Current issue

• 2022 Vol.38 No.5 Published:15 February 2022

  Advances in Research on the Storability of Rice Seeds YAN Yuntao, HE Xi, ZHANG Haiqing, HE Jiwai 2022, 38 (5):  1-8.  DOI: 10.11924/j.issn.1000-6850.casb2021-0279 Abstract + ( 558 )   HTML ( 13 )   PDF ( 1304KB )   ( 376 ) The storability of rice seeds is an important trait related to grain storage safety and the safety of seed use, it is also the focus in seed research and by seed enterprises. Rice seeds with strong storability still exhibit high seed vigor after long-term storage, these rice varieties can be better used to solve the problem of grain storage and the safety of seed use. In this review, we introduced the reasons of seed aging and deterioration, discussed the physiological and biochemical mechanisms of seed during storage, summarized the research progresses of genetic mechanism of rice seed storability. Finally, we made an outlook for how to breed the new variety of rice with strong storability.

  224 Maize Inbred Lines from Shanxi: Genetic Structure and Genetic Relationships Based on SSR Markers by Fluorescence Detection LI Rui, SHANG Xiao, SHANG Chunshu, CHANG Lifang, YAN Lei, BAI Jianrong 2022, 38 (5):  9-16.  DOI: 10.11924/j.issn.1000-6850.casb2021-0281 Abstract + ( 322 )   HTML ( 4 )   PDF ( 2023KB )   ( 48 ) In order to use the heterosis, it is necessary to analyze the genetic structure and genetic relationships of maize inbred lines. Based on the analysis of 40 SSR loci, the genetic structure and genetic relationships of 224 maize inbred lines from Shanxi were analyzed. A total of 171 alleles were detected with 4.28 alleles per locus. The average of the PIC, MI and gene diversity was 0.44, 2.02 and 0.50 respectively. There were 9 unique alleles among 9 SSR loci. These lines could be divided into three groups by model-based cluster method, which were Reid, Lancaster and SPT. According to the result of genetic structure component (Q-value), there were some cross-group inbred lines in each group. The 224 lines could be divided into 4 groups by distance-based cluster method, which were Reid, Lancaster, SPT and Others. About 90% inbreed lines were included in Reid group and Lancaster group. This study also discussed the choice of tester for heterotic groups, the types of SSR markers and cluster methods of heterotic grouping in maize commercial breeding. The study could provide a basis for the improvement of inbreed lines and the selection of new hybrid combinations in maize commercial breeding.

  Effect of Main Cultivation Factors on Yield of Oil Sunflower in North Hebei BAI Wei, HU Yang, HU Qingqing, CUI Jinli, ZHANG Baoying, YANG Sumei 2022, 38 (5):  17-22.  DOI: 10.11924/j.issn.1000-6850.casb2021-0154 Abstract + ( 346 )   HTML ( 4 )   PDF ( 1234KB )   ( 92 ) The study aims to explore the effect of main cultivation factors on the yield of oil sunflower, and determine the optimal cultivation scheme of oil sunflower in northern Hebei Province. Five-factor quadratic orthogonal regressive rotation design was applied to establish an effect function of sowing date, density, nitrogen fertilizer, phosphate fertilizer, potash fertilizer and the yield of oil sunflower. The results showed that the yield of oil sunflower increased first and then decreased with the change of sowing date, the increase of planting density and the increasing application rate of nitrogen fertilizer, phosphate fertilizer and potash fertilizer, wherein sowing date and the interaction between sowing date and nitrogen fertilizer played an important role. When the target yield was more than 2916.67 kg/hm2, the optimal cultivation scheme was as follows: the sowing date of June 30th -July 5th, the sowing density of 54749-55478 plants/hm2, the application amount of nitrogen fertilizer of 80.0-85.7 kg/hm2, phosphate fertilizer of 44.4-45.0 kg/hm2 and potash fertilizer of 70.3-75.0 kg/hm2.

  Garlic Chitinase Gene AsCHI1: Identification and Its Response to Salt Stress ZHANG Yuyang, ZHOU Xue, LIU Lingyi, XU Wujun, REN Xuqin, WANG Guanglong, XIONG Aisheng 2022, 38 (5):  23-29.  DOI: 10.11924/j.issn.1000-6850.casb2021-0275 Abstract + ( 358 )   HTML ( 4 )   PDF ( 1984KB )   ( 150 ) The study aims to investigate the sequence characteristics of garlic chitinase gene and its response to salt stress, and to identify its function in resistance to stresses. The AsCHI1 gene was isolated by RT-PCR technology using garlic cultivar ‘Cangshan siliuban’ as the research material. BioXM 2.6, ProtParam, DNAMAN, SignalP 5.0, SOPMA, SWISS-MODEL, NCBI and MEGA5 were adopted to analyze the sequence characteristics of nucleotides and its encoded amino acids. Fluorescent quantitative PCR technology was introduced to detect its expression in different tissues and under salt stress. The open reading frame of the gene was 933 bp in length encoding 310 amino acids. The protein encoded by AsCHI1 gene belonged to chitinase Class I and GH19 family. Amino acid sequence analysis showed that AsCHI1 contained a signal peptide region at the N-terminus possessed by most chitinases, whereas the C-terminus was highly consistent with the amino acid sequences of CHI from other species. In terms of genetic relationship, it was relatively close to Lilium longiflorum LlCHI (QBZ68892.1) in the Liliaceae family and tea CsCHI (XP_028075045.1) in the Theaceae family. Real-time fluorescent quantitative PCR analysis showed that the AsCHI1 gene was expressed in garlic roots, garlic cloves and leaves, but the highest expression was observed in the roots. In addition, salt stress could significantly induce the expression of AsCHI1 gene in various tissues. This gene may play an important role in the resistance to salt stress in garlic plants.

