Current issue

• 2024 Vol.40 No.18 Published:25 June 2024

  Seedling Establishment Rate of Double-cropping and Direct-seeded Rice under Submergence in South China: Germplasm Screening and Comparative Analysis ZHU Manshan, FU Chongyun, LIU Wuge, LIAO Yilong, MA Xiaozhi, WANG Feng 2024, 40 (18):  1-8.  DOI: 10.11924/j.issn.1000-6850.casb2023-0389 Abstract + ( 143 )   HTML ( 12 )   PDF ( 1813KB )   ( 211 ) The widely used rice varieties (parents) in the rice-growing area of South China were used as test materials and the field direct seeding and flooding seedling emergence tests were conducted in both early and late seasons, respectively, in South China. The aim was to identify and screen out germplasm with higher rate of seedling establishment under flooding and submergence conditions (under the condition of water depth of 6 cm), and provide material support for the development of new rice varieties suitable for direct seeding under natural conditions in South China. The results showed that the seedling establishment rate under flooding and submergence conditions in the early season was significantly higher than that in the late season, and there was no significant correlation between the rates of seedling establishment in the early and late seasons (R2=-0.1253). In the early season, the rates of seedling establishment of ‘Francis’, ‘starbonett99’, ‘Runfeng B’, ‘Kasalath’, and ‘Yuekang 1614’, were the highest five materials, up to 65.0% to 76.5%. Cluster analysis grouped these five materials into the same cluster I. In the late season, the rates of seedling establishment of ‘Yujingruanzhan’ and ‘Conventional Rice 5’ were the highest ones, but only accounted for 42.5% and 39.5%, respectively, and they were also grouped into the same cluster. This indicates that due to different climatic conditions in the early and late rice-growing seasons in South China, different types of germplasm materials with high seedling establishment rate under flooding and submergence conditions should be selected for the breeding of new direct-seeded rice varieties.

  Study on Yielding Ability, Stability and Adaptability in Maize Based on GGE-Biplot TANG Yi, LIU Jianxin, LI Qingchao, GE Pingzhen 2024, 40 (18):  9-13.  DOI: 10.11924/j.issn.1000-6850.casb2023-0431 Abstract + ( 107 )   HTML ( 7 )   PDF ( 1025KB )   ( 67 ) The aims were to explore the main functions and characteristics of GGE double plot, and to select new maize varieties with high and stable yield. In this study, the yield data of 5 new maize combinations in 7 experimental sites were analyzed by GGE-biplot, the high yield, stable yield and adaptability of maize varieties tested at high altitudes in northwest Guizhou were evaluated, and the discrimination and representativeness of the test sites were analyzed. The results showed that the experimental sites could be divided into two ecological zones, with Panzhou as an ecological zone and Liupanshui, Hezhang, Dafang, Nayong, Shuicheng and Weining as an ecological zone. ‘Huinongdan No.5’ performed well in high and stable yield. The results showed that Panzhou and Dafang were the best experimental sites with high discrimination and good representativeness. This study provided a theoretical basis for comprehensive evaluation of new maize varieties and selection of experimental sites.

  Effect of 5 Strains of Nitrogen-fixing Bacteria on Maize Growth and Antistress Enzyme in Different Saline-alkali Soil JI Yan, ZHANG Wenming, LIU Jizhi, HAN Xuyan, LI Mei 2024, 40 (18):  14-21.  DOI: 10.11924/j.issn.1000-6850.casb2024-0121 Abstract + ( 107 )   HTML ( 8 )   PDF ( 1719KB )   ( 342 ) In order to study the effects of nitrogen-fixing bacteria on maize growth and antistress enzyme in different saline-alkali soils, five nitrogen-fixing bacteria were selected, including Bacillus stratosphericus, Bacillus subtilis, Bacillus cereus, Bacillus aerophilus and Serratia liquefaciens, and the effects of nitrogen-fixing bacteria on the growth, root morphology and antistress enzyme activities of maize were studied by pot experiments using the liquid medium without inoculation of nitrogen-fixing bacteria as the control. The results showed that the five nitrogen-fixing bacteria could increase the growth and root morphology indexes of maize, and promote the dry matter accumulation of maize in saline-alkali soil. Compared with the control, the aboveground dry matter of the five nitrogen-fixing bacteria was increased by 22.22%, 62.96%, 44.44%, 40.74% and 37.04% in mild saline-alkali soil, respectively. The aboveground dry matter in severe saline-alkali soil was increased by 29.41%, 29.41%, 41.18%, 23.53% and 11.76%, respectively. The five nitrogen-fixing bacteria increased the activities of antioxidant enzymes such as CAT, SOD and POD in maize in mild and severe saline-alkali soil, and significantly decreased the content of malondialdehyde (MDA). A comprehensive analysis of the membership function method showed that Bacillus subtilis had the best effect on the growth promotion and stress resistance of maize in mild saline-alkali soil, while Bacillus cereus had the best effect on growth promotion and stress resistance of maize in severe saline-alkali soil. The study indicates that the application of nitrogen-fixing bacteria can effectively enhance the adaptability and productivity of maize in saline-alkali soils, holding significant practical value.

