Current issue

• 2020 Vol.36 No.33 Published:25 November 2020

  Cold-resistant Agent: Foliar Spraying Application Method and Its Effect on Cold Resistance of Rice Seedlings Ren Bo, Wang Hanying, Fu Tingyu, Wen Zhuyou, Xiong Hairong, Zhang Xianwen 2020, 36 (33):  1-6.  DOI: 10.11924/j.issn.1000-6850.casb2020-0024 Abstract + ( 524 )   HTML ( 23 )   PDF ( 1304KB )   ( 126 ) The purpose is to study the foliar spraying application method of cold-resistant agent KHYE-1 and its effect on cold resistance of rice seedlings. The early rice variety ‘Zhongjiazao 17’ was used as material, the seedlings were treated with cold-resistant agent and cold stress, and the biochemical indexes of seedlings were further detected with chemical and biochemical method. The results showed that the best application method of KHYE-1 was spray concentration of 0.5%, one time per day for 3 days and spray dosage of 5.0 g/box. Compared with CK, the content of N (Nitrogen), P (Phosphorus), K (Potassium) and the value of chlorophyll SPAD in rice seedlings treated with cold-resistant agent under cold stress maintained at a relatively high level, and the content of soluble sugar and proline increased by 147.4% and 72.0%, and the activities of peroxidase (POD) and catalase (CAT) were 80.2% and 2.63% higher, respectively. In conclusion, the overall effect of KHYE-1 is better than that of ABA, and it could improve the cold-resistance of rice seedlings.

  Chemical Regulation Technology of Drought Resistance in Maize: A Review Du Zhuo, Lu Yuncai 2020, 36 (33):  7-11.  DOI: 10.11924/j.issn.1000-6850.casb20191100890 Abstract + ( 515 )   HTML ( 10 )   PDF ( 1243KB )   ( 199 ) Drought is one of the main meteorological factors affecting the growth and yield of maize. In order to find effective ways to reduce drought damage, keep maize yield and increase drought resistance of maize, this study introduced the chemical control technology of drought resistance in maize, concluded the effects of drought on seed germination and the physiological and biochemical indexes of maize seedling, reviewed the drought-resistance mechanism of plants, and summed up the application of chemical regulation in the drought resistance of maize. At last, the problems in the chemical regulation were pointed out, and some advices were proposed, including highlighting the research and application of mixed dosages.

  Maize Varieties with Different Genotypes: Study on Yield, Drought Resistance and Water Use Efficiency Liu Huatao, Huang Xuefang, Huang Mingjing, Zhang Dongmei, Zhang Wei, Zhao Cong 2020, 36 (33):  12-18.  DOI: 10.11924/j.issn.1000-6850.casb20191100878 Abstract + ( 621 )   HTML ( 13 )   PDF ( 1293KB )   ( 100 ) To enhance crop drought resistance and water use efficiency, the most effective and easy technical measure is choosing new varieties, which can solve the problems of varieties used blindly and passive resistance to drought. Under the arid field of Jinzhong Basin in Shanxi Province, eleven different genotype maize varieties, which were widely applied in production, were selected as materials, three different water treatments were set up at maize jointing stage, and the differences of yield, drought resistance and water use efficiency among the test varieties were studied. The results showed that: the rank of yield and drought resistance of the varieties changed under different water treatments, ‘Dafeng30’ and ‘DikaM753’ were the best varieties that had high and stable yield and drought resistance. Under normal water supply, the yield could reach 13634 kg/hm2 and 14478 kg/hm2, respectively, and the drought resistance index could reach 0.999 and 1.029, respectively. After analyzing water use efficiency and water production efficiency, the results showed that irrigating 45 mm at jointing stage not only obtained higher water use efficiency, but also got the highest water production efficiency, which were 29.77 kg/(mm·hm2) and 30.92 kg/(mm·hm2), respectively. Thus, ‘Dafeng30’ and ‘DikaM753’ can be used as main varieties in production, and the use of deficit irrigation could be significant for water resources protection and the development of organic agriculture in this region.

