Current issue

• 2022 Vol.38 No.17 Published:15 June 2022

  Genetic Diversity of Rice Varieties in Heilongjiang Province ZHANG Jiaqi, GUO Zongshan, LIU Changhua, LI Rongtian 2022, 38 (17):  1-9.  DOI: 10.11924/j.issn.1000-6850.casb2021-1183 Abstract + ( 390 )   HTML ( 6 )   PDF ( 1842KB )   ( 352 ) In order to study the genetic basis and genetic relationship of current rice varieties in Heilongjiang Province, 47 pairs of SSR markers published in the agricultural industry standard Protocol for the Identification of Rice Varieties SSR Marker Method (NY/T 1433—2014) were used to analyze the genetic diversity among 231 rice varieties from different accumulated temperature regions in Heilongjiang Province. The results showed that a total of 136 alleles were detected form the 47 pairs of SSR markers, alleles per locus ranged from 2 to 5, the average was 2.92. Genetic diversity ranged from 0.11 to 0.79, with an average of 0.56. The polymorphic information content (PIC) was 0.11-0.76, with an average of 0.49. The value of marker index (MI) ranged from 3.18 to 18.39, with an average of 6.52. Cluster analysis divided the 231 rice varieties into 3 categories and 7 groups, and the clustering results were consistent with the results of principal component analysis. Taken together, the genetic diversity of rice varieties in Heilongjiang Province is not rich enough (the average polymorphic information content index is 0.49), and the genetic relationship among the varieties in the same accumulated temperature area is relatively close. In variety breeding, attention should be paid to the hybridization of northern and southern varieties, in order to broaden the genetic background and cultivate new environment-friendly varieties with high-quality and high-yield.

  Effects of Formula Fertilization on the Growth and Development of Spring Maize YU Bo, ZHANG Xuefang, XU Songhe, REN Qin, YANG Yuting, ZHOU Mengyang, PAN Yu, LIU Mengqi 2022, 38 (17):  10-16.  DOI: 10.11924/j.issn.1000-6850.casb2021-0967 Abstract + ( 301 )   HTML ( 5 )   PDF ( 1433KB )   ( 67 ) The irrigated area of Inner Mongolia plain has dry climate and low soil fertility, and spring maize production is highly dependent on nitrogen, phosphorus and potassium nutrients. In order to explore the suitable fertilizer formula and input amount in this area and their effects on the growth and development of spring maize, two varieties of spring maize, ‘Xianyu 1619’ and ‘A2636’, were selected as test materials. A random block test with no fertilizer (CK), 26-16-8 (treatment Ⅰ), 25-10-16 (treatment Ⅱ), 15-15-15 (treatment Ⅲ) and 34-9-7 (treatment IV) was designed. The effects of different fertilizer formula on the aboveground morphology, photosynthetic efficiency and leaf physiology of spring maize were studied. The results showed that: for spring maize variety ‘Xianyu 1619’, the plant height under treatment Ⅲ was significantly higher than that under other treatments, and the stem diameter under treatment Ⅰ was significantly higher than that under other treatments, and net photosynthetic rate (Pn), intercellular CO2 concentration (Ci), transpiration rate (Tr), stomatal conductivity (Gs), chlorophyll content, peroxidase activity and soluble protein content under treatment IV were significantly higher than those under other treatments. For spring maize variety ‘A2636’, the plant height under treatment Ⅰ was significantly higher than that under other treatments, the stem diameter under treatment IV was significantly higher than that under other treatments, and Pn, Ci, Tr, Gs, chlorophyll content, peroxidase activity and soluble protein content under treatment Ⅲ were significantly higher than those under other treatments. In conclusion, the 34-9-7 formula with a high nitrogen ratio had significant influence on the growth of spring maize ‘Xianyu 1619’, and the 15-15-15 formula with balanced ratio of N, P and K had significant effect on the growth and development of spring maize ‘A2636’. The conclusion can provide a fertilization basis for spring maize production in arid area with low soil fertility.

