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• 2021 Vol.37 No.32 Published:15 November 2021

  Basal Application and Topdressing of Selenium-enriched Organic Fertilizers: Effects on Chlorophyll Fluorescence, Yield and Selenium Enrichment of Wheat Ma Jie, Yin Xuehong, Li Zhi, Yang Juan, Zheng Guoqi, Liang Xinhua 2021, 37 (32):  1-9.  DOI: 10.11924/j.issn.1000-6850.casb2021-0116 Abstract + ( 169 )   HTML ( 3 )   PDF ( 1423KB )   ( 30 ) In order to ensure the safe production of selenium-rich agricultural products and provide a theoretical basis for high efficient selenium enrichment of wheat, wheat variety ‘Ningchun 55’ was used as material in this study. Under the condition of field experiment, the effects of different application methods and application rates of selenium-enriched organic fertilizers on chlorophyll fluorescence, yield and selenium content of aboveground organs of wheat were studied. The results showed that the chlorophyll content and chlorophyll fluorescence value increased with the increase of selenium application rate, and there were significant differences in chlorophyll content and Fo of wheat leaves at booting stage and filling stage under the two selenium application methods. The total selenium content in wheat stem and wheat bran of different treatments was significantly higher than that of the control. On the whole, the total selenium content of aboveground organs of basal application of selenium-enriched organic fertilizer was higher than that of topdressing, but the difference between them was not significant. The results showed that the two fertilization methods had a certain promoting effect on the accumulation of selenium in wheat. Under the basal application mode, the wheat yield increased by 0.9%-8.9% compared with the control, while under topdressing, the wheat yield decreased at first and then increased, and there was no significant difference in wheat yield between the two fertilization methods. Therefore, according to the chlorophyll fluorescence, yield and selenium enrichment effect of wheat under the two fertilization methods, it is suggested that basal application of selenium-enriched organic fertilizer should be carried out in the production of wheat selenium-rich agricultural products to reduce the agronomic operation of wheat and reduce the cost of labor input.

  Effect of Different Temperature and Time on Seed-borne Fungi and Seed Germination of Maize Li Wenming, Ma Jiancang, Lei Yuming, Xing Huiqin, Shang Liqi 2021, 37 (32):  10-14.  DOI: 10.11924/j.issn.1000-6850.casb2021-0605 Abstract + ( 181 )   HTML ( 4 )   PDF ( 1311KB )   ( 27 ) To reduce the occurrence of maize seed-borne fungi disease, reasonable seed treatment methods should be explored to reduce the rate of fungi. ‘Zheng 58’ was used as material, and the fungal rate of seed-borne fungi and the seed germination were detected by the methods of PDA plate culture and germination test of filter paper with different temperature treatments. The results showed that seeds could carry fungi at the temperature of 30℃ to 50℃, the fungal rates changed from 3.3% to 23.3%, which decreased significantly with the increase of temperature and extension of treatment time, and fungal species also reduced. In the treatments at 40℃ and 45℃ (10-20 min), the fungal rates of seeds ranged from 10% to 13.5%, significantly lower than that of the control (P <0.05). The internal fungal rates of 3.3%-6.7% at 45℃ (30 min) and 50℃ were the lowest. Effects of different temperature on the germination rate, germination potential and germination index of seeds were significantly different. 30℃ treatment had no effect on seed germination. The germination potential and germination index of seeds treated at 35℃ and 40℃ (10-20 min) increased significantly, but the germination rate of seeds at 40℃(30 min) reduced significantly (P<0.05). At the temperature from 45℃ to 50℃, the germination potential, germination rate and germination index decreased significantly. The rates of fungi inside seeds treated at 40℃ for 10-20 min were reduced effectively by 33.5%-50.0%, and seed germination was promoted, which could be used as reasonable temperature and time of maize seed treatment before sowing.