  Effects on Seedling Growth and CqNHX1 Gene Expression of Different Quinoa Varieties: Salt Stress Shi Pibiao, Wang Jun, Fei Yueyue, Hong Lizhou, Wang Weiyi, Lv Yuanda, Gu Minfeng 2020, 36 (33):  19-24.  DOI: 10.11924/j.issn.1000-6850.casb20191200914 Abstract + ( 354 )   HTML ( 11 )   PDF ( 1338KB )   ( 72 ) In order to select out the quinoa varieties with strong salt tolerance and provide reference for the identification of salt tolerance at seedling stage, three different quinoa varieties were used as experiment materials. The relative growth indexes were determined by measurement, the chlorophyll content was determined by ultraviolet spectrophotometer, the relative ion permeability was determined by conductance method, and the relative expression of salt-tolerant gene CqNHX1 was compared by real-time quantitative PCR under salt stress. The results showed that the plant height of SQ1 was decreased slightly, the biomass was increased, the relative ion permeability remained almost unchanged, and the expression levels of CqNHX1a and CqNHX1b were both significantly increased under salt stress, indicating that SQ1 could grow normally under a high salt environment. Compared with the control, the plant height and chlorophyll content of SQ34 was significantly decreased, the biomass remained unchanged, while the expression levels of CqNHX1a and CqNHX1b were significantly increased. The root-shoot ratio and chlorophyll content of QQ61 were significantly decreased under salt stress, while the relative ion permeability was significantly increased, and the expressions of CqNHX1a and CqNHX1b were down-regulated, demonstrating that the salt tolerance of this variety was weak. Salt tolerance between different quinoa varieties differed remarkably, the rank was: SQ1 > SQ34> QQ61. SQ1, as a high salt tolerant variety, can be further popularized in saline-alkali land.

  Adaptability Evaluation of Millet Varieties Based on Grey Multidimensional Comprehensive Membership Grade Method Yang Ping, Chen Yuli, Qin Ling, Chen Erying, Gong Fajiang, Bi Haibin, Gao Minghui 2020, 36 (33):  25-30.  DOI: 10.11924/j.issn.1000-6850.casb20191100837 Abstract + ( 463 )   HTML ( 5 )   PDF ( 1272KB )   ( 81 ) To quantitatively analyze the agronomic traits and adaptability of new summer millet varieties from different ecological areas in Luzhong, the authors carried out a field experiment of variety comparison in 2017-2018 summer growing seasons. Based on field test data, the adaptability evaluation of 16 millet varieties was conducted with grey multidimensional comprehensive membership grade method. The results showed that the varieties belonging to the excellent grade were ‘Yugu 32’, ‘Jibaimi 1’, and ‘Jinuomi 2’, the varieties belonging to the good grade were ‘Yugu 18’, ‘Jigu 22’, ‘Jigu 19’, ‘Jigu 20’ and ‘Jigu 21’, the varieties belonging to the general grade were ‘Zhonggu 2’, ‘Jigu 17’, ‘Baogu 23’, ‘Canggu 9’, ‘Yugu 31’ and ‘Jigu 39’, and the varieties belonging to the poor grade were ‘Zhonggu 7’ and ‘Jigu 42’. The study indicates that ‘Yugu 32’, ‘Jibaimi 1’ and ‘Jinuomi 2’ have good adaptability in Luzhong and could be cultivated in large area.

  Orthogonal Polynomial Regression: Application in the Prediction Model of High-protein Soybean Fertilization and Economic Benefit Tian Yixin, Gao Fengju, Cao Pengpeng, Gao Qi, Li Hongbo 2020, 36 (33):  31-37.  DOI: 10.11924/j.issn.1000-6850.casb20191100838 Abstract + ( 379 )   HTML ( 8 )   PDF ( 1287KB )   ( 136 ) The purpose is to further explore the optimal fertilization pattern combination of high-protein soybean and obtain the best economic benefit. The high-protein soybean ‘Jidou 12’ was used as the test material, and three treatments were set for nitrogen, phosphorus and potassium. With different application amounts of nitrogen, phosphorus and potassium as independent variables and the corresponding soybean economic benefits as dependent variables, the orthogonal polynomial regression method was used to establish the economic benefit prediction model equation of high-protein soybean, and the significance (F) test was carried out for each item. The results showed that potassium and phosphate fertilizer could play a better role in fertilizer efficiency only when nitrogen fertilizer reached a certain level (60-90 kg/hm2). Too low or too high potassium application was not conducive to the increase of soybean economic benefit value. The economic benefit of soybean was positively correlated with the amount of phosphorus applied between 50 and 110 kg/hm2. According to F test, nitrogen fertilizer had the largest effect on the economic benefit of high-protein soybean, followed by phosphorus and potassium. The estimated variance was $\hat{σ}$=134.5508, and the 95% confidence interval of economic benefit per hectare of high-protein soybean was predicted to be $\hat{W}$±1.96s=W±263.7196, and the prediction effect was better. Under the model fitting, the application rate of nitrogen, potassium and phosphorus was 54.67, 62.38 and 140 kg/hm2, respectively, with the highest soybean economic benefit of 13276.13yuan/hm2. The multivariate orthogonal polynomial regression model has practical reference value for predicting the economic benefit of high-protein soybean under multi-factor fertilization.

