Current issue

• 2022 Vol.38 No.33 Published:25 November 2022

  Breeding Introgression Line ‘Jijing 88’ (hd2/hd4) with Molecular Selection LI Rongtian, SHI Liu, HUANG Liying, LIU Changhua 2022, 38 (33):  1-9.  DOI: 10.11924/j.issn.1000-6850.casb2022-0062 Abstract + ( 344 )   HTML ( 13 )   PDF ( 4224KB )   ( 27 ) The aim of this study is to transform rice heading stage genes hd2 and hd4 into an excellent variety ‘Jijing 88’, and further develop rice ‘Jijing 88’ (hd2/hd4) introgression lines which are suitable for planting in the northern part of Heilongjiang Province. With ‘Jijing 88’ as the receptor and ‘Kongyu 131’ as the donor, ‘Jijing 88’(hd2/hd4) introgression lines were created by molecular selection and backcrossing. The growth period, agronomic characters and yield of the introgression lines were identified in the third accumulated temperature area of cold region. ‘Jijing 88’ was crossed with ‘Kongyu 131’, ‘Jijing 88’ was used as the recurrent parent for 4 backcrosses, and the backcross offspring were self-crossed for 2 times. In each generation, Hd2-Caps and Hd4-Caps were used for foreground selection, and SSR markers were used for background selection. Thus, ‘Jijing 88’(hd2/hd4) introgression lines-1 and ‘Jijing 88’ (hd2/hd4) introgression lines-2 were obtained. Both of them had similar heading stage to ‘Kongyu 131’ and plant type characteristics to ‘Jijing 88’, but the yield was significantly higher than that of ‘Kongyu 131’. The successful breeding of rice ‘Jijing 88’ (hd2/hd4) introgression lines has made it possible for the lines to be used in the third accumulated temperature region and the lower limit of the second accumulated temperature region in Heilongjiang Province.

  Salt Tolerance of Rice Varieties at Germination Stage: A Comparative Study YI Jiawen, FENG Di, ZHU Wei, QI Na, TENG Fengkui, LU Xiaoyin 2022, 38 (33):  10-14.  DOI: 10.11924/j.issn.1000-6850.casb2022-0091 Abstract + ( 254 )   HTML ( 5 )   PDF ( 1098KB )   ( 91 ) The aims of this study are to compare the salt tolerance of different rice varieties at the germination stage and to select varieties that have more salt tolerance. Rice seeds were treated with 0, 0.3% and 0.5% NaCl to analyze the differences in growth indices of 9 rice varieties. The results showed that the germination and growth of rice were significantly inhibited under 0.3% and 0.5% NaCl treatments at the germination stage. Among them, ‘9311’ rice variety had the least change. Compared with those of the salt-free treatment, the bud length and root length were significantly reduced only under 0.5% NaCl treatment, with a decrease rate of 11.9% and 11.5%, respectively. The inhibition degree of rice seed germination rate by salt stress was ‘G1’ > ‘Yin Xiang 38’ > ‘Jin Yuan U99’ > ‘Soft Aromatic Japonica’ > ‘Jin Dao 919’ > ‘Jin Yuan 77’ > ‘Jin Yuan E28’ > ‘Tian Long Japonica No. 2’ > ‘9311’. The comprehensive analysis showed that the growth of rice was significantly inhibited with the increase of salt concentration, and the salt tolerance of ‘9311’ was the highest among the 9 rice varieties.

  AMF Complex Fungicides: Effects on Photosynthesis and Growth of Rice in Cold Region ZHANG Bo, SHI Feng, SONG Fuqiang 2022, 38 (33):  15-22.  DOI: 10.11924/j.issn.1000-6850.casb2022-0114 Abstract + ( 201 )   HTML ( 3 )   PDF ( 4626KB )   ( 58 ) This study investigated the promoting effect of AMF complex fungicides on the growth and yield of rice, aiming to provide a technological basis for the cultivation of green and high-yielding rice. This experiment was conducted on rice (Oryza sativa L.) to determine photosynthetic parameters, total biomass, yield and yield constituent factors of rice plants under field condition. AMF complex fungicides significantly increased the infestation rate of endophytic fungi in rice roots, and the colonization rate of AMF+PI+AR treatment was as high as 86.7%, which established a good symbiotic relationship with rice roots. The application of the AMF complex fungicides increased the photosynthetic intensity of rice leaves and total rice biomass, and the total rice biomass increased by 25.9%, 31.7%, 24.4%, 17.2% and 38.1% compared with that of PI, AR, AMF, FP and CK, respectively. AMF complex fungicides planting increased the rice yield by 6.9% compared with the conventional crop fertilization planting. AMF complex fungicides can effectively promote the growth and improve the yield of rice. Compared with traditional crop fertilization, AMF complex fungicides have the advantages of zero fertilization, low cost and high yield, and can enable clean rice production and solve the problem of non-point source pollution in rice fields.