  132 Sweetpotato Landraces: Genetic Diversity and Population Structure CHEN Yihang, TANG Chaochen, ZHANG Rong, YAO Zhufang, JIN Jingwei, WANG Zhangying 2024, 40 (18):  22-30.  DOI: 10.11924/j.issn.1000-6850.casb2023-0505 Abstract + ( 120 )   HTML ( 6 )   PDF ( 1580KB )   ( 132 ) Understanding the genetic diversity and population structure of sweetpotato landraces in China is helpful for the protection of sweetpotato germplasm resources and the cultivation of new varieties. In this study, 132 sweet potato landraces were used as materials to analyze the genetic diversity and population structure of phenotypic traits, carotenoid content, and SSR molecular markers. The results showed that the average coefficient of variation of phenotypic traits of 132 sweetpotato landraces was 45.84%, the average carotenoid content was 6.33 μg/g, and the highest was 59.90 μg/g. The average Nei's diversity index of SSR molecular markers was 0.15, and the average Shannon's diversity index was 0.23. Based on the population structure analysis, the 132 sweetpotato landraces were divided into five subpopulations. Further analysis of molecular variation revealed that 84% of the variation existed within populations and 16% between populations. In summary, sweetpotato landraces have rich genetic diversity, and the genetic variation among germplasms is mainly concentrated within the subpopulation. This provides important information for the protection of local sweetpotato germplasm resources and the cultivation of new varieties in China.

  Nine Different Usage Types of Cassava Lines: Adaptability Study in Hepu LUO Yanchun, ZHAO Xinxin, PAN Huan, LIAO Qi, YU Benchi, LAO Shangye, PHAM Thinhan, LIU Cuijuan, LI Rongyun, ZENG Xinhua, FU Haitian 2024, 40 (18):  31-37.  DOI: 10.11924/j.issn.1000-6850.casb2023-0593 Abstract + ( 103 )   HTML ( 6 )   PDF ( 1245KB )   ( 105 ) In order to select suitable cassava lines for extending in Hepu, the biological characteristics of 9 cassava lines were observed with the main cultivar variety ‘Nanzhi 199’ as control, and their agronomic and economic characters were determined and the correlation analysis were conducted. The results showed that the branch angles of 9 cassava lines were small, the root lengths were moderate and the main stem heights were above medium. The tuber yield of ‘RC4’ was significantly higher than the control, but other 8 cassava lines had no significant difference. The starch yields of 8 cassava lines such as ‘RC4’ were higher than that of the control. The starch contents of 9 cassava lines were higher than that of the control, among which 5 cassava lines such as ‘RC3’ were significantly or extremely significantly higher than that of the control. The amylose contents of 9 cassava lines were significant or extremely significantly lower than that of the control. The hydrocyanic acid contents of 6 cassava lines such as ‘RC6’ were lower than 50 mg/kg. The results of correlation analysis showed that the tuber yield was extremely significantly positive related to plant height at middle growth stage, plant height at maturity stage and diameter of tuber root, and was significantly positive related to stem diameter. Starch content was significantly positive related to plant height at middle growth stage, plant height at maturity stage and stem diameter. Starch yield was extremely significantly positive related to plant height at middle growth stage, plant height at maturity stage, stem diameter, tuber diameter, tuber yield, and was significantly positive related to starch content. In conclusion, the 9 new cassava lines had good comprehensive characters and were suitable for extending in Hepu. ‘RC3’, ‘RC4’ and ‘RC7’ can be used for further processing. ‘RC5’ and ‘RC10’ can be used for fresh consumption. ‘RC2’, ‘RC6’, ‘RC11’ and ‘RC12’ can be used for both fresh consumption and further processing. ‘RC2’ and ‘RC5’ have great prospects for popularization as edible lines.