  Research Progress of Plant SWEET Gene Family HUANG Cheng, LI Xunan, LI Shiyan, WANG Jinda 2022, 38 (17):  17-26.  DOI: 10.11924/j.issn.1000-6850.casb2021-0669 Abstract + ( 654 )   HTML ( 11 )   PDF ( 1634KB )   ( 151 ) The SWEET gene family of plant sugar transporters is a class of important sugar transporters discovered in recent years, which plays an important role in plant growth and development, physiological metabolism, and resistance to stress by regulating the transport and distribution of sugar in plants. SWEET gene has different biological functions in different species and plays an important role in plant life activities. In this study, we reported the research status of the protein structure, transport mechanism and biological function of the SWEET gene family in plants, aiming to provide a theoretical basis for further study on other structures and functions of SWEET gene family.

  Plant Growth and Development and Response to Adversity Stress Regulated by miR172: A Review WANG Chen, ZHANG Juping, DING Han 2022, 38 (17):  27-34.  DOI: 10.11924/j.issn.1000-6850.casb2021-1021 Abstract + ( 346 )   HTML ( 10 )   PDF ( 1238KB )   ( 180 ) microRNA (miRNA) is a kind of endogenous non-coding small RNA, it plays significant role in the whole process of plant growth and development, and it is an important regulator in the gene expression. miR172 is an important member among various miRNA families. In order to understand the role of miR172 in plants more intuitively, the authors classified and summarized the research progress of miR172 in regulating plant growth and development, as well as plant response to adversity stress. miR172 is involved in many processes, such as vegetative phase transition, flowering, floral organ development, internode length, plant commodity organs’ development and plant response to adversity stress. The authors think that miR172 still has many unknown functions in plants. Therefore, it is an important research direction to deeply explore more roles of miR172 in plant growth process in the future. Based on this, the function and molecular regulation mechanism of miR172 should be deeply analyzed, which will lay a theoretical foundation for artificially using miR172 to regulate plant growth and development.

  Photosynthetic Mechanism of Algae in Response to Iron Deficiency Stress: Research Progress XU Mingyu, BAI Tianyu, WANG Jiayue, TIAN Lirong 2022, 38 (17):  35-43.  DOI: 10.11924/j.issn.1000-6850.casb2021-1142 Abstract + ( 225 )   HTML ( 4 )   PDF ( 1970KB )   ( 50 ) In order to deep understand the effect of iron deficiency stress on photosynthesis in algae, the authors summarized the important role of iron in photosynthetic electron transport chain, and concluded the destruction effect of iron deficiency on photosynthetic elements and the photosynthetic response mechanism of algae. Focused on the photosynthetic electron transport chain, the photosynthetic elements which were easily affected by iron deficiency, such as chlorophylls, photosystems and light-harvesting antennas, were summarized. This study concluded that iron deficiency stress could severely damage chlorophyll biosynthesis and affect the contents, activity and protein stability of photosystem I (PSI), photosystem II (PSII) and their peripheral light-harvesting antennas in algae. Algae can adjust the structure and function between the photosystems and their peripheral light-harvesting antennas by generating new iron-inducible proteins or functional replacement proteins around PSI/PSII to cope with iron deficiency stress.