  Suitable Density of Single-seed Precision Sowing for Peanut Varieties HE Mengxia, CUI Shunli, ZHENG Baozhi, BI Zhile, LU Suizeng, QI Liya, LI Xinna, LIU Hong, HAN Peng, WANG Jin, LIU Lifeng 2022, 38 (33):  23-27.  DOI: 10.11924/j.issn.1000-6850.casb2021-1130 Abstract + ( 230 )   HTML ( 4 )   PDF ( 1073KB )   ( 34 ) Three peanut varieties of ‘Jihua 18’, ‘Jinonghua 6’ and ‘Xinghua 9’ were used to explore the suitable density of single-seed precision sowing under the cultivation mode of ridging without plastic film mulching. A 2-factor and 3-level random block design was conducted with sowing densities of 165000 holes/hm2, 195000 holes/hm2, 225000 holes/hm2 and 255000 holes/hm2, respectively. The results showed that the effect of sowing density on peanut yield was extremely significant, and different sowing densities had very significantly different influence on the yield of different peanut varieties. The suitable planting density of ‘Jihua 18’ was 225000 holes/hm2, and that of ‘Jinonghua 6’ and ‘Xinghua 9’ was 195000 holes/hm2. The study can lay a basis for the extension and application of the three peanut varieties.

  Methanol Aging Treatment: Effect on Germination of Sugar Beet Seeds LIU Na, HU Huabing, WANG Ronghua, LIU Xiaoyue, LIU Zhaoyang, LIU Xiaohan, WANG Maoqian 2022, 38 (33):  28-33.  DOI: 10.11924/j.issn.1000-6850.casb2022-0023 Abstract + ( 236 )   HTML ( 2 )   PDF ( 2123KB )   ( 15 ) The paper aims to study the effect of artificial aging treatment with methanol solution on the germination index of sugar beet seeds, explore the storage resistance and aging mechanism of sugar beet seeds, and provide a theoretical basis for understanding the artificial aging of sugar beet seeds. In this study, TX2020, a newly harvested single seed, was used as experimental material, and 6 aging time (5, 10, 15, 20, 25 and 30 min) were set up. The seeds were treated with methanol aging method, and the germination test was carried out on the seeds. The germination potential, germination rate, germination index, vigor index, total length of radicle and hypocotyl and conductivity of seed extract were determined. The results showed that germination indexes of seeds decreased after aging treatment. Compared with those of the control, the germination potential, germination rate, germination index, vigor index and total length of radicle and hypocotyl were decreased by 8.8%-31.41%, 13.96%-34.23%, 2.66%-22.44%, 16.63%-36.44% and 7.54%-23.06%, respectively, while the conductivity of seed extract was increased compared with that of the control by 34.73%-76.19%. The results showed that methanol solution could inhibit the germination of sugar beet seeds. With different aging time, the inhibition effect of methanol solution on the germination indexes of sugar beet seeds was also different.

  Exogenous Melatonin Affects the Germination and Resistance Ability of Common Bean Seeds Under Chilling Stress YANG Xiaoxu, LI Mengdi, LIU Dajun, FENG Guojun, LIU Chang 2022, 38 (33):  34-38.  DOI: 10.11924/j.issn.1000-6850.casb2021-1218 Abstract + ( 171 )   HTML ( 6 )   PDF ( 2545KB )   ( 44 ) In order to explore the effect of melatonin (Mt) on common bean seeds under chilling stress, the seeds of common bean were treated with chilling stress (LT) and chilling stress with melatonin (LT+Mt), and the normal temperature treatment was set as the control (CK). The physiological indexes of seeds of the same period were measured. The results showed that Mt could improve the germination rate of seeds under chilling stress, but the germination rate was lower than that of CK. The content of osmoregulatory substances, O2- and MDA and the activities of antioxidant enzymes were measured. It was found that the content of osmoregulatory substances increased under chilling stress, and the content further increased when Mt was added. The content of O2- and MDA increased after chilling stress, while the content of MDA decreased significantly after Mt addition, but was higher than that of CK. The activities of antioxidant enzymes after low temperature treatment were slightly lower than those of CK, and the content of antioxidant enzymes was significantly increased when Mt was added. To sum up, exogenous Mt could effectively reduce the damage of chilling stress on seed germination, thus promoting the ability of seeds to resist chilling stress during germination.