  Determination of Five Kinds of Flavonoids in the Medicinal Herbs of Thesium chinensis ZHENG Lingling, JI Ruifeng, HAN Hongliang, LUO Yilu, LUO Jiayi, GUAN Yueqin, YAO Qisheng, ZHENG Weibing, CHEN Meilan, ZHOU Xiuteng 2022, 38 (5):  30-36.  DOI: 10.11924/j.issn.1000-6850.casb2021-0737 Abstract + ( 373 )   HTML ( 6 )   PDF ( 1475KB )   ( 308 ) To reveal the differences in the contents of five kinds of flavonoids between wild and cultivated Thesium chinensis, the contents of Kaempferol-3-O-rhamnose(1-2)glucoside, Kaempferol -3-O- rutinoside, Astragaline, Kaempferol-7-glucoside and Apigenin-7-O-β-D-glucopyranoside in Thesium chinensis were determined by Ultra-High Performance Liquid Phase. The results showed that the linear ranges of Kaempferol-3-O-rhamnose(1-2)glucoside, Kaempferol -3-O- rutinoside, Astragaline, Kaempferol-7-glucoside and Apigenin-7-O-β-D-glucopyranoside were 10-1000 (0.9995), 1-200 (0.9992), 1-200 (0.9995), 1-200 (0.9994), 10-2000 g/mL (0.9998), respectively; RSD of precision, stability and reproducibility tests was 0.17%~3%. The average recoveries of the five kinds of flavonoids were 91.99%~107.40% with RSD less than 3.24%. Compared with that of the wild Thesium chinensis, the contents of Kaempferol-3-O-rhamnose(1-2)glucoside, Astragaline, Kaempferol-7-glucoside and Apigenin-7-O-β-D-glucopyranoside in cultivated Thesium chinensis were significantly higher (P<0.05), and the content of Kaempferol -3-O- rutinoside tended to be higher but showed no significant difference. This study shows that the method has good repeatability, accuracy and simplicity. It can determine the contents of the five kinds of flavonoids in wild and cultivated Thesium chinensis at the same time, and is recommended to be popularized.

  The Disinfection Effect of Allyl Isothiocyanate Applied in Nursery Greenhouse ZHAO Liqun, TIAN wen, TIAN Yanan, CAO Lingling, XU Xiulan 2022, 38 (5):  37-42.  DOI: 10.11924/j.issn.1000-6850.casb2021-0515 Abstract + ( 261 )   HTML ( 5 )   PDF ( 1256KB )   ( 132 ) Allyl isothiocyanate is a secondary metabolite extracted from Brassicaceae plants and used as a new pesticide with features of quick-acting, high-efficiency and low-toxicity. Three greenhouses from Beijing Daxing and Tongzhou were selected for the testing. The efficacy of Allyl isothiocyanate on greenhouse disinfection by spraying was studied. By comparing the population and type of microorganisms of indoor environment, facilities and equipment surface before and after the treatment, the results showed that the amount of fungi and bacteria in the air reduced significantly after disinfection treatment. The total amount of bacteria on the surface of the greenhouse film and the seedbed decreased, and the number of bacteria before and after disinfection on the surface of some greenhouse nursery beds was significantly different; the dominant fungi isolated in this experiment were Alternaria spp., Curvularia spp., Rhizopus spp., Aspergillus spp. and Penicillium spp. Further test identified plant pathogenic fungi Alternaria tenuissima and Alternaria alternate, and both fungi reduced in population and isolation frequencies after the disinfection treatment. This result indicates that Allyl isothiocyanate application is an effective way for greenhouse disinfection.

