Current issue

• 2022 Vol.38 No.30 Published:25 October 2022

  Effects of High Temperature at Booting Stage on Physiological Characteristics and Yield Traits of Rice WANG Ming, WU Hui, SUN Xiaocheng, JIANG Xiaojun, LEI Gannong, TAO Wei, BAI Changqing, XU Min 2022, 38 (30):  1-5.  DOI: 10.11924/j.issn.1000-6850.casb2021-1054 Abstract + ( 251 )   HTML ( 7 )   PDF ( 1209KB )   ( 80 ) To explore the effects of high temperature on physiological and biochemical characteristics and yield traits of rice at booting stage, and to provide a theoretical basis for reducing the harm of high temperature to rice at booting stage during rice growth and development, ‘Taiyou 553’ and ‘Longjingyou 1212’ were taken as materials, the effects of different temperatures at booting stage on physiological characteristics and yield traits of rice were studied by using artificial climate chamber of 29℃, 32℃, 35℃ and 38℃ for 7 days at IV-VI stage of young panicle differentiation, and natural temperature condition in field at the same time was used as control (CK, average temperature of 30.6℃). Compared with the control, 38℃ treatment significantly decreased the fertile pollen number and fertility rate of ‘Taiyou 553’ and ‘Longjingyou 1212’, and the fertility rate decreased by 60.2 % and 54.7 %, respectively. With the increase of temperature, the content of proline and malonaldehyde (MDA) of the two varieties showed an upward trend, which were significantly higher than those of CK and other treatments at 38℃. The peroxidase (POD) activity showed a trend of first increase and then decrease. High temperature treatment significantly reduced seed setting rate, 1000-grain weight and the yield of the two varieties, and had little effect on effective panicles. High temperature at booting stage of rice can significantly reduce the number of fertile pollen and fertility rate, and affect the change of physiological indexes of young panicles, resulting in the decrease of seed setting rate and yield. Different varieties have different responses to high temperature damage.

  Ludao and Cultivated Rice: Genetic Diversity Analysis and Germinability Evaluation Under Submerged Condition by SNP Markers SUN Zhiguang, PAN Gen, CHEN Tingmu, LI Jingfang, ZHAO Lijun, CHI Ming, XU Bo, XING Yungao, LIU Jinbo, LIU Xiaomin, GE Gaoning, XU Jintao, WANG Baoxiang, XU Dayong 2022, 38 (30):  6-13.  DOI: 10.11924/j.issn.1000-6850.casb2021-1213 Abstract + ( 188 )   HTML ( 3 )   PDF ( 3521KB )   ( 28 ) The research aims at analyzing genetic diversity between Ludao and cultivated rice, and providing molecular reference for the protection, exploitation and utilization of Ludao. Forty-eight germplasm resources, including Ludao, were selected as experimental materials. A 1K mGPS SNP chip was used for genotyping. Cluster analysis based on the unweighted pair group method of mathematical averages (UPGMA) was performed using PowerMaker 3.25 software. The results showed that a total of 9570 alleles were detected using 4785 pairs of polymorphic SNP markers. The mean number of alleles detected for each locus was 2.0. The polymorphism information content (PIC) ranged from 0.0400 to 0.5957, with a mean value of 0.3123. The gene diversity index (GD) ranged from 0.0408 to 0.6667, with a mean value of 0.3839. UPMGA cluster analysis separated the 48 accessions into two subgroups (indica and japonica), and Ludao belonged to the japonica subgroup. The evaluation of anaerobic germination tolerance showed that Ludao displayed high tolerance to hypoxia during germination, which could provide an important germplasm base for breeding new cultivars suitable for direct seeding. The results presented here also provide a theoretical basis for exploiting and utilizing the elite genes of Ludao.