  Effect of Exogenous Melatonin on Germination and Resistance Ability of Peanut Seeds Under Drought Stress SUN Sainan, MIAO Penghui, QUAN Yuewei, MU Guojun, GUO Liguo, YANG Xinlei 2024, 40 (18):  38-44.  DOI: 10.11924/j.issn.1000-6850.casb2023-0613 Abstract + ( 112 )   HTML ( 7 )   PDF ( 1194KB )   ( 43 ) The study aimed to explore the effect of exogenous melatonin on seed germination and resistance of peanut under drought stress. In this study, the drought-sensitive peanut variety ‘Jihua 5’ was used as the test material, and four treatments were set up, including blank water-soaked seed (CK), melatonin-soaked seed (T1), 10% PEG-6000 treatment (T2), and melatonin-soaked seed plus 10% PEG-6000 treatment (T3), and four other treatments were used to determine the antioxidant physiological and biochemical indices after seed germination. The results showed that the 10% PEG-6000 was effective in simulating the drought environment. Meanwhile, melatonin concentration of 100 µmol/L was the best choice to promote peanut seed germination. Further analyzing the length and thickness of radicle and antioxidant physiological and biochemical indexes of peanut seeds under each treatment, we found that the application of 100 µmol/L melatonin under drought stress significantly enhanced the growth potential of radicle and increased the contents of SOD, POD and Pro, and effectively reduced the contents of MDA and H2O2 in peanut seeds. This study indicated that exogenous melatonin could effectively improve the germination of peanut seeds under drought stress, and provided a theoretical basis for further investigation of the regulatory mechanism of melatonin in promoting peanut seed germination under drought stress.

  Research Progress of Cultivation Techniques in Late Sowing Rapeseed After Rice Stubble YANG Guang, LIN Guobing, QIAN Chen, LI Jing, WANG Long, LI Yiyang, ZUO Qingsong 2024, 40 (18):  45-52.  DOI: 10.11924/j.issn.1000-6850.casb2023-0410 Abstract + ( 111 )   HTML ( 5 )   PDF ( 1160KB )   ( 100 ) The planting area of rice stubble rapeseed in China is mainly in the winter rapeseed area of the Yangtze River Basin. In recent years, the yield of rice stubble rapeseed has been continuously increasing, and the planting area has also steadily improved, making important contributions to the safety of oil crops in China. However, with the promotion and application of light and simplified cultivation techniques for mid to late maturing rice varieties in the winter rapeseed area of the Yangtze River Basin, the maturity period of rice has been significantly delayed, leading to further compression of the pre winter growth time of rapeseed. The area of late sowing and over late sowing of rapeseed has been increasing year by year, which seriously restricted the production potential of rapeseed. The phenomenon of late sowing of rapeseed in the rice oil dual cropping areas of the Yangtze River Basin is particularly prominent, and has become a widespread concern for many scholars. This article aims to identify important issues in late sowing rapeseed production by analyzing the current situation of late sowing rapeseed and related high-yield limiting factors. Through the analysis of the current situation of late sowing, we aim to improve the quality and yield of rapeseed in rice oil rotation areas. The use of advanced cultivation techniques can reduce the impact of late sowing of rapeseed, and provide theoretical reference for promoting the vigorous development of the future rapeseed industry.

  Application of Principal Component Analysis in Quality Evaluation of Upper Flue-cured Tobacco Leaves in Shandong Province ZHANG Yang, KONG Decai, DONG Xiaowei, SUN Yanguo, QU Yuankai, YAN Huifeng 2024, 40 (18):  53-57.  DOI: 10.11924/j.issn.1000-6850.casb2023-0473 Abstract + ( 98 )   HTML ( 2 )   PDF ( 1217KB )   ( 60 ) The method of principal component analysis was used to comprehensively evaluate the quality of flue-cured tobacco. It provided scientific basis for accurately evaluating the quality characteristics of upper flue-cured tobacco leaves in Shandong Province. A total of 105 B2F grade tobacco samples from 10 main tobacco planting counties in Shandong Province in 2020 and 2021 were selected as materials. Standardization and principal component analysis methods were applied to classify physical and chemical composition indicators, and the quality of upper flue-cured tobacco leaves in tobacco planting counties. There were significant positive correlations between single leaf weight and leaf length and width, leaf density and leaf thickness, total sugar and reducing sugar, nicotine and nitrogen, and the principal component eigenvectors were consistent, which could be classified as one type of indicator. According to the evaluation results of physical properties, the upper flue-cured tobacco leaves in Shandong production area could be divided into three categories. Based on the evaluation results of chemical composition, the upper flue-cured tobacco leaves in Shandong production area could be divided into two categories. Based on the comprehensive evaluation results of physical properties and chemical composition, the upper tobacco in Shandong production area could be divided into four categories. Yiyuan, Wulian, Linqu were in a class, Lanling, Yishui, Juxian, Laiwu were in a class, Zichuan and Huangdao were in a class, Zhucheng alone was a class.