  Effects of Different Nitrogen Supply on Photosynthetic Characteristics and Growth of Calamagrostis angustifolia Under Elevated CO2 Concentration WANG Jianbo, WANG Jifeng, FU Xiaoling, ZHONG Haixiu, LIU Yingnan, NI Hongwei 2022, 38 (17):  44-50.  DOI: 10.11924/j.issn.1000-6850.casb2021-1196 Abstract + ( 200 )   HTML ( 2 )   PDF ( 1425KB )   ( 23 ) In order to reveal the effects of elevated CO2 concentration and different nitrogen supply on the photosynthetic characteristics and growth of wetland plants, the marsh predominated with Calamagrostis angustifolia in Sanjiang Plain was studied. A manipulative in situ experiment was performed. Open top chambers (OTCs) were used for the CO2 concentration treatment in order to model the effects of elevated CO2 concentration in the atmospheric environment. Three levels of CO2 concentration, i.e., E0 (380±20 μmol/mol), E1 (550±20 μmol/mol) and E2 (700±20 μmol/mol), and three levels of nitrogen fertilization, i.e., N0 (0 g N/m2 ), N1 (4 g N/m2 ) and N2(8 g N/m2), were applied in the study. Under treatment N0, after a long period of elevated CO2 concentration treatment (72 days), the net photosynthetic rate of C. angustifolia under E1 and E2 was reduced by 11% and 12% (P<0.05) respectively compared with that under E0, and the leaf soluble protein content, nitrogen content (72 days by CO2 fumigation) and the plant height (86 days by CO2 fumigation) were all significantly lower than those under E0 (P<0.05). Under treatment N1, the net photosynthetic rate of C. angustifolia under E1 and E2 (72 days) decreased by 5% (P>0.05) and 10% (P<0.05) compared with that under E0, respectively, and the leaf nitrogen content (P<0.05) and plant height were lower than those under E0. Under treatment N2, the net photosynthetic rate of C. angutifolia under E1 and E2 (72 days) had a slight increase trend (P>0.05), the leaf soluble protein content was significantly enhanced (P<0.05), and the leaf nitrogen content and plant height had no significant change (P>0.05). The elevated CO2 concentration significantly increased the soluble sugar content in the leaves of C. angustifolia under treatment N0, N1 and N2. Our results indicate that the long-term increase of CO2 concentration may decrease the net photosynthetic rate of C. angustifolia leaves by reducing the activity of photosynthesis enzyme, and the high-rate application of nitrogen fertilizer can alleviate the negative effects of long-term high CO2 concentration on photosynthesis and growth of wetland plants.

  Regulation Mechanism of Low Temperature Stress on Plants: Research Progress CHEN Siqi, SUN Jingshuang, MA Wenjun, WANG Junhui, ZHAO Xiyang, HU Ruiyang 2022, 38 (17):  51-61.  DOI: 10.11924/j.issn.1000-6850.cabs-2021-0656 Abstract + ( 1309 )   HTML ( 26 )   PDF ( 1344KB )   ( 312 ) Low temperature is an abiotic stress that could affect plant growth and vegetation distribution. Once the environmental temperature is continuously lower than the optimal temperature for plant growth, the plant would suffer low temperature stress, including chilling injury and freezing injury. Chilling injury refers to the damage on plant caused by low temperature of zero degree or above. The cells do not freeze at this temperature, but the cold will have physiological obstacles for thermophilic plants, causing injury or death. Freezing damage refers to the phenomenon that plants are damaged or die because of the low temperature below the freezing point. Previous studies mainly focused on the regulation mechanism of low temperature stress on plants, including the process in plants from the perception of low temperature signal to the expression of functional genes, and to the resistance to low temperature stress. This article reviews the research on cold stress on plants in recent years, analyzes the research status from the aspects of signal perception, signal transduction, functional gene expression, cold-induced physiological and cellular regulatory mechanism, and discusses the prospect of the research on plant cold resistance. It will provide a theoretical basis for cultivating new cold-resistant plant germplasms.

  Evaluation of the Salt Tolerance of Five Hybrid Mulberry Germplasms ZHANG Liqin, YIN Hongyan, MU Shuyuan, FU Junhui, LI Yan 2022, 38 (17):  62-68.  DOI: 10.11924/j.issn.1000-6850.casb2021-0848 Abstract + ( 267 )   HTML ( 1 )   PDF ( 1641KB )   ( 30 ) In order to select varieties with high salt tolerance from widely planted hybrid mulberry germplasms, the authors took ‘Jisang 3’, ‘Luza 1’, ‘Zheza 1’, ‘Guisangyou 12’ and ‘Guisangyou 62’ as the research objects. Through the seedling growth test under salt stress, the physiological and biochemical indexes of seedling height, plant biomass, leaf chlorophyll content, net photosynthetic rate, stomatal conductance, proline content and malondialdehyde content were analyzed. The results showed that in 6‰ NaCl treatment, the growth and development, plant height and biomass of mulberry seedlings were inhibited to varying degrees. At the same time, the chlorophyll content and photosynthetic physiological parameters of mulberry seedlings under salt stress were measured. As a result, ‘Guisangyou 62’ showed only slight leaf yellowing, good plant growth, little change in plant height and biomass, and strong salt tolerance. As an ecological forest tree species, mulberry plays an important role in soil and water conservation, returning farmland to forest and improving saline-alkali land.