  Quality Traits of Sweet Corn: Major Gene +Polygene Genetic Analysis JIANG Feng, YAN Yan, MAI Jiaqi, LIANG Rilang, ZHOU Jiecheng, LI Pingyao, LIU Pengfei 2022, 38 (30):  14-20.  DOI: 10.11924/j.issn.1000-6850.casb2021-1155 Abstract + ( 225 )   HTML ( 3 )   PDF ( 1713KB )   ( 30 ) The major gene + polygene genetic analysis of quality traits in sweet corn was carried out to provide a theoretical basis for quality improvement of sweet corn. In this experiment, the hybrid combination T77 (high-value parent) ×T15 (low-value parent) was prepared from sweet corn inbred lines with significantly different fructose content, dietary fiber content and vitamin C content. Three quality traits, namely fructose content, dietary fiber content and vitamin C content, were measured in the F2 generation population of this combination. The optimal genetic model and related genetic parameters of the three traits were analyzed by using the major gene + polygene genetic model. The experiment showed that the optimal genetic model for fructose content was A-1, which was a mixed one additive-dominant major gene genetic model, and the heritability of major gene was 76.4%. The optimal models for dietary fiber content and vitamin C content were both B-1, which indicated that these two traits conformed to the genetic model of two additive-dominant-epistatic major genes, and the heritability of major genes was 63.6% and 64.7%, respectively. In breeding practice, the genetic improvement and selection of fructose content, dietary fiber content and vitamin C content of sweet corn could be carried out in the early generation, and at the same time, certain environmental factors should be highlighted, and the method of polymerization backcross or recurrent selection should be adopted to accumulate minor genes to improve breeding efficiency.

  Twenty-four Sweet Sorghum Materials: Comprehensive Analysis of Main Agronomic Traits and Biological Yield LUO Wei, ZHOU Wei, WANG Zhenguo, LI Yan, YU Wenhao, YANG Zhiqiang, YU Zhonghao, LI Ziwen, ZHOU Yaxing 2022, 38 (30):  21-28.  DOI: 10.11924/j.issn.1000-6850.casb2022-0019 Abstract + ( 313 )   HTML ( 2 )   PDF ( 1511KB )   ( 58 ) The aims are to investigate the relationship between major agronomic traits and biological yield of sweet sorghum, select sweet sorghum materials with excellent overall performance, and provide a theoretical basis for sweet sorghum breeding in the future. The main agronomic traits and biological yield of 24 sweet sorghum cross combinations were subjected to grey correlation degree analysis, correlation analysis, path analysis and principal component analysis. The results showed that the variation coefficient of main spike length and grain number per spike was large; and the grey correlation degree results showed that the correlation degree between sugar brix and biological yield was the largest. Correlation analysis showed that plant height and stalk length, main spike length and 1000-grain weight had highly significantly positive correlations. The path analysis results showed that the direct effects of main panicle length, stem length, 1000-grain weight, juice extraction rate and sugar brix on the biological yield of sweet sorghum were positive. Principal component analysis showed that the seven traits of plant height, stalk length, grain number per spike, sugar brix, juice extraction rate, main spike length, and biological yield were more influential to the overall performance of the varieties. Therefore, in the selection of sweet sorghum hybrids, we should focus on sugar brix, stem thickness and stalk length, while take into account the height of the plant, number of grains per spike, length of the main spike, juice extraction rate, and 1000-grain weight.

  Sugar Accumulation Characteristics and Sucrose Metabolism Enzyme Activities of Peanut During Seed Development LIU Yonghui, SHEN Yi, SHEN Yue, LIANG Man, CHEN Zhide 2022, 38 (30):  29-34.  DOI: 10.11924/j.issn.1000-6850.casb2021-0578 Abstract + ( 223 )   HTML ( 2 )   PDF ( 2824KB )   ( 46 ) The sugar content of peanut seed is closely related to its edible quality and processing characteristics. In order to clarify the characteristics of sugar accumulation and the relationship between sucrose content and sucrose metabolism related enzyme activities during seed development, three peanut varieties with different sucrose contents were used as the materials, the contents of total soluble sugar, sucrose, fructose, glucose and the activities of key enzymes in sucrose metabolism, such as sucrose phosphate synthase (SPS), sucrose synthase (SS), neutral invertase (NI) and acid invertase (SAI), were compared at different stages of seed development. The results showed that the changes of sugar component content and enzyme activity in different varieties during seed development were similar. SS activity value was the highest in both synthetic direction and decomposition direction. The correlation analysis showed that the sucrose content at the late development stage was significantly negatively correlated with NI and significantly positively correlated with SPS. It is speculated that the sucrose content can be increased by regulating the activities of NI and SPS during the seed maturing period.