  Effects of Rice-crab Coculture on Soil Physical and Chemical Properties and Soil Enzyme Activities CHEN Youming, GUO Yanru, MA Xingkong, TIAN Jian, DONG Yuanhua 2024, 40 (18):  58-65.  DOI: 10.11924/j.issn.1000-6850.casb2023-0592 Abstract + ( 107 )   HTML ( 6 )   PDF ( 1333KB )   ( 52 ) To explore the effects of rice-crab coculture on soil physical and chemical properties and soil enzyme activities, the differences of seven soil physical and chemical indexes and four soil enzyme activities between rice-crab coculture and rice monoculture were studied by using the cement pond simulating paddy field environment. The results showed that there were significant differences in soil bulk density, soil water content and total reducing substances between rice-crab coculture and rice monoculture (P<0.05). The total organic carbon of the rice-crab group was slightly higher than that of rice filed group, but the total nitrogen was slightly lower than that of rice field group. There was a significant difference in Eh between the rice-crab group and the rice monoculture group with a difference of 20.95%. The mechanical composition of soil particle size in rice-crab group and rice field group was silt>clay >coarse and fine sand, and the proportion of silt was more than 80%, and there was a significant difference between the two groups (P<0.05). With the increase of soil depth, the activities of four enzymes in rice filed group decreased significantly. The activities of urease, cellulase and sucrase in the rice-crab group showed the same trends as those in the rice field group, but the acid phosphatase did not change. It could be seen that the introduction of crabs into the integrated rice-crab system reduced the soil bulk density, increased the soil water content, and improved the soil quality. Soil enzyme activities were stronger in the 10-15 cm bottom soil where rice roots were more distributed, which promoted the efficient utilization of carbon and nitrogen by rice in the integrated rice-crab system. Therefore, the integrated rice-crab system is beneficial to both rice growth and crab culture, and can be used as an ecological planting and breeding model in Jiangsu Province.

  Effects of Bio-organic Fertilizer Combined with Chemical Fertilizer Reduction on Soil Nutrients and Tobacco Yield and Quality ZENG Xiangnan, LI Si, YUAN Caiyun, YANG Zhujun, OU Yi, LIU Yongbin, PENG Bo, YU Yuguang, FAN Peng, LIN Wanhuang, WEI Jianyu 2024, 40 (18):  66-72.  DOI: 10.11924/j.issn.1000-6850.casb2023-0597 Abstract + ( 121 )   HTML ( 6 )   PDF ( 1179KB )   ( 49 ) To reduce the excessive application of chemical fertilizers and improve the soil fertility and tobacco production efficiency in Yizhang County, Hunan Province, a field experiment using flue-cured tobacco variety ‘K326’ as material was conducted to study the effects of different proportions of bio-organic fertilizers and chemical fertilizers reduction on soil nutrients and the yield and quality of tobacco. The results showed that the increasing appropriate proportion of bio-organic fertilizers combined with chemical fertilizers reduction could improve soil fertility and promote the growth of tobacco plants. And tobacco plants growth agronomic traits, sensory evaluation of smoking, yield, output value and the first-class proportion of tobacco leaves showed a trend of rising firstly and then falling with the increase of proportion of bio-organic fertilizers combined with chemical fertilizers reduction. Among them, the T2 treatment with 20% reduction in chemical topdressing showed the best growth characteristics and leaf quality of tobacco plants. Compared with the control of conventional fertilization (CK), tobacco plant height, effective leaf number and maximum leaf area of T2 treatment were increased by 8.24%-17.00%, 13.81%-23.22% and 12.63%-16.86%, respectively. The contents of total sugar and potassium in C3F tobacco leaves reached 26.51%-30.01% and 2.16%-2.86%, respectively. The C3F and B2F tobacco leaves sensory evaluation of smoking increased by 1.67%-2.98% and 3.12%-4.10%, respectively. The yield, first-class proportion and output value of tobacco leaves were increased by 3.76%-6.58%, 3.38%-3.79% and 8.24%-9.58%, respectively. The results provided a scientific reference for the application of bio-organic fertilizers combined with chemical fertilizers reduction in tobacco-growing areas of southern Hunan Province.

