Current issue

• 2020 Vol.36 No.2 Published:15 January 2020

  Seed Germination of Rice Cultivars: Differences in Physiological Characteristics Ni Wanchao, Shu Hongmei, Guo Shuqiao, Jiang Lu, He Xiaolan, Cui Xiaoxia, Gong Yuanyong 2020, 36 (2):  1-5.  DOI: 10.11924/j.issn.1000-6850.casb18080094 Abstract + ( 439 )   HTML ( 7 )   PDF ( 1041KB )   ( 136 ) To study the physiological characteristics of seed germination of different rice cultivars, we selected 5 cultivars from 24 based on their seed germination rate, which represented 3 types of quick, medium and slow germination. The physiological characteristics of seed germination showed that: there were some differences in amylase activity and soluble sugar content among the cultivars with different germination rates; the cultivars (‘Yanliangyou 888’ and ‘Yanhui 888’) with quick germination rate had higher α-amylase activity and β-amylase activity, which were helpful to decompose starch, and had higher soluble sugar content during germination period, which could offer the energy and substances for seed germination; on the contrary, the cultivars with slow germination rate had lower amylase activity and soluble sugar content of seed. This study indicates that the amylase activity and soluble sugar content of rice seed have a positive correlation with the germination rate.

  New Maize Variety ‘LT5918’ Suitable for Machine Harvesting: Breeding and Cultivation Techniques Bu Huahu, Ren Zhiqiang, Xiao Jianhong, Zhang Ning, Yang Huizhen, Wang Xiaoqing 2020, 36 (2):  6-9.  DOI: 10.11924/j.issn.1000-6850.casb18110015 Abstract + ( 1193 )   HTML ( 8 )   PDF ( 886KB )   ( 297 ) Mechanized grain harvesting of maize reduces the manual removal of bracts and threshing and drying in the harvesting process, which can save labor cost and has important significance for improving the economic benefits of maize planting, but few varieties suitable for mechanized grain harvesting have been reported. In this study, a new mechanical grain harvesting variety ‘LT5918’, suitable for spring sowing in early-maturing and middle-late-maturing areas in Shanxi Province, was selected and identified in multi-ecological areas for many years, with high yield, density tolerance, multi-resistance and suitable mechanized grain harvesting as the breeding objectives. It was approved by Shanxi Crop Variety Examination and Approval Committee in 2018. Compared with the control variety, the average yield of ‘LT5918’ increases by more than 5%, and the stalk is strong, lodging-resistant, dewatering fast, and suitable for mechanical grain harvesting, the variety could be a material foundation for improving the mechanized harvesting degree of maize, reducing labor costs and ensuring food security.

  Absorptive Capacity of Potato Varieties to Four Heavy Metals in Soil Yan Zheng, Peng Qiong 2020, 36 (2):  10-17.  DOI: 10.11924/j.issn.1000-6850.casb18090049 Abstract + ( 872 )   HTML ( 7 )   PDF ( 939KB )   ( 204 ) The paper aims to breed potato varieties with low accumulation of heavy metals and solve the problem of heavy metal accumulation in food chain. Using 11 potato varieties as materials, the absorptive and transport capacity of Cd, Pb, As and Cr in different organs of potato plants were studied. The results showed that, among the 11 varieties, the contents of Cd, Cr, As and Pb in different organs of different genotypes of potato were significantly different. The average content order of the four heavy metals in potato roots, skins and tubers was Cr> Pb> Cd> As, but was Pb> Cr> Cd> As in potato stems and leaves. Moreover, the contents of the four heavy metals in all the potato varieties did not exceed the national standard for heavy metals in food. For heavy metal accumulation in various organs of potato, the average enrichment coefficient of Cr, As, Pb and Cd in potato roots was the highest. The average enrichment coefficient of Cd in potato roots, stems and leaves were all greater than 1, indicating a strong enrichment capacity. The transfer coefficient of heavy metals in different organs of potato also showed significant differences. The average transfer coefficient of Cd and As in potato organs followed an order of stem> leaf> skin> tuber, while that of Cr and Pb was leaf> stem> skin> tuber. Additionally, Cd enrichment coefficient and transport coefficient in ‘D597’ were the lowest, indicating that ‘D597’ was a low Cd absorption and accumulation variety.