  The Regression Model and Correlation Analysis Between Maize Yield and Planting Density Zhang Zheng, Dong Chunlin, Yang Rui, Chang Jianzhong, Zhang Yanqin 2021, 37 (32):  15-19.  DOI: 10.11924/j.issn.1000-6850.casb2021-0397 Abstract + ( 448 )   HTML ( 10 )   PDF ( 1205KB )   ( 60 ) To explore the relationship between maize planting density and yield, and the relationship between actual yield and standard yield among different planting densities, ‘Bingdan 16’ was used as the material, six planting densities were set, which were 52500、56250、60000、63750、67500、71250 plant/hm2, and the SPSS was applied to analyze the linear regression of the standard yield and main agronomic traits like spike length, spike diameter, bald tip length, rows per spike, grains per row, 100-grain weight, seed rate, planting density and actual yield, and then the regression analysis model was constructed. The regression model of actual yield, planting density and standard yield was y=403.997-0.15×planting density+0.558×actual yield. The regression model between standard yield and traits was y=-123.292-0.037×density-34.237× ear diameter-55.099×ear length+31.950 row number+23.801 row number+7.023×bald tip length+10.649×grain water content-3.006×100 grain weight+9.193 seed yield-0.204×actual yield; the regression model constructed by actual yield, planting density and standard yield was more significant.

  Chemotaxis Test of Sweetpotato Weevil (Cylas formicarius) to Sweet Potato Varieties Lei Jian, Zhang Meng, Zhang Jingzhen, Wang Lianjun, Chai Shasha, Jin Xiaojie, Cheng Xianliang, Yang Yuanyuan, Yang Xinsun 2021, 37 (32):  20-24.  DOI: 10.11924/j.issn.1000-6850.casb2020-0249 Abstract + ( 186 )   HTML ( 2 )   PDF ( 1200KB )   ( 29 ) Odor induction and feature preference are major factors affecting sweetpotato weevil’s feeding. In order to understand the selectivity of sweetpotato weevil to odor of different sweet potato varieties and correlation between sweet potato’s odor and weevil resistance, an odor selection test of 14 sweet potato varieties was carried out by using Y-type olfactometer, and each variety’s resistance was calculated. The results showed that the response rate, trapping rate, and selection coefficient of sweetpotato weevil to 14 sweet potato varieties were significantly different. The response rate, trapping rate, and selection coefficient was 0.3-1, 02-0.9556, and -0.03-0.91, respectively. Among the 14 varieties, Eshu 15 had the minimum selection coefficient of -0.03, showing the highest weevil resistance, while both Eshu 6 and Shangshu 19 had the maximum selection coefficient of 0.91, showing the highest susceptive to weevil. This study establishes a basis for sweetpotato weevil control and will help the identification of weevil-resistant sweet potato variety.

  A Novel Low Temperature Cellulose-degrading Strain Streptomyces azureus and Its Enzymatic Production Condition Optimization Li Ting, Wang Yue, Liu Zhongshan, Liu Qi, Xu Henan, Li Chongwei 2021, 37 (32):  25-33.  DOI: 10.11924/j.issn.1000-6850.casb2021-0107 Abstract + ( 200 )   HTML ( 2 )   PDF ( 2809KB )   ( 26 ) To screen an actinomycete which can efficiently degrade cellulose in low temperature composting, and improve the degradation rate of cellulose under low temperature, a strain from litter layer of mixed forest of Korean pine was screened with Congo red staining (hydrolysis circle method) and 3,5-Dinitrosalicylic acid (DNS) method. The physiological, biochemical and molecular identification of the strain was carried out. The results showed that a strain which could degrade cellulose effectively at low temperature were named T23-B, identified as Streptomyces Azureus, and could grow at 15℃. Response surface method was performed to optimize production condition of cellulose as mannose of 15.6 g/L, yeast extract of 7.8 g/L, initial pH of 5.2, culture time of 96 h, shaking speed of 160 r/min, and culture temperature of 35℃. The cellulase activity could reach 123.43 U/mL which was 4.4 times higher than that before the optimization. Therefore, this study provides a theoretical and practical basis for applying T23-B to winter compost fermentation. It is of great significance for improve the utilization of agricultural waste resources and protect the ecological environment in cold region.