  Effects of Different Fertilization Modes on the Growth, Dry Matter Accumulation, Yield and Quality of Paddy-tobacco HOU Jianlin, LI Sijun, HE Mingyu, XIAO Hanqian, XIANG Tiejun, HUANG Jie, LI Wujin, XIAO Yansong, JIANG Zhimin, XU Junhua, DENG Xiaohua 2022, 38 (33):  39-43.  DOI: 10.11924/j.issn.1000-6850.casb2021-0720 Abstract + ( 169 )   HTML ( 7 )   PDF ( 1061KB )   ( 35 ) To reduce the nitrogen application rate on tobacco in the paddy-tobacco growing area and clarify the effect of nitrogen reduction fertilization mode on paddy-tobacco, taking flue-cured tobacco variety ‘Yunyan 87’ as the test material, a field experiment was conducted to study the effects of nitrogen reduction fertilization mode and traditional fertilization mode on growth, dry matter accumulation, yield and quality of paddy-tobacco. The results showed that the nitrogen reduction fertilization mode was beneficial to the early growth of tobacco in the field and the development of middle and lower tobacco leaves, the mode increased the total dry matter accumulation of tobacco by 5.03%, promoted the dry matter distribution to tobacco leaves. Under the nitrogen reduction fertilization mode, the contents of total sugar, reducing sugar and potassium in middle leaves increased by 5.99%, 5.42% and 0.14% respectively; the nicotine content of middle and upper leaves decreased by 0.37% and 0.09% respectively, that of lower leaves increased by 0.4%, and the availability of chemical components in flue-cured tobacco was improved. The nitrogen reduction fertilization mode can be adopted by reducing the basal nitrogen and increasing the proportion of topdressing nitrogen, applying basal fertilizer in holes, increasing the watering root fertilizer and multiple watering the topdressing fertilizers, to reduce the amount of nitrogen fertilizer, improve the quality of tobacco leaves and increase the income of tobacco farmers in paddy-tobacco growing area of south China.

  Forest Litter Decomposition: Research Progress and Prospect ZHOU Tingyu, XIAO Yang, HUANG Qingyang, XIE Chen, LUO You 2022, 38 (33):  44-51.  DOI: 10.11924/j.issn.1000-6850.casb2021-1133 Abstract + ( 396 )   HTML ( 9 )   PDF ( 1129KB )   ( 56 ) In order to clarify the research on various aspects of forest litter decomposition, this paper summarized the research progress of forest litter decomposition, mainly including the concept and research history of leaf litter, the decomposition process and nutrient release of litter, the influencing factors of litter decomposition, and the research on forest litter in the ‘home’/‘away’ habitat. The study is of certain significance to the sustainable use of forest resources. As global climate change is increasingly concerned by people, there are more and more reports about the impact of CO2 emission and N deposition on litter decomposition, but to better deal with these changes, the comprehensive and widely used technologies and indicators of litter analysis and prediction have not yet been established. Facing the development of the external environment and disciplines in the future, more comprehensive and effective measures need to be proposed. Based on summarizing the research progress of forest litter, this study aims to build a basis for further exploration in this field.

  Current Situation and Development Prospects of Wampee (Clausena lansium) Industry in Danzhou ZHAO Kaili, LI Fulong, LUO Can, WU Fanhua, CAI Zeping, YU Xudong 2022, 38 (33):  52-59.  DOI: 10.11924/j.issn.1000-6850.casb2021-1165 Abstract + ( 425 )   HTML ( 5 )   PDF ( 1228KB )   ( 71 ) Wampee (Clausena lansium) is a tropical and subtropical evergreen fruit tree species, its different parts could be served as fresh food and medicine, and have high nutritional values. Danzhou has put forward the call to vigorously develop the primary, secondary and tertiary industries of wampee to promote rural revitalization. In order to provide a theoretical basis for the development of the wampee industry chain in Danzhou, this paper made an in-depth study. Based on field investigation and literature review, the paper made a preliminary investigation on the planting distribution, unique variety characteristics and industrial status of wampee in Danzhou. The results show that wampee is a good economic tree species that can be planted on the side of roads, fields, houses and villages. Wampee industry can be taken as a driving force for local rural revitalization, and has a broad prospect as leisure food industry. Currently, there are some problems in Danzhou wampee industry, such as land resource constraint, small production scale, backward cultivation technology, less diversity of varieties, insufficient processing and deep processing, and so on. Due to the development needs of characteristic agriculture in Danzhou and the development prospect of wampee industry in Hainan Province, we should increase policy support and guidance, actively carry out mother tree protection, variety breeding, deep processing, trademark registration and industrial promotion, and push forward the development of wampee industry in Danzhou.

