Current issue

• 2022 Vol.38 No.32 Published:15 November 2022

  Mineral Accumulation Characteristics of Red Beet Seedlings Under Exogenous Selenium Treatment WANG Jiaqi, ZHANG Zixuan, LIU Naixin 2022, 38 (32):  1-5.  DOI: 10.11924/j.issn.1000-6850.casb2021-1172 Abstract + ( 251 )   HTML ( 13 )   PDF ( 1288KB )   ( 43 ) Red beet has high nutritional value and medicinal value. Selenium is an essential element for human body and is regarded as the ‘kindling of life’ by the medical and nutritional circles at home and abroad. In order to explore the effect of selenium on the accumulation of mineral substances in red beet seedling stage, this study took the Dutch red beet variety ‘Bijiu’ as the research material and applied different kinds and concentrations of exogenous selenium to it (0, 0.5, 5, 10 mol/L). The experiment results showed the following conclusions. When Na2SeO4 and Na2SeO3 were 0.5 mol/L, the effect had little difference on the absorption of Na, Mg, Ca, Mn and Fe in red beet, Na2SeO4 and Na2SeO3 at the concentration of 5 mol/L could promote the absorption of Na, Mg, Ca, Mn and Fe in red beet. At the concentration of 10 mol/L, Na2SeO4 and Na2SeO3 could inhibit the absorption of Mg, the amount of Na, Mg, Ca, Mn and Fe absorbed by red beet was slightly higher than those of the control, but the absorption boost was reduced. In summary, applying proper concentrations of exogenous selenium in red beet seedling stage could increase the absorption of Na, Mg, Ca, Mn and Fe in red beet.

  Spatial-temporal Evolution of Normalized Difference Vegetation Index in Burqin County of Xinjiang in Five Years HU Xinyue, SUN Qian, GULI GULI·Miedi Lihazi 2022, 38 (32):  6-11.  DOI: 10.11924/j.issn.1000-6850.casb2021-1121 Abstract + ( 185 )   HTML ( 3 )   PDF ( 3875KB )   ( 30 ) Based on the monthly MODIS-NDVI remote sensing data from 2010 to 2014, this paper took Burqin County of Xinjiang as the research area and grasped the temporal and spatial differentiation of the normalized vegetation index (NDVI) of four seasons in Burqin County. The trend analysis method was used to analyze the temporal dynamic characteristics and spatial change trends of NDVI in Burqin County in the five years, and quantitatively discuss the temporal and spatial evolution of NDVI in the study area. The results showed that: (1) the time series of NDVI in Burqin County from 2010 to 2014 presented a downward trend, and the magnitude order of NDVI in different seasons was summer>autumn>spring>winter; (2) the variation of NDVI in the same season of different years was generally small, while the inter-annual variation characteristics of NDVI in different seasons were significant; among them, the variation characteristics in spring were significant, while the spatial distribution change in summer was not obvious and its variation was relatively stable; (3) during the five years, the average annual NDVI change trend in summer in Burqin County gradually increased; in spring, the NDVI change trend decreased, and the vegetation index gradually decreased; in autumn, the NDVI change trend increased while the plant distribution decreased in the north of the county; in winter, the NDVI change trend decreased. This study analyzes the temporal and spatial distribution and evolution of vegetation coverage in Burqin County, aiming to provide certain scientific reference for regional protection of the ecological environment.

  Study on Callus Induction and Anti-browning of Rosa roxburghii Tratt Leaves LI Tingting, CHEN Hong 2022, 38 (32):  12-21.  DOI: 10.11924/j.issn.1000-6850.casb2022-0016 Abstract + ( 273 )   HTML ( 8 )   PDF ( 1768KB )   ( 37 ) In order to further optimize the callus induction conditions of Rosa roxburghii Tratt leaves, the leaves of four genotypes of Rosa roxburghii Tratt, ‘Guinong 1’, ‘Guinong 2’, ‘Guinong 5’ and ‘Guinong 7’, were used as test materials. The effects of pretreatment, sampling time, plant growth regulator and anti-browning agent on leaf callus induction and browning rate reducing were studied by tissue culture method. The results showed that being soaked in 100 mg/LVc for 12 h could significantly increase the induction rate of the four genotypes’ leaves and reduce the browning rate, among which, ‘Guinong 1’ had the highest induction rate of 97.44 %. Spring was the best time for selecting leaves of different genotypes, and the callus induction rate was the highest and the browning rate was the lowest in March. The suitable combination of plant growth regulators for callus induction of ‘Guinong 1’ and ‘Guinong 2’leaves was 1.0 mg/L6-BA+0.5 mg/LNAA, while the optimal combination of plant growth regulators for callus induction from leaves of ‘Guinong 5’ and ‘Guinong 7’ was 1.0 mg/L6-BA+1.0 mg/LNAA+1.0 mg/LTDZ. The effect of three anti-browning agents on callus proliferation and culture of Rosa roxburghii Tratt leaves of the four genotypes was AgNO3 > citric acid > PVP. Citric acid or AgNO3 supplementation could significantly reduce the browning rate of Rosa roxburghii Tratt leaves, and 2.0 g/L citric acid or 0.4 g/LAgNO3 was the most suitable, under which, the browning rate of leaves of the four genotypes reached the lowest value. In this experiment, we obtained the most suitable combination of growth regulators for callus induction of the four genotypes of Rosa roxburghii Tratt, which could reduce the browning rate. The study lays a foundation for the establishment of subsequent in vitro regeneration system.