  Comparison of Different Methods of Pollen Viability Determination and Preliminary Study on in Vitro Culture——Taking Yulania cylindrica as an Example HU Yingfeng, XIA Qiping 2022, 38 (5):  43-47.  DOI: 10.11924/j.issn.1000-6850.casb2021-0773 Abstract + ( 380 )   HTML ( 7 )   PDF ( 1570KB )   ( 1327 ) To compare the effects of different methods for measuring pollen viability, taking the pollen of Yulania cylindrica as the experimental material, we adopted the MTT staining, TTC staining and acetic acid magenta staining method to determine the pollen viability of Yulania cylindrica under natural blooming, at full bloom in indoor hydroponic culture, and at wilting in indoor culture. Meanwhile, different concentration gradients of boric acid and sucrose solution were used for pollen culture in vitro. The results showed that the viability measured by acetic acid magenta staining was relatively high, the average value was 96.94%; and that of TTC staining was relatively low, the average value was 39.52%; and only MTT staining was the most suitable one, the average value was 85.46%. The best solution for in vitro culture of pollen was 5% sucrose solution and 0.01% boric acid solution. The comparison of different methods for measuring the pollen viability of Yulania cylindrica flower powder and the in vitro pollen culture could provide certain reference for breeding research on other species.

  Effects of Fulvic Acid Potassium on Germination and Seedling Growth of Cherry Radish Under NaCl Solution Hydroponics LI Sen, FENG Di, ZHANG Jingmin, ZHU Haiyan, PENG Dianliang, WANG Zhihe, WANG Qinqin 2022, 38 (5):  48-53.  DOI: 10.11924/j.issn.1000-6850.casb2021-0278 Abstract + ( 680 )   HTML ( 8 )   PDF ( 1213KB )   ( 73 ) To study the salt tolerance of cherry radish at germination and seedling stage, and explore the effect of fulvic acid potassium on improving salt tolerance, in this experiment, four NaCl concentration treatments (1.5, 3.0, 4.5 and 6.0 g/L) were used in hydroponics, and 0 g/L was used as control. Two treatment methods were set as adding 0.2 g/L fulvic acid potassium and not adding fulvic acid potassium, to investigate the germination rate, survival rate, morphological index and chlorophyll content of cherry radish. The results showed that with the extension of culture time in salt solution and the concentration increase of culture solution, the rate and extent of survival rate reduction of cherry radish seedlings both increased. The germination rate of cherry radish decreased slightly when the culture solution reached 3.0 g/L, and the dead seedling rate increased with the increase of salt concentration in the hydroponic solution. With the increase of the concentration of hydroponic solution, the root length, hypocotyl length, root-shoot ratio and dry matter weight of cherry radish were all inhibited to different degrees. At the same concentration of hydroponic solution, compared with the treatment without fulvic acid potassium, the germination rate of the treatments with fulvic acid potassium increased by 3.4%, 3.4%, 2.4%, 2.4% and 3.6%, respectively, and the time of the emergence of dead seedlings was delayed, but the dead seedling rate of the treatments of 1.5, 3.0 and 4.5 g/L increased by 188.9%, 21.2% and 8.1%, respectively. In the control treatment, the addition of fulvic acid potassium significantly increased the chlorophyll-a content, carotenoid content, root length and dry matter weight of cherry radish (P<0.05). The salt tolerance of cherry radish at germination stage was greater than that in the seedling growth stage, fulvic acid potassium could promote the germination and growth of cherry radish in salt-free hydroponic, but under salt stress, although it could promote the germination of cherry radish, it is not conducive to the survival of the seedlings.

  Two Soil Compound Amendments: Improvement and Fertility Effect on Coastal Saline Soil HAN Xiaofang, TIAN Xiaoming, YANG Yongli, ZHANG Jingzhi, ZHANG Qing, ZHANG Kai, ZHANG Tao, JIA Lin 2022, 38 (5):  54-59.  DOI: 10.11924/j.issn.1000-6850.casb2021-0486 Abstract + ( 353 )   HTML ( 6 )   PDF ( 1181KB )   ( 492 ) To study the improvement and fertility effects of two soil compound amendments (composed of microbial agents and decomposed garden wastes) on saline soil, this study used the 60-day indoor constant temperature (30℃) cultivation method to study the physical and chemical properties of saline-alkali soil with different treatments. The results showed that: decomposed garden wastes could improve the conductivity and soil alkalinity of saline-alkaline soil, while adding different concentrations of microbial agents on the basis of decomposed garden wastes had no significant effect on the conductivity and soil alkalinity of saline-alkaline soil, indicating that the two compound amendments had no significant effect on improving the conductivity and soil alkalinity of saline-alkali soil. Adding decomposed garden wastes and two compound amendments could increase the total nitrogen, alkali-hydrolyzed nitrogen, available phosphorus and organic matter content of saline-alkali soil, of which, A3 compound amendment had the largest increase range and the best effect. Adding decomposed garden wastes and two compound amendments all could reduce the available iron, available manganese and available copper content, and increase the available zinc content. Among them, compound amendment A had a significant effect, and A1 had the best effect. From the perspective of the number of soil bacteria, the two compound amendments could significantly increase the content of soil bacteria, and the content order was A3>B2>A2>B1>A1 and B3. The correlation analysis of soil indicators and bacteria content showed that bacterial content had a very significantly positive correlation with soil total nitrogen, available phosphorus and organic matter, and a significantly positive correlation with available potassium. In summary, the two compound amendments could significantly increase the nutrient indexes and bacterial content of saline soil, and could be applied to the improvement and remediation of saline soil, the compound modifier A3 (LX3 and decomposed garden wastes) has the best effect.