  GbASR gene from Ginkgo biloba: Cloning, Bioinformatics and Expression Analysis Xie Daolong, Tang Zhi, Li Hongye, Fu Xiaoxia, Wang Fan, Liu Xiaoxia, Qin Zuodong, He Fulin, Luo Ying 2021, 37 (32):  34-41.  DOI: 10.11924/j.issn.1000-6850.casb2021-0162 Abstract + ( 280 )   HTML ( 3 )   PDF ( 1573KB )   ( 24 ) The aims are to clarify the role of ASR (ABA-stress-ripening) gene from Ginkgo biloba in response to abiotic stress, and provide materials for studying ASR gene function and environment stress. In this study, Ginkgo biloba was used as material, GbASR gene was cloned and the fusion expression vector pCAMBIA1300-ASR-GFP was constructed by molecular biology techniques, then the subcellular localization of GbASR protein was analyzed. Protein domains and phyletic evolution were analyzed by sequence alignment method. Tissue-specific expression and expression level of GbASR gene under abiotic stress were analyzed by qRT-PCR method. The results showed that the total length of GbASR coding region was 546 bp, encoding a 182 amino acid protein. The theoretical isoelectric point was 5.33 and the molecular weight of GbASR protein was 20111.24 Da, which was a stable hydrophilic protein. Sequence alignment and phylogenetic analysis showed that GbASR protein contained a highly conserved ABA/WDS domain and had high homology with PtASR protein. The subcellular localization analysis showed that GbASR protein was a nucleoprotein. In addition, GbASR gene was widely expressed in different tissues such as root, steam and leaf from Ginkgo biloba, and the GbASR gene was induced under salt, drought and heat stresses, and there were significant different expressions at 0 h, 6 h, 24 h and 48 h under salt, drought, and heat stresses. These results suggest that GbASR might participate in response to abiotic stresses such as salt, drought and heat stresses, and this study could provide a basis for plant breeding and explaining ASR gene function.

  Spatial Variability Characteristics of Forest Soil Factors in Shanxi Province Ren Yukun 2021, 37 (32):  42-50.  DOI: 10.11924/j.issn.1000-6850.casb2021-0004 Abstract + ( 224 )   HTML ( 1 )   PDF ( 2657KB )   ( 23 ) To reveal the spatial distribution characteristics of forest soil factors in Shanxi Province, provide reference for the evaluation of forest soil fertility, technical support for sustainable forest management, and a basis for the establishment of forestry sustainable development policy, based on the soil sampling and testing data of 297 sample spots in Shanxi, the study used GIS techniques to do trend analysis and select the optimal semi-variogram model of 7 factors of forest soil, including alkali-hydrolyzed nitrogen, total nitrogen, organic substance, available phosphorus, total potassium, pH and water content. Then, Kriging interpolation was adopted to analyze the spatial variability characteristics of the forest soil factors. The results show that: the optimal semi-variogram model of total nitrogen, alkali-hydrolyzed nitrogen and pH is Gaussian function model; that of total potassium is exponential function; that of the organic matter and water content is trigonometric and spherical function, respectively. Finally, we used Kriging interpolation method to map the spatial distribution of the forest soil factors, to display the distribution characteristics of them in Shanxi directly. The spatial differentiation characteristics of the forest soil factors in Shanxi are obvious. For alkali-hydrolyzed nitrogen, total nitrogen and organic substance, the relatively high contents are mainly concentrated in the mid-high mountainous area along the main mountain range in the province. The content of total potassium is relatively rich. The water content shows obvious difference of more in southeast and less in northwest. As an instantaneous variable, the spatial distribution of available phosphorus is rather disordered. The spatial variability of pH indicates that the whole forest soil in Shanxi is weakly alkaline, particularly in some areas of Shuozhou, the forest soil is strong alkalinity, which could be used as the typical area of saline-alkali land in research.