  Trial Analysis of 10 Seedless Watermelon Varieties in Different Places in China HE Nan, LU Xuqiang, ZHAO Shengjie, ZHU Hongju, ZHANG Hui, LIU Wenge 2022, 38 (17):  69-74.  DOI: 10.11924/j.issn.1000-6850.casb2021-0786 Abstract + ( 486 )   HTML ( 3 )   PDF ( 1218KB )   ( 31 ) To speed up the breeding and promotion of new seedless watermelon varieties, the National Seedless Watermelon Research and Production Cooperation Group carried out demonstration experiments of 10 new seedless watermelon varieties in different places in 2020. By evaluating the disease resistance, fruit setting habits and fruit related traits of the tested varieties, we found that the comprehensive performance of the tested varieties was relatively good. Among them, ‘Jinglong-2’and ‘Jinglong-3’ were small fruit varieties. Compared with medium and large fruit types, the single melon of the above two varieties had smaller weight, higher sugar content and thinner peel, and the two varieties were suitable for facility cultivation. Three varieties, including ‘Red Lycopene No.4’, ‘Xuefeng New 2’, and ‘Jinhuami 2108’, had more outstanding resistance to fusarium wilt at 7 different test sites and the overall performance was relatively stable, which presented a certain promotion value, and were recommended for trial planting in a small area first and then promoted in large area. In summary, 5 of the tested varieties in this study have relatively stable performance in 7 provinces across the country, and have outstanding performance in fusarium wilt resistance, fruit setting habits and sugar content, with certain promotion and application value. The study can provide some suggestions for breeding and cultivating of seedless watermelon.

  Functional Utilization of Zanthoxylum bungeanum Waste: Research Progress YUAN Congjun, YANG Guangneng, HU Hong, HUANG Anxiang, YANG Shoulu, LI Xun, ZHAO Yong 2022, 38 (17):  75-81.  DOI: 10.11924/j.issn.1000-6850.casb2021-0633 Abstract + ( 343 )   HTML ( 8 )   PDF ( 1665KB )   ( 775 ) A large amount of waste produced in the process of planting, harvesting and processing of Zanthoxylum bungeanum, which is usually discarded or burned directly, can result in environmental pollution and waste of resources. It is of significance to develop corresponding products of the functional components of Zanthoxylum bungeanum waste to improve the added value of Zanthoxylum bungeanum industry and promote its healthy and sustainable development. The article reviewed the functional components of Zanthoxylum bungeanum seed, pomace, seed cake, leaves and root. Moreover, the pharmacological activities of anti-inflammatory and anti-tumor, insecticidal effect, anti-oxidation and anti-platelet aggregation of Zanthoxylum bungeanum waste were summarized. The application of Zanthoxylum bungeanum waste in high adsorption activated carbon, medical functional materials, environmental protection coatings, leather fat liquoring agents and functional additive agents were introduced. Finally, based on the previous research on the functional components and utilization of Zanthoxylum bungeanum waste, a new direction of Zanthoxylum bungeanum waste utilization was discussed.

  Study on the Quality of Yunnan White Tea HE Mingzhu, LI Jinqiu, WAN Renyuan, YUAN Yuwei, ZHOU Dapeng, YANG Guangrong 2022, 38 (17):  82-89.  DOI: 10.11924/j.issn.1000-6850.casb2021-0644 Abstract + ( 308 )   HTML ( 2 )   PDF ( 3566KB )   ( 46 ) White tea is one of the six kinds of tea in China, and it is loved by consumers for its unique processing technology, sweet and fresh sensory quality and health care effect. To understand the quality status and characteristics of Yunnan white tea, in this study, six samples of Yunnan white tea made of the fresh leaves of Yunnan local tea varieties and through local processing methods and six samples of traditional Fujian Zhenghe white tea were selected as the research objects. The water content, water extracts, free amino acids, tea polyphenols and caffeine were determined and the sensory evaluation was conducted. The differences of biochemical composition and sensory quality between Yunnan white tea and Zhenghe white tea were analyzed and compared. The results show that the average content of polyphenols, amino acids and caffeine in Yunnan white tea are 30.83%, 5.00% and 4.87%, respectively, and those of Zhenghe white tea are 29.76%, 7.22% and 5.02%, respectively; from the sensory evaluation, Yunnan white tea is sweet and refreshing, Zhenghe white tea is sweet and smooth. The appearance of Zhenghe white tea is better than that of Yunnan white tea. There are relatively big differences between Yunnan white tea and Zhenghe white tea in terms of biochemical composition and sensory quality.