  Genetic Diversity Analysis of Monogerm Cytoplasmic Male Sterile Lines and Maintainer Lines of Sugar Beet ZHAO Yaru, PI Zhi, LIU Rui, MA Yuyan, WU Zedong 2022, 38 (30):  35-40.  DOI: 10.11924/j.issn.1000-6850.casb2021-1062 Abstract + ( 219 )   HTML ( 2 )   PDF ( 1540KB )   ( 20 ) 35 pairs of SSR primers were used to analyze the genetic diversity of 40 pairs of monogerm cytoplasmic male sterile lines and maintainer lines of sugar beet. The results showed that: the number of bands amplified by each pair of primers ranged from 2 and 12, and the average value of effective number of alleles (Ne), Shannon’s information index (I) and Nei’s gene diversity index (H) was 2.306, 0.891 and 0.519 respectively. The UPGMA method was used for cluster analysis and genetic distance calculation. The cluster analysis results showed that tested material 22 had a far genetic distance from other materials, which indicated a distant genetic relationship, and the material belonged to a separate group. The rest of the tested sugar beet lines could be divided into four groups. A total of 14 pairs of monogerm cytoplasmic male sterile lines and maintainer lines of sugar beet were completely polymerized together, indicating that after backcrossing, the nuclear genomes of male sterile lines and maintainer lines were almost identical with high purity, which could be directly used in sugar beet breeding in the future. The other 26 pairs of low purity, large genetic distance, still need to continue to backcross to homozygous. The maximum genetic distance of the 80 tested materials was 0.462 and the minimum was 0.120. The genetic distances of the sterile lines in the 14 pairs of primary mating groups were different. In the future, sugar beet cytoplasmic male sterile lines with large genetic distance from the 14 pairs could be selected with their heterogeneous maintainer lines to prepare binary male sterile lines for female parents in hybrids. The study can promote new sugar beet variety breeding and effectively improve the breeding efficiency.

  Effects of Sowing Date on Yield, Quality and Agronomic Characters of Flax (Linum usitatissimum L.) CUI Yanqin, GUO Yuanzhang, LI Sida, HOU Shaofeng, ZHANG Lili, QIAO Haiming, XU Guizhen 2022, 38 (30):  41-50.  DOI: 10.11924/j.issn.1000-6850.casb2021-1096 Abstract + ( 246 )   HTML ( 5 )   PDF ( 4671KB )   ( 29 ) To further clarify the effects of sowing date on yield, quality and agronomic characters of flax (Linum usitatissimum L.), 5 flax varieties were selected and 4 sowing dates were set to investigate 15 characters related to yield, quality and agronomy. The results showed that: (1) with the delay of the sowing date, the yield per unit area of the 5 flax varieties decreased significantly, and the nutrients in grains also decreased, except that the content of palmitic acid remained stable or increased slightly; (2) the yield per unit area of ‘Baxuan 16’ and ‘Xuan 3’ was higher than that of other varieties at the 4 sowing dates, among them, ‘Baxuan 16’ had the highest yield per unit area and was rich in linolenic acid, linoleic acid, protein, lignans, etc., with high oil content, and it was the best one among the tested varieties. This study further quantified the effects of sowing date on flax yield, quality and agronomic characters. Early sowing was conducive to obtaining high yield and high quality, and ‘Baxuan 16’ was selected as the best variety. The study can provide a theoretical basis for matching good varieties and practices in flax production.

  Characteristics and Distribution of Walnut Seed Resources in Bashan Mountains XU Yongjie, HAN Huabai, PEI Dong 2022, 38 (30):  51-55.  DOI: 10.11924/j.issn.1000-6850.casb2021-1060 Abstract + ( 200 )   HTML ( 3 )   PDF ( 1182KB )   ( 17 ) In order to find out the characteristics and distribution of walnut seed resources in Bashan Mountains, we visited 17 key counties of walnut production from the west to the east along the Bashan Mountains. The results show that: (1) there is a large amount of walnut resources in Bashan Mountains, and walnut trees and fruit characters have an abundant variation, which contains valuable walnut breeding materials; (2) the vertical distribution range of walnut in Bashan Mountains is 250-1800 m, which is consistent with the mountain terrain in each region, showing a trend of distribution along the mountains; (3) there are three types of walnut cultivation, among which, J. regia and J. sigillata are the main distribution species, J. regia is widely distributed over Bashan Mountains, while J. sigillata is mainly distributed in the southeast of Bashan Mountains with an altitude of 200-600 m; the intermediate type between these two species is the second distributed species, which is concentrated in the middle range of Bashan Mountains. In conclusion, walnut in Bashan Mountains contains important genotypes, which may play an important role in studying the genetic differentiation of Juglans in China.