  Comparison of Volatile Components of Three Kinds of Wormwood Cultivated in Zhangzhou Area WU Weijian, YANG Min, LI Shanshan 2022, 38 (33):  60-67.  DOI: 10.11924/j.issn.1000-6850.casb2022-0445 Abstract + ( 418 )   HTML ( 2 )   PDF ( 2570KB )   ( 16 ) This paper analyzed and compared volatile components of Artemisia argyi var. argyi ‘Qiai’, Artemisia indica and A. vulgaris produced in Zhangzhou. The volatile components were determined by headspace gas chromatography-mass spectrometry (HSGC-MS) and compared. GC-MS analysis show that there are 30 volatile components in A. argyi var. argyi ‘Qiai’, of which monoterpenoids account for 91.40%, sesquiterpenoids account for 2.02%, and components of high content are eucalyptol (73.56%), o-Cymene(4.94%), camphor (3.65%) α-pinene (3.41%), camphorene (2.66%), thujanol(2.41%), 4-hexenylacetate (1.95%), caryophyllene (1.83%), β-pinene (1.49%) and terpinene (1.15%). A. indica contains 17 volatile components, of which monoterpenoids account for 68.91%, sesquiterpenoids account for 31.22%, and volatile components of high content are artemisyl ketone (50.29%), caryophyllene (15.56%), germacrene D (9.05%), α-pinene (7.57%), artemisyl ketone (3.75%), thujone (3.49%), 4-hexenylacetate (2.29%) and β-longleaf pinene (1.60%). A. vulgaris contains 14 volatile components, of which monoterpenoids account for 77.22%, sesquiterpenoids account for 4.98%, and volatile components of high content are sabinene (44.08%), leafacetate (16.51%), α-pinene (15.37%), chrysanthenone (7.70%), eucalyptol (3.83%), caryophyllene (3.33%), β-pinene (2.08%), β-phellandrene (1.61%) and d-limonene (1.46%). According to GC-MS analysis and principal component analysis (PCA), the aroma components of A. vulgaris and A. indica are more similar, which have significant differences with those of A. argyi var. argyi ‘Qiai’.

  Antifungal Activities of the Extracts from Branches of Sophora japonica by Different Solvents ZHANG Yu, LI Yunsheng, CHENG Jun, JIANG Xingfu, LIU Yueqiu, WU Yuying 2022, 38 (33):  68-73.  DOI: 10.11924/j.issn.1000-6850.casb2021-1125 Abstract + ( 194 )   HTML ( 3 )   PDF ( 2927KB )   ( 22 ) The Chinese scholar tree (Sophora japonica L.) is an important garden plant and medicinal plant in China. The study aims to explore the function of Sophora japonica in inhibiting plant pathogens. The inhibitory activities of branch extracts by different polar solvents (ethanol, petroleum ether, ethyl acetate, n-butanol and water) against four plant pathogens were determined by using growth rate method, and the chemical components of ethyl acetate extract were analyzed by GC-MS. The results showed that the extracts of Sophora japonica branches by different solvents had significantly different inhibitory effects against four plant pathogens. Ethyl acetate extract had the best antifungal effect, and its toxicity to Colletotrichum gloeosporioides was the highest, with an EC50 of 2.58 mg/mL at 48 h, followed by its toxicity to Ectohoma multirostrata, Botrytis cinerea and Fusarium foetens. The main chemical components of ethyl acetate extract were aliphatic and terpenoids, and the highest content was octadecyl pentafluoropropionate (14.77%). The antifungal active substances in the branches of Sophora japonica were mainly concentrated in the ethyl acetate phase, followed by n-butanol phase, water phase, and petroleum ether phase.

  Resource Utilization System of Agricultural Organic Waste After Centralized Recovery and Treatment: A Case Study of Xingxian Village in Gannan County REN Xvrui, WANG Yihui, YANG Hongyu, YUAN Liang, ZHAO Yue 2022, 38 (33):  74-79.  DOI: 10.11924/j.issn.1000-6850.casb2021-1161 Abstract + ( 194 )   HTML ( 2 )   PDF ( 3046KB )   ( 26 ) The agricultural wastes in northeast China mainly consist of straw and chicken manure, which contain not only a large amount of material and energy resources, but also a large number of antibiotics and pathogenic bacteria. Properly handled, the wastes can be turned into resources, otherwise, they could be the biggest pollution source in agricultural production. Meanwhile, the cold climate in northeast China makes it difficult to raise the temperature in the process of thoroughly decomposing of the wastes. High temperature decomposing in the aerobic composting process can seal heavy metals on the surface of wastes, degrading antibiotics and eliminating pathogenic bacteria. It is regarded as the most harmless treatment method at present. In this study, Xingxian village was taken as the example. The utilization potential of fertilizer was estimated and analyzed by using the grass-seed ratio and nutrient balance ratio. The siting factors and systematic treatment scheme of compost in the cold region were determined by using a satellite remote sensing map. It was estimated that the total nitrogen yield of agricultural organic waste compost in the village could satisfy the production of 454.341 t maize or 474. 993 t rice each year. The aerobic composting could produce 400 t of organic fertilizer per year after centralized treatment. This study has certain practicability, and can provide reference for the resource utilization and harmless treatment of rural agricultural wastes in northeast China.