  Effect of Plant Covering on Soil Microbial Community Functional Diversity Under Banana Cropping System WEI Jiadi, WANG Yongfen, HE Xiang, YANG Peiwen, YU Yanchun, ZHENG Sijun, XU Shengtao 2022, 38 (17):  90-97.  DOI: 10.11924/j.issn.1000-6850.casb2021-0672 Abstract + ( 248 )   HTML ( 2 )   PDF ( 1390KB )   ( 48 ) Bared soil causes the decline of soil fertility in the banana cropping system, which is one of the crucial factors limiting the sustainable development of banana industry. Plant covering could be an effective way to alleviate the decline of soil fertility in banana cropping system. The functional diversity of soil microbial communities could sensitively reflect the variation of soil properties, and is an important indicator for assessing soil quality. In this study, conventional planting method with bare soil between rows was used as control (CK), natural weeds covering (NW) and artificially planted legumes [Macroptilium atropurpureum (DC.) Urb.] covering (CP) were taken as the treatments in banana cropping system. The effects of plant covering on the functional diversity of soil microorganisms under banana cropping system were studied with microbial Biolog identification technology. The results showed that the carbon utilization of soil microorganisms had significant differences under different covering plants, ranked as: CP> NW> CK. Compared with CK, plant covering significantly (P<0.05) improved the Richness Index, Shannon-Wiener Index and Simpson Index of soil microorganisms under banana cropping system; the soil microorganisms showed a high utilization rate of sugars, amino acids and carboxylic acids. The soil microorganisms under NW showed better utilization of carboxylic acid carbon sources, and the soil microorganisms under CP showed better utilization of sugars and amino acid carbon sources. Different covering plants had significantly affected soil microbial community functional diversity under banana cropping system. Compared with CK, CP could improve the soil microbial community and effectively mitigate the degree of soil degradation. Promoting soil microbial diversity by covering plant diversity, the healthy and sustainable utilization of soil could be achieved in banana industry.

  Improvement Effect of Different Ameliorants on Acidified Soil of Rhizoma corydalis - Rice Rotation YANG Xiaomin, SI Hua, GAO Peng, JIAN Hongzhong, YANG Xiao, CUI Ning, YU Zhengjun, ZHANG Genglong 2022, 38 (17):  98-102.  DOI: 10.11924/j.issn.1000-6850.casb2021-0654 Abstract + ( 245 )   HTML ( 4 )   PDF ( 1298KB )   ( 31 ) To explore the improvement effect of different ameliorants on acidified soil of Rhizoma corydalis - rice rotation, we took the rotation as the research object, set treatments of applying different soil ameliorants to Rhizoma corydalis single-cropping and Rhizoma corydalis - rice rotation, and then analyzed the soil chemical properties and the economic benefits of crop yield after harvest. The results showed that continuous application of lime, calcium-magnesium-phosphate fertilizer and conditioner of acidic soil to the Rhizoma corydalis - rice rotation could improve soil pH and exchangeable calcium, and the yield of the two crops under the rotation was significantly higher than that of single-cropping application of ameliorants to Rhizoma corydalis. The continuous application of calcium-magnesium-phosphate fertilizer and acidic soil conditioner could supplement soil potassium and increase soil exchangeable magnesium content. The continuous application of calcium-magnesium-phosphate fertilizer could also significantly increase soil available phosphorus and the pure benefits of the two crops. On the whole, in the production practice of improving acidified soil of Rhizoma corydalis - rice rotation, it is recommended to apply calcium-magnesium-phosphate fertilizer of 1500 kg/hm2 in Rhizoma corydalis cropping and 750 kg/hm2 in rice cropping to obtain good soil improvement effects and economic benefits.