  Characteristics of Nutrients and Microbial Community Composition of Different Panax ginseng Cultivation Soil WANG Yan, WANG Liwei, ZHAO Hongyan, ZHAO Min, YANG Hongyan 2022, 38 (5):  60-68.  DOI: 10.11924/j.issn.1000-6850.casb2021-0564 Abstract + ( 329 )   HTML ( 4 )   PDF ( 2377KB )   ( 36 ) To alleviate the demand for ginseng soil and accelerate the development of cultivating ginseng in farmland, nutrients and microbial population in farmland soil, forest soil and 4-year ginseng-cultivated soil were investigated. The differences among the three kinds of soil were explored to provide a basis for improving farmland soil used for cultivating ginseng. High-throughput sequencing was used for investigating the microbial diversity and composition. The results of physical and chemical analysis show that the pH of 4-year ginseng soil is the lowest, but the contents of ammonium nitrogen, available phosphorus, total nitrogen, total phosphorus and organic matter are significantly higher than those of farmland and forest soil. The results of high-throughput sequencing show that the richness and diversity of bacterial and fungal communities in farmland soil are higher than those in 4-year ginseng-cultivated soil and lower than those in forest soil. The bacteria compositions in different soil are basically similar, mainly include Proteobacteria, Acidobacteria, Actinobacteria, Chloroflexi and so on. Mortierella is the dominant genus in forest soil. Fusarium is abundant in farmland soil, and the accumulation of pathogenic bacteria Sclerotinia is detected in 4-year ginseng-cultivated soil. The analysis of db-RDA reveals that the pH, and nitrogen, phosphorus and organic matter contents could all affect the microbial community structure, and there is a stronger correlation between environmental factors and fungal community. Based on the above results, the effective improvement of farmland soil should focus on controlling fungal community.

  Abundance-deficiency Index of Soil Nutrients and Appropriate Fertilizer Application Rates for Apple Planting in China: A Preliminary Study WANG Yan, ZHU Kaidi, SUN Hongren, ZHANG Jiping, LV Yucai, WANG Jian 2022, 38 (5):  69-78.  DOI: 10.11924/j.issn.1000-6850.casb2021-0292 Abstract + ( 422 )   HTML ( 6 )   PDF ( 1299KB )   ( 44 ) To lay a theoretical basis for apple soil testing and fertilizer recommendation in China, the method of scattered experimental data integration and the method of nutrient balance and target yield minus soil fertility yield were employed to study the abundance-deficiency index (rich-lack index, RLI) of soil nutrients and the recommended soil fertilizer application rates (RSFAR) for apple plangting in China. The results showed that the RLI of soil available P for apples in China from the first to the seventh level was ≥51, 16-51, 5-16, 2-5, 0.4-2, 0.1-0.4 and <0.1 mg/kg, respectively; the RLI of soil available K from the first to the fifth level was≥381, 126-381, 42-126, 14-42 and <14 mg/kg, respectively; the RLI of soil total nitrogen from the second to the ninth level was ≥1.4, 1.1-1.4, 0.8-1.1, 0.6-0.8, 0.5-0.6, 0.4-0.5, 0.26-0.4 and <0.26 g/kg, respectively. When the N, P, K fertilizer use efficiency was 40%, 20% and 50% and the target yield was 30-75 t/hm2, the range of the RSFAR of P for the first to the seventh level soil was 0-0, 12-30, 24-60, 36-90, 48-120, 60-150 and 72-180 kg/hm2, respectively; the range of the RSFAR of K for the first to the fifth level soil was 0-0, 20-51, 41-102, 61-153 and 82-204 kg/hm2, respectively; and the range of the RSFAR of N for the second to the ninth level soil was 19-47, 38-94, 56-141, 75-188, 94-234, 113-281, 131-328 and 150-375 kg/hm2, respectively. In this study, the recommended fertilization system of N, P and K in China’s apple soil was established preliminarily, which could provide a scientific basis for apple soil testing and fertilization. But the research on the index of nutrient abundance and deficiency of apple soil in China is still not perfect, and apple fertilization should be explored further.