  Canopy Leaf Turning of Spring Soybean at Seed-filling Stage: Reasons and Effects on Net Photosynthetic Rate and Grain Weight Wang Cong, Zhao Lianjia, Zhang Jianxun, Zhang Jianxin 2020, 36 (33):  38-44.  DOI: 10.11924/j.issn.1000-6850.casb20191200926 Abstract + ( 426 )   HTML ( 7 )   PDF ( 1367KB )   ( 45 ) The purpose is to determine the causes of canopy leaf turning and the effect on grain weight. 28 soybean cultivars were used as materials in the field experiment. The relationship between leaf area, specific leaf weight, leaf shape index, water content and the rate of canopy leaf turning of the top 4 leaves at the early seed-filling stage was studied by random block design. The differences between leaf turning and the net photosynthetic rate, 100-grain weight and grain weights were compared. The results showed that the rate of canopy leaf turning of different soybean varieties was 0-26.5%, which was significant, and the rate of canopy leaf turning of ‘zhonghuang 31’, ‘zhonghuang 42’ and ‘zhonghuang 13’ were the highest. The area of single leaf was 46-151 cm2, and that of ‘zhonghuang39’, ‘zhonghuang 42’ and ‘zhonghuang 13’ were the largest. Specific leaf weight was 0.536-1.64 mg/cm2, among which, that of ‘zhonghuang 322’, ‘zhonghuang 313’and ‘zhonghuang 13’ were the lowest. The leaf shape index was 1.35-3.51, among which, that of ‘zhonghuang 70’, ‘zhonghuang 80’ and ‘zhonghuang 42’ were the lowest. The tested soybean varieties were divided into three groups. Group I had smaller single leaf area, higher leaf weight and larger leaf shape index, and the rate of leaf turning was 1.03%. Group III varieties had larger single leaf area and smaller leaf weight, and the rate of leaf turning was up to 19.7%. There were four species in group II, with leaf area, specific leaf weight, leaf shape index and the rate of leaf turning all between those of group I and group III. After leaf turning, the net photosynthetic rate was significantly reduced, with an average decrease of 31.7%. The 100-grain weight of ‘Xindadou27’ with more grains decreased by 10.38%-22.4%, while the grain weight of ‘Jiyu60’ with fewer grains did not decrease. The upper leaves of soybean with higher rate of reversing leaf were more observed in leaves with larger single leaf area, smaller specific leaf weight and lower leaf shape index, this could reduce the net photosynthetic rate of leaves and thus cut down the same-node and single-node grain weight, and is not conducive to the high yield of soybean.

  Varieties and Pruning Methods: Effects on Cotton Yield and Fiber Quality Components Liu Guodong, Zhang Guizhi, Wang Aiyu, Zhao Hongjun, Zhao Jinhui, Zhang Xiaojie, Chen Lan 2020, 36 (33):  45-49.  DOI: 10.11924/j.issn.1000-6850.casb20191200927 Abstract + ( 580 )   HTML ( 12 )   PDF ( 1110KB )   ( 79 ) The main objective is to explore the effects of simplified cultivation on the yield and fiber quality characters of different cotton varieties. Using three different cotton varieties, the effects of normal pruning and non-pruning on cotton yield and fiber quality were studied under moderate plant density (52000 plants/hm2). The results showed that pruning measures had no obvious effects on boll weight, seed index, lint percentage, fiber length, micronaire value, uniformity index and fiber elongation, but significantly influenced the fiber strength (F=7.27). There was no significant interaction effect between pruning measures and varieties on yield components and fiber quality traits. Pruning significantly improved fiber strength of cotton variety under moderate plant density (52000 plants/hm2), but it had no significant effect on yield components (boll weight, seed index and lint percentage).

  Grain Amaranth Germplasm Resources in Guangxi: Identification and Evaluation of the Quality Characters Qin Chuxian, Qin Xinguang, Wang Feiyong, Xing Yihao, Wen Dongqiang 2020, 36 (33):  50-57.  DOI: 10.11924/j.issn.1000-6850.casb2020-0063 Abstract + ( 355 )   HTML ( 4 )   PDF ( 1177KB )   ( 76 ) The local germplasm resources of grain Amaranth in Guangxi are extremely rich and diverse. In order to provide a theoretical basis for breeding and production of grain Amaranth in Guangxi, 61 Guangxi grain Amaranth germplasm resources were used as materials, and 4 main quality characteristics of protein, starch, fat and selenium content of Amaranth were detected, analyzed and evaluated. The results showed that the average content of protein, starch, fat, selenium was 14.59%, 41.37%, 4.89%, 0.056 mg/kg, respectively. The variations of different traits were different, and the selenium content varied the most. Different relationships appeared among different characters. Protein was significantly and positively correlated with starch, while it was significantly and negatively correlated with fat. Fat was significantly and negatively correlated with starch, and it was significantly and negatively correlated with selenium. The quality characteristics comparison of the species from different sources showed that the average contents of protein, starch, fat and selenium of local seed resources in Baise City were significantly better than those of other cities in Guangxi. 4 multi-item high-quality resources, 7 two-item high-quality resources and 16 single-item high-quality resources (higher-protein, higher-starch, higher-fat or rich-selenium) were screened out.