  CaWRKY Transcription Factors Induced by Phytophthora capsici: Screening and Signal Pathway Analysis XU Xiaomei, LI Ying, HENG Zhou, XU Xiaowan, LI Tao, WANG Hengming 2022, 38 (32):  22-31.  DOI: 10.11924/j.issn.1000-6850.casb2021-1119 Abstract + ( 215 )   HTML ( 9 )   PDF ( 2291KB )   ( 32 ) The aims of this study are to identify WRKY transcription factors in the whole genome of pepper, select the CaWRKYs induced by Phytophthora capsici and analyze the signal pathways involved in the key CaWRKY genes. CM334 and NMCA10399 were used as experimental materials. Based on genome and RNA-seq data, gene expressions were obtained by qRT-PCR under the treatment of salicylic acid (SA) and methyl jasmonate (MeJA). The results showed that 69 CaWRKYs were identified in the whole genome of pepper. At the time point of 12 hpi, there were 7 and 3 CaWRKYs significantly and differentially expressed in resistant and susceptible materials, respectively. At 36 hpi, 13 and 22 genes were significantly and differentially expressed in resistant and susceptible materials, respectively. These results indicated that resistant material could respond more quickly to the pathogens. Among the 8 key CaWRKYs selected, CaWRKY19 and CaWRKY65 were induced by SA and up-regulated expressed, while CaWRKY50 was induced by MeJA and up-regulated expressed. CaWRKY25 was up-regulated by SA and down-regulated by MeJA, while CaWRKY49 was down-regulated by both SA and MeJA. Signal pathway analysis speculated that CaWRKY19 and CaWRKY65 were involved in pepper defense against Phytophthora through SA signal pathway, CaWRKY50 through JA signal pathway, while CaWRKY25 and CaWRKY49 through both SA and JA signal pathway.

  Effects of Leaching and Organic Fertilizer on Improvement of Saline-Alkali Soil and Growth of Sapindus mukorossi LI Wei, XU Zhonghua, ZHENG Mingjie 2022, 38 (32):  32-37.  DOI: 10.11924/j.issn.1000-6850.casb2021-1107 Abstract + ( 194 )   HTML ( 7 )   PDF ( 1251KB )   ( 23 ) Low cost, sustainable and ecological ways are of great significance to the improvement of saline-alkali soil. In this study, indoor simulated experiment and field application were simultaneously carried out to test the effects of leaching, organic fertilizer and gravel on the improvement of saline-alkali soil. The plant growth of Sapindus mukorossi was used to examine the improvement results. There were three different treatments, 10 cm depth of gravel adding 10, 15 and 20 cm depth of organic fertilizer respectively. The results showed that leaching reduced soil pH, electrical conductivity and sodium adsorption ratio (SAR), and caused the loss of mineral nutrients. The combination of leaching and organic fertilizer produced better results because of the supplement of mineral nutrients and organic matter. The leaching and soil improvement effects were positively correlated with the addition of organic fertilizer. Compared with the control, 20 cm depth of organic fertilizer decreased soil pH by 7%, Na+ content by 28%, and SAR by 45%, but increased the content of soil organic matter, available nitrogen and available phosphorus by 37%, 43% and 73%, respectively. Leaching and 20 cm depth of organic fertilizer and 10 cm gravel were applied to soil improvement in landscape engineering, and for S. mukorossi, the leaf color was normal, the gas exchange was high and the death rate was zero.

  Producing Organic Fertilizer by Fermentation of Macadamia Peel SONG Haiyun, XIAO Haiyan, ZHANG Tao, HE Peng, ZHENG Shufang, XU Peng, WEI Yuanrong, WANG Wenlin 2022, 38 (32):  38-44.  DOI: 10.11924/j.issn.1000-6850.casb2022-0032 Abstract + ( 317 )   HTML ( 4 )   PDF ( 1624KB )   ( 36 ) Producing organic fertilizer by the fermentation of macadamia peel was studied to provide method and a basis for the utilization of macadamia peel waste. By laboratory test, the suitable auxiliary material was selected as wheat bran with 3% of bacterial agent inoculation and 60% water content. The dried macadamia peel was used as raw material for composting, wheat bran was added, and the decomposition was conducted with aerobic bacteria. The changes of nutrients and organic matter contents in different fermentation stages were measured and evaluated. The results showed that: when wheat bran was used as auxiliary material and bacteria agent was inoculated at 3% amount, under the condition of water content maintained at 50%-60% in the early stage (the first 40 days) and no water addition in the late stage (after the first 40 days), after 55 days of composting, the carbon to nitrogen ratio was lower than 20%, the organic matter content was 89.1%, the total nitrogen, phosphorus and potassium was 5.19%, pH was 6.92, and the water content was 25.79%. The products had brown color, no odor and soft texture, and were completely decomposed, which could meet the national standards of organic fertilizer. In conclusion, the fermentation of macadamia peel waste to produce organic fertilizer is an effective way of waste utilization.