  The Yield and Quality of Rapeseed ( Brassica napus L.) at Different Altitudes Zhao Caixia, Ciren Baizhen, Tang Lin, Yuan Yuting 2021, 37 (32):  51-56.  DOI: 10.11924/j.issn.1000-6850.casb2021-0176 Abstract + ( 379 )   HTML ( 1 )   PDF ( 1213KB )   ( 27 ) Three Brassica napus L. varieties, ‘Dadi 95’, ‘Jinghua 165’, and ‘Shanyou 2’, were used as materials to analyze the effects of different altitudes on agronomic and quality traits of rapeseed. The results showed that: with the increase of altitude, the whole growth period of rapeseed was prolonged, the plant height, branch height, number of branches, number of siliques per plant and number of seeds per silique decreased, so did the yield per plant and yield, while the thousand-grain weight increased; the protein content decreased and oil content increased, and the content of glucosinolate and erucic acid showed inconsistence among different varieties. Correlation analysis showed that the altitude was significantly and positively correlated with the growth period, and significantly and negatively correlated with the plant height and yield per plant, the correlation coefficient was 0.519, -0.548, and -0.528 respectively; the altitude was significantly and negatively correlated with the protein content, and positively correlated with the content of oil, glucosinolates and erucic acid, the correlation coefficient was -0.590, 0.262, 0.161, and 0.138, respectively.

  The Optimization of Hard Seed Breaking Condition of Snap Bean Zhang Guanghui, Liu Dajun, Yang Xiaoxu, Liu Chang, Yan Zhishan, Feng Guojun 2021, 37 (32):  57-65.  DOI: 10.11924/j.issn.1000-6850.casb2020-0825 Abstract + ( 216 )   HTML ( 1 )   PDF ( 1378KB )   ( 23 ) To optimize the conditions for removing hard seeds from snap bean seeds, the study screens out the best condition by comparing the effects of different temperatures of warm water immersion, hot water immersion and low temperature storage on the removal of hard seeds. The results showed that when the seed water content was 14.28%, the seed hard rate was 38%. The germination rate, germination potential and vigor index of untreated hard seeds were 26.5%, 17% and 23.17, respectively. The hard seeds soaked in warm water, hot water and stored at low temperature could relieve the hard seeds to a certain extent and promote the germination of seeds. The optimal conditions for each treatment were as follows: soaking seeds at 60℃ for 30 min, soaking seeds at 80℃ for 2 min and storing seeds at -20℃ for 7 days. Finally, the best conditions for hard seed breaking were compared among the three treatments, considering the actual planting situation and the best effect of hard seed breaking, it is more appropriate to soak seeds with high hard seed rate at 60℃ for 30 min.

  Spermidine Alleviating Low Temperature Stress of Phaseolus vulgaris Seedlings Liu Chang, Li Jiayin, Feng Guojun, Liu Dajun, Yang Xiaoxu 2021, 37 (32):  66-72.  DOI: 10.11924/j.issn.1000-6850.casb2021-0506 Abstract + ( 252 )   HTML ( 3 )   PDF ( 1255KB )   ( 29 ) The aim is to study the effect of exogenous Spd on the tolerance of snap bean under low temperature. The seedlings of the low-temperature sensitive cultivar ‘P16093’ and the low-temperature tolerant cultivar ‘P16165’ were used as test materials, and three treatments were set up, including normal temperature control (CK), 4℃ low temperature treatment (LT) and 4℃ low temperature with spraying exogenous Spd (LT+Spd). The plant growth morphology, antioxidant system, osmotic adjustment substance, biofilm and endogenous polyamine content were measured in the three treatments. The results showed that the spraying of exogenous Spd at low temperature promoted plant growth and alleviated the effects of low temperature on plant height, stem thickness, fresh weight and dry weight of snap bean seedlings; the spraying of exogenous Spd reduced the electrolyte permeability in the seedlings’ leaves of both varieties at low temperature compared with the LT group with a maximum decrease of 16.94%. The malondialdehyde content of the two varieties increased, rising by 42.81% and 70.59% on the 8th day, respectively. The soluble protein content decreased while the proline content increased; the antioxidant enzyme activity increased, as well as the endogenous Put and Spd content. The results indicate that the exogenous Spd could alleviate the damage of snap bean seedlings under low temperature stress by regulating polyamine metabolism and enhancing ROS scavenging system in plants.