  Effects of Enhanced UV-B Radiation on Greenhouse Gas Emissions in Terrestrial Ecosystem: Research Progress CHENG Lu, WEN Yongli, CHENG Man 2022, 38 (33):  80-88.  DOI: 10.11924/j.issn.1000-6850.casb2021-1209 Abstract + ( 152 )   HTML ( 5 )   PDF ( 1624KB )   ( 51 ) Ultraviolet-B (UV-B, 280-320 nm) radiation enhancement and climate change are critical global environmental issues. The depletion of the stratospheric ozone layer and the increase of greenhouse gases (GHGs, e.g. CO2, CH4 and N2O) emissions are major factors driving these issues. Enhanced UV-B radiation would affect carbon and nitrogen balance of terrestrial ecosystem through a series of biogeochemical processes, and influence the emission of GHGs to the atmosphere, further impact the global climate change. In this paper, we systematically reviewed the effect of enhanced UV-B radiation on CO2 emissions in terrestrial ecosystems through litter or soil and the mechanisms involved in these processes (photochemical degradation of recalcitrant organic molecules into soluble organic carbon, abiotic photo-mineralization of organic compounds and photo-induced microbial degradation). Besides, the influence of enhanced UV-B radiation on CH4 and N2O emissions (through changes in the chemical structure of plant tissue and the composition of root exudate) were summarized. The emission patterns of CH4 and N2O under the interaction of UV-B radiation enhancement and other environmental factors in different ecosystems were also discussed. In addition, the elevated temperature and reduced precipitation could promote photodegradation of organic matter induced by UV-B radiation enhancement, and further increase GHGs emissions. At present, studies regarding the effects of UV-B radiation enhancement on terrestrial ecosystem are still limited, while most of which focus on arid ecosystems and there are few quantitative studies. In the future, more long-term and large-scale field studies combining with models are needed to quantify the contribution of enhanced UV-B radiation to greenhouse gas emissions in terrestrial ecosystem. The study will provide theoretical reference for the accurate prediction of GHGs emissions under global environment change scenario.

  Effects of Typical Land Use Types on Soil Nitrogen Characteristics in Karst Agricultural Areas of Southwest China TIAN Yutong, HAN Zhiwei, ZHAO Ran, TIAN Yongzhu, LUO Guangfei, YANG Miao 2022, 38 (33):  89-96.  DOI: 10.11924/j.issn.1000-6850.casb2021-1216 Abstract + ( 142 )   HTML ( 5 )   PDF ( 3836KB )   ( 19 ) To investigate the influence of different land use types on soil nitrogen characteristics in karst area and clarify the migration characteristics and influencing factors of soil nitrogen under different land use types and depths, we took different types of soil (grassland, riverside zone, paddy field and dry land) around Kaizhang reservoir in Huaxi River Basin as the research objects, measured the basic physical and chemical properties of soil, the contents of total nitrogen, nitrate nitrogen and ammonium nitrogen, and analyzed the spatial distribution characteristics of different forms of soil nitrogen under different land use conditions in karst area, the composition proportion of nitrogen and the correlation between nitrogen and various environmental factors. The results showed that the average content of soil total nitrogen in agricultural land (paddy field and dry land) was higher than that in non-agricultural land (grassland and riverside zone), showing ‘surface accumulation’ in the vertical direction and a decrease with the soil depth increase as a whole. Affected by agricultural activities, the content of nitrate nitrogen in agricultural land was higher than that in non-agricultural land. In the vertical direction, the content of nitrate nitrogen in agricultural land changed greatly, and the overall trend decreased with soil depth. The content of ammonium nitrogen had little difference under different land use types, and was relatively stable in the vertical section. Comparing the proportion of nitrate nitrogen and ammonium nitrogen in inorganic nitrogen, it showed that the soil inorganic nitrogen in the study area was mainly ammonium nitrogen. There was a very significantly positive correlation between soil organic matter content and nitrogen in the study area (P<0.01), and there was a significantly negative correlation between soil pH and nitrogen (P<0.05). In summary, the soil nitrogen content of agricultural land is generally higher than that of non-agricultural land, and different land use types have a significant impact on nitrogen distribution in karst agricultural area.

  800 g/L Prosulfocarb EC: Annual Weeds’ Control Effect and Safety Analysis in Broad Bean Field ZHU Haixia, LI Xiang, WEI Youhai 2022, 38 (33):  97-102.  DOI: 10.11924/j.issn.1000-6850.casb2021-0968 Abstract + ( 265 )   HTML ( 3 )   PDF ( 1158KB )   ( 19 ) The study aims to determine the safety of herbicide 800 g/L prosulfocarb EC for crops, its control effect on broad-leaved weeds and the appropriate dosage. ‘Green Broad Bean 14’was selected as the test material, the soil before seedling was sprayed with 800 g/L prosulfocarb EC at the concentration of 2040, 3960 and 7920 g/hm2, and 960 g/L S-metolachlor EC was used as the control agent at the concentration of 1080 g/hm2. The control effects of prosulfocarb EC and S-metolachlor EC were determined. The results showed that when the effective amount of 800 g/L prosulfocarb EC was 2040-7920 g/hm2, the control effect on the annual broad-leaved weeds in broad bean field in Qinghai Province was 86.99%-89.00%, and the control effect on fresh weight was 85.10%-89.29%. After sowing broad bean, spraying 800 g/L prosulfocarb EC at different doses before seedling period could increase the yield of broad bean by more than 5.93% in different treatment areas. This herbicide has significant control effect on annual broad-leaved weeds in broad bean field and safe for crops.