  Copper Content Characteristics of Main Grain Crops and Their Influencing Factors in Shizuishan of Ningxia WANG Zhiqiang, YANG Jianfeng, SHI Tianchi 2022, 38 (32):  45-54.  DOI: 10.11924/j.issn.1000-6850.casb2021-1148 Abstract + ( 261 )   HTML ( 3 )   PDF ( 1627KB )   ( 26 ) To investigate the content characteristics of trace element copper in main grain crops in Shizuishan and their influencing factors, the contents of total Cu and available Cu in soil and main grain crops such as maize, wheat and rice in the area were analyzed. Linear regression method was used to analyze the correlation between crop Cu uptake and soil environmental factors, such as total Cu, available Cu, pH, cation exchange capacity (CEC), organic matter, available Fe, alkali-hydrolyzed N, available P, available K, available B, available Se and available Mo. The results showed that Shizuishan had soil pH 7.97-9.09, and the median pH of soil in maize, wheat and rice fields was pH 8.47-8.53, indicating that the soil was weakly alkaline or alkaline. The total Cu content in soil of maize, wheat and rice fields ranged from 11.70 to 30.40 mg/kg, with a median value of 20.95 to 25.32 mg/kg; the average value was 21.12 to 24.65 mg/kg, which was equivalent to the average content of soil Cu of 24 mg/kg in China. The available Cu content ranged from 0.74 to 7.51 mg/kg, and the median available Cu content in maize, wheat and rice plots ranged from 1.65 to 2.99 mg/kg. The ratio of available Cu to total Cu in maize, wheat and rice plots ranged from 6.32%-48.10%. The content of total Cu and available Cu were not high, but the proportion of available Cu was relatively high. The Cu content in maize, wheat and rice ranged from 1.20 to 3.24g, 4.11 to 11.70 and 14.80 to 53.21 mg/kg, respectively, and the median Cu content was 1.66, 5.95 and 27.80 mg/kg, respectively. Cu enrichment coefficient of crops was in the order of rice > wheat > maize, and Cu enrichment capacity of rice was much higher than that of wheat and maize. Analysis of influencing factors showed that soil available Cu content was significantly correlated with soil total Cu content, maize Cu content was significantly correlated with soil total Cu content, and rice Cu content was significantly correlated with soil organic matter content. However, the environmental factors including soil pH, CEC, available Fe, alkali-hydrolyzed N, available P, available K, available B, available Se and available Mo had no significant correlation with Cu uptake in maize, wheat and rice. Rice products in Shizuishan belong to high-quality rice rich in trace element Cu, and vigorously developing Cu-rich rice could provide safe, healthy and nutritious Cu-rich food for consumers.

  Environmental Factors Influencing Spring Wheat Yield in Semi-arid Region of Loess Plateau LEI Jun, ZHAO Funian, LU Guoyang, YAO Rui, NIU Haiyang, LI Wenju, YANG Huining 2022, 38 (32):  55-62.  DOI: 10.11924/j.issn.1000-6850.casb2021-1098 Abstract + ( 237 )   HTML ( 4 )   PDF ( 1404KB )   ( 43 ) To investigate the effect of environmental factors on spring wheat yield in the semi-arid region, the correlation between environmental factors and spring wheat yield was analyzed based on the long-term data (1987—2011) from agrometeorological observation station in Dingxi of Gansu Province. Meanwhile, data about the correlation between water consumption and yield of spring wheat of the study area（1993—2013）were also collected from literature. The results showed that there was a significantly negative correlation between spring wheat yield and the difference between evaporation and precipitation in May and main growth periods. However, the negative correlation was influenced by the soil water content before sowing. The greater the soil water content before sowing, the higher the spring wheat yield was under the same atmospheric evaporation condition, and vice versa. The spring wheat yield had a positive correlation with the precipitation in May and the soil water content before sowing. Under the same precipitation amount, the higher the soil water content before sowing, the higher the spring wheat yield was. Under the same soil water content, the drier the atmosphere in main wheat growth periods, the lower the wheat yield was. The effective water supply could explain 60.4% of the yield variation, and the water consumption could explain 93.4% of the yield variation. Furthermore, the temperature had no direct impact on the spring wheat yield in the study area, but it might affect the spring wheat yield formation through air saturation deficit.