  Effects of Cow Dung Substrate on the Growth and Photosynthesis of Muskmelon Seedlings Mao Ke, Tian Qiaoling, Yu Fengqiu, Zhang Jiaxin, Zhou Luyao, Fan Yuting, Wang Jiqing 2021, 37 (32):  73-77.  DOI: 10.11924/j.issn.1000-6850.casb2020-0322 Abstract + ( 431 )   HTML ( 2 )   PDF ( 1157KB )   ( 24 ) Peat is recognized as an excellent substrate for horticultural seedling and cultivation all over the world, while excessive exploitation of peat will damage the ecological environment. It has practical significance to study the materials that can replace the peat substrate. This experiment took fermented cow dung as the main material, and used different volume ratios of cow dung, vermiculite and perlite to prepare seedling substrates, a commercial peat substrate was used as the control to carry out a melon seedling experiment. The authors measured the physical properties, emergence rate, growth index and photosynthetic index of different treatment substrates, and studied the effects of different ratios of cow dung substrates on melon seed germination and seedling growth. The results showed that the emergence rate of muskmelon and the physical properties of treatment I were similar to those of the control peat substrate. At the same time, the seedling root length and underground fresh weight of treatment I increased by 19.3% and 60.6% respectively compared with the peat substrate, the intercellular CO2 concentration of seedling leaves was reduced by 12.8% compared with the control, and the net photosynthetic rate was 14.1% higher than that of the control. Therefore, the substrate prepared by fermented cow dung: vermiculite: perlite volume ratio of 6:3:1 with the adding of appropriate amount of chicken manure and citric acid could replace the peat substrate for melon seedlings.

  Effect of Fertilization on Vitamin C Content in Jujube of Mountain Region Deng Xinwei, Liu Meng, Liu Shipeng 2021, 37 (32):  78-82.  DOI: 10.11924/j.issn.1000-6850.casb2021-0175 Abstract + ( 290 )   HTML ( 1 )   PDF ( 1211KB )   ( 80 ) The study aims to investigate the effects of different fertilizers and fertilization frequency on vitamin C content in jujube of mountain region, and select suitable fertilization schemes for the growth of jujubes. Three jujube varieties of mountain region, Goutou jujube, Jun jujube, and Mu jujube, were used as materials to conduct different treatments with different fertilization frequency. Complex fertilizer, bio-organic fertilizer, special fertilizer of jujube, and microbial fertilizer were used at different jujube growth stages, including white ripe stage, green and red stage and mature stage. The molybdenum-blue colorimetry method was used to determine the vitamin C content of jujube at different growth and development stages. The results show that for Goutou jujube, the vitamin C content of white ripe stage reached the highest under the application of microbial fertilizer twice a year, and the vitamin C content of the jujube at the green and red stage and the mature stage was significantly increased. For Jun jujube, the vitamin C content in the green and red stage and the mature stage reached the highest under the application of microbial fertilizer twice a year, and the vitamin C content reached the highest under the application of special fertilizer of jujube twice a year during the white ripe stage. For the Mu jujube, applying special fertilizer of jujube twice a year during the white ripe stage could significantly increase the vitamin C content, and reached the best. In the green and red stage, the application of microbial fertilizer twice a year could significantly increase the vitamin C content of jujube, reaching the highest in the whole group. Applying microbial fertilizer once a year in the mature stage could increase the vitamin C content of jujube, and the effect is the best. For the three varieties of jujube, when fertilizing the jujube at different development stages, the schemes of fertilizing twice a year could obtain jujube with higher vitamin C content, and the effect of microbial fertilizer is particularly significant.