  Improving Broccoli Soil Nutrients and Fungal Community: Application of Different Rotation Patterns in Soil Health ZHANG Kai, CHENG Yandi, HU Haonan, FENG Haiping, WU Hongliang, KANG Jianhong 2024, 40 (18):  73-82.  DOI: 10.11924/j.issn.1000-6850.casb2023-0604 Abstract + ( 106 )   HTML ( 4 )   PDF ( 1417KB )   ( 18 ) To solve the soil health problems such as fertility decline and quality degradation caused by unreasonable factors in the utilization and management of cultivated land resources, a field experiment was conducted to study the effects of planting broccoli under different rotation patterns on soil nutrients, fungal community structure and diversity. The rhizosphere soil of broccoli after different rotation modes was used as the research object, and the soil chemical properties and enzyme activities were measured and analyzed. Six rotation modes were set, including continuous cropping of broccoli (BB), broccoli-millet (MB), broccoli-onion (OB), broccoli-soybean (SB), broccoli-potato (PB) and broccoli-welsh onion (GB), with broccoli as a control. Illumina MiSeq high-throughput sequencing technology was used to analyze the fungal community structure and diversity under different rotation modes. The results showed that compared with the continuous cropping of broccoli, the chemical properties of soil rhizosphere in each rotation treatment were significantly different, and there was no significant difference in pH, and the chemical properties of MB were significantly increased. By Alpha diversity analysis, the Chao1 index and the observed species number index of other treatments showed an upward trend compared with BB, while the Simpson index showed a downward trend. As for the Shannon index and Pielou’s evenness index, the performance was SB<GB<MB<BB<PB<OB. The results of the abundance and composition of the fungal community showed that the dominant flora was composed of chytridiomycota, ascomycota, sporophytes and chaetomium. Correlation analysis showed that total phosphorus and nitrate nitrogen were the main factors affecting soil beneficial bacteria. By comprehensive comparison, MB can significantly optimize soil chemical properties, enhance enzyme activity, and increase the abundance and diversity of beneficial microbial communities, thereby enhancing soil nutrient regulation and plant disease resistance. MB is the best in all aspects of indicators, which can effectively alleviate the continuous cropping of broccoli and improve soil health problems. It is recommended as a promotion planting mode.

  Plant Auxin Responsive Gene SAUR: A Review LIU Chaoyi, WANG Yuhang 2024, 40 (18):  83-89.  DOI: 10.11924/j.issn.1000-6850.casb2023-0534 Abstract + ( 125 )   HTML ( 6 )   PDF ( 1099KB )   ( 723 ) Auxin is an important regulatory factor in the process of plant growth and development, and plants achieve their own growth and development through the regulation of auxin. As a member of the early auxin response gene family, the SAUR gene family is one of the indispensable regulatory factors in the auxin signal transduction pathway. In order to study the role of SAUR genes in biological processes such as plant growth and development and stress response, the bioinformatics characteristics, expression patterns, and regulatory mechanisms of the SAUR gene family were analyzed. The functions of SAUR genes in plant cell elongation growth, light-mediated cotyledon and apical hook opening, flower organ formation, fruit development, and stress response were summarized. It was pointed out that SAUR genes not only affected plant growth and development in multiple aspects, but also participated in the response of plants to abiotic stress. This study provides a theoretical basis for future research on the molecular mechanisms of SAUR genes and the cultivation of plant varieties.

  Rice Restorer Line with Fragrance and Disease Resistance: Molecular Identification and Application ZHANG Yuting, WANG Hongchao, LIANG Yingying, KUANG Mengxin, WU Xin, JIANG Yunlin, CHENG Zuxin, LIN Lihui 2024, 40 (18):  90-95.  DOI: 10.11924/j.issn.1000-6850.casb2023-0548 Abstract + ( 92 )   HTML ( 2 )   PDF ( 1316KB )   ( 13 ) Improving the grain quality and blast resistance of rice restorer lines is the foundation for breeding new hybrid rice combinations with high yield, superior quality and disease resistance. By using molecular markers closely linked to the fragrance gene fgr and rice blast resistance genes Pi-1, Pi-9 and Pi-kh, the molecular marker -assisted selection of fragrance and blast resistance genes was performed in 265 F6 restore line generations derived from aromatic variety ‘Yuzhenxiang’ crossed with disease resistant restorer lines ‘Fuhui 683’ and ‘Jinhui 1131’. Six excellent restore lines carrying the aforementioned four target genes were selected. Combined with comprehensive character investigation, an aromatic restore line ‘Runxiang’ with medium resistance to rice blast was bred. And a new combination of high-yield and superior-quality aromatic black hybrid rice ‘Ziliangyou Runxiang’ had passed the approval of new crop varieties in Guangxi Province (Guishendao NO.2021200) and Fujian Province (Minshendao 20220024), which exhibited high yield, superior grain quality, and great potential for widespread cultivation. Molecular marker-assisted technology is a rapid and effective modern biotechnology breeding technique for the targeted improvement of rice aroma and blast resistance.