  Diversity Analysis of Leaf Phenotypic Characters of Musa spp. Germplasms ZHAO Lijuan, ZHI Jiazeng, ZHANG Jianchun, DU Hao, ZHOU Jinsong, LIU Xuemin, ZHANG Rongqin 2022, 38 (30):  56-64.  DOI: 10.11924/j.issn.1000-6850.casb2022-0073 Abstract + ( 237 )   HTML ( 3 )   PDF ( 1745KB )   ( 38 ) In order to understand the diversity of leaf phenotypic characters of Musa spp. (banana) germplasm resources and improve the protection and utilization of excellent banana germplasms in Yunnan, 18 leaf phenotypic characters of 49 Musa spp. germplasms were observed and described, and the data were analyzed by variation analysis, Shannon-weaver diversity index analysis, correlation analysis, principal component analysis and cluster analysis. The genetic diversity index of leaf phenotypic quantitative characters was higher than that of qualitative characters. The variation degree of quantitative characters was high, and the differences among Musa spp. germplasms were obvious. The correlation analysis showed that 31 pairs of characters had extremely significant correlation (P<0.01), and 18 pairs had significant correlation (P<0.05). The leaf phenotypic characters were closely related to each other. The principal component analysis showed that the 18 characters were transformed into 6 principal components, and the cumulative contribution rate was 78.80%, which reflected most information of leaf phenotypic characters of banana germplasms. Cluster analysis was conducted on the 49 banana germplasms. The germplasms were divided into four groups at the European genetic distance of 10, which were M. acuminate, M. paradisiaca and M. sapientum, wild Musa, and M. cauendisihii. The leaf orientation, shape of leaf base edge, color of petiole base plaques and petiole groove shape were the main characters to distinguish different groups. The leaf phenotypic diversity of Musa spp. germplasm resources is rich, and the 11 characters obtained by analysis and screening are the key indexes for the analysis of leaf phenotypic diversity of Musa spp. germplasm resources.

  Effects of East and West Ridge Cluster Cultivation on the Growth of Autumn and Winter Tomato and the Temperature and Light Environment in Solar Greenhouse TANG Jianing, CHEN Qifeng, YU Chaoge, FU Hongdan, LIU Changchun, ZHENG Shurong, SONG Weili, SUN Zhouping 2022, 38 (30):  65-71.  DOI: 10.11924/j.issn.1000-6850.casb2021-1166 Abstract + ( 252 )   HTML ( 2 )   PDF ( 3607KB )   ( 22 ) In order to solve the shading problem of east and west ridge cultivation in solar greenhouse in Beipiao of Liaoning, the effects of east and west large ridge cluster cultivation, large ridge double row cultivation and large ridge single row cultivation on tomato growth, canopy environment, yield and quality were studied. The north and south ridge cultivation was taken as the control. The results showed that there was no significant difference in plant height, stem diameter and aboveground dry matter accumulation among the four cultivation methods. In terms of environment, the large ridge cluster cultivation had the best canopy light environment and the horizontal light transmittance, and the radiation quantity between ridges was better than that of large ridge double row cultivation and large ridge single row cultivation. The canopy air temperature and soil temperature of the large ridge cluster cultivation were higher than those in north and south ridge cultivation and the canopy air relative humidity was lower. The yield of large ridge cluster cultivation was 47577 kg/hm2, which was significantly higher than that of the other three cultivation methods. Under the same planting density, the per unit area yield of the large ridge cluster cultivation was 12.93% higher than that under north and south ridge cultivation. In terms of quality, there was no significant difference of the sugar-acid ratio and the content of soluble sugar, organic acid and vitamin C among the four cultivation methods. In conclusion, the large ridge cluster cultivation is superior to traditional cultivation in light environment, and yield and quality of tomato, and the east and west large ridge cluster cultivation with 95 cm row spacing can be popularized in high latitude areas.