  Biological Control of Tobacco Root-knot Nematode Disease by Penicillium purpurogenum K1 YAN Fangfang, KONG Chuixu, ZHANG Yingjie, MAO Min, JIAN Lianjun, WANG Rong 2022, 38 (33):  103-108.  DOI: 10.11924/j.issn.1000-6850.casb2022-0106 Abstract + ( 166 )   HTML ( 7 )   PDF ( 1182KB )   ( 21 ) In order to evaluate the biological control potential of Penicillium purpurogenum against tobacco root-knot nematode disease, the activity of P. purpurogenum K1 against the second stage juveniles and eggs of Meloidogyne incognita were tested in laboratory, and the control effect of P. purpurogenum K1 on tobacco root-knot nematode disease was tested in 2 fields for 2 years. The results were obtained as follows. (1) P. purpurogenum K1 strain had strong virulent activity against M. incognita. The corrected mortality rate of the second stage juveniles of M. incognita at 48 h was 94.53%, and the relative inhibition efficiency of egg hatching was 90.75%. (2) The control effects of P. purpurogenum with three application rates on tobacco root-knot nematode disease, and the comprehensive agronomic traits, yield and quality, and average price of flue-cured tobacco were better than those of Paecilomyces lilacinus treatment with the application rate of 33.00 kg/hm2. The control effect of P. purpurogenum at the rate of 41.25 kg/hm2 was the best with an average control effect of 80.60%, and the comprehensive agronomic traits, output value and average price of tobacco under this treatment were the best. The tobacco leaf yield, output value and average price were 2119.50 kg/hm2, 56762.77 yuan/hm2 and 26.78 yuan/kg, respectively. Therefore, P. purpurogenum K1 has great potential of biological control of tobacco root-knot nematode in field, and it can be developed and applied as biocontrol fungi against tobacco root-knot nematode disease in Panzhihua. The recommended application method is using 41.25 kg/hm2 P. purpurogenum K1 at tobacco transplanting.

  Current Situation and Virus Identification of Sweet Potato Virus Disease (SPVD) in Shaanxi Province YANG Yiwei, LIU Chen, WEI Peiyao, LI Yingmei 2022, 38 (33):  109-115.  DOI: 10.11924/j.issn.1000-6850.casb2021-1164 Abstract + ( 298 )   HTML ( 4 )   PDF ( 3827KB )   ( 28 ) To clarify the occurrence range and severity of sweet potato virus disease (SPVD) in Shaanxi Province, 98 samples of sweet potato suspected of virus disease were collected from seven cities in the province, including Xi’an, Xianyang, Weinan, Yulin, Shangluo, Ankang and Baoji, and tested for SPVD by using multiplex RT-PCR assay. The results showed that the total virus detection rate of the samples was 52.04%, and sweet potato chlorotic stunt virus (SPCSV) was detected in 38 samples (38.78%); sweet potato feathery mottle virus (SPFMV) was detected in 25 samples (25.52%). Among the 51 samples detected with viruses, 38 samples were infested with a single virus and 13 samples were infested with a combination of two viruses, and the detection rate of SPVD was 13.27%. Except that no SPFMV-CH2 strain was detected in Xianyang, SPCSV and SPFMV-CH and CH2 strains were all detected in other six cities. SPCSV was detected in 2 of the 46 breeding materials, with a detection rate of 4.35%, indicating that SPVD has occurred widely in Shaanxi Province, and the incidence is rather serious.

  Antagonistic Streptomyces Against Pepper Root Rot Pathogen (Fusarium oxysporum): Screening and Phylogenetic Analysis of 16S rRNA Gene Sequence Nuerxiati·Nuermaimaiti , LI Huanyu, YANG Chengde 2022, 38 (33):  116-123.  DOI: 10.11924/j.issn.1000-6850.casb2022-0027 Abstract + ( 213 )   HTML ( 5 )   PDF ( 5190KB )   ( 19 ) In order to obtain Streptomyces strains with antagonistic effect on Fusarium oxysporum causing pepper root rot and clarify their antagonistic effect and classification, F. oxysporum was used as the indicator strain to screen by plate confrontation method. The inhibition rate was determined by mycelial growth rate method. Phylogenetic analysis was conducted based on 16S rRNA gene sequence. In this study, eight antagonistic Streptomyces strains were obtained by primary screening. The results of confrontation culture showed that the inhibition rate against F. oxysporum was 45.18%-62.81%, and the inhibition rate against the other four root rot fungi was 28.51%-60.00%. Among them, the strain ZY12.53b showed the best antagonistic effect with more than 50% inhibition rate against five root rot fungi. The fermentation filtrates of strains MDI2.4 and ZY12.23a had the highest antagonistic effect on F. tricinctum, and the inhibition rates were both more than 60%. In the phylogenetic tree of 16S rRNA gene sequence, the eight antagonistic Streptomyces strains clustered into five different branches, and two of them were likely to be potential new species. In this study, eight antagonistic Streptomyces strains belonging to at least five species were obtained, among which three strains showed satisfied antagonistic effect with the value of potential exploration.