  Effects of Continuous High Temperature and Drought Stress on the Growth of Spring Maize JIANG Jufang, YANG Hua, HU Wenqing, WEI Yuguo 2022, 38 (32):  63-68.  DOI: 10.11924/j.issn.1000-6850.casb2021-1109 Abstract + ( 320 )   HTML ( 6 )   PDF ( 1455KB )   ( 56 ) In order to explore the effects of high temperature and drought on the growth of spring maize, this paper took spring maize ‘Kehe No.28’ as the material, and set up three treatments of normal irrigation, continuous drought and continuous high temperature during the whole growth stage. The effects of high temperature and drought on spring maize growth in arid area were studied. The results showed that: (1) under continuous high temperature treatment, the spring maize seedling period was shortened by 9-13 days, the growth interval of the ear period was extended by 6-12 days, and the flowering and kernel period were incomplete; while under continuous drought treatment, the simultaneous period of spring maize vegetative growth and reproductive growth was prolonged by 3-8 days, and the grain filling and maturity could not be completed normally; (2) under continuous high temperature treatment, the spring maize grew fast in the early stage, and the height did not increase after tasseling; while under continuous drought treatment, the spring maize grew slowly, and the plant height was significantly smaller after the jointing period; under continuous high temperature and drought treatment, the total leaf area and specific leaf area per plant were smaller than those of the control after jointing period; (3) under continuous high temperature, dry matter distribution in spring maize was stem > leaf > leaf sheath, while under continuous drought, that was leaf > stem > leaf sheath, and the dry matter distribution in ears was very small, resulting in less economic output; while under the control, the order was ear>stem>leaf>leaf sheath; (4) under continuous high temperature and drought treatment, the moisture content was leaf sheath>stem>leaf. Under the stress of high temperature and drought, when the yield cannot be guaranteed, it is more appropriate to transfer grain to feed during the tasseling period. This study can provide a theoretical basis for scientific drought relief and disaster reduction.

  Effects of Land Use Change on Ecological Service Value in Mountainous County of Northern Guangdong GAO Lin, HU Jinhao, WANG Zhichao, LIN Changhua, FENG Huimin 2022, 38 (32):  69-77.  DOI: 10.11924/j.issn.1000-6850.casb2021-1104 Abstract + ( 183 )   HTML ( 2 )   PDF ( 1992KB )   ( 24 ) Mountainous area is one of the ecologically fragile systems. To clarify the impact of land use change on the ecological service value of mountainous area is beneficial to the protection of ecological environment and the land use planning in urban and rural areas. This study took Renhua County as an example, based on Landsat TM images in 2000, 2010 and 2020, RS and GIS software were adopted to analyze the land use change in Renhua County in the 20 years, and the impact of land use change on land system stability and ecosystem service value were analyzed from the perspective of ecological service value. The result showed that: (1) the land use types in Renhua County were forestland, cropland, grassland, water area and construction land, and their area was in a descending order; from 2000 to 2020, forestland, cropland and grassland showed a trend of increasing first and then decreasing, while the area of construction land increased year by year, and the area of water area showed a trend of decreasing first and then increasing; (2) from 2000 to 2020, the land use degree index showed an increasing trend, the information entropy of land use structure ranged from 0.76 to 0.82, the stability of land use structure increased, and the land use balance degree ranged from 0.47 to 0.51, with an increase year by year; (3) the change of land use type affected the change of ecological service value, from 2000 to 2020, the overall ecological service value of Renhua County showed a trend of decreasing first and then increasing, with a net increase of 394.4078 million Yuan; (4) among the 11 secondary service functions, the value of hydrological regulation function had an obviously increasing trend, increased from 3.4241679 billion Yuan in 2000 to 3.8055619 billion Yuan in 2020. The research results could provide a basis for the protection of natural resources, the sustainable economic and ecological development, and the land structure adjustment in mountainous areas.

  Pollution Trend and Prevention Measures of Livestock and Poultry Breeding in Ningxia During the 14th Five-Year Plan Period HUANG Yajie, CUI Yanzhi, Jia Xiaomei, YU Qi 2022, 38 (32):  78-85.  DOI: 10.11924/j.issn.1000-6850.casb2021-1129 Abstract + ( 156 )   HTML ( 2 )   PDF ( 1641KB )   ( 18 ) To assess the pollution risk and environmental loaded pressure (ELP) caused by the rapid development of livestock and poultry breeding (LPB) during the 14th Five-Year Plan period in the Ningxia Hui Autonomous Region, according to the data of LPB, the emissions of livestock and poultry manure (LP), chemical oxygen demand (COD), nitrogen (N) and phosphorus (P) were estimated by the pollutant discharge coefficient method. Environmental loaded pressure of LPB was evaluated by the indexes, including the suitability evaluation, land-loaded pressure and the nutrient-loaded pressure. The results showed that: (1) the emissions of COD, N and P were 1.23 million, 68600 and 7440 tons, respectively; (2) the suitability areas of LPB were mainly distributed in the southern mountainous area, in total, the land-loaded capacity was greater than the amount of LPB; however, the amount of LPB in Litong District was 3.1 times that of the land-loaded pressure, which posed a great risk of breeding pollution; the manure could not be all returned to field in Yinchuan urban area, Litong District and Jingyuan County; (3) the N emission was estimated to reach 120000 tons in 2025, showing an increase of more than 50000 tons compared with that of 2020; the P emission was estimated to reach 12000 tons, correspondingly 1.7 times that of 2020; the COD emission was estimated to reach 2.517 million tons, correspondingly 1.5 times that of 2020. In 2025, the loaded warning value of cultivated land for LP will reach 3.50. Therefore, countermeasures were put forward from six aspects: proper control of breeding scale, strict LP returning to field, strengthening fertilizer use of LP, scientific treatment of LP pollution, setting up LP centralized treatment center and policy support.