  Effects of Partial Substitution of Chemical Fertilizer by Organic Fertilizer on Lettuce Yield in Newly Reclaimed Red Soil ZHANG Yong, XU Zhi, GAO Lifang, DENG Yaqin, WANG Ruixue, WANG Yuyun 2022, 38 (5):  79-85.  DOI: 10.11924/j.issn.1000-6850.casb2021-0257 Abstract + ( 291 )   HTML ( 4 )   PDF ( 1279KB )   ( 36 ) The study aims to explore the effect of partial replacement of chemical fertilizer by organic fertilizer on the yield of lettuce in newly reclaimed red soil. According to the principle of equal replacement of 20% chemical fertilizer nitrogen, five treatments, including no fertilizer (CK), conventional fertilizer (CF), biological organic fertilizer + 80% chemical fertilizer (B), refined organic fertilizer + 80% chemical fertilizer (O) and biological organic fertilizer + refined organic fertilizer + 80% chemical fertilizer (B + O), were set to study their effects on soil physical and chemical properties, and lettuce nutrient uptake, yield and sustainability index. Structural equation model was used to analyze the relationship between soil organic matter and nutrient supply and yield. Boundary line method was used to reveal main factors affecting the yield of lettuce. The results showed that compared with CF, B and B+O treatment significantly increased the yield by 28.8% and 13.8%, respectively. Compared with CF, lettuce nitrogen and potassium uptake under B, O and B+O treatment significantly increased by 12.9%-29.0% and 28.1%-40.6%, yield sustainability index significantly increased by 10.4%-23.8%, soil organic matter and aggregates significantly increased by 27.0%-53.0% and 25.0%-32.4%, respectively. Soil bulk density significantly decreased by 7.2%-10.5%, the contents of soil alkali-hydrolyzed nitrogen, available phosphorus and available potassium under O and B+O treatment were not significantly different from those under CF. Structural equation model analysis showed that organic fertilizer substitution mainly increased soil organic matter to improve the structure of soil aggregates and ensure the supply of soil nutrients, and then increased the lettuce nutrient absorption and yield. Boundary line analysis showed that the boundary yield reached the maximum when the soil organic matter was 21.05 g/kg, alkali-hydrolyzed nitrogen was 88.07 mg/kg, available phosphorus was 45.17 mg/kg, and available potassium was 210.51 mg/kg. However, the effect of the addition of refined organic fertilizer on soil available nutrient supply was not obvious. Therefore, soil organic matter is the main factor that limiting the boundary yield increase, the replacement of 20% nitrogen fertilizer by biological organic fertilizer could significantly increase the content of soil organic matter, ensure the supply of soil nutrients, and promote the yield increase of lettuce.

  Spatial and Temporal Variation Characteristics of Vegetation Productivity in Fen River Basin ZHU Xiaocong 2022, 38 (5):  86-93.  DOI: 10.11924/j.issn.1000-6850.casb2021-0264 Abstract + ( 343 )   HTML ( 4 )   PDF ( 3224KB )   ( 380 ) Vegetation productivity (GPP, NPP) and carbon use efficiency (CUE) are important indicators for monitoring and assessing ecosystems, which can effectively reflect changes in the ecosystem environment. The Fen River Basin is an important watershed in the typical ecologically fragile area of the Loess Plateau, and a key area for soil erosion control and ecological protection in China. This study took the basin scale as the basis and focused on analyzing the temporal and spatial characteristics and influencing factors of GPP, NPP and CUE based on MODIS data in the Fen River Basin from 2000 to 2015. The results showed that GPP and NPP presented increasing trends in the Fen River Basin as a whole, while CUE had a decreasing tendency, with an average value of GPP 665.88 g C/(m2·a), NPP 252.77 g C/(m2·a) and CUE 0.36. The southern part of the basin had higher GPP, NPP and CUE than the northern part, and the mountains on both sides of the basin edge were obviously different from other areas. The vegetation productivity of the Fen River Basin was mainly affected by precipitation. In the north, GPP, NPP, and CUE were negatively correlated with temperature, while in the southern part of the basin, GPP was positively correlated with temperature, and NPP and CUE were negatively correlated with temperature. The northern part of the Fen River Basin was more sensitive to the changes of water and heat condition than the southern part, and the increase of temperature and precipitation in the Fen River Basin led to the decrease of CUE.

  The Influence of Meteorological Factors on Grain Filling Speed of Spring Maize in the Plateau Area of Eastern Gansu ZHOU Zhongwen, ZHANG Moucao, LIU Ying, LIU Donghui, ZHANG Hongni, ZHANG Junlin, HAN Bo 2022, 38 (5):  94-98.  DOI: 10.11924/j.issn.1000-6850.casb2021-0268 Abstract + ( 338 )   HTML ( 3 )   PDF ( 1308KB )   ( 75 ) To study the influence of meteorological factors on spring maize grain filling speed in the plateau area of eastern Gansu Province, the authors used maize sowing data and meteorological data in Xifeng test site of the National Agrometeorological Experimental Station from 2018 to 2020, to analyze the relationship between meteorological factors and maize grain filling. The results showed that the variation of grain-filling speed and grain-filling days presented a quadratic curve. The 100-grain weight increased the fastest from the 24th to 46th day after flowering, and the grain filling speed reached the peak on the 38th day after flowering. The main meteorological factors affecting the grain filling speed included the average temperature, the maximum temperature, the minimum temperature, daily range of temperature, sunshine hours, air humidity and precipitation. Temperature and sunshine had positive effects, while humidity and precipitation had negative effects. The suitable sowing time of maize should be determined according to the climate of the year, so that the rapid growth period of the 100-grain weight could coincide with the period of high temperature and little rain in Qingyang, avoiding the influence of the weather with more rain and less sunlight, thus achieving stable and high yield.