  Bio-organic Fertilizer: Effects on the Growth of Oats Under Drought Stress Ma Xiang, Jia Zhifeng, Zhao Yiwei 2020, 36 (2):  18-25.  DOI: 10.11924/j.issn.1000-6850.casb20190600230 Abstract + ( 353 )   HTML ( 1 )   PDF ( 1103KB )   ( 231 ) To explore the effects of bio-organic fertilizer on the growth and development of oats, we took ‘Linna’ as the test material and set 5 fertilizer treatments to carry out the drought stress during different periods. The results showed that: in the initial drought period, the soil moisture under the chemical fertilizer treatment was higher than that under the bio-organic fertilizer treatment; however, in the late period of drought stress, the soil moisture under the bio-organic fertilizer treatment was higher than that under the chemical fertilizer treatment, which meant applying the bio-organic fertilizer had a certain effect on soil moisture; generally speaking, the weight of stem and root under the bio-organic fertilizer were bigger than those under the chemical fertilizer, meanwhile, the ratio of stem to root under the treatment of chemical fertilizer was lower than that under the treatments of bio-organic fertilizer except treatment W4. The root and leaf traits also performed differently under different fertilization treatments. These results indicate that the application of organic fertilizer could promote the tillering of root as well as the growth of the aboveground and underground part of plants, and effectively increase the biomass. In conclusion, 6000 kg/hm 2 of bio-organic fertilizer applied to oats has the most significant response to drought.

  The Interaction Mechanism Between Plant Rhizosphere Secretion and Soil Microbe: A Review Yuan Renwen, Liu Lin, Zhang Rui, Fan Shuying 2020, 36 (2):  26-35.  DOI: 10.11924/j.issn.1000-6850.casb18090023 Abstract + ( 675 )   HTML ( 22 )   PDF ( 1003KB )   ( 520 ) To reveal the pathways and mechanisms of the interaction between plants and soil microorganisms, the authors reviews the research progress of the promotion of plant growth and development by rhizosphere beneficial microorganisms and the effects of plant rhizosphere secretions on soil microbes, mainly include the promoting effect of rhizosphere-promoting microorganism PGPM on plant growth and development, the promotion of biocontrol microorganism BCA on plant growth and development, the composition of root exudates, the function of root exudates, and the pathway of root exudates affecting soil microbes, etc. The authors point out that the research on the mechanism of interaction between plants and soil microorganisms is not deep enough. The research on the screening and adaptability of PGPM strains, the ecological adaptability of biocontrol microorganisms and the mechanism of action on target pathogens, the separation of root secretion, the optimization of the identification method and the allelopathic approach all need to be further studied. In the future, the application of modern molecular biology technology in related research should be increased, and the interaction between plant and soil microorganisms should be further revealed by combining molecular biology techniques with traditional culture methods.

  Dehydration Tolerance of Plant Seeds: Current Research Situation and Prospects Liu Zhongqi, He Jiwai, Zhang Haiqing, Liu Aimin 2020, 36 (2):  36-41.  DOI: 10.11924/j.issn.1000-6850.casb20190600291 Abstract + ( 435 )   HTML ( 5 )   PDF ( 978KB )   ( 91 ) The objective is to clarify the differences of dehydration tolerance of plant seeds and excavate key genes of relative rapid dehydration. We summarized the formation hypothesis, physiological basis and dehydration tolerance difference in the plant seed desiccation tolerance, analyzed the molecular mechanism of seed desiccation tolerance in genome-wide, transcriptome and proteome. At last, we pointed out that the genome-wide methods could be used to locate systematically the genetic diversity and related genes of different types of varieties in the world, and to excavate key genes for seed dehydration sensitivity.

  Ratios of Organic Nitrogen: Effects on Growth and Nutrient Uptake of Salix matsudana Du Junlan 2020, 36 (2):  42-47.  DOI: 10.11924/j.issn.1000-6850.casb18100017 Abstract + ( 350 )   HTML ( 1 )   PDF ( 1041KB )   ( 90 ) To study the effect of different ratios of organic nitrogen on the growth and nutrient uptake of Salix matsudana, and provide a basis for scientific application of organic fertilizer in cuttage seedlings of S. matsudana, taking 1-year-old cuttage seedlings of S. matsudana as test materials, we set 6 treatments with no fertilizer (T1), pure inorganic nitrogen (T2), 30% organic nitrogen (T3), 50% organic nitrogen (T4), 70% organic nitrogen (T5), 100% organic nitrogen (T6) and repeated 3 times. The results showed that: the plant height of T4 was higher than that of T2, T3, T6 by 26.91%,14.67%, 21.02%, respectively; the ground diameter of T4 was higher than that of T2, T5, T6 by 42.70%, 34.29%, 48.41%, respectively; the chlorophyll content of T4 was lower than that of T2 by 0.24, 0.11 mg/g from May to June, and then, higher than that of T2 by 9.16%, 35.29% from July to August; the nitrogen uptake in roots, skins, branches, leaves of T4 was higher than that of T2 by 27.13%, 26.08%, 31.32%, 43.30%, respectively; the phosphorus absorption of T4 was higher than that of T2 by 32.04%, 47.37%, 49.63%, 37.61%, the potassium absorption of T4 was higher than that of T2 by 24.14%, 18.83%, 29.95%, 30.51%. It is concluded that T4 is the best treatment on promoting growth and nutrient uptake of S. matsudana.