  The Application of Artificial Intelligence in Landscape Architecture Wang Xiaofei 2021, 37 (32):  83-88.  DOI: 10.11924/j.issn.1000-6850.casb2020-0670 Abstract + ( 486 )   HTML ( 8 )   PDF ( 1127KB )   ( 80 ) This article introduced the role of artificial intelligence in landscape architecture research. According to the functions and attribute of artificial intelligence, the commonly used artificial intelligence methods in landscape architecture research were divided into intelligent random optimization, machine learning and artificial life. The application dynamics of different types of artificial intelligence methods in landscape architecture were analyzed. The problems in the application of artificial intelligence in various fields of landscape architecture were pointed out, and the limitation of artificial intelligence methods in landscape architecture research was explored. The establishment of hybrid intelligent system model was an inevitable trend of landscape architecture research towards intelligence, digitalization and automation.

  Effects of Different Soil Modifiers on Improving Secondary Salinization Soil Under Drip Irrigation Zhong Huili, Lu Xiangsheng, Liu Xingcheng, Chen Tianshan, Ma Tianwei 2021, 37 (32):  89-95.  DOI: 10.11924/j.issn.1000-6850.casb2021-0006 Abstract + ( 249 )   HTML ( 2 )   PDF ( 1628KB )   ( 24 ) To screen out suitable soil modifiers for the secondary salinized soil under the dropper mode, 5 soil modifiers were selected for field test in perennial dripping irrigation and serious secondary salinized plot, to study their improvement effect. The results showed that the soil modifiers could improve the secondary salinized soil structure, reduce the soil salt content, and increase soil nutrients. The effect of soil modifiers on waxy corn plant height has a gradual improving trend. The effect of soil modifiers on the chlorophyll content of waxy corn presents a “strong, weak, flat” trend, and could improve the yield, output value, net yield increase and yield composition of waxy corn, but the effect on soil moisture content, total nitrogen content and waxy corn thick stems is not obvious. The comprehensive evaluation of the soil modifiers’ suitability shows that the dripping irrigation type of soil modifier is more effective than the basal application type of soil modifier in improving soil physical and chemical properties and increasing waxy corn yield, and the maleic acid dripping irrigation modifier is the most suitable for the local secondary salinized soil, followed by the fulvic acid soil modifier.

  Effects of Different Amounts of Phosphate Fertilizer on Rice Yield, Fertilizer Utilization and Soil Nutrients Zhang Jinbin, Wang Xiaoyun, Meng Yuan, Sun Yuxiang, Ma Hongbo 2021, 37 (32):  96-101.  DOI: 10.11924/j.issn.1000-6850.casb2021-0671 Abstract + ( 286 )   HTML ( 3 )   PDF ( 1119KB )   ( 46 ) To optimize the phosphorus (P) fertilizer application practices and improve the yield and economic benefits of rice production, we selected rice ‘9108’ as an experimental variety, and evaluated the rice yield, economic benefit, utilization rate of P fertilizer and soil nutrient contents under different P application rates. The results showed that the highest yield (11781.15 kg/hm 2) was achieved under the P application rate of 37.5 kg/hm2. The parameters of the use efficiency, the physiological use efficiency, the agronomic use efficiency and the partial productivity of P fertilizer decreased with the increasing of P fertilizer application rate. The highest P use efficiency was also achieved under the rate of 37.5 kg/hm2. Increasing the P application rate could decrease soil pH and the content of soil organic matter and soil alkali hydrolyzable nitrogen, but increase the content of soil available P and soil available potassium. Increasing the P application rate had a positive effect on the economic benefit of rice, but the economic benefit tended to decline when the application rate exceeded 37.5 kg/hm2. In short, 37.5 kg/hm2 could be recommended as the optimal P application rate for rice production in Xinghua.