  Extract of Bacillus velezensis SX-45: The Antifungal Mechanism Against Fusarium oxysporum of Ginseng ZHANG Tingting, MA Guilong, XIE Xiaobao, GAO Xinxin, CAI Qi 2022, 38 (33):  124-131.  DOI: 10.11924/j.issn.1000-6850.casb2021-0906 Abstract + ( 166 )   HTML ( 6 )   PDF ( 3558KB )   ( 24 ) Ginseng root rot is one of the serious diseases in the production of ginseng. The objective of this study is to clarify the antifungal mechanism of the extract of Bacillus velezensis SX-45 against Fusarium oxysporum of ginseng. In this study, Bacillus velezensis SX-45 and Fusarium oxysporum of ginseng were used as materials, the antifungal mechanism data were determined by thiobarbituric acid, coomassie bright blue G-250 methods etc. The results showed that after being treated with the extract of Bacillus velezensis SX-45 at the concentration of 15 μg/mL, the mycelia of Fusarium oxysporum of ginseng had malformation, the hypha surface protrusion and the hypha tip expansion were observed. The electrical conductivity and malondialdehyde content in the fungal suspension increased significantly, which were respectively 4.24 and 42.0 times those of the control group. The OD260 value of the fungal suspension also increased from 3.48 to 3.83. With the increase of extract concentration, the soluble protein content, reducing sugar content, NAD-MDH activity and SDH activity decreased significantly by 97.7%, 56.6%, 97.5% and 48.4%, respectively. This study indicates that the extract of Bacillus velezensis SX-45 has a good inhibition effect on Fusarium oxysporum, and can lay a foundation for the research and development of new biocontrol agent against ginseng diseases.

  The Shelf Life of Wet Rice Noodle: Prediction Based on Arrhenius Equation CHEN Jiacong, HUANG Yongde, ZHU Wenjuan, YE Wenfang, WENG Jia, HUANG Xiuli, CHEN Rongde, CHEN Shuidao 2022, 38 (33):  132-138.  DOI: 10.11924/j.issn.1000-6850.casb2022-0117 Abstract + ( 148 )   HTML ( 3 )   PDF ( 2584KB )   ( 15 ) The aim is to provide technical support for wet rice noodle manufacturers to improve technology and optimize transportation and storage conditions. 2N+2L standard wet rice noodles developed by the research team, old wet rice noodles and market wet rice noodles were selected as research objects. The quality changes of wet rice noodles under different storage temperatures were investigated, the kinetic model was established and the shelf life of wet rice noodles was predicted. The results showed that the microbial and sensory indexes of the three kinds of wet rice noodles stored at 4℃, 10℃ and 25℃ had certain effects on the quality deterioration. The shelf life of 2N+2L standard wet rice noodles was 96 h, 72 h and 36 h at 4℃, 10℃ and 25℃, respectively, which was better than that of the other two products. On this basis, taking the overall acceptability of sensory quality as the limiting factor, the shelf life prediction models of the three kinds of products were established. It is verified that the relative error between the predicted value of the model and the measured value is less than 10%, indicating that the model is accurate and effective and has a good application prospect in the wet rice noodle industry.

  Analysis of Fatty Acids in Different Strains of Burkholderia gladioli HUANG Xiuli, LUO Yuezhen, HUANG Yongde, WAGN Xiaoqin, ZHU Wenjuan, ZHANG Fengyun, ZHAO Zhifeng, CHEN Jiacong 2022, 38 (33):  139-144.  DOI: 10.11924/j.issn.1000-6850.casb2021-1185 Abstract + ( 191 )   HTML ( 5 )   PDF ( 2392KB )   ( 12 ) In order to explore the correlation between fatty acids and the production of bongkrekic acid from Pseudomonas cocovenenans subsp. farinofermentans, the fatty acids of different toxin-producing strains were separated by gas chromatography, and the chromatographic peaks were quantitatively analyzed by area normalization method. The results showed that a total of 11 components were isolated from 9 strains, including hexadecanoic acid (C16:0), cis-10-heptadecaenoic acid (C17:1) and cis,cis-9,12-octadecadienoic acid (C18:2n6c), with an average content of 43.85%, 25.84% and 14.75%, respectively. Culture medium and culture temperature were the main factors affecting fatty acid composition. Under the same culture conditions, the similarity of fatty acid composition of the 9 strains was more than 90%. After the toxicity test, the fatty acids of non-virulent strain 10574 and toxin-producing strain showed similar changes, the content of cis-9-octadecenoic acid (C18:1n9c) decreased, while the content of cis,cis-9,12-octadecadienoic acid (C18:2n6c) increased. The culture condition is the main factor affecting the fatty acid composition of Pseudomonas cocovenenans subsp. farinofermentans, and there is little correlation between fatty acids and the production of bongkrekic acid.