  Tamarix chinensis: Technique of Tissue Culture and Rapid Propagation Wei Haixia, Wang Xia, Li Shuangyun, Zhou Jian, Wang Lili, Liu Dexi 2020, 36 (2):  48-52.  DOI: 10.11924/j.issn.1000-6850.casb18100033 Abstract + ( 401 )   HTML ( 5 )   PDF ( 1507KB )   ( 98 ) The paper aims to better preserve the germplasm of Tamarix chinensis. We took the stems of Tamarix chinensis segments as explants and carried out the tissue culture and rapid propagation. The results show that the optimum sterilization scheme is: soaked in 75% ethanol for 30 s, 2% sodium hypochlorite for 3-5 min and mercury dichloride for 5 min. MS+sucrose 20 g/L+agar 6.5 g/L is the optimum primary medium for Tamarix chinensis, and MS+sucrose 30 g/L+agar 7 g/L+6-BA 0.5 mg/L+NAA 0.1 mg/L is the optimum subculture medium for Tamarix chinensis, 1/2MS medium is the best rooting medium.

  Volatiles in Leaves of Melaleuca bracteata: Headspace Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry Wu Yingxiang, Ye Zhengmei, Wang Wenting, Zong Weixun, Guo Bingchun, Li Yongyu 2020, 36 (2):  53-63.  DOI: 10.11924/j.issn.1000-6850.casb18080055 Abstract + ( 506 )   HTML ( 2 )   PDF ( 1185KB )   ( 173 ) To study the constituents of volatiles from Melaleuca bracteate leaves, we analyzed and identified the volatile constituents in M. bracteate leaves with headspace solid-phase micro extraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) techniques. In addition, the results were compared with the essential oil in M. bracteate leaves extracted by steam distillation (HD). The results showed that 76 kinds of volatile compounds were detected, accounted for 97.28% of the total peak area, while 37 kinds of volatile compounds were detected from the essential oil extracted by HD, accounted for 99.67% of the total peak area. The volatile compounds extracted from M. bracteate leaves by HS-SPME, mainly contained ether, alkene, esters, alcohols, phenol, and aldehydes. The relative content of ether was the largest and the methyleugenol was the maximum constituent, up to 72.42%. Methyleugenol was also the main compound of essential oil from M. bracteate leaves extracted by HD, reached 91.48%. Therefore, M. bracteate shows the great potential in plant protection because of the high content of methyleugenol.

  Affecting Factors of Chlorophyll Content of Sweet Cherry Leaves in Solar Greenhouse Tian Yongqiang, Nie Guowei, Li Kai, Zhang Xiaoping, Dai Lirong 2020, 36 (2):  64-67.  DOI: 10.11924/j.issn.1000-6850.casb18100020 Abstract + ( 574 )   HTML ( 3 )   PDF ( 976KB )   ( 189 ) To explore the influencing factors of chlorophyll content of sweet cherry leaves in solar greenhouse, the content of chlorophyll a, chlorophyll b and total chlorophyll in sweet cherry leaves under different greenhouse locations, different tree directions, different tree shapes and varieties, different leaf fertilizer treatments were measured. The results showed that the chlorophyll content of sweet cherry leaves in the east of the greenhouse was significantly lower than that in the west and central part, and the chlorophyll content in the south and east direction of the tree were significantly higher than that in the west and north direction. The contents of chlorophyll a, chlorophyll b and total chlorophyll were different among sweet cherry varieties. The chlorophyll content of sweet cherry leaves was increased by spraying leaf fertilizer. There was no significant difference in chlorophyll content in sweet cherry leaves between three tree shapes in the test.