  Spatial-temporal Change of Negative Accumulated Temperature in the Main Agricultural Regions of the Yarlung Zangbo River and Its Two Tributaries of Tibet During 1981-2020 Tsewang Thondup, DU Jun, , Phuntsok Samten 2022, 38 (5):  99-105.  DOI: 10.11924/j.issn.1000-6850.casb2021-0267 Abstract + ( 277 )   HTML ( 3 )   PDF ( 1627KB )   ( 119 ) Based on the daily mean air temperature at 9 meteorological stations in the Yarlung Zangbo River and its two tributaries (BRTT) of Tibet from 1980 to 2020, the relationships between the spatial-temporal distribution characteristics of the negative accumulated temperature (NAT) and its corresponding factors, including air temperature, snow cover and permafrost, were explored with the methods of linear regression, Mann-Kendall test and correlation analysis. The study results indicated that NAT decreased generally from west to east in BRTT, and it also decreased with altitude decreasing. The initial day of NAT was delayed at a rate of 3.11 d/10 a, while the final day was advanced at a rate of 2.53 d/10 a. The duration days decreased at a rate of 6.03 d/10 a, with the significant increase of NAT at a rate of 24.93(℃·d)/10a. The NAT exhibited an increasing trend at the decadal scale, with a low value in 1980s—1990s and a significant high value in 2000s—2010s. The trends of decadal variation features, such as the delayed initial day, the advanced final day, the shortened duration days and the elevated NAT, had become significant since the beginning of the 21st century. The abrupt changes detected by the M-K mutation test indicated that the abrupt changes of the final day of NAT was earlier, occurred in 1993. The abrupt change of both the initial day and the duration days of NAT occurred simultaneously in 1996, while the abrupt change of NAT was detected in 1995. After the mutation, the initial day of NAT was delayed by 9 days, while the final day was advanced by 6 days. The duration was shortened by 17 days, and the NAT was reduced by 68.6℃·d accordingly. The increase of NAT was in accordance with the increasing mean temperature, decreasing snow cover days in winter and permafrost degradation. The NAT variation had both positive and negative effects on agricultural productions in this highland region.

  The Space-temporal Changes of Thermal Resources in Inner Mongolia from 1959 to 2018 YANG Xiujuan, SUN Jiying, GAO Julin, QIAO Shuaishuai, YU Xiaofang, WANG Zhigang, BAO Haizhu, HUANG Zhiyuan, HU Shuping 2022, 38 (5):  106-116.  DOI: 10.11924/j.issn.1000-6850.casb2021-0426 Abstract + ( 302 )   HTML ( 2 )   PDF ( 2633KB )   ( 105 ) Climate warming has significantly changed the thermal resources in Inner Mongolia, and understanding thermal resource changes in this region can provide a research basis for crop production and spatial layout. Based on the daily average temperature of 50 meteorological stations from 1959 to 2018, this paper discussed space-temporal distribution characteristics of the initial day, ending day and duration days≥0℃ and ≥10℃, as well as cumulative temperature in Inner Mongolia by adopting five-day sliding average method. The results indicated that: (1) the average initial day ≥0℃ and ≥10℃ in Inner Mongolia was March 29, and May 5, respectively, the initial day ≥0℃ and ≥10℃ showed an ahead of time trend, the average ending day≥0℃ and ≥10℃ was October 28 and September 24, respectively; (2) the advance of the initial day and the delay of the ending day significantly increased the cumulative temperature and the duration days in Inner Mongolia, the cumulative temperature and duration days were similar in spatial distribution, and were different greatly between east and west; the cumulative temperature ≥0℃ was between 1874 and 4433℃, and the cumulative temperature≥10℃ was between 1360 and 4024℃,duration days ≥0℃ were between 168 and 246, and duration days ≥10℃ were between 89 and 180; the cumulative temperature and duration days ≥0℃ and≥10℃ showed an increasing trend; (3) the initial day ≥0℃ and ≥10℃ showed a positive correlation with latitude and longitude, the ending day, while the cumulative temperature and duration days showed a negative correlation with latitude and longitude; (4) the mutation date of the initial day, the ending day and duration days, as well as that of the cumulative temperature mainly focused between 1991 and 1996.