  Spatial Distribution Characteristics and the Impact Factors of Heavy Metals in Peri-urban Soils Under the Background of Fast Urbanization GUO Jia, JIN Shaofei, WANG Ku 2022, 38 (17):  103-109.  DOI: 10.11924/j.issn.1000-6850.casb2021-0995 Abstract + ( 294 )   HTML ( 5 )   PDF ( 1797KB )   ( 35 ) To reveal the effects of rapid urbanization on soil quality in peri-urban areas in Fuzhou, spatial distribution of five heavy metals (Cr, Mn, Cu, Pb and Zn) in these areas were analyzed from 134 soil samples by geostatistic method. The potential ecological risk index was used to evaluate the pollution degree of soil heavy metal, and the impact factors were analyzed by the random forest model. The results showed that great variations were found among the five heavy metals on spatial distribution pattern. The maximum value of each heavy metal was not accordant in space. The average value of the potential ecological hazard index of the five heavy metals was in the order of Pb > Cu > Cr > Mn > Zn. Pb and Cu had the highest value of potential ecological risk index, which reached the degree of strong ecological risk. The relative importance of the impact factors of the five heavy metals in soil was screened by random forest model, and the impact factors were various for the five heavy metals. The results could provide a scientific basis for soil conservation and utilization in urban expansion process.

  Optimization of the Extraction Process of Total Flavonoids from Broussonetia papyrifera Leaves by Ethanol Heating Reflux Method QIN Zhihua, CAI Qingxia, WANG Jianlin, WANG Shubai, TAN Zichao, ZHANG Linlin, GUO Pei, SHAN Hu 2022, 38 (17):  110-114.  DOI: 10.11924/j.issn.1000-6850.casb2021-1059 Abstract + ( 290 )   HTML ( 4 )   PDF ( 1357KB )   ( 23 ) The aim of this experiment is to study the optimum extraction technique of total flavonoids from leaves of Broussonetia papyrifera by using the method of heating reflux. A single factor experimental design was used to study the optimum reaction time, reaction temperature, liquid to solid ratio and ethanol concentration of the extraction of total flavonoids from leaves of the tree. The above four factors were set at five levels, respectively. The extraction amount of total flavonoids was used as the evaluation index to screen the optimal reaction condition. On this basis, orthogonal experiment was used to design the optimal extraction process, and the optimal extraction process was further verified by repeated validation test and process amplification test. The results showed that the optimum ethanol concentration was 70%, reaction time was 2.5 h, solid-liquid ratio was 1:30 and reaction temperature was 70℃. The optimum extraction condition was determined by orthogonal test as follows: ethanol concentration of 70%, reaction time of 2.5 h, solid-liquid ratio of 1:30, and reaction temperature of 80℃. The yield was 23.11 mg/g in repeated validation test and 23.13 mg/g in process amplification test, respectively. This process has good stability and operability, and is suitable for the extraction of total flavonoids from leaves.

  Test and Analysis of Work Efficiency of Sugar Beet Seeder and Harvester LU Bingfu, LIU Na, YU Lihua, ZHANG Wenbin, LIU Xiaoxue 2022, 38 (17):  115-120.  DOI: 10.11924/j.issn.1000-6850.casb2021-0609 Abstract + ( 211 )   HTML ( 2 )   PDF ( 1309KB )   ( 29 ) To analyze the actual operation time, auxiliary operation time and following operation time for each operation link of tractor-unit of sugar beet, and to optimize unit operation management and maximize the potential of sugar beet mechanical operation, in this paper, field operation of sugar beet seeder and harvester were tracked to test and record the related data, which was analyzed and processed to calculate the working efficiency. The results showed that the efficiency of seeder operation was 63.99%, that of topper operation was 60.51%, and that of digger operation was 64.32%. The operation efficiency of sugar beet machines has become an important basis for the selection and reasonable application of sugar beet operating units.