  Isolation and Identification of Pathogenic Fungi Causing Panax ginseng Root Rot in Xinbin of Liaoning LIU Kun, SUN Wensong, SHEN Baoyu, ZHANG Tianjing 2022, 38 (32):  86-91.  DOI: 10.11924/j.issn.1000-6850.casb2021-1117 Abstract + ( 184 )   HTML ( 4 )   PDF ( 2122KB )   ( 21 ) In order to isolate and identify pathogenic fungi of root rot disease in main ginseng producing areas of Liaoning Province, and provide theoretical support for subsequent ginseng disease resistance breeding and green control of root rot disease, by using tissue isolation technique and malt-agar method, the pathogens of ginseng root rot were isolated and purified and the pathogenicity was tested with 2-5 years old infected plants from serious disease areas of Xinbin. Combined with morphological observation, rDNA-ITS and EF-1α sequence analysis, morphological and molecular biological identification of the strains were carried out. Finally, 2 pathogenic fungi were isolated, with different colony morphology, named strain JS64-1 and strain JS64-3, which were identified as Fusarium solani and Fusarium oxysporum, respectively. The malt-agar method, which was used to determine the pathogenicity of ginseng root rot in this article, was convenient and time-saving, and the results were accurate and reliable. The study could lay a foundation for research on root diseases of other plants.

  Biocontrol Fungus Coniothyrium minitans: Effects on Microbial Community Structure in Oilseed Rape Rhizosphere Soil YANG Xiaoxiang, HUANG Xiaoqin, ZHANG Lei, ZHANG Zhongmei, XIAN Yunxi, ZHOU Xiquan, LIU Yong 2022, 38 (32):  92-98.  DOI: 10.11924/j.issn.1000-6850.casb2022-0381 Abstract + ( 190 )   HTML ( 3 )   PDF ( 1791KB )   ( 71 ) The aims are to determine the effect of Coniothyrium minitans on soil microbial community structure, and to provide a theoretical basis for the application of this biocontrol fungus in production. The occurrence of Sclerotinia stem rot was investigated by spraying C. minitans as treatment group (CM) and spraying clean water as control group (CK), and the changes of soil microbial community were analyzed by high-throughput sequencing technology. The results showed that the incidence rate and disease index of Sclerotinia stem rot in control group were up to 74.64% and 46.13, respectively. While, the incidence rate and disease index were reduced to 23.33% and 9.37, respectively, in treatment group, and the control effect was 79.70%. In addition, the soil microbial community structure was changed and the abundance and diversity of soil fungi were significantly increased after spraying C. minitans. At the phylum level, the relative abundance of Proteobacteria, Gemmatimonadetes, Ascomycota, Mortierellomycota and Basidiomycota were increased, but the relative abundance of Actinobacteria was decreased after spraying with C. minitans. At the genus level, the abundance of Sphingomonas, Lysobacter, Dokdonella, Trichocladium, Fusarium, Aspergillus and Plectosphaerella were increased, while, the relative abundance of unidentified_Chitinophagaceae, Stenotrophomonas, Geobacter, Thielavia and Cutaneotrichosporon were decreased after spraying with C. minitans. The application of C. minitans could effectively control Sclerotinia stem rot, increase the abundance and diversity of soil fungi, and improve soil microbial community structure. The results of this study can provide a basis for the large-scale promotion of C. minitans in the field.

  Screening Nutrient Solution Formulas for Static Hydroponics of Sweet Potato ‘Shangshu 19’ Plantlet and Analysis of Endogenous Hormone Concentrations WANG Yongjiang, WANG Shuang, QIAO Qi, TIAN Yuting 2022, 38 (32):  99-105.  DOI: 10.11924/j.issn.1000-6850.casb2021-1083 Abstract + ( 317 )   HTML ( 2 )   PDF ( 1288KB )   ( 29 ) To provide reference for establishing rapid propagation system for virus-free ‘Shangshu 19’ plantlet, this study screened the optimal nutrient solution formula for sweet potato ‘Shangshu 19’ plantlets growing under static hydroponics, clarified the kinds of endogenous hormones and the effects of hydroponics on hormones in sweet potato plantlet leaves. The effects of different nutrient solution formulas with different concentrations on the growth of virus-free ‘Shangshu 19’ plantlets were studied by using the nutrient solutions including circulating water lettuce nutrition formula, Hoagland nutrient solution, and MS microelement, clear water was used as the control treatment. Under hydroponics and soil culture, endogenous hormones were detected by ultra-performance liquid chromatography-triple quadrupole tandem mass spectrometry. The results showed that: under the static hydroponics for 20 days, the maximum root length, average fresh root weight, relative chlorophyll content and average stem length of sweet potato plants were the best in 1/2 Hoagland nutrient solution, better than those in other nutrient solution treatments. 16 kinds of endogenous hormones were tested, 11 of them were detected in the sweet potato plants. Compared with those of the control, the concentration of abscisic acid (ABA) decreased by 71.37%, the concentration of indole-3-acetic acid (IAA) decreased by 51.64%, and the concentration of jasmonic acid (JA) increased by 231.68% in hydroponic plants. To our knowledge, this is the first report on virus-free ‘Shangshu 19’ plantlets which were cultured under hydroponics. 1/2-Hoagland nutrient solution is the most suitable solution for hydroponics. For the first time, 11 endogenous hormones in sweet potato were detected under hydroponic conditions. Compared with the control, the concentration of ABA and IAA in sweet potato plants under hydroponics decreased, and the concentration of JA increased. The concentration of ABA, JA and IAA varied greatly. The results can provide reference for further research and utilization of sweet potato hydroponic technology and the establishment of sweet potato plant factories.