  Effects of Leaf Picking on Fruit Quality of ‘Italian Riesling’ and ‘Cabernet Gernischet’ at Different Color-changed Stages in Hexi Corridor Hao Yan, Bai Yaodong, Ma Qilong, Zhang Kun, Zhu Yanfang 2020, 36 (2):  68-73.  DOI: 10.11924/j.issn.1000-6850.casb18100066 Abstract + ( 339 )   HTML ( 3 )   PDF ( 1005KB )   ( 53 ) The paper aims to study the effect of leaf picking on fruit quality of wine grape (‘Italian Riesling’ and ‘Cabernet Gernischet’) in different color-changed stages, and screen out the period of leaf picking which is suitable for improving the quality of the two varieties. The ‘Italian Riesling’ and ‘Cabernet Gernischet’ were treated by leaf picking in different stages, and the grape fruits without leaf picking were taking as control. The total soluble solid, total soluble sugar, titratable acid, tannin and total phenol content in the two varieties were measured and analyzed by principal component analysis. The total soluble sugar, total soluble solids, total phenol, and sugar/acid were improved, and the titratable acid content was reduced in middle and later stage of full color-changed stages. In the two stages, the soluble sugar content of ‘Italian Riesling’ and ‘Cabernet Gernischet’ of the treatment group were significantly higher than those of the control group by 13.07%, 22.03%, 6.40%, and 43.38%, respectively. In later stage of full color-changed stages, the titratable acid content of the ‘Cabernet Gernischet’ treatment group decreased most significantly, 48.94% lower than that of the control group. The total phenol content in the treatment group of ‘Cabernet Gernischet’ was the highest in the two stages, which was 3.05 and 3.02 mg/g. According to the comprehensive evaluation, the score of grape fruit quality improved by leaf picking from high to low was: C-9.7>I-9.7>I-8.17>C-8.17>I-CK>C-CK. In later stage of full color-changed stages, leaf picking had great influence on fruit quality of ‘Italian Riesling’ and ‘Cabernet Gernischet’.

  Biogas Residue Substituting Chemical Fertilizer Nitrogen as Basal Fertilizer: Effect on Grape Yield and Quality Wang Shouhong, Wang Guiliang, Kou Xiangming, Zhang Jiahong, Zhu Lingyu, Xu Rong, Han Guangming, Wu Leiming, Tang Hejun, Bi Jianhua 2020, 36 (2):  74-79.  DOI: 10.11924/j.issn.1000-6850.casb18090098 Abstract + ( 339 )   HTML ( 2 )   PDF ( 994KB )   ( 102 ) The content of nitrogen was taken as quantitative index, one full chemical fertilizer treatment and five treatments of chemical fertilizer nitrogen substituted by biogas residue as basal fertilizer were designed to study the application potential of biogas residue as basal fertilizer for grape production in large area. The results showed that the grape yield first increased and then decreased, with the increase of the ratio of chemical fertilizer nitrogen substituted by biogas residue as basal fertilizer, and the yield of 100%NZY treatment was the highest, as 18197.03 kg/hm 2; grape weight and grape bunch weight showed the same trend. With the increase of the ratio of chemical fertilizer nitrogen substituted by biogas residue as basal fertilizer, some growth indicators, such as days from germination to maturity, leaf SPAD values, the internode length and roughness of new tip, 100 leaves fresh weight and single leaf area, showed a gradually growing trend, and reached the highest in 150%NZY treatment, showing delayed maturation period and remaining green when it due to become ripe, which affected the yield. The quality of grape fruit can be improved by using biogas residue as basal fertilizer, 70%NZY and 100%NZY treatments had good effect. The content of Cu, Zn and Pb in grape fruit increased slightly, while the content of Cr decreased slightly, the content of Cd and As showed no remarkable change, with the increase of the ratios of chemical fertilizer nitrogen substituted by biogas residue as basal fertilizer. The contents of heavy metal in grape fruit of all treatments were lower than the maximum levels of contaminants in foods (GB 2762-2005). Therefore, considering grape yield and quality indicators, 100% chemical fertilizer nitrogen substituted by biogas residue as basal fertilizer could be used as a reference for quantitative application of biogas residue as basal fertilizer in grape production.

  Spatial Heterogeneity of Soil Nutrients and pH Value in Macadamia ternifolia Orchard in Karst Region Tan Qiujin, Wang Wenlin, Chen Haisheng, Zheng Shufang, Qin Zhenshi, He Xianyang, Huang Xiyun, Xu Peng 2020, 36 (2):  80-83.  DOI: 10.11924/j.issn.1000-6850.casb19010069 Abstract + ( 379 )   HTML ( 3 )   PDF ( 934KB )   ( 95 ) Evaluation of spatial heterogeneity of soil nutrients and pH value forms a basis for the management of soil nutrients and fertilization in Macadamia ternifolia orchard in Karst region of southwest Guangxi. In the paper, the spatial heterogenity of soil nutrients and pH value in M. ternifolia orchard was evaluated using classical statistics and geostatistics. The results indicated rich soil organic carbon and poor total phosphours in the study area, the variation coefficients of four soil nutrient indicators ranged from 7.14% to 33.92%, belonged to moderate variability. The pH value and soil nutrients were characterized by strong spatial autocorrelation, the largest spatial autocorrelation distance was organic carbon, the smallest was total phosphorus.