  Strong Cool Summer in East Gansu in 2020: Climate Characteristics and the Impact on Agriculture ZHANG Hongfen, YANG Lijie, ZHAO Yujuan, ZHANG Feng 2022, 38 (5):  117-123.  DOI: 10.11924/j.issn.1000-6850.casb2021-0282 Abstract + ( 347 )   HTML ( 2 )   PDF ( 1348KB )   ( 54 ) To study the climate characteristics of strong cool summer and the impacts on agriculture, the data of precipitation, temperature, sunshine, development period and yield of spring maize in the summer of 2020 (June to August) in east Gansu Province were analyzed. The results showed that the summer in 2020 was a typical regional strong cool summer. In 2020, the average temperature in summer was lower than that in the same period of previous years, except that the temperature of the first ten days of June was slightly higher than that in the same period of previous years, and the temperature of the first ten days of July and the first ten days of August were slightly high. The average temperature in summer was generally lower than that of the previous years in all counties, except Huanxian and Xifeng, whose temperature was slightly lower than the normal values in the same period over the years. Zhenyuan and Huachi recorded the second lowest average temperature of summer in historical records. The precipitation in summer was more than that in the same period over the years, and there were more rainy days; the precipitation amount of Zhengning and the rainy days of Huanxian were the second in history. The sunshine in summer was less than that in the same period of previous years, and Xifeng and Ningxian had the least summer sunshine in history. Strong cool summer caused the extension of the growth period of crops in autumn, which was about 12 days longer than that in previous years on average. 2020 was not a high yield year, although climate yield was a positive effect. The main reasons for the decrease of yield were the low temperature and less sunlight in the later stage of reproductive growth and high soil moisture. However, the sufficient precipitation, especially soil moisture at the key maize development stage, and the particularity and adaptive adjustment of spring maize growth, were still the main factors for the climate yield to be positive effect.

  PGPR in Atrazine Contaminated Soil: Effect on the Growth and Physiology of Zoysia japonica Steud ZHENG Peifeng, JIANG Xiaolei, ZHAI Yanlin, GUO Shaoxia, LI Wei 2022, 38 (5):  124-131.  DOI: 10.11924/j.issn.1000-6850.casb2021-0272 Abstract + ( 244 )   HTML ( 4 )   PDF ( 1358KB )   ( 67 ) To provide a theoretical basis for planting Zoysia japonica Steud seedlings in atrazine contaminated soil, the effects of plant rhizosphere growth promoting bacteria (PGPR) on plant growth and physiological characteristics of Zoysia japonica Steud seedlings in atrazine contaminated soil were investigated. A two-factor experimental design was conducted. One-year-old Zoysia japonica Steud seedlings were used as materials, the seedlings were divided into two groups of PGPR (Pseudomonas fluorescens) inoculated and non-inoculated, and treated with atrazine (concentration gradient: 0, 3, 15, 75 mg/kg). The growth index, defensive enzyme activity, photosynthetic parameters and chlorophyll fluorescence of the seedlings under different atrazine concentrations were measured. The results showed that the inoculation of Pseudomonas fluorescens promoted the growth of Zoysia japonica Steud and alleviated the stress of atrazine at different concentrations. And the promoting effect of inoculation was the most obvious at the atrazine concentration of 3 mg/kg. Compared with the non-inoculated plants, the chlorophyll a and b of Zoysia japonica Steud leaves increased by 45.8% and 39.5%, respectively; net photosynthetic rate (Pn) increased by 184.83%; the maximum photochemical efficiency (Fv/Fm) and PSII potential activity (Fv/Fo) increased by 9.9% and 41.04%, respectively; peroxidase (POD) activity, soluble protein and proline content were 2.96, 1.94 and 2.37 times that of those of the control, The plant height, shoot fresh weight and dry weight of Zoysia japonica Steud increased by 71.43%, 47.69% and 78.13%, respectively. In conclusion, PGPR inoculation can promote the growth of Zoysia japonica Steud, increase chlorophyll content, improve photosynthesis, and has a significant effect on alleviating the toxicity of low concentration atrazine.

  The Dynamic Tracking of Wheat Lodging Resistance Research: Bibliometric Analysis Based on WoS and CNKI Database WANG Xiaofei, ZHANG Jiawei, LIU Tiening, REN Xiaolong, JIA Zhikuan, CAI Tie 2022, 38 (5):  132-142.  DOI: 10.11924/j.issn.1000-6850.casb2021-0305 Abstract + ( 259 )   HTML ( 5 )   PDF ( 2215KB )   ( 34 ) To track the development trends of wheat lodging resistance research based on the Web of Science database and the China National Knowledge Infrastructure (CNKI) database, a bibliometric analysis of relevant literature from 1990 to 2020 was carried out to visualize the research trend in this field. The results show that the lodging resistance of wheat has gradually become a hot topic of crop research in the past 30 years, and research institutions mainly concentrated in the United Kingdom and China. The representative journals on lodging resistance are Field Crops Research, Journal of Triticeae Crops, and etc. The main research directions are the genetic effects and gene mapping of lodging in wheat, the relationship between the phenotype and composition of stem and the resistance to lodging, the evaluation and monitoring of the occurrence of lodging, and the agronomic measures for lodging prevention and control. With the interdisciplinary integration, dynamic monitoring and intelligent regulation of the whole process of wheat growth will become the focus of research on wheat lodging resistance. The results of this study are helpful for researchers to understand the development trend of wheat lodging resistance research and could provide a basis for the research on wheat lodging resistance theory and technology.