  The Application of Excel VBA Array in the Design of Matching Test List for Maize Inbred Lines SONG Yingbo, WANG Nannan, ZHANG Hongquan, FAN Weimin, LI Yu, MENG Fanxiang, LI Candong, CHEN Qingshan 2022, 38 (32):  106-110.  DOI: 10.11924/j.issn.1000-6850.casb2021-1082 Abstract + ( 227 )   HTML ( 3 )   PDF ( 1377KB )   ( 21 ) The core of maize inbred line matching test is the determination of combining ability. How to input a huge amount of data of inbred lines and testers into the computer quickly in the design of test list, and how to edit the data to form a list of the field trials quickly need to be considered by every breeder. In this study, a coding method for matching test of maize inbred lines was proposed by using VBA technology, to realize quick data input, optimize the tedious operation with repeated steps and avoid human operation errors, thus achieving automation and high working efficiency. The results show that, compared with the conventional basic Excel method, VBA method is simple to operate and easy to learn, with higher accuracy and speed. With the expansion of the scale of the inbred lines, the advantages of VBA method has become more obvious. By using the VBA method programming scheduling, a large number of manual operation steps could be simplified. It is suggested that VBA method should be popularized in the design of maize inbred line matching test.

  Accuracy Analysis of Soybean Vegetation Coverage Measurement by Photo Line Transect Method WANG Huanhuan, YANG Qin, PU Hongmei, HE Jin, CHENG Hua, HAN Min, ZHAO Xuechun, WANG Zhiwei, JIN Baocheng 2022, 38 (32):  111-118.  DOI: 10.11924/j.issn.1000-6850.casb2021-1111 Abstract + ( 197 )   HTML ( 2 )   PDF ( 1787KB )   ( 20 ) Vegetation coverage is the percentage of the total ground area covered by the vertical projected area of vegetation. It is an important parameter in ecology and an important agronomic index of crops such as soybean. The ideal coverage measurement is less time consuming, requires simple tools, provides accurate results, and is less influenced by human factors. In this study, 24 soybean varieties, such as ‘Qiandou 3’, ‘Chuandou 16’ and ‘Daheidou’, were used for assessment. Different methods, including visual estimation, field line transect method and photo line transect method, were used to estimate soybean vegetation coverage and identify one with the maximum accuracy and applicability, using the measured values of the photography method as the reference. The results showed that visual estimation produced the largest error in vegetation coverage measurement, with an average of 7.8%. The error increased first and then decreased with the increase of plant height. The field line transect method displayed higher accuracy, the error was less than 3% (2.8%), but it took the longest time of 6.2 min for a 1 m × 1 m quadrat. The error of the photo line transect method was less than 3%, and it consumed less time for field sampling; processing the photos of each quadrat took only 3 min. Compared with visual estimation, the photo line transect method showed higher measurement accuracy. Besides, it saved the sampling time and improved work efficiency compared with the field line transect method. Therefore, the present study proposed the photo line transect method as the ideal method for vegetation coverage measurement of soybean and similar plant species. Two line-transects (the total length of the line transect was 2.8 m) via this method could meet the accuracy requirements, with an error of less than 5%. However, the applicability of the photo line transect method in measuring the coverage of other crops should be further explored.