  Effects of Reducing Fertilizer Application on Growth, Yield and Substrate Environment of Brassica pekinensis Lour. Rupr. Under Water-Fertilizer Integration CHEN Zhedong, HOU Huijing, XU Xiao, WANG Qiang, ZHOU Mingyao 2022, 38 (30):  72-76.  DOI: 10.11924/j.issn.1000-6850.casb2021-1091 Abstract + ( 177 )   HTML ( 3 )   PDF ( 1707KB )   ( 21 ) To provide a theoretical basis for water-fertilizer integration in the greenhouse cultivation of B. pekinensis, this study set up four treatments: conventional fertilization (CK), and conventional topdressing amount (T1), 33.4% reduction of topdressing fertilizer (T2) and 66.7% reduction of topdressing fertilize (T3) under drip irrigation and fertilizer integration, and used potted substrate cultivation method to explore the effects of reducing the amount of topdressing on growth, yield, partial factor productivity of fertilizer (PFP) and substrate environment. The results showed that compared with CK, T1, T2 and T3 increased the yield by 51.61%, 44.15% and 29.28%, respectively, and the yield increase was significant. PFP in T3 treatment group was the highest, reaching 139.55 kg/kg, which was 2.4 times that of CK. The water-fertilizer integration is beneficial to increasing the number of leaves, leaf divergence and the maximum leaf area, and the treatments under water-fertilizer integration after topdressing have a faster effect. High water-fertilizer can significantly increase the alkali-hydrolyzable nitrogen content of the substrate, but at the same time it will cause the concentration of soluble ions in the substrate to be too high. In conclusion, the application of water-fertilizer integration can effectively improve the yield, growth index and PFP of B. pekinensis. It is recommended that 33.4% reduction in topdressing fertilizer application can not only significantly improve the yield and PFP but also be less likely to cause salt damage.

  Rational Nitrogen Fertilizer Application Rates Improving the Bacterial Community Structure and Physicochemical Properties of Winter Wheat Tillage Soil LIU Qi, GAO Zhiqiang, YANG Zhenping, QIAO Yuejing 2022, 38 (30):  77-84.  DOI: 10.11924/j.issn.1000-6850.casb2021-1058 Abstract + ( 212 )   HTML ( 4 )   PDF ( 2714KB )   ( 70 ) Through the study of soil bacterial community diversity and soil physicochemical properties of winter wheat under different nitrogen application rates in the Loess Plateau, the changes of soil bacterial community structure under different nitrogen application rates are revealed, which can provide a basis for scientific fertilization and sustainable soil ecosystem. The experiment set treatments of 5 different nitrogen rates, which were 0 (N0), 90 (N6), 180 (N12), 240 (N16) and 300 (N20) kg/hm2, and N0 treatment was used as a control. Using the high-throughput sequencing method, the effects of different nitrogen application rates on soil bacterial community structure and physicochemical properties were studied. The results showed that the increase of nitrogen fertilizer significantly increased the soil water-stable aggregate mean weight diameter (MWD) (P<0.05). With the increase of nitrogen application rate, soil enzyme activity first increased and then decreased, and the soil enzyme activity was the highest under N12 treatment. The nitrogen application rates had a significant effect on the soil bacterial diversity index. The 16S rRNA gene copy number of soil bacteria in different nitrogen application treatments was 6.47×1010 to 15.18×1010, which reached the maximum in N12 treatment. At the level of the phylum, Proteobacteria, Actinobacteria, Acidobacteria, Chloroflexi and Gemmatimonadetes were the dominant in the 15 samples; N12 treatment significantly increased the relative abundance of Proteobacteria and Nitrospira, and the relative abundance of Acidobacteria was the lowest in N12 treatment. Principal component analysis results showed that N12 treatment was far away from other treatments. Redundancy analysis showed that soil physicochemical properties and soil enzymes were closely related to bacterial communities. Therefore, the nitrogen application rate could significantly affect the soil bacterial community structure and physicochemical properties. When the nitrogen application rate is 180 kg/hm2, it is beneficial to increasing the bacterial community diversity and improving the soil structure.