  Extended Understanding of Soil Pollution Risk Management Standards for Agricultural Lands and the Status of Evaluation Standards Yuan Guojun, Lu Shaohui, Mei Xiangxin, Pang Rongli 2020, 36 (2):  84-89.  DOI: 10.11924/j.issn.1000-6850.casb18110123 Abstract + ( 515 )   HTML ( 5 )   PDF ( 1393KB )   ( 112 ) On reviewing the revision process of China’s current soil environmental quality standards, we studied the newly promulgated Soil Environmental Quality: Risk Control Standard for Soil Contamination of Agricultural Land (Trial) (GB 15618—2018). Extended reading of the main characteristics, standard value connotation and application of risk screening and regulatory value was conducted, and the basic framework of the soil environmental assessment standard for agricultural land in China was analyzed. We put forward suggestions on main problems of the soil environmental assessment standard for agricultural land, in order to provide data for the publicity and correct use of the land standards to serve the pollution prevention, risk screening and safe use, restoration and risk management of agricultural land in China, and support scientific research and technological progress in soil pollution prevention and control.

  Selection and Layout Method of Well-facilitated Farmland Construction Project at County Scale:A Case Study of Shulan City Fan Wenyang, Jiang Haiyang, Li Bin 2020, 36 (2):  90-96.  DOI: 10.11924/j.issn.1000-6850.casb18120128 Abstract + ( 355 )   HTML ( 3 )   PDF ( 1773KB )   ( 65 ) This paper aims to provide technical support for scientific layout of well-facilitated farmland construction projects. By analyzing the construction suitability and spatial stability, we proposed the selection method for project area based on coupling coordination degree model and hot and cold spots analysis. Shulan City in Jilin Province was taken as an example for the empirical research. The results showed that Shulan City had a good potential for developing well-facilitated farmland. The high suitability and medium suitability areas mainly distributed in northern towns and villages, occupying 74.91% of the total cultivated area. The distribution of spatial stability and construction suitability was roughly the same, presenting the general feature that the northern area was better than the southern area. The northern area was obviously easier for constructing well-facilitated farmland than the southern area. Well-coordinated land covered 52.92% of the total cultivated area, mainly distributed in Ping’an Town, Jinma Town, Qili Village, Kaiyuan Town, Shuiquliu Town, Tiande Village and so on. Such cultivated land had good natural endowment and complete infrastructures. In addition, they had some distance away from towns and main lines of communication, with less possibility of being occupied for construction and least difficulty in constructing well-facilitated farmland. The hot spots of desirable construction suitability, spatial stability and coupling coordination degree were mainly distributed in northern towns and villages such as Fate Town, Lianhua Village, Tiande Village, Ping’an Town and Qili Village, which were preferred areas for constructing well-facilitated farmland. Based on the actual situation of the research area, the total area for constructing well-facilitated farmland in Shulan City is 10828.89 hm 2 during the 13th Five-Year Plan Period.

  Climate Factors Affecting the Seasonal Variation of Soil Salinity Under Different Salinity Levels in Reclamation Area of Tidal Flats Zhang Jiao, Wang Bo, Zhai Caijiao, Huang Zhaoping, Cui Shiyou 2020, 36 (2):  97-103.  DOI: 10.11924/j.issn.1000-6850.casb18090135 Abstract + ( 416 )   HTML ( 0 )   PDF ( 1447KB )   ( 196 ) To explore the variation rules of soil salinity under different salinity levels in reclamation area of tidal flats, we set a field experiment [including 3 levels of salinity: low salinity (LS), medium salinity (MS), and heavy salinity (HS)] in tidal flats of Rudong, Jiangsu from May 2014 to May 2015 to determine the dynamic changes of soil salinity and climate factors. The results showed that: (1) the surface salinity showed significant salt accumulation from September to December at MS and HS level with the maximum value in October as 26.66 g/kg and 14.13 g/kg, respectively; however, there was no significant seasonal change of surface and subsurface salinity at LS level with the fluctuation from 0.50 to 2.00 g/kg and 1.20 to 2.90 g/kg, respectively; (2) at MS, HS levels, the change of surface salinity was negatively correlated with precipitation, and had a significantly positive correlation with the vapor-drop ratio; meanwhile, there was a significantly positive correlation between soil salinity and atmospheric temperature at LS level. Therefore, some artificial measures such as planting vegetation and straw mulching to intensify the effects of precipitation on soil salinity change can be adopted to take full advantage of the characteristics of precipitation concentration in coastal areas, which maybe an important measure to reduce salinity in coastal beaches in the future.