  A Bibliometric Analysis of Research Trends in Soil Remediation from 2011 to 2020 MA Biao, LIU Xuelu, NIAN Lili, LI Liangliang, YANG Yingbo 2022, 38 (5):  143-151.  DOI: 10.11924/j.issn.1000-6850.casb2021-0309 Abstract + ( 392 )   HTML ( 5 )   PDF ( 2295KB )   ( 71 ) Soil pollution has become a global problem and is one of the most serious environmental problems in China. To discuss the current status and future development trend of soil remediation, the present study visually analyzed the information of related literature from 2011 to 2020 collected from CNKI and Web of Science (WOS) by using CiteSpace software. The results indicated that, for research in soil remediation field from 2011 to 2020: (1) the number of publications had increased gradually, five countries with the top English publication numbers were China, the United States, Spain, India and Australia, the Chinese Academy of Sciences was the main institution contributing to the number of publications in China; (2) the centrality of keywords and the frequency of literature citation showed that the research focus in this field was on the remediation of contaminated soil caused by heavy metal, while bioremediation and biochar were research hotspots; (3) the remediation of pesticide-contaminated soil, ecological remediation, research and development of restoration material and technology will be important directions in soil remediation research in the future.

  Modelling of High Voltage Electrostatic Field Induced Total Flavan-3-ols Accumulation in Postharvest Grape Berries LIANG Changmei, WANG Jianwei, WEN Pengfei, YANG Hua 2022, 38 (5):  152-156.  DOI: 10.11924/j.issn.1000-6850.casb2021-0171 Abstract + ( 290 )   HTML ( 5 )   PDF ( 1282KB )   ( 192 ) The accumulation of polyphenols in post-harvest grape berries can be induced by high voltage electrostatic field (HVEF). In order to optimize and accurately control the total flavan-3-ols accumulation in post-harvest grape berries, a continuous model of total flavan-3-ols content change in grape berries under HVEF treatment was established. Firstly, the grape berries of Cabernet Sauvignon were used as test materials, and the HVEF of -2 kV / cm was adopted, the total flavan-3-ols content was sampled at equal and random intervals, and two sets of data were determined by DMACA. Secondly, according to the data of equal intervals, the response model of the total flavan-3-ols in grape berries to HVEF was established by using least-square method. Finally, the data of random intervals was used to verify the constructed model. The MSE of the predicted value was 0.0036, and the RAE was 0.28%. The results show that the model has high accuracy and could provide theoretical and technological support to quantitatively regulate the total flavan-3-ols accumulation in grape berries under HVEF treatment.

  The Construction of Regional Grain Industry Chain and Supply Chain in Yunnan Province WANG Xuejiao, LI Liang, MAO Zhaoqing, LI Longwei, CHEN Liangzheng 2022, 38 (5):  157-164.  DOI: 10.11924/j.issn.1000-6850.casb2021-0290 Abstract + ( 299 )   HTML ( 5 )   PDF ( 1269KB )   ( 108 ) As a southwestern border province of China, Yunnan is featured by the geographical advantage of proximity to the Indo-China Peninsula which is named ‘World Rice Warehouse’, and its capital and technology are ahead of the neighboring countries of China. Therefore, to enhance its support capability in consolidating and improving the national food security strategy, Yunnan should further develop its comparative advantages by building the regional food industry chain and supply chain depending on the province’s grain system of production, processing, storage and transportation, as well as its agricultural economic and trade cooperation platforms and channels with the neighboring countries of China. In this study, we used comparative analysis and related methods to systematically analyze the scale of grain production in Yunnan, the proportion of its grain production to the national total amount, the transition of its grain variety structure and the characteristics of its food security system, as well as the grain export trade of the 6 countries in the Indo-China Peninsula from 2010 to 2019. Then, we identified the problems in grain production in Yunnan such as the decrease of grain ration production capacity, the decline of comparative benefits of grain production and the insufficient support for agricultural ‘go global’ strategy. Finally, a series of countermeasures were put forward, including further implementing the strategy of ‘reserving grain in land and technology’ to increase Yunnan’s production capacity of grain, focusing on agricultural products storage and transportation system to improve the ability to obtain grain from abroad, expanding the border processing and logistics industry, optimizing the policy of agricultural products’ import and export, and etc.