850.casb2020-0435 Abstract + ( 722 )   HTML ( 6 )   PDF ( 1167KB )   ( 70 ) To select effective, economical and safe insecticides suitable for the control of sweet potato weevil in tropical areas such as Zhanjiang, the toxicity indoor test, pot experiment and field trial of 12 insecticides were carried out on the adults of sweet potato weevil. The results showed that the insecticides with better control effects on sweet potato weevil in Zhanjiang were 3.2% abamectin EC, 20% tebufenozide SC, 5% acetamiprid EC and 16% tebufenozide·indoxacarb EC. The control effects of 3.2 % abamectin EC and 20% tebufenozide SC in pot experiment at 72 h were 97.78% and 91.59%, respectively. After 4 days of field trial, the control effects of 3.2% abamectin EC and 20% tebufenozide SC reached 91.01% and 92.26%, respectively, and still reached 70.76% and 67.84% after 8 days. 3.2% abamectin EC and 20% tebufenozide SC exhibit better control effect and persistence on the adult of sweet potato weevil, which are suitable for field control in tropical areas such as Zhanjiang.

  Herbicides Selection in Sorghum Breeding Field Chen Minju, Sun Xiyun, Yuan Haibo, Zhang Fujuan, Meng Xianzheng, Meng Yan 2021, 37 (18):  159-164.  DOI: 10.11924/j.issn.1000-6850.casb2020-0771 Abstract + ( 385 )   HTML ( 4 )   PDF ( 1111KB )   ( 96 ) The aim of this study is to screen the herbicide types and using time scientifically in the sorghum breeding fields, and provide a theoretical basis for the management of sorghum breeding field. Six kinds of sorghum germplasms and three herbicides were used as experimental materials, and the suitable herbicides and using time were determined by variance analysis. The results showed that: T3 had little effect on the sprouting rate, and the average sprouting rate of sorghum germplasms was 94.32%. The herbicide hazard of T6 was the worst, its average value was 3.87%; compared with other treatments, the difference was obviously significant. T2 had not toxicity, T4 was mild, and their average value was 0.13%. According to the germplasms analysis, there was a significant difference in the herbicide hazard caused by pre-seedling treatment, and herbicide hazard on the non-hybrid strains was more serious with an average of 1.44%, which was significantly higher than that of hybrid strains (1.07%). The weed control effect of all treatments was ideal, and T6 had the best effect, the mean value of weeds damage among different strains was 0.11%. In conclusion, T4 could effectively control weeds in the field and cause less harm to sorghum germplasm.