  Ozone in Zunyi: Spatio-temporal Variation Characteristics and the Relationship with Meteorological Conditions Shang Yuanyuan, Zheng Yi, Song Dan, Xia Xiaoling 2020, 36 (2):  104-108.  DOI: 10.11924/j.issn.1000-6850.casb18080044 Abstract + ( 323 )   HTML ( 4 )   PDF ( 1789KB )   ( 56 ) The paper aims to study the distribution characteristics of O3 in Zunyi of Yun-Gui plateau and their relationships with meteorological conditions. We analyzed the data from environment monitoring stations and weather stations in Zunyi during 2014-2017. The results showed that: (1) the concentration of O3 in Zunyi fast exceeded the previous growth rate than before; (2) the concentration of O3 in Zunyi was higher in summer and autumn, and lower in spring and winter; the highest concentration of O3 was in May, the peak value of O3 was in November (52.71 μg/m 3), and the valley value was 26.18 μg/m 3; this was closely related to the long average sunshine and the high average temperature in summer and autumn; (3) the day variation curve of O3 concentration in Zunyi showed a single peak distribution, the concentration at daytime was obviously higher than that at night, and the peak value generally appeared at about 16:00; (4) urban air pollution mainly came from local emissions, and chemical transformation, solar radiation, air temperature, wind speed, sunshine and relative humidity were the main meteorological factors affecting the concentration of O3 in urban area, and the influence of the precipitation amount in complex terrain and air pressure on the transport capacity of O3 concentration were relatively weak.

  Extreme Precipitation Events in the Northeast of Qinghai Lake from 1976 to 2017: Variation Characteristics Analysis Chao Hongyan, Zhang Juan, Chen Hailian, Yu Zhenbang 2020, 36 (2):  109-116.  DOI: 10.11924/j.issn.1000-6850.casb18080122 Abstract + ( 325 )   HTML ( 12 )   PDF ( 2371KB )   ( 88 ) To further understand the climate change in alpine pastoral areas, based on the daily precipitation data of Haiyan Station in the northeast of Qinghai Lake from 1976 to 2017, we determined the extreme precipitation (snow) threshold in winter (summer) half year and counted extreme precipitation events by using the percentile method, analyzed the variation characteristics, future trends and cycles of extreme precipitation events by linear trend, R/S and wavelet analysis. The results showed that: the extreme precipitation days and extreme precipitation in the northeastern of Qinghai Lake did not increase significantly in winter and summer half year; the extreme precipitation intensity and daily maximum precipitation did not increase significantly in winter half year, but did not decrease significantly in summer half year; the contribution rate of extreme precipitation to annual precipitation increased at different rates, and the extreme precipitation in summer half year had a greater impact on annual precipitation; the number of precipitation days in winter half year did not decrease significantly, while the precipitation increased significantly, indicating that the probability of short-term heavy precipitation in winter half year increased, and the number of precipitation days and precipitation in summer half year were not obvious; in the future, the trend of increasing the number of extreme precipitation days in winter half year would change; the extreme precipitation would continue to show volatility irrespective of the previous trend, and other factors would continue to change in the early stage; the number of extreme precipitation days and precipitation in winter (summer) half year had obvious periodic variation characteristics. The study of extreme precipitation in alpine pastoral areas is of significance in preventing the occurrence of snowstorms and floods caused by short-term heavy precipitation.

  Underground Pests by Black Light Trapping in Linfen, Shanxi: Species Composition and Dominant Population Dynamics Lu Junjiao, Ren Meifeng, Li Daqi, Wu Yupeng, Sun Peipei, Dong Jinming 2020, 36 (2):  117-121.  DOI: 10.11924/j.issn.1000-6850.casb19020024 Abstract + ( 366 )   HTML ( 3 )   PDF ( 1464KB )   ( 160 ) To clarify the species composition and annual dynamics of dominant population of underground pests which caused serious damage to wheat and maize in Linfen, Shanxi, we investigated the populations of underground pests in two crops (wheat and maize) a year farmland by the method of black light trapping, and analyzed the trapped adults by the methods of indoor identification, data analysis, and literature retrieval. The results showed that: 7 species were the dominant populations, such as Anomala corpulenta and Metabolus tumidifrons; and the occurrence quantity and period of different dominant populations were different, their phototactic responses to black light were also different; the occurrence period of the absolute dominant population (Anomala corpulentai) adults was relatively concentrated from late June to mid-july, and A. corpulentai was highly sensitive to black light and could be monitored and controlled by black light trapping.