  Metabolic Diversity of Microbial Communities in the Lower Reaches of the Yangtze River and the Influencing Factors Dong Xinxu, Fan Limin, Qiu Liping, Li Dandan, Dong Yuanyuan, Guo Nannan, Liu Xiangli, Qin Lu, Deng Ru, Chen Jiazhang 2020, 36 (33):  58-65.  DOI: 10.11924/j.issn.1000-6850.casb2020-0212 Abstract + ( 319 )   HTML ( 6 )   PDF ( 1298KB )   ( 65 ) The purpose is to analyze the metabolic diversity of microbial community and the impact of environmental factors on it, so as to provide reference for the improvement and restoration of ecological environment in the lower reaches of the Yangtze River. Biolog-ECO technology was used to analyze the microbial metabolic diversity in the lower reaches of the Yangtze River, and to explore the relationship between the changes of physical and chemical factors of water quality and the metabolic diversity of microbial communities. The results showed that except TP and TN, other water quality indexes in the lower reaches of the Yangtze River met the above class II standards; the overall metabolic capacity of the microbial community in Anqing and Nanjing river sections was relatively strong; the richness index of microbial community was the highest in Nanjing river section; the sequence of diversity index and evenness index from high to low was Anqing river section, Nanjing river section, Jingjiang river section, Tongling river section and Wuhu river section. The results of RDA analysis showed that TP and Pb were positively correlated with the six major carbon sources. Based on the analysis of water quality index and microbial metabolic diversity, the eutrophication degree of Anqing and Nanjing river section is relatively high, and TP and Pb can promote the metabolic diversity of microbial communities in the lower reaches of the Yangtze River.

  Trichoderma longibrachiatum T6: Strains Screening with Microwave Mutagenesis and Salt-tolerance Identification Cheng Kaiyong, Xu Bingliang, Wu Huayu, Chen Jinghuan, Zhang Shuwu 2020, 36 (33):  66-70.  DOI: 10.11924/j.issn.1000-6850.casb2020-0069 Abstract + ( 309 )   HTML ( 6 )   PDF ( 1311KB )   ( 48 ) The aim is to obtain the high-efficiency salt tolerant Trichoderma strains. The strain of Trichoderma longibrachiatum T6 was used as the original strain. Microwave mutagenesis and NaCl solution were used to simulate the salt stress condition. The colony growth rates, sporulation and mycelium dry weight were considered as indexes to screen the optimal salt tolerant strains. The results showed that the microwave mutation had a significant effect on the growth of Trichoderma longibrachiatum T6, and the effect was different with the different time of microwave mutation. The colony diameter, mycelium dry weight and sporulation of the mutant strain were significantly higher than those of the original strain at 60 s after microwave mutation. In addition, the colony growth rate of the mutant strain was significantly faster than other treatments, and showed stronger salt tolerance than the original strain. The colony growth rate was increased by 32.98% after 72 h of culture compared with the original strain. The high-yield and high-efficiency Trichoderma strains with salt tolerance were selected and obtained in this experiment, which laid a theoretical foundation for the development and application of multifunctional Trichoderma preparation in the future.

  Passivation and Remediation of Heavy Metals in Acid Soil with Different Passivators: A Research Progress Zhou Chunhai, Zhang Zhenqiang, Huang Zhihong, Xiao Xuanhu, Yang Yongkang, Zu Yanqun, Li Yuan 2020, 36 (33):  71-79.  DOI: 10.11924/j.issn.1000-6850.casb20191200928 Abstract + ( 530 )   HTML ( 12 )   PDF ( 1187KB )   ( 232 ) With its low passivation cost, high efficiency, rich variety and good prospects, chemical passivation repair technology is one of the important methods for soil heavy metal pollution restoration. As current environmental factors become more complex and soil acidification becomes more serious, heavy metals are common and diverse in acidic soil. Passivation and remediation can better response to changes of soil environment, and have a good prospect in the restoration of acid soil polluted by heavy metals. In this paper, the types, working principles and existing problems of single and composite passivators are summarized, and the research progress and current status of each type of passivators are reviewed. The single type of passivators is mainly divided into inorganic and organic. Among them, inorganic passivators are various and widely used, mainly passivated the heavy metals in the soil by adsorption, complexation, coprecipitation and so on. The composite passivators mainly include inorganic-inorganic, inorganic-organic and organic-organic, with the action principle similar to that of single-type passivators. Compared with composite passivators, the single-type passivators have a less significant result in the restoration of multi-metal contaminated soil. At the same time, the research progress of passivation and remediation of cadmium, lead and arsenic in acid soil is reviewed. The acid soil is mainly restored by adjusting soil pH. Based on this, the optimum passivator type and mechanism of the three heavy metals in acid soil are summarized, and the types of agents and their mechanism of action in heavy metal contaminated soil remediation are discussed, to provide references for the use of passivators to restore heavy metal contaminated soil.