  Alcohol Dehydrogenase Gene Deletion Mutant of Enterobacter cloacae by Suicide Plasmids Homologous Recombination: Construction and Biological Characteristics XIE Lele, HE Ping, TANG Xiaoyue, GE Jingping, LING Hongzhi 2024, 40 (18):  96-104.  DOI: 10.11924/j.issn.1000-6850.casb2023-0610 Abstract + ( 106 )   HTML ( 2 )   PDF ( 1723KB )   ( 1106 ) The aim of this study was to investigate the effects of knockout of ethanol dehydrogenase gene in Enterobacter cloacae metabolic pathway on the metabolism and synthesis of acetoin, and further improve the production of acetoin. Based on the ethanol dehydrogenase (adh) gene sequence from E. cloacae SDM, a primer was designed to construct the adh gene suicide plasmid pKR6K-∆adh. Subsequently, this suicide plasmid was introduced into E. cloacae ∆budC-ldh through heat shock method. The resulting polygene deletion strain E. cloaca ∆budC-ldh-adh was successfully constructed and subjected to fermentation analysis. The findings revealed that the recombinant strain exhibited a 20.6% increase in acetoin production intensity, a 22.6% increase in yield, and a remarkable 92.8% increase in ethanol yield compared to control strains due to successful knockout of ethanol dehydrogenase (adh) gene which in charge of microbial ethanol synthesis pathways. Furthermore, as a consequence of blocking multiple branch metabolic pathways through genetic modification, carbon flux towards succinic acid metabolic pathway increased significantly leading to an impressive 101.3% enhancement in succinic acid yield. This experiment has provided valuable insights for constructing high-yielding strains for acetoin production and establishing large-scale industrial manufacturing processes.

  Analysis of Structure and Functional Properties of Glucansucrase Based on Bioinformatics Method CAI Huayang, YU Liansheng, LI Tengxin, LIN Yimeng, Du Renpeng 2024, 40 (18):  105-114.  DOI: 10.11924/j.issn.1000-6850.casb2023-0670 Abstract + ( 107 )   HTML ( 3 )   PDF ( 2286KB )   ( 888 ) Glucansucrase is a glycosyltransferase (GTF) that can synthesize dextran or oligosaccharides with sucrose as a substrate, and is a key enzyme protein for the synthesis of exopolysaccharide (EPS) by lactic acid bacteria (LAB). However, the metabolic system of LAB is complex, and the mechanism of EPS biosynthesis has not been elucidated, which limits the development of EPS. In order to further analyze the biosynthetic mechanism of LAB EPS and characterize the structure of dextransucrase from different sources, it is necessary to explore the catalytic regulation mechanism of enzyme. In this study, the structure and function of glucansucrase GtfB from Leuconostoc mesenteroides DRP105 were predicted with bioinformatics techniques. The results showed that GtfB belonged to the GH70 family, which was an extracellular enzyme with no transmembrane region, containing 7 conserved regions and 39 repeats. The theoretical molecular weight of GtfB was 308986.21, and the theoretical isoelectric point was 4.59, which was an acidic protein. The phosphorylation site contained 110 Thr, 89 Ser, and 53 Tyr, and GtfB contained 5 domains, which were U-folded, and the active center was in the A domain, containing (β/α)8 barrel-like structures. Molecular docking prediction analysis showed that sucrose was tightly bound to the active pocket of GtfB. The results of this study preliminarily revealed the characteristic structure and function of GtfB as a glucanase, proving that this enzyme is a key regulatory enzyme in the EPS synthesis pathway of LAB and has potential application value in the EPS production process.