  Extraction Technology and Antioxidant Activity of Polysaccharides from Cordyceps militaris Fruiting Body Lin Fan, Hou Xiaoxiao, Liu Jingyu, Chang Mingchang, Meng Junlong 2020, 36 (2):  122-128.  DOI: 10.11924/j.issn.1000-6850.casb18120014 Abstract + ( 425 )   HTML ( 1 )   PDF ( 2010KB )   ( 55 ) The paper aims to obtain the optimal condition for extracting polysaccharide from Cordyceps militaris fruiting body by hot water and to provide reference for the study of its immune activity. Taking C. militaris fruiting body as the research object, using the new deproteinization method, based on the single factor experiment and the response surface method, we optimized the extraction process parameters of the polysaccharide of C. militaris fruiting body, and studied the antioxidant activity of the polysaccharide. The optimum extraction condition is: the extraction temperature of 80℃, the extraction time of 3.1 h, the ratio of liquid to material of 41:1 (mL:g), and the extraction of 2 times. Under this condition, the actual yield of polysaccharide is 6.3328%, and the relative error from the predicted value of 6.5877% is less than 5%, indicating that the optimization parameters of extraction process are reliable. The scavenging ability of hydroxyl radical is 53.8%, the reduction ability of iron ion is 1.133 and the total antioxidant activity is 0.807 when the polysaccharide obtained by this method is 8 mg/mL. The scavenging ability of 50% inhibiting concentration is 1.449 mg/mL. The method of extraction of polysaccharide with high extraction rate and high antioxidant activity is obtained, which could lay a foundation for the separation, purification and bioactivity of polysaccharide from C. militaris fruiting body.

  Chestnut-like Aroma of Green Tea: Research Progress of Formation and Technology Zhang Mingming, Jiang Yongwen, Yuan Haibo, Yang Yanqin, Deng Yuliang, Dong Chunwang, Li Jia, Hua Jinjie, Wang Jinjin 2020, 36 (2):  129-137.  DOI: 10.11924/j.issn.1000-6850.casb18090036 Abstract + ( 683 )   HTML ( 5 )   PDF ( 1497KB )   ( 223 ) To investigate the drying technology and formation mechanism of chestnut-like aroma of green tea, this paper systematically summarized the relevant researches on tea aroma and chestnut-like aroma in the past 30 years at home and abroad. Although there had been numerous reports on the aroma compounds of green tea, while studies on chestnut-like aroma were relatively scarce. So far, the chestnut-like aroma type was subdivided and the key components were explored. However, the formation mechanism of the aroma was confined to theoretical conjecture, and the specific mechanism was not investigated based on the processing technology. In addition, the influencing factors of chestnut-like aroma had not been studied thoroughly, and it could only be speculated that the fixation and drying process were the critical factors. Thus, the systematic research based on the drying process and parameters should be carried out in the future. The present study aims to summarize the relevant researches on chestnut-like aroma, discuss the key technology for the formation of chestnut-like aroma, and emphatically analyze the effects of related parameters of drying process. The results will provide theory basis for the processing of chestnut-like aroma of green tea.

  Artificial Fish Nest and Its Function in Fishery Resources Proliferation Deng Ru, Meng Shunlong, Chen Jiazhang 2020, 36 (2):  138-143.  DOI: 10.11924/j.issn.1000-6850.casb18100102 Abstract + ( 405 )   HTML ( 2 )   PDF ( 1311KB )   ( 184 ) To further promote the in-depth development of the research on artificial fish nest technology and the popularization and application of fishery resources proliferation technology, we summarize the development status of artificial fish nest breeding technology at home and abroad, sum up the research examples of different types of artificial fish nests in fishery resources proliferation, and expound the effects of artificial fish nest breeding technology on increasing yield and efficiency. In addition, we summarize the types, structures and materials of artificial fish nests, put forward the requirements of site selection, construction and management of artificial fish nests, discuss the development prospect of artificial fish nest, and point out the key research direction of artificial fish nest technology.