  Construction of Flood Disaster Risk Assessment Model Based on Principal Component Analysis in Hubei Province LU Mengyao, LIU Dehu, LU Xueli, LIANG Heng, SUN Yuanyuan, LIU Yalin, SONG Tingqiang, FAN Haisheng 2022, 38 (32):  119-127.  DOI: 10.11924/j.issn.1000-6850.casb2021-1089 Abstract + ( 254 )   HTML ( 5 )   PDF ( 2502KB )   ( 41 ) Over the years, floods have caused serious damage to crops in Hubei Province, restricting agricultural economy and threatening social development. It is necessary to carry out flood risk assessment in Hubei. This paper proposed a method of modeling quantitative risk assessment in Hubei Province. Fifteen indicators were extracted from multi-source data (meteorological, socio-economic, geographical characteristics and other data), and the principal component analysis method was adopted to determine the weight of each indicator on flood disaster to establish a risk assessment model, and the geographic information system (GIS) analysis technology was used to get the flood disaster risk zoning map. On the basis of the existing evaluation index system, through the way of web crawler, we obtained better disaster emergency indicators to reflect the ability of prevention and reduction, and used the principal component analysis method to reduce the subjective factors in model building. The results show that: (1) rainfall and topography are the most important factors of flood occurrence in Hubei; (2) most of the central and eastern parts of Hubei are high-risk areas, among which, Wuhan, Huangshi and other parts along the Yangtze River basin in the east are in a heavy risk area; the southwest of the province is mostly in a medium risk area, and the northwest is in a low risk area. In conclusion, this model could provide scientific support and a decision-making basis for carrying out comprehensive disaster reduction, adjusting regional sustainable development structure and monitoring agricultural production in Hubei Province, which has great scientific and practical significance.

  Residue Characteristics and Risk Assessment of Mercury in Chinese Mitten Crab Culture Environment WANG Xinchi, CAO Guoqing, YIN Yuting, WANG Qian, SONG Chao, CHEN Jiazhang 2022, 38 (32):  128-132.  DOI: 10.11924/j.issn.1000-6850.casb2021-1046 Abstract + ( 211 )   HTML ( 2 )   PDF ( 1314KB )   ( 23 ) To gain an in-depth understanding of the residue characteristics and risk assessment of mercury in the pond culture environment of Eriocheir sinensis, a total of 14 samples of water bodies and sediment from 7 Eriocheir sinensis aquaculture ponds were collected in Wuxi of Jiangsu. The residue levels of mercury in different forms were analyzed by liquid chromatography-inductively coupled plasma mass spectrometry (LC-ICP-MS), and the risk of mercury residues was assessed by the single-factor method. The results showed that the mercury content in water bodies ranged from ND (not detected) to 18.20 μg/L, mainly inorganic mercury (Hg2+), and other forms included methylmercury (MeHg) and ethylmercury (EtHg). The mercury content in sediment environment ranged from 0.01 to 0.022 μg/g, in which the content of inorganic mercury decreased and the content of methyl mercury increased. Compared with NYT 5361-2016 Environmental Conditions of Pollution-Free Agricultural Products - Freshwater Aquaculture Origin, it was found that the mercury content in the water body exceeded the standard in 5 samples, and the exceeding rate was 71.43%; the mercury content in the sediment environment exceeded the standard in 1 sample, and the exceeding rate was 14.29%. Further research on the ecological risk of water inorganic mercury residues to Eriocheir sinensis showed that the risk quotient ranged from 0 to 0.05, far below 1, indicating that the mercury residues in the water body did not affect the safe growth of Eriocheir sinensis. The detection of heavy metal mercury in aquaculture water is of great significance to the healthy growth of Eriocheir sinensis and food safety.

  Effects of Water Flow on Fish Swimming Behavior and Physiological Metabolism: Research Progress QIAN Zhenjia, XU Jincheng, YU Youbin, ZHANG Chenglin, LIU Huang 2022, 38 (32):  133-138.  DOI: 10.11924/j.issn.1000-6850.casb2021-1092 Abstract + ( 224 )   HTML ( 4 )   PDF ( 1277KB )   ( 31 ) In order to grasp the water flow conditions suitable for fish growth, a systematic review was conducted on the behavioral characteristics and physiological metabolism of fish at home and abroad under different water flow conditions. The effects of water flow on water quality and the behavioral differences of different fish stimulated by water flow were analyzed and compared, and the effects of water flow on fish from the perspective of fish physiological metabolism was explored. The results show that the maximum water velocity that fish could withstand is generally related to body length (BL), and lower water velocity (<0.5 bl/s) has no significant effect on fish, higher water velocity (>2 bl/s) has more negative effects on fish behavior, survival rate and physiological metabolism, while medium water velocity (0.5-2 bl/s) is suitable for fish growth, which can improve fish immunity and enhance antioxidant level of fish. The current research on fish tolerance to water velocity was discussed and optimized from an experimental perspective in the study, in order to obtain a more accurate growth-flow velocity curve.