  Effect of Oscillation Modes on Soil Phosphorus Fraction Xue Yanling, Chen Xinping, Zhang Wei 2020, 36 (33):  80-86.  DOI: 10.11924/j.issn.1000-6850.casb20191100831 Abstract + ( 627 )   HTML ( 10 )   PDF ( 1314KB )   ( 115 ) The study aims to evaluate the effect of different oscillation modes on soil P fractions, which contributes to understanding the determination conditions of P fractions. We used Tiessen method to reveal the influence of external conditions on the P fractions in soil treated with two oscillation modes. The results showed that the two modes of oscillation significantly affected the water-soluble P and residual P concentration. Compared to vertical placement, digestion with horizontal oscillation increased water-soluble P for 1.8 folds and decreased residual P concentration by 19 mg/kg. The two modes had no effect on total P, total organic P, total inorganic P and other P forms concentration. The distribution percentage of water-soluble P for horizontal oscillation increased by 6% compared to vertical placement. The water-soluble P and residual P concentration extracted by means of horizontal placement was higher than that by means of vertical oscillation.

  The Impact of Wetland Climate on Grain Production in Its Surrounding Areas -An Example of the Qixinghe Wetland National Nature Reserve in Heilongjiang Shi Hongyan, Yao Junying 2020, 36 (33):  87-94.  DOI: 10.11924/j.issn.1000-6850.casb20191100867 Abstract + ( 414 )   HTML ( 5 )   PDF ( 1431KB )   ( 69 ) The paper aims to study the impact of wetland climate on grain production and achieve the purpose of increasing production. Taking the Qixinghe Wetland National Nature Reserve as an example, and annual mean temperature, precipitation of wetland from 1961 to 2008, and total yield and yield per unit of its surrounding three villages and one farm as the data, we adopted trend analysis, grain production decomposition, and correlation coefficient calculation to analyze the change trend of grain production and the impact of wetland climate on grain production of its surrounding villages and farm. The results showed that the Wujiuqi farm was ranked the first in terms of total yield, yield per unit and increasing rate. Qingyuan was ranked the second, Jianshanzi was the third and Qixinghe was the last. It illustrated that the distance from the wetland had a certain impact on the grain production, the grain production of those four areas, especially the variance of grain production of Wujiuqi farm, had a rapid response to the change of wetland precipitation, grain production increased in the dry year with less precipitation, on the contrast, decreased in the wet year with more precipitation. Simultaneously, the temperature change also had a greater impact on the grain production of the current year, but less impact on the trend of grain production Yw increase or decrease, while the change of the precipitation had the domain impact on the Yw production changes. Therefore, it concluded that the wet and cold climate of the wetland was unfavorable to its surrounding grain production. The results of the experiment were consistent with the above conclusions, especially through the actual monitoring of climate and grain production in the recent 10 years. Taken together, measures need to be taken to control the flood, strengthen the farmland infrastructure construction, and develop ecological agriculture to ensure grain production under both drought and flood.

  Biosynthesis and Function of Flavonol in Plants: A Review Fan Yanting, Fan Ruonan, Zhang Hui, Li Baozhu 2020, 36 (33):  95-101.  DOI: 10.11924/j.issn.1000-6850.casb20191100863 Abstract + ( 854 )   HTML ( 17 )   PDF ( 1242KB )   ( 262 ) The aim is to provide a theoretical basis for improving the biosynthesis of flavonol in plant, the growth and development of plant and crop resistance. In this paper, the basic biosynthesis of flavonol was clarified, the key enzymes of flavonols and their functions were concluded, the regulation of flavonols in the transcription level of the biosynthesis was reviewed, and the biological functions of flavonols in plant were also summarized, including the regulating action of flavonols in the growth and development of plant, the abiotic-stress regulation of plant and its functions in plant defense response. At last, the research directions of flavonols in plant were proposed.

  Plant Lipoxygenases: Advance of the Function in Stress Response Dong Chunyan, Liang Weihong, Cheng Hui, Yu Dongming, Lv Dong, Sun Yanfeng, Miao Chen 2020, 36 (33):  102-107.  DOI: 10.11924/j.issn.1000-6850.casb20191100870 Abstract + ( 287 )   HTML ( 6 )   PDF ( 1177KB )   ( 73 ) Lipoxygenase (LOX) catalyzes the oxygenation of polyunsaturated fatty acids to further produce oxylipins via the enzymatic or non-enzymatic pathway, thereby participating in the processes of regulation of growth and development, and stress response. To deeply understand the function and mechanism of LOX for plants under stress conditions, this study summarizes recent research progress on the functions of LOX in biotic and abiotic stress responses in such model plants and crops as Arabidopsis thaliana and corn; reveals functions of LOX family members in response to abiotic (e.g., mechanical wounding, drought, and salt stress) and biotic stress (e.g., Verticillium wilt, Aspergillus flavus infection, nematode invasion, and aphid bite); analyzes how these members share out the work and cooperate with one another, and even antagonize each other during the stress response, along with the “cross-talk” between 13-LOX pathway and 9-LOX pathway; and points out that LOX activity and regulation of transcriptional expression are important parts of regulation of oxylipin synthesis and stress responses, as well as potential targets for genetic improvement of crops. The expression regulation and mechanism of LOX, and the identification and detailed study of a series of downstream metabolites in the lipoxygenase pathway will be research focuses in this field in the future.