  Ammonia-oxidizing Microorganisms and Their Application in Water Quality Control of Pond Aquaculture in China LU Shimin, LI Yayuan, LIU Chong, LIU Xingguo, BAO Xuteng, TIAN Changfeng, GU Zhaojun, ZHOU Liang, WU Fan 2022, 38 (33):  145-151.  DOI: 10.11924/j.issn.1000-6850.casb2022-0687 Abstract + ( 188 )   HTML ( 5 )   PDF ( 1738KB )   ( 27 ) Ammonia is a pollutant that needs to be considered in the treatment of pond aquaculture discharge. The oxidation of ammonia in pond aquaculture mainly depends on ammonia-oxidizing bacteria, ammonia-oxidizing archaea and anaerobic ammonia-oxidizing bacteria. This study briefly introduces the nitrogen metabolic mechanism of several ammonia-oxidizing microorganisms found in nature, and explains the ecological regulation mechanism of these microorganisms in pond aquaculture water from perspectives of temperature, pH, dissolved oxygen, attached substrate and light, in combination with the characteristics of pond aquaculture ecosystem. Based on attached growth habits of ammonia-oxidizing microorganisms, kinds of pond aquaculture water purification technologies have been developed, which play a role in water purification to a certain extent. However, there are common problems such as large floor area required, high cost and low efficiency. At present, the application and research of ammonia-oxidizing probiotics and high-efficiency microbial reactors in pond aquaculture water treatment in China are still relatively underdeveloped. It is suggested to strengthen the screening and enrichment of low-temperature and high-efficiency ammonia oxidation strains in the future, and to promote research on compact microbial reactors for water treatment, as well as to enrich the means of ammonia removal from freshwater pond aquaculture water.

  The Design of Quality Supply Chain of Characteristic Agricultural Products Based on Blockchain Technology: Taking ‘Mentougou Jingbai Pear’ Pyrus ussuriensis Maxin as an Example WU Yajuan, SU Benying, LI Jing, GAO Tongyu 2022, 38 (33):  152-157.  DOI: 10.11924/j.issn.1000-6850.casb2021-1188 Abstract + ( 213 )   HTML ( 2 )   PDF ( 2933KB )   ( 34 ) In view of the serious damage to the characteristic agricultural product brand caused by adverse economic activities, and the easy tampering of the traditional agricultural product quality traceability technology data, we design the quality supply chain technology based on blockchain, to ensure the effective role of the traceability technology in the quality supply chain of characteristic agricultural products. Taking ‘Mentougou Jingbai Pear’ as an example, this study systematically expounds the current situation of ‘Jingbai Pear’ industry in Mentougou District of Beijing and the problems existing in the quality supply chain of characteristic agricultural products, and analyzes the technical feasibility of applying blockchain to the traceability of characteristic agricultural products. Based on the characteristics of distributed storage, decentralization and immutability of blockchain technology, the overall framework of the quality, safety and traceability system for ‘Mentougou Jingbai Pear’ is designed. The realization methods of whole-process recording and traceability management of quality information in the links of planting, warehousing, transportation, consumption and supervision are expounded, in order to provide support for the construction of the quality and safety traceability technology of characteristic agricultural products based on blockchain. The established quality supply chain system of characteristic agricultural products will enable more effective protection, supervision and management of the brand and quality of characteristic agricultural products.

  Status Quo and Future Development Direction of Science and Technology of Grain Production at Home and Abroad XU Ning, ZHAO Xia, WANG Rui, ZHANG Hui, LI Chunxi, ZHANG Zhao 2022, 38 (33):  158-164.  DOI: 10.11924/j.issn.1000-6850.casb2021-1194 Abstract + ( 228 )   HTML ( 5 )   PDF ( 1175KB )   ( 33 ) “Chinese people’s rice bowl should be firmly in their own hands at all times. Our rice bowl should be mainly filled with Chinese grain.” Food security is an important basis for national security, and ensuring food security is an eternal topic. Therefore, it is very important to systematically analyze the status quo and development trend of grain production science and technology (S&T) at home and abroad. This paper studied subjects involving the characteristics and development trend of the world grain production S&T, the successful experience of grain production in typical agricultural developed countries, and the development trend and major tasks of China’s grain production S&T in the new period. The purpose of this paper is to provide reference for relevant scientific researchers in the field of grain production management and research.