  Physical Mutagenesis Technology in Enhancing Antagonism of Beneficial Microorganisms Against Banana Fungal Pathogens: A Review WU Li, WANG Yongfen, YU Hongwei, DING Mingbi, BAI Tingting, LI Shu, ZHENG Sijun 2024, 40 (18):  115-124.  DOI: 10.11924/j.issn.1000-6850.casb2023-0587 Abstract + ( 94 )   HTML ( 2 )   PDF ( 1612KB )   ( 144 ) Banana fungal disease is one of the main diseases in banana production, which can seriously hinder the sustainable development of banana industry. The biological control based on biocontrol bacteria has great application prospects in the prevention and control of banana fungal diseases. However, the effective colonization of biocontrol bacteria to the host in the field and its stability of disease prevention ability have always been the problems to be solved. The mutation and improvement of biocontrol strains by physical mutagenesis technology can significantly improve the colonization ability of biocontrol bacteria to hosts and the control effect of diseases. In order to elucidate the impact of physical mutagenesis technology on improving the field control efficiency of biocontrol bacteria, this paper provides a comprehensive overview of the various types and mechanisms of physical mutagenesis technology, as well as its application in antagonizing bacteria. Additionally, it summarizes the utilization of physical mutagenesis in improving the resistance of beneficial microorganisms to banana fungus pathogens, along with the screening and identification methods for mutant strains. Furthermore, an analysis is conducted on the advantages and disadvantages associated on each mutagenesis technology. It is pointed out that the physical mutagenesis technology has some problems of difficulty to master the direction of induced mutation, low efficiency and instability. In order to address these limitations, novel physical mutagenesis techniques such as ion beam, intense pulsed light and space mutagenesis are proposed. The aim of this paper is to provide a comprehensive reference for the application of physical mutagenesis technology in enhancing the efficacy of biocontrol bacteria for plant disease management. The application prospect of physical mutagenesis technology in enhancing antagonistic bacteria on banana fungal pathogens is also discussed.

  Streptomyces acidiscabies: Identification and Screening of Antibacterial Organic Acids HUANG Xun, FENG Jiawen, HE Wenrui, XU Yajin, DENG Linmei, ZHOU Kunyan, ZHANG Xiaofang, YANG Yanli, LIU Xia 2024, 40 (18):  125-134.  DOI: 10.11924/j.issn.1000-6850.casb2023-0573 Abstract + ( 120 )   HTML ( 3 )   PDF ( 2774KB )   ( 21 ) In order to clarify the types of pathogens causing potato common scab in the micro potato continuous cultivation substrate, organic acids with good inhibitory activity were screened to control this disease. In this study, pathogenic bacteria were isolated and purified from diseased potato, and their pathogenicity was detected by potato chip method, radish chip method and greenhouse pot inoculation method. The species were determined by morphological observation, physiological and biochemical characteristics determination and 16S rRNA gene sequence analysis. The biological characteristics such as salt tolerance were studied, the effects of organic acids such as formic acid on the growth of Streptomyces spp. were determined using paper plate method. Streptomyces strain 19311 was pathogenic, and its pathogenic island virulence related genotype was txtAB+/tomA+/necI+. Strain 19311 was identified as Streptomyces acidiscabies based on the morphological, physiological and biochemical characteristics and 16S rRNA sequence analysis. Formic acid, acetic acid, propionic acid, lactic acid, citric acid, and tartaric acid could significantly inhibit the growth of S. acidiscabies, and formic acid had the best antibacterial effect with the antibacterial zone diameter of 45.43 mm and the lowest effective concentration of 1%, which could inhibit the growth of S. acidiscabies by increasing the permeability of cell membrane. In this study, the species and biological characteristics of Streptomyces strain 19311 in the micro potato cultivation substrate were identified. The use of 1% formic acid to control the occurrence of this disease and evaluate its impact on the original seed production can be carried out in the future.

  Effect of Bacillus amyloliquefacien Mixed with Other Agents on Wheat Crown Rot Disease and Yield WANG Jun, HU Yinghua, WANG Xianghui, ZHANG Li 2024, 40 (18):  135-139.  DOI: 10.11924/j.issn.1000-6850.casb2023-0874 Abstract + ( 133 )   HTML ( 8 )   PDF ( 1165KB )   ( 67 ) In order to explore the effective control methods for wheat crown rot, Bacillus amyloliquefacien（≥100 million cfu/g) AS, 5% mepiquat chloride AS and thifluzamide (240g/L) SC were selected to control the disease in this study. The results showed that the combination of the three agents increased the four evaluation indexes and reduced diseased plants in seeding stage. The combinations also significantly reduced the incidence speed in jointing stage, the treatment 6 was the best and the diseased stem rate was 20.00%. The results of the survey during the seed filling stage showed that the three combinations could control the spread of wheat crown rot and the diseased stem rate was 23.33%-24.44%, the control efficiency was more than 75%. The combinations of the three agents increased the yield rate by more than 21.23%. The result showed that the combinations of the three agents could control the wheat crown rot and increase the wheat yield, which could be popularized in the future.