  The High-yield Glucoamylase Strains in Daqu: Screening and Optimization of Enzyme Production Liu Yanbo, Wang Xiaohang, Zhao Zhijun, Wang Huihui, Xing Xingyue, Pan Chunmei, Sun Xiyu 2020, 36 (33):  108-113.  DOI: 10.11924/j.issn.1000-6850.casb20191100839 Abstract + ( 405 )   HTML ( 8 )   PDF ( 1395KB )   ( 66 ) To obtain the strains with high-production glucoamylase and strengthen the production of Daqu, with Zhang Gong Liquor Daqu as test material, a strain WD11 with high-production glucoamylase was screened initially with the transparent circle method and re-screened through measuring enzyme activity method. The initial enzyme activity was 101 U/mL, and the strain was preliminarily determined and belonged to bacillus genus by 16S rDNA sequence homology analysis. Based on the above, the strain was also studied by the physiological and biochemical characteristics analysis. The results showed that methyl red test, V.P test, nitrate and ornithine reaction presented positive, lysine showed negative. Therefore, WD11 strain was identified as Bacillus amyloliquefaciens. After that, the conditions of enzyme production were optimized by orthogonal experiment. The results showed that, on the solid fermentation medium, with the sorghum flour as the optimal carbon sources (mass fraction 2%), peptone as the optimal nitrogen source (mass fraction 4%), and the inoculated quantity of 6%, the saccharifying enzyme activity was up to 160 U/mL, which was1.6 times that of the initial enzyme activity. The strain is expected to increase the liquor yield.

  Maintain System of Loose Embryonic Callus of Green Bean: Induction Method Gu Yu, Liu Yanjun, Han Qihou, Yu Hailong, Sun Deling 2020, 36 (33):  114-119.  DOI: 10.11924/j.issn.1000-6850.casb20191200939 Abstract + ( 342 )   HTML ( 4 )   PDF ( 1614KB )   ( 55 ) The research aims to provide basic materials for the inducing regeneration of seedlings, and lay a foundation for the breeding of green bean (Phaseolus vulgaris L.). Using green bean asexual cells (stem, leaf, cotyledon, etc.) as experiment materials, the loose callus cell clusters which were mainly based on globular cells with dense cytoplasm were obtained by screening phytohormones and their optimum combination. Finally, the “Induction Medium I” (MS +2,4-D 1 mg/L+ sucrose 30 g/L) which could induce asexual cells to produce common callus was screened. Moreover, we obtained the “Induction Medium II” (MS+6-BA 0.25 mg/L+2,4-D 0.5 mg/L+ AgNO310 mg/L) which could induce and maintain the loose embryogenic callus. In this research, we screened a series of media which could induce asexual cells to loose embryogenic cell clusters and maintain embryogenic cell proliferation, solved the problem of callus darkening during induction, and established a new method to induce loose embryogenic callus.

  Cenchrus pauciflorus in Khorchin: The Screening of Chemical Control Herbicide Yang Xiaosong, Wen Chao, Jia Weixing, Jiang Lan, Si Riguleng, Zhang Jun, Chu Jingfen, Yang Shuai, Shan Yumei, Xie Yourong, Yu Lan 2020, 36 (33):  120-126.  DOI: 10.11924/j.issn.1000-6850.casb20200300197 Abstract + ( 439 )   HTML ( 6 )   PDF ( 1340KB )   ( 157 ) In the invasion area of Cenchrus pauciflorus in Khorchin, in order to select the suitable chemical control herbicide in Khorchin area, different chemical control herbicides and combinations were used as test materials, the method combining field investigation with lab analysis was adopted to obtain the experimental data of the effects of different herbicide treatments and spraying time on control, relative control and vegetation coverage. The results showed the effects were significant. The optimal insecticide for the control and relative control on Cenchrus pauciflorus was 41% Glyphosate-Isopropylammonium, followed by 10% quizalofop-p-ethyl, 10% quizalofop-p-ethyl mixed with 90% acetochlor, 12.5% sethoxydim and 10.8% haloxytop-r-methyl. However, in view of vegetation coverage, the suitable herbicides were 10% quizalofop-p-ethyl, 12.5% sethoxydim, 5% imazethapyr, 23.5% sethoxydim and 10.8% haloxytop-r-methyl. In conclusion, the appropriate chemical control herbicides include 10% quizalofop-p-ethyl, 12.5% sethoxydim and 10.8% haloxytop-r-methyl in Khorchin, and only spraying once could obtain better effects.