  Effects on Ammonium Nitrogen and Nitrate Nitrogen in Rhizosphere Soil of Highland Barley Under Different Fertilization Treatments ZHOU Lanlan, LIU Meijin, LI Mingjun, XU Dongli, WANG Guoping, GUO Jianwei, HU Zaiqing, ZHANG Zhongguang, LI Fengqing, SANG Anping, ZHANG Tao, XIAO Yunshan, YAN Chunmei 2022, 38 (30):  85-90.  DOI: 10.11924/j.issn.1000-6850.casb2021-1063 Abstract + ( 207 )   HTML ( 2 )   PDF ( 1687KB )   ( 25 ) The experiment took the rhizosphere soil of the new highland barley variety ‘Huangqing No.2’ in different growth stages as material, comparatively measured the contents of ammonium nitrogen and nitrate nitrogen in different soil layers under different fertilization treatments and studied the dynamic change rule of ammonium nitrogen and nitrate nitrogen in soil. The results showed that the content of ammonium nitrogen and nitrate nitrogen in the soil demonstrated a trend of ‘decrease, increase and then decrease’ during the whole growth period of highland barley; the content of ammonium nitrogen reached the highest during the heading period and the content of nitrate nitrogen reached the highest during the seedling period, which were 2.75 mg/kg and 22.64 mg/kg, respectively. The contents of ammonium nitrogen and nitrate nitrogen in the 0-20 cm soil layer were 1.76 mg/kg and 11.82 mg/kg, respectively, which were 1.76 and 2.00 times of those in the 20-40 cm soil layer, indicating that the transformation, absorption and transportation of substances were mainly carried out in the upper soil. Meanwhile, it was also shown that when ammonium nitrogen in soil reached a certain concentration, nitrate nitrogen content had no correlation with ammonium nitrogen concentration, but was related with nitrate enzyme activity. The content of ammonium nitrogen and nitrate nitrogen were different under different fertilization treatments, while the effective utilization rates of ammonium nitrogen and nitrate nitrogen were higher in the soil treated by three kinds of slow released fertilizers.

  Rice Bacterial Blight Resistance Genes and Resistance-related Factors: A Review on Research and Utilization LI Zhou, YANG Yayun, DAI Luyuan, ZHANG Feifei, A Xinxiang, DONG Chao, WANG Bin, TANG Cuifeng 2022, 38 (30):  91-99.  DOI: 10.11924/j.issn.1000-6850.casb2021-0941 Abstract + ( 404 )   HTML ( 15 )   PDF ( 1172KB )   ( 97 ) Bacterial blight severely restricts the production of rice. The discovery and utilization of disease-resistant genes is currently the most environment-friendly and effective way to control the disease. In order to efficiently discover, study and utilize bacterial blight resistance genes, this paper summarized the interaction mechanism between bacterial blight and rice, concluded the location and cloning status of bacterial blight resistance genes, and classified their functional types. Research progress on disease resistance-related factors was reviewed. In view of the current situation that the research progress of bacterial blight resistance genes is slow and the overview research reports are relatively lagging behind, we put forward the research prospect, and believe that more in-depth research should be done on the location cloning and utilization of rice bacterial blight resistance genes, and the synergistic relationship between genes and disease resistance-related factors should be explored.

  Advances in New Nematicides and Their Action Mechanism WANG Qing, FANG Wensheng, LI Yuan, WANG Qiuxia, YAN Dongdong, CAO Aocheng 2022, 38 (30):  100-107.  DOI: 10.11924/j.issn.1000-6850.casb2021-1045 Abstract + ( 307 )   HTML ( 4 )   PDF ( 1274KB )   ( 56 ) Plant-parasitic nematodes cause huge losses worldwide every year, and among the many prevention and control measures, chemical control is still the main one. According to the action mechanism of nematicides classified by the Insecticide and Fungicide Resistance Action Committee (IRAC and FRAC), this study summarized the action mechanisms of some traditional and new nematicides, in order to provide a theoretical basis for the research of nematicides.

  Pseudomonas fluorescens Strain CLW17: Degradation of Glyphosate and Its Mechanism CAO Yongqing, LIU Yan, ZHANG Lihui, JIN Tingting, REN Jiahong 2022, 38 (30):  108-117.  DOI: 10.11924/j.issn.1000-6850.casb2022-1170 Abstract + ( 245 )   HTML ( 3 )   PDF ( 2784KB )   ( 50 ) The subject is to study the degradation of glyphosate by the rhizobacteria-promoting strain Pseudomonas fluorescens CLW17 and the molecular mechanism of the strain. The glyphosate degradation ability of strain CLW17 was evaluated by plate culture method and molybdenum antimony resistance colorimetric method. An optimized condition of degrading glyphosate by strain CLW17 was achieved by employing Plackett-Burman (PB) design, and central composite design (CCD). Bioinformatics analysis was carried out for understanding the key gene thiO in glyphosate degradation. Deletion mutant strain (CLW17ΔthiO) and complement strain (ΔthiO/thiO) were constructed, and their effects on glyphosate degradation were studied. The maximum concentration of glyphosate tolerance of strain CLW17 was 0.7%. The degradation rate of CLW17, CLW17ΔthiO and ΔthiO/thiO was 72.81%, 32.78% and 54.33%, respectively, under the optimal condition for glyphosate degradation. Bioinformatics analysis revealed that thiO gene encoded 366 amino acids and included signal peptide and transmembrane domain. CLW17 was capable of degrading glyphosate effectively. Moreover, thiO gene was closely related to glyphosate degradation ability. These findings can provide valuable bacterial resources for glyphosate pollution control and soil remediation.