  Research of Quizalofop-p-ethyl Based on Web of Science: Trend Analysis and Visualization YANG Lili, LIU Chunguang, FU Haiyan, SONG Xinyu, YANG Fengshan 2024, 40 (18):  140-149.  DOI: 10.11924/j.issn.1000-6850.casb2024-0123 Abstract + ( 98 )   HTML ( 3 )   PDF ( 1470KB )   ( 66 ) This study objectively analyzed the research status and clarified the research frontiers of quizalofop-p-ethyl to provide scientific data reference for relevant scholars. In this study, "Quizalofop-p-ethyl" was retrieved by Science Citation Index Expanded to obtain data sources. There were 181 articles from 2007 to 2023, and the information on the number of publications, research institutions, and authors related to quizalofop-p-ethyl were obtained. Python and VOSviewer were used for visualization to obtain a co-occurrence map of keywords in the field of quizalofop-p-ethyl. The main results were as follows. (1) The overall number of publications and the frequency of citations in the field of quizalofop-p-ethyl showed an upward trend worldwide. The country with the most publications was China, and most of the top 10 research institutions with the number of publications worldwide were from China. (2) The author with the most publications was Webster EP from the United States, and research institutions from China had relatively high citation frequency per paper. (3) The research hotspots mainly focused on degradation, herbicides and other aspects. Therefore, China was relatively advanced in the field of quizalofop-p-ethyl, and the strength and influence of relevant domestic scholars were also relatively strong. However, the number of papers published in China has declined in recent years. With the deepening of research on quizalofop-p-ethyl, China still needs to maintain its leading advantage.

  Effects of Endophytic Fungus RP4 Fermentation on Contents of Three Major Cannabinoids in Cannabis sativa L. GUAN Xin, ZHANG He, QI Kexiang, LI Wanru, JIANG Shuo, ZHENG Chunying 2024, 40 (18):  150-156.  DOI: 10.11924/j.issn.1000-6850.casb2023-0645 Abstract + ( 94 )   HTML ( 3 )   PDF ( 1388KB )   ( 12 ) In order to efficiently produce cannabidiol (CBD) raw materials, Cannabis sativa L. was fermented by using the endophytic fungus RP4 strain of licorice with good biological activity. Three major cannabinoids, CBD, CBDA and THC were selected as the research objects to study the dynamic changes of CBD, CBDA and THC contents before and after fermentation. The dynamic changes of CBD, CBDA and THC contents in Cannabis sativa L. during fermentation were analyzed by HPLC. Results showed that during the fermentation process, the contents of CBD and THC increased first and then decreased. When the fermentation time was 3 days, both the contents of CBD and THC reached the maximum value of 5.8643±0.0726 and 0.4878±0.0002 (mg/g) respectively, and the increase of THC was always kept within the scope of national control (THC<0.3%), the content of CBDA decreased continuously, especially in the first day of fermentation. After fermentation in different regions and different parts of Cannabis sativa L., the content of cannabinoid components increased differently. The above results indicated that the microbial fermentation technology could be used to produce CBD in Cannabis sativa L. directly and efficiently, which greatly improved the utilization rate of Cannabis sativa L. resources and laid a foundation for the extraction and separation of CBD and other secondary metabolites.

  Essential Oil Preparation and Volatile Components Analysis in Acanthopanax senticosus Leaves LI Wanru, GUAN Xin, QI Kexiang, ZHANG He, ZENG Weimin, ZHENG Chunying 2024, 40 (18):  157-164.  DOI: 10.11924/j.issn.1000-6850.casb2023-0777 Abstract + ( 112 )   HTML ( 4 )   PDF ( 1296KB )   ( 170 ) In order to compare the yield of essential oil from Acanthopanax senticosus leaves prepared by different extraction methods and to analyze its quality, Acanthopanax senticosus leaves were used as raw materials, essential oils were prepared using both steam distillation and supercritical CO2 extraction methods, followed by the analysis of volatile components using GC-MS. Additionally, the prepared oils were analyzed for their antibacterial and antioxidant activities. The yield of essential oil obtained by steam distillation was 0.10%, whereas the yield obtained by supercritical CO2 extraction was 0.47%. GC-MS analysis identified 35 components out of 57 separated from the essential oil prepared by steam distillation, and 57 components out of 94 separated from the oil prepared by supercritical CO2 extraction. Antibacterial tests indicated that Acanthopanax senticosus leaf essential oil possessed certain antibacterial activity. Moreover, the essential oil exhibited good antioxidant activity, with a DPPH radical scavenging rate of 30.7% and an IC50 value of 3.510±0.175 μg/mL. The results suggest that Acanthopanax senticosus leaf essential oil contains a variety of aromatic compounds that not only contribute to the oil's fragrance but also possess multiple active properties, providing a reference for the rational use of Acanthopanax senticosus leaves and the preparation of essential oils.