  Antibacterial Mechanism of Active Substances from Laminaria japonica Petroleum Ether Phase Against Clavibacter michiganensis subsp. michiganensis Du Beibei, Xie Shulian, Wang Mengliang, Cai Jin 2020, 36 (33):  127-133.  DOI: 10.11924/j.issn.1000-6850.casb20191200930 Abstract + ( 453 )   HTML ( 6 )   PDF ( 1744KB )   ( 57 ) The aim is to clarify the mechanism of Laminaria japonica active substances inhibiting Clavibacter michiganensis subsp. michiganensis, and to provide a theoretical basis for the development of green antibacterial agents. Antibacterial components of L. japonica were detected by the tracking method. The study of the mechanism was carried out from multiple perspectives, including electron microscopy (SEM), membrane potential, reactive oxygen species, soluble proteins, and cell cycle. The results showed that the petroleum ether phase of L. japonica had the best bacteriostatic effect (P<0.05), and the diameter of inhibitory zone was 26.00 mm. The study of mechanism showed that cell morphology of C. michiganensis subsp. michiganensis changed significantly, the potential of membrane decreased by 17.49%-56.60%, the content of intracellular active oxygen increased by 1.19-3.98 times, intracellular protein content reduced significantly (P<0.05), and the proportion of C. michiganensis subsp. michiganensis in the cell division stage reduced significantly. The results indicate that active substances of L. japonica mainly act on the cell membrane, causing accumulation of free radicals, blocking normal passage, and ultimately achieving the effect of killing bacteria.

  Genetic Parameters of Growth Traits of Carassius auratus var. pengzesis: Estimation Xu Jingen, Cao Lie, Jin Wu, He Yijin, Bing Xuwen, Wang Jianmin 2020, 36 (33):  134-137.  DOI: 10.11924/j.issn.1000-6850.casb20191200929 Abstract + ( 470 )   HTML ( 7 )   PDF ( 1162KB )   ( 58 ) To study the genetic rules of growth traits of Carassius auratus var. pengzesis, and make a breeding plan of C. auratus var. pengzesis, 23 full sibs families from Jiujiang Fisheries Research Institute were used as materials, and the raw data of growth traits (total length, body length, body height, body width, body weight) of about a-whole-year individuals were detected, and the genetic analysis was conducted with animal model. The results showed that the heritability of the above five traits was 0.64±0.17, 0.51±0.16, 0.79±0.18, 0.57±0.16, 0.65±0.17, respectively. The heritability of these traits was all at a high level. The phenotypic correlation (0.79 to 0.94) and the genetic correlation (0.95 to 1.00) between these five traits were all relatively high. All the results show that individual selection or individual selection combining with family selection will get the ideal genetic gain, and if we continue to select one of these traits, the other traits will be improved in the same time.

  Probiotics and Antibiotic: Effects on Non-specific Immune and Intestinal Microbe in Litopenaeus vannamei Fan Ying, Wang Xiaolu, Wang Youhong, Liu Hongjun, Diao Jing, Li Le, Wang Shuxian, Yu Xiaoqing, Gai Chunlei, Ye Haibin, Xu La, Mu Chuanchuan, Ma Xingkun 2020, 36 (33):  138-146.  DOI: 10.11924/j.issn.1000-6850.casb20191100891 Abstract + ( 291 )   HTML ( 8 )   PDF ( 1735KB )   ( 61 ) This study is conducted to investigate the effects of probiotics and antibiotic on non-specific immune and intestinal microbiome of Litopenaeus vannamei. L. vannamei with an average body weight of (2.2 ±0.1) g were randomly divided into three groups, 3 repeats in each group and 100 shrimp in each repeat. The control group was fed with basic diet (C0), the experimental groups were fed with 0.5% probiotic preparation (E1) and 0.5% antibiotic oxytetracycline (E2), respectively. The non-specific immune function of serum and composition of intestinal microbiome in L. vannamei were detected by biochemistry and high-throughput sequencing methods. The experiment lasted 14 days. The results showed that the activities of ACP and POD in the serum of E1 were significantly increased (P<0.05), the activities of GOT and GPT were reduced. But these effects in E2 antibiotic group were opposite. Antibiotics oxytetracycline enhanced the activity of T-AOC in the serum of L. vannamei significantly, but the effect was short, the activity dropped sharply when time went on. Probiotics had improved significantly activities of digestive enzymes such as amylase, lipase, trypsin in the intestine of L. vannamei (P<0.05), and those in antibiotic group were lower. And probiotics could optimize the composition of intestinal microbiome, the abundances of Proteobacteria, Actinobacteria, Verrucomicrobia and Candidatus Saccharibacteria were increased in E1 group, while the abundances of Actinobacteria, Candidatus Saccharibacteria and Bacteroidetes were increased slightly in E2 group. Therefore, 0.5% probiotics has positive effects on non-specific immune function and intestinal microbiome of L. vannamei, and the effects are better than those of oxytetracycline, which is suitable for using as an immunostimulants and feed-additives in the aquaculture of L. vannamei.