  Ultrasonic Extraction Process of Total Saponins from Leaves of Solanum torvum Swartz. WANG Wenxuan, LI Yunpeng, XU Hening, ZHAO Xin, MA Rou, ZHANG Lina, ZHANG Yingying 2022, 38 (30):  118-125.  DOI: 10.11924/j.issn.1000-6850.casb2021-1055 Abstract + ( 200 )   HTML ( 4 )   PDF ( 5008KB )   ( 24 ) In order to improve the extraction rate of total saponins from leaves of Solanum torvum Swartz., the study optimized the extraction process. Taking the extraction rate of total saponins as the evaluation index, we studied the effects of ethanol concentration, solid-liquid ratio, extraction time and extraction temperature on the extraction rate by single factor experiment. On the basis of single factor experiment, response surface methodology was carried out to optimize the ultrasonic extraction process of total saponins from leaves of Solanum torvum Swartz.. The results showed that the optimum technological condition was ethanol concentration of 80.30%, solid-liquid ratio of 1:15.06 (g/mL), extraction time of 95.56 min and extraction temperature of 62.29℃. Under this condition, the theoretical extraction rate of total saponins from leaves of Solanum torvum Swartz. was 38.82%, and the response surface model had good fitting, good prediction and reliable operation. The ultrasonic extraction process of total saponins from leaves of Solanum torvum Swartz. optimized by response surface methodology is stable and feasible.

  Flavor Substances in Rice: Formation and Change HAN Lixin, REN Hongbo, MENG Li 2022, 38 (30):  126-134.  DOI: 10.11924/j.issn.1000-6850.casb2022-0166 Abstract + ( 234 )   HTML ( 8 )   PDF ( 1279KB )   ( 34 ) In order to study the formation and changes of flavor substances in rice, this study summarized the composition of the main flavor substances in rice, analyzed the effects of growth factors and genetic factors on the formation of flavor substances and changes of volatile matter content during storage, and discussed the way about rice releasing aroma. The whole process from source, accumulation and release of flavor substances in rice was expounded. In the process of flavor formation, the conditions under which some volatile compounds produced were unclear, and the research on the genetic factors of rice was not comprehensive. At present, the research on the aroma substance 2-acetyl-1-pyrroline (2-AP) is extensive, but the study on genetic factors of other substances is incomprehensive.

  Influencing Factors of Agricultural Technology Extension Efficiency——A Case Study of Pingdu City, Shandong Province ZHANG Xia, XU Xiumei 2022, 38 (30):  135-140.  DOI: 10.11924/j.issn.1000-6850.casb2021-1044 Abstract + ( 198 )   HTML ( 3 )   PDF ( 1201KB )   ( 20 ) In this study, the agricultural technology extension input-output data of Pingdu City from 2016 to 2020 were selected, and the agricultural technology extension efficiency of Pingdu City in the 5 years was measured by using DEA model. Based on the results, it was concluded that the average agricultural extension efficiency of Pingdu City in the 5 years was 0.905, and the extension efficiency in 2020 was lower than the average value. Problems of low extension efficiency and input redundancy were found in agricultural extension, so we proposed countermeasures to improve the incentive assessment system of agricultural extension personnel. Then, we carried out the satisfaction analysis of agricultural technology extension effects in five towns in Pingdu City, and obtained the results that gender, health status of family labor force, household farming area, total annual household income, and whether agricultural income was transferred to land were important influencing factors. Finally, based on the findings of this study, we put forward suggestions for improving agricultural technology extension from the perspectives of the government, agricultural extension personnel and farm household to provide a basis for agricultural technology extension analysis and research.