  The Application Strategy of Probiotics Affects Growth and Cultural Water Quality of Apostichopus japonicus Han Sha, Qu Hongxia, Li Chenglin, Hu Wei, Zhao Bin, Liu Zhaocun 2020, 36 (2):  144-148.  DOI: 10.11924/j.issn.1000-6850.casb18090090 Abstract + ( 454 )   HTML ( 2 )   PDF ( 1458KB )   ( 52 ) The paper aims to study the effects of the application strategy of probiotics on growth and cultural water quality of Apostichopus japonicus. The Apostichopus japonicus with body weight of (7.81±0.25) g were fed with diet mixed with probiotics (mainly bacillus and lactobacillus) for different time (0, 6, 9, 12, 15 h). The experiment was continued for 30 days and the water was changed every 10 days. The results showed that the specific growth rate (SGR) of A. japonicus in experimental groups were significantly higher than that in control group (P<0.05). The SGR of the A. japonicus fed with diet mixed with probiotics for 12 hours was the highest of 0.618%/d,which was 1.52 times as that of the control group, but there was no significant difference with the group of diet mixed for 9 hours. The level of ammonia, nitrite and COD in the water of the control group increased with the time extended, and the water indicators of the experiment groups increased with the time extending of the mixed diet. The level of the water indicators in group with diet mixed for 0 hours was the lowest,but there was no significant difference among the experiment groups and the indicators were significantly lower than those in the control group at the end of the experiment. The results indicated that the A. japonicus fed with the diet mixed with probiotics for 9 to 12 hours had the best effect on the growth and water quality.

  Revitalization of Rural Industry Huang Guoqin 2020, 36 (2):  149-154.  DOI: 10.11924/j.issn.1000-6850.casb20190700455 Abstract + ( 867 )   HTML ( 9 )   PDF ( 1188KB )   ( 85 ) At present, the whole country is making every effort to promote the implementation of Rural Revitalization Strategy, whose focus is industrial prosperity. How to realize the revitalization and prosperity of rural industry is an urgent and realistic issue which is worthy of study. Firstly, this paper analyzes the status and role of rural industry revitalization in Rural Revitalization Strategy, and briefly reviews the development process of rural industry in China since 1949, and divides the process into four development stages: The first stage (1949-1977): the slow development of traditional industries; the second stage(1978-2000): the emergence of township enterprises; the third stage(2001-2011): the emergence of new industries; the fourth stage(from 2012 to now):the green "transformation" of rural industry. Secondly, it points out the prominent problems existing in current rural industry in China, such as: fewer categories of industries, small production scale, shallow industrial level, short industrial chain, low production efficiency, weak characteristic industries, lack of brand industries, poor industrial environment, low product quality and lack of competitiveness. Finally, in view of the above problems, this paper puts forward six principles and 10 specific measures to implement the Rural Revitalization Strategy and realize the rural industry revitalization, aiming at making a contribution to the implementation of the Rural Revitalization Strategy.

  Thoughts on Accelerating Chinese Urban-Rural Integration and Promoting Rural Construction Li Ying, Jia Lianqi, Zhang Qiuling, Jian Baoquan, Li Yi, Li Miao 2020, 36 (2):  155-159.  DOI: 10.11924/j.issn.1000-6850.casb20190900655 Abstract + ( 404 )   HTML ( 0 )   PDF ( 1296KB )   ( 70 ) At present, China is in the stage of rapid urbanization, and mutual promotion is found between agriculture and industry, the urban and the rural. However, the income and consumption gap between urban and rural areas still has great disparity, so does the overall labor productivity. The basic infrastructures of rural areas are weak, as well as the rural social security level. With the development of urbanization, some villages are integrated into towns and cities, rural labors go out in large numbers, causing hollow villages with aging problems. At the same time, with the implementation of some major projects, some new problems have emerged, such as relocation, integration and etc. Under the background of rural revitalization, based on studying the situation and characteristics of the rural construction in Europe, we put forward some suggestions on China’s current rural construction problems, including balancing urban and rural development space, making distinctive rural construction planning, cultivating new-type agricultural business entities, and maintaining rural vitality through integrated development.

  From Knowledgeable to Professional: the Reality Path of Modernity Reconstruction of Rural Culture Yin Jian, Sha Bin 2020, 36 (2):  160-164.  DOI: 10.11924/j.issn.1000-6850.casb18120056 Abstract + ( 550 )   HTML ( 2 )   PDF ( 6752KB )   ( 62 ) The paper aims to analyze the modernity reconstruction of rural culture and explore the modernity reconstruction path of rural culture on the basis of building the theoretical framework of cultural transition in the perspective of rural revitalization strategy. Through the analysis of the internal conformity logic, the necessity and the urgency of the modernity reconstruction of rural culture, according to the logical thinking of clarifying the subject, defining the goal and exploring the path, the author established the strategy system of self-confidence reconstruction of rural culture with ideological consensus, institutional arrangements, policy implementation and governance operation which conformed to China’s national conditions; clarified that “modern villagers” were the main body of reconstruction of rural culture, cultural self-confidence could be achieved through strengthening cultural identity, cultivating “modern villagers”, cultural innovation and cultural integration.