  Aeromonas caviae from Macrobrachium rosenbergii: Isolation and Identification Guo Ying, Zhou Miao, Li Yanhe, Wang Weimin 2020, 36 (33):  147-153.  DOI: 10.11924/j.issn.1000-6850.casb20191200924 Abstract + ( 335 )   HTML ( 4 )   PDF ( 1947KB )   ( 50 ) To identify the mortality cause of Macrobrachium rosenbergii, the strain with growth advantage was isolated from the dying M. rosenbergii, and its hemolysis, gram staining, morphological characteristics, physiology and biochemistry were determined. The results showed that, the isolated strain was a gram-negative while oxidase, l-arabinose, glucose (acid), peptone water, arginine dihydrolase, gelatin, and phenylalanine were positive. The 16S rRNA gene of this isolate was sequenced and the phylogenetic tree was constructed. The isolated strain was clustered with Aeromonas caviae and had a close genetic relationship. The isolated strain was confirmed as Aeromonas caviae (Accession number MN736843) based on its biochemical characters and 16S rRNA sequence analysis. The artificial infection experiment with the injection method confirmed that the isolated strain was highly pathogenetic to M. rosenbergii. The results of drug susceptibility tests revealed that the strain was highly sensitive to ceftriaxone, chloramphenicol, florfenicol, tetracycline and doxycycline; it was moderately sensitivity to kanamycin and resistant to ciprofloxacin, norfloxacin, erythromycin, azithromycin, novobiocin, streptomycin, compound sulfamethoxazole and rifampicin. This study provides a reference and theoretical basis for the pathogen identification, drug diagnosis and treatment of Aeromonas cavia in M. rosenbergii.

  Fixative Fluid and Hematoxylin: Effects on Staining Animal Reproductive Organs Mao Caiqin, Liu Miaomiao, Fu Dehai, Wang Xinrong 2020, 36 (33):  154-158.  DOI: 10.11924/j.issn.1000-6850.casb20191100825 Abstract + ( 555 )   HTML ( 5 )   PDF ( 1598KB )   ( 87 ) To provide a basis for histological staining of different animal reproductive organs, the organs including ovary, testicle, uterine horn and epididymis were collected from small tailed han sheep, Tibetan sheep and yak after slaughtering as test materials, and paraffin sections and hematoxylin-eosin (H-E) staining methods were adopted to observe and compare the dyeing effects of reproductive organs with different fixation solution and hematoxylin staining time. Results showed that the fixation effect with 4% paraformaldehyde for 36 h was similar to that with AAF for 48 h, but the dyeing effect after fixing with AAF showed a distinct advantage, meanwhile the dyeing time after fixing with 4% paraformaldehyde was shortened by 1/2. The study found that, by fixing reproductive organs with different fixed fluids and adjusting the dyeing time of hematoxylin, fixation effects with 4% paraformaldehyde and AAF fixed liquid were different respectively. The time of both fixing the tissues with AAF fixed liquid and dyeing on them with hematoxylin were longer than that of the fixing time on tissue with 4% paraformaldehyde, and the dyeing effect with AAF fixed liquid demonstrated a distinct advantage.

  Sustainable Innovation and Practice Based on Rural Ecological Livable Construction Wang Jiuchen, Wu Xiaochun, Liu Jie, Zhang Yanping, Yu Qiuyue, Wang Su, Wang Quanhui 2020, 36 (33):  159-164.  DOI: 10.11924/j.issn.1000-6850.casb2020-0590 Abstract + ( 484 )   HTML ( 4 )   PDF ( 1234KB )   ( 71 ) Ecological livability is a key link in the implementation of the rural revitalization strategy, and an important foundation and guarantee for improving the ecological well-being of farmers. It requires continuous enrichment and development on the basis of past practices. This article summarizes the practices and innovations achieved in the implementation of the Global Environment Facility project-"Market Transformation of Energy Efficient Bricks and Rural Buildings", and combined with the vision and expected results of the "China Zero Carbon Village and Town Construction Promotion" project, puts forward suggestions on the construction of zero-carbon villages and distributed energy system in rural areas under the rural ecological livable construction, including strengthening policy planning and guidance to improve the design of rural clean energy development system; strengthening infrastructure construction to build a rural distributed renewable energy system; strengthening urban and rural coordination to enhance the interconnection of urban and rural energy; strengthening the development of industrial integration to coordinately solve environmental problems in the rural ecologically livable construction; strengthening innovation support to promote the high-quality development of rural energy. These measures will accelerate the sustainable development of rural ecological livability and build a beautiful new countryside.