  The Path to Speed up the Whole Vegetable Industrial Chain Cultivation in Yunnan LI Liang, DONG Xiaobo, MAO Zhaoqing 2022, 38 (17):  121-127.  DOI: 10.11924/j.issn.1000-6850.casb2021-0621 Abstract + ( 229 )   HTML ( 1 )   PDF ( 1394KB )   ( 41 ) The aim is to promote the high-quality development of the whole industrial chain of vegetables in Yunnan, increase farmers’ economic benefits and enhance efforts on rural revitalization in the province. From the perspective of the whole industrial chain, the current situation of each link of the vegetable industry in Yunnan was analyzed and the problems were screened, and the advanced experience at home and abroad was used to explore the countermeasures. Targeting at the problems such as low production level of the industry, weak intensive processing capability, unqualified circulation chain, insufficient leisure agriculture, unsound interest binding mechanism of the industrial chain, slow construction of regional public brands and so on, some countermeasures were put forward, including developing the whole industrial chain horizontally and vertically, adopting the approach of ‘Internet +’, establishing regional public brands, promoting the effective value-added upstream, midstream and downstream in the industrial chain, and building industrial clusters to cultivate the whole vegetable industrial chain in line with the actual situation of Yunnan Province.

  SWOT Analysis and Development Strategy of Tea Industry in Ninghua LIU Xinyong, CHI Minqing, LIN Guohua, MA Qiufeng, YI Zewen, LI Qisheng 2022, 38 (17):  128-133.  DOI: 10.11924/j.issn.1000-6850.casb2021-0637 Abstract + ( 302 )   HTML ( 1 )   PDF ( 1186KB )   ( 148 ) Ninghua County is a tea producing key area in China and the tea industry is the characteristic industry of the county. At present, there are some problems in the development of tea industry in Ninghua, such as inadequate brand influence, weak enterprise competitiveness, unbalanced development of the whole industrial chain, and low degree of industrial integration. Based on the investigation of the basic situation of tea industry in Ninghua, this study used the SWOT analysis method to summarize the advantages of location, policy, ecology and cultural tourism resources of Ninghua County, analyzed the disadvantages in the development of the county’s tea industry. It is suggested that through building standardized tea gardens, improving the characteristic tea varieties, making five ‘forest health + red tourism (revolutionary sites) + Hakka culture’ tea culture tourism integration routes and strengthening Ninghua tea brand, the county could promote the transformation and upgrading of its tea industry.

  The Impact of Cooperative Membership on the Economic Benefits of Cigar Leaf Cultivation: A Case of Shifang in Sichuan Province ZHONG Qiu, LIU Tao, WU Junqian, CHEN Yong, XU Hao, YI Kai, FAN Dan 2022, 38 (17):  134-142.  DOI: 10.11924/j.issn.1000-6850.casb2021-0638 Abstract + ( 270 )   HTML ( 1 )   PDF ( 1366KB )   ( 61 ) With the strong development trend of domestic cigar production and consumption, the innovation and transformation of the organization mode of cigar tobacco leaf raw material production is an important issue to promote the high-quality and high-efficient supply of tobacco leaves. Based on the field research data of Shifang in Sichuan Province, this study examined the impact of cooperative membership on the economic benefits of cigar leaf cultivation from the perspective of farmers’ professional cooperatives. The results show that:（1）from the statistical results, cigar leaf planting unit yield and unit output value in the planting scale of (0.2, 0.267) hm2 and (0, 0.133) hm2 are respectively the highest; and (0, 0.133) hm2 and (0.2, 0.267) hm2 are the unit low-cost and unit high-income planting scale ranges for cigar leaf, respectively;（2）from the empirical results, joining cooperatives has a significant effect on increasing the unit yield of cigar leaf cultivation for farmers, and has a greater impact on low-income farmers; positive effects on increasing unit output value and unit income and decreasing unit cost are observed, but the effects are not significant. In summary, the participation of tobacco farmers in the production cooperatives is beneficial to promoting quality efficiency and ensuring the stable supply of tobacco leaves. All tobacco areas should give full play to the organizational advantages of cooperatives, optimize the organizational structure of production, and further regulate the development of cooperatives in tobacco industry, so that they can keep pace with the overall development of agricultural economy.