  Indexation Measurement of the Advantage of Main Grain Crops in Yunnan Province Based on the Comparative Advantage Theory MA Yuemei, WANG Rongdang 2022, 38 (30):  141-150.  DOI: 10.11924/j.issn.1000-6850.casb2021-1066 Abstract + ( 155 )   HTML ( 2 )   PDF ( 4479KB )   ( 34 ) Food security and farmers’ income increase have always been the focus of China’s Sannong issues (namely, agriculture, rural community and farmers), especially under the COVID-19, it is more urgent to take effective measures to ensure the nation’s food security. Based on the comparative advantage theory, this study adopts the comprehensive comparative advantage index model, and uses the sowing area and yield data of five main grain crops, including rice, wheat, corn, beans and tubers in Yunnan Province from 2009 to 2018, to calculate the scale advantage index, efficiency advantage index and comprehensive comparative advantage index, so as to reveal the changing law of the strong and weak comparative advantages of main grain crops in Yunnan Province and its 16 prefectures and cities. The study found that in the 10 years, the three grain crops of tubers, beans and corn had strong average scale, efficiency and comprehensive comparative advantage at the same time, while the average scale, efficiency and comprehensive comparative advantage of rice and wheat were weak, and the strong and weak dominant grain crops in the prefectures and cities were different. Therefore, it is suggested that Yunnan Province should use the study result to make a reasonable layout and arrangement of the production of main grain crops in the whole province, and give full play to the planting and yield advantages of various main grain crops, so as to maximize the increase of income and yield of main grain crops.

  Promoting High-quality Agricultural Green Development: Policy Research and Practice Enlightenment LIN Qiao, YANG Xiaowei, WANG Xiaomei, HE Wei, KONG Lingbo, WANG Hui 2022, 38 (30):  151-157.  DOI: 10.11924/j.issn.1000-6850.casb2021-1137 Abstract + ( 214 )   HTML ( 2 )   PDF ( 1332KB )   ( 36 ) Agricultural green development is related to the protection and sustainable development of the entire ecological environment and resources, at the same time, it is an important way to beautify the rural human settlement environment and promote the construction of a new countryside. This paper analyzes the situation of agricultural green development at home and abroad through investigation and analysis, confronts the severe situation facing China’s agricultural green development, and puts forward suggestions for promoting the high-quality agricultural green development, aiming to provide information support for the strategic layout of green development of agriculture during the ‘14th Five-Year Plan’ period. Literature research, quantitative analysis, expert consultation and other methods were comprehensively used to conduct in-depth analysis of the pattern and path of agricultural green development in the United States, the European Union, Australia, the Netherlands, Japan and other developed countries and China. The research results show that the United States and other developed countries have formed a fruitful development concept and path for agricultural green development through a series of measures. They have cutting-edge technologies in molecular breeding and other fields. The agricultural green development in China has undergone more than 30 years of policy evolution and path practice, which has also formed a typical, extendable and referential agricultural green development model system. But currently, China’s agriculture is still facing tightening resource constraints, serious non-point source pollution, prominent ecological problems, obvious regional supply differences of green agricultural products, and a guarantee system that needs to be improved. The situation is pressing. Combining international development experience and China’s national conditions, suggestions were put forward on optimizing the main functions of agriculture, promoting resource protection and efficient use, purifying the environment of production areas, promoting ecosystem conservation and restoration, driving green supply, and improving market evaluation standards and subsidy systems for green agricultural products to high-quality agricultural green development.

  Sci-tech Innovation Empowering Industrial Revitalization Under Rural Revitalization: Paths and Countermeasures YUAN Hetao 2022, 38 (30):  158-164.  DOI: 10.11924/j.issn.1000-6850.casb2021-1099 Abstract + ( 212 )   HTML ( 4 )   PDF ( 2110KB )   ( 28 ) Under the background of rural revitalization, industrial revitalization is the basis, and scientific and technological innovation is the key to industrial revitalization. Strengthening the role of scientific and technological innovation in supporting industrial revitalization is of practical significance for the implementation of the Rural Revitalization Strategy. Based on the practices of Ankang in Shaanxi Province, this study deeply analyzes the current situation, existing problems, opportunities and challenges of scientific and technological development, investigates the actual demand of industrial revitalization for science and technology from the micro perspective and empirical level, and explores the effective path to improve the supporting capability of science and technology to modern agricultural innovation, the innovation level of emerging industries and the development ability of social undertakings. It puts forward countermeasures and suggestions for empowering industrial revitalization from the aspects of major innovation of leading industries, upgrading and development of innovation platforms, innovative services of scientific and technological resources, and good environment construction of scientific and technological innovation, so as to provide a case study and decision-making reference for scientific and technological innovation empowering industrial revitalization in regions with similar conditions.