  Development Strategy of Tropical Crop Industry in China Based on SWOT- PEST Analysis LIU Dong, LIU Ruijin 2022, 38 (32):  139-147.  DOI: 10.11924/j.issn.1000-6850.casb2022-0492 Abstract + ( 250 )   HTML ( 3 )   PDF ( 1277KB )   ( 29 ) Tropical crop industry is an important part of China’s agriculture, which is of great significance to national resource security, rural revitalization, national unity and diplomacy. Using SWOT-PEST method in combination with the current development status of China’s tropical crop industry, this paper analyzes the internal advantages, disadvantages, external opportunities and challenges of China’s tropical crop industry from four aspects of politics, economy, society and technology, and constructs an analysis matrix. The study shows that China’s tropical crop industry has internal advantages such as government emphasis, diversified natural resources, location advantages, good industrial development foundation and scientific and technological strength reserve. At the same time, there are also disadvantages such as relatively insufficient support, lagging development of management level, high pressure of resource and environment constraints and production costs, and low contribution rate of scientific and technological progress. It is suggested that four strategies of growth, torsion, diversification and defense for the development of China’s tropical crop industry should be comprehensively applied. Taking the Belt and Road Initiative, the Rural Revitalization Strategy and the continuous opening-up policy as an opportunity, we should make good use of the development opportunities of strong domestic market, growing diversified demand and increasing application of new technologies, and fully tap and play the internal advantages. By strengthening government policy support for the tropical crop industry, improving the construction of the management system of the tropical crop industry, promoting the ‘go global’ of the tropical crop enterprises, and upgrading of the industrial chain driven by scientific and technological innovation, we can reduce or avoid the impact of the international tropical agricultural market on the domestic market, the uncertainty of supply security and the threat of insufficient supply of scientific and technological innovation, and comprehensively improve the international competitiveness of China’s tropical crop industry.

  Phyllanthus emblica L. Industry in China: Current Situation and Development Suggestions GAN Yangying, XIAO Guangjiang, CAI Shike, LAI Duo, LIU Weina 2022, 38 (32):  148-154.  DOI: 10.11924/j.issn.1000-6850.casb2021-1162 Abstract + ( 255 )   HTML ( 6 )   PDF ( 1156KB )   ( 67 ) Phyllanthus emblica L. is a characteristic economic tree species in southern China. Up to now, there is still no systematic statistics and research report on the overall picture of Phyllanthus emblica L. industry in China, and the development of the industrial chain is not yet clear. In this study, the information on the cultivation, processing and industrial development of Phyllanthus emblica L. were collected through field investigation, telephone interview, literature analysis and data statistics. Our results show that the total cultivation area of Phyllanthus emblica L. in China is nearly 38,000 hm2 and the main production areas include Yunnan, Fujian, Guangdong and Guangxi. The main cultivars include ‘Gaoligongnuo’, ‘Yingyu’, ‘Sweet’, ‘Pink’, ‘Lanfeng’, ‘Glass-sweet’, ‘Dayu’, etc. There are more than one hundred processing enterprises of Phyllanthus emblica L. in China’s southern provinces, with products of dry fruit, preserved fruit, fruit juice, fruit tea, fruit powder, throat lozenge, etc. Generally, there are still some problems in China’s Phyllanthus emblica L. industry, such as insufficient resource conservation and utilization, imperfect standardization system, shortage of deep processing, and weak scientific technological support. It is suggested that the local governments should increase the policy and capital support to Phyllanthus emblica L. industry, highlight the conservation and utilization of germplasm resources, strengthen the exchange and cooperation among the enterprises of Phyllanthus emblica L. industry, and extend the industrial chain to the downstream.

  Characteristics of Production Measures and Benefits of Wheat After Rice in the Central Area of Jiangsu Province: Investigation and Analysis FAN Ting, ZHAO Kaimin, LIU Mingmin, YANG Didi, DING Jinfeng, ZHU Min, LI Chunyan, ZHU Xinkai, GUO Wenshan 2022, 38 (32):  155-164.  DOI: 10.11924/j.issn.1000-6850.casb2021-1120 Abstract + ( 153 )   HTML ( 1 )   PDF ( 1923KB )   ( 32 ) In order to further clarify the wheat production situation in the central area of Jiangsu Province, the survey data about wheat production of rural households were obtained by questionnaires in Xinghua and Gaoyou from 2016 to 2020. The survey showed that the main workforce of farmers in wheat production were between the age of 51 and 60 with junior high school education level. This group urgently needed new agricultural technologies, but their acceptance ability was relatively low. There were significant differences in wheat sowing date, sowing rate and fertilizer application rate taken by different farmers. The farmers were more likely to obtain high yield when wheat was planted from October 26th to November 5th with the sowing rate of 211-240 kg/hm2. The average nitrogen application rate taken by farmers was 308 kg/hm2 and 281 kg/hm2 in Xinghua and Gaoyou, respectively. The wheat yield decreased when nitrogen application rate was higher than 350 kg/hm2. Under the combination of sowing date, sowing rate and nitrogen application rate, the average yield of wheat in Xinghua and Gaoyou was 6129.64 kg/hm2 and 6788.25 kg/hm2, respectively. The yield gap between high and low yield was 2270.36 kg/hm2 in Xinghua and 1611.75 kg/hm2 in Gaoyou, respectively. The economic benefits of different wheat planting scales were different. When the planting area was 6.67-20 hm2, most farmers could get relatively high benefits, only a few farmers had economic loss. When the planting scale was more than 33.33 hm2, the proportion of farmers with loss was relatively high, and farmer with benefits had low per unit area reward in wheat planting. In conclusion, farmers with 20 hm2 wheat planting scale can obtain higher yield and benefits when the sowing date is from October 26th to November 15th, the sowing rate is 200-240 kg/hm2 and nitrogen application rate is 250-300 kg/hm2,the scheme can be promoted in the central area of Jiangsu Province.