  Basic Situation and Problems of Conservation Tillage in Black Soil in Heilongjiang Province MA Chao 2022, 38 (17):  143-147.  DOI: 10.11924/j.issn.1000-6850.casb2022-0092 Abstract + ( 269 )   HTML ( 1 )   PDF ( 1245KB )   ( 138 ) Black soil, rich in organic matter and soil nutrients, is one of the excellent soil resources in the world and a valuable strategic resource for China. Located in northeastern China, Heilongjiang Province is home to fertile black soil area, hence is an important commercial grain base in the country. In recent years, the fertility of black soil has decreased and the black soil layer has become thinner as a result of soil erosion and other factors. In such a context, fully implementing conservation tillage in black soil has become a necessity. This paper applied the data analysis method and literature analysis method to analyze the status quo of the implementation of conservation tillage in black soil in Heilongjiang Province as well as existing problems. The study found that the implementing of conservation tillage in black soil faces many difficulties, including farmers’ low awareness of black soil conservation tillage, nonstandard application of technologies, shortage in technologies, machines and tools, and absence of a long-term mechanism for conservation tillage in black soil. In this regard, to promote conservation tillage in black soil, this paper proposed following feasible measures: improving farmers’ awareness, setting up large-scale demonstration bases of conservation tillage, enhancing government support, providing specialized funds for technology R&D and equipment of conservation tillage, and establishing a long-term mechanism for conservation tillage in black soil.

  Current Situation, Prevention and Control Dilemma and Countermeasures of Agricultural and Rural Water Pollution in Jiujiang WANG Zhiqiang, SONG Shengbang, XIAO Tao, WEN Yi, ZENG Ming, LI Jun 2022, 38 (17):  148-155.  DOI: 10.11924/j.issn.1000-6850.casb2021-0663 Abstract + ( 274 )   HTML ( 2 )   PDF ( 1345KB )   ( 164 ) Clean rural water is the key to the construction of beautiful countryside. With the continuous promotion of rural revitalization, the rural water environment has been significantly improved. However, due to the facts of the wide dispersion of agricultural and rural water pollution, difficulties in implementing the responsibility of governance, and the lack of governance funds, it is difficult to solve the core problems, and the effect of water pollution prevention and control is not ideal. Firstly, this article investigated the current situation of water pollution in agricultural production and rural areas of Jiujiang City, so as to analyze the regional characteristics of water pollution caused by different pollutants. Secondly, this article discussed the predicament of water pollution prevention and control in four aspects, including laws and regulations, institution and mechanism, responsible entities and governance models, on the basis of analyzing the core causes of agricultural and rural water pollution. Finally, this article put forward countermeasures for the prevention and control of agricultural and rural water pollution in Jiujiang City from improving laws and regulations, establishing long-term institution and mechanism, strengthening the responsible entities and optimizing governance.

  Deepening Effect in Dilution: The Impact of Urbanization on Rural Human Capital Accumulation LIU Qi, WEN Xinqi, HOU Juanjuan 2022, 38 (17):  156-164.  DOI: 10.11924/j.issn.1000-6850.casb2021-0746 Abstract + ( 204 )   HTML ( 1 )   PDF ( 1354KB )   ( 43 ) The relationship between urbanization and rural human capital accumulation will affect the implementation of the Rural Revitalization Strategy and urban-rural integration development. Based on the theoretical analysis and the provincial panel data of China from 2005 to 2017, this paper used fixed effect and panel IV estimation method to test the causal effect and internal mechanism of urbanization on rural human capital accumulation. The results showed that: (1) under the condition of controlling other variables, urbanization had a significant positive impact on the accumulation of rural human capital, and the per capita human capital in rural areas increased by 1200-1300 yuan for each percentage point of urbanization rate; (2) urbanization strengthened the preference of rural families for human quality, and the investment in rural human capital continued to increase, indicating that urbanization had a positive impact on rural human capital. The deepening effect was realized by the mechanism of population quality preference. The above findings further clarify the logical relationship between urbanization and rural human capital accumulation, and provide theoretical inspiration and empirical evidence for government departments in designing and improving relevant policies.