  Effect of Selenium and Passivator Application on Available Cadmium Passivation in Soil and Cadmium Reduction in Rice Chai Guanqun, Liu Guihua, Luo Muxinjian, Qin Song, Fan Chengwu 2021, 37 (32):  102-107.  DOI: 10.11924/j.issn.1000-6850.casb2020-0845 Abstract + ( 233 )   HTML ( 1 )   PDF ( 1284KB )   ( 28 ) To study the effect of different selenium fertilizer application methods combined with passivation material on soil cadmium passivation and rice cadmium reduction, a pot experiment was set up. In the study, sodium selenite was taken as selenium fertilizer, calcium magnesium phosphate fertilizer and diatomite were taken as passivation materials. The effects of basal application of selenium fertilizer + calcium magnesium phosphate fertilizer + diatomite and foliar application of selenium fertilizer + calcium magnesium phosphate fertilizer + diatomite on remediation and safe utilization of cadmium-contaminated acidic paddy field were studied. The results showed that the rice yield increased with the increase of selenium fertilizer and passivation material application. The yield of basal application of selenium fertilizer was slightly higher than that of foliar application, and the yield gap was 2.115 g/pot. Compared with the control (CK), basal application of 0.28% calcium magnesium phosphate fertilizer + 0.12% diatomite + 0.004‰ selenium (T3) could increase rice yield by 1.68 times. With the increase of selenium fertilizer and passivation material application, pH increased, available Cd decreased, while the organic matter and CEC changed a little. There was no significant difference in soil pH, organic matter and CEC between basal application and foliar application, but the available Cd content of basal application of selenium fertilizer was slightly lower than that of foliar application. T3 treatment had the best passivation effect on soil Cd than other treatments. The Cd content in rice decreased with the increase of basal application rate of Se fertilizer. The Cd content in rice decreased first and then increased with the increase of foliar application rate of Se fertilizer. The reduction of Cd in rice with basal application of Se fertilizer was stronger than that with foliar application, and the gap was 0.021 mg/kg. Compared with the control (CK), the Cd content in rice of T3 treatment was decreased by 0.063 mg/kg. It could be seen that selenium plays an important role in regulating Cd accumulation in rice, and the effect of basal application of selenium fertilizer is stronger than that of foliar application. Therefore, the effect of basal application of 0.28% calcium magnesium phosphate fertilizer + 0.12% diatomite + 0.004‰ selenium on soil Cd passivation and rice Cd reduction is the best, and the formula is worthy of popularization and application in Cd-contaminated paddy field.

  Pollution Characteristics and Potential Risk Assessment of Heavy Metals in Tea Garden Soil Treated with Soil Conditioning Powder Liu Xiaolan, Wei Fuxiao, Wang Daoping, Zhang Qinghai, Lin Shaoxia, Pan Weidong, Wang Ruoyan 2021, 37 (32):  108-115.  DOI: 10.11924/j.issn.1000-6850.casb2021-0306 Abstract + ( 254 )   HTML ( 1 )   PDF ( 1312KB )   ( 26 ) In this paper, the characteristics of heavy metal content and pollution level of “waterfall Maofeng” tea garden soil under different soil conditioning powder treatments in Anshun, Guizhou Province were studied by means of sample test and physical and chemical analysis. The heavy metal content and pollution level of tea garden soil under CK treatment (0 kg/hm 2), A treatment (600 kg/hm2), B treatment (750 kg/hm2) and C treatment (900 kg/hm2) were discussed. The results showed that: under different soil conditioning powder treatments, the variation degree of heavy metal Cr, Hg, Pb, Cu, Zn, Ni, As and Cd in the study area were different, and the content of the eight heavy metals in the soil were also different. The pH and content of Cr, Pb and Ni were the highest in treatment C, the content of As, Hg and Cd were the highest in treatment A, and the content of Cu and Zn were the highest in treatment B. Correlation analysis showed that there was a significant correlation between Ni and Pb, indicating that they had high level of homology, while the correlation characteristics of other elements were not obvious. According to the comprehensive pollution index (P综), treatment A was slightly polluted, CK, B and C were all moderately polluted. Cr in different soil treatments were within the scope of national class II standard (GB15618—2008), and the sample points were up to the standard and the rate was 100%. Among the selected pollution assessment factors, Cu was the most important factor, followed by Cd and Ni. As to the single potential ecological risk index ($E_{r}^{i}$) of heavy metals in the study area, Hg belonged to strong ecological risk, and the other seven heavy metals were in slight potential ecological risk level. The average value of the comprehensive potential ecological risk index (RI) was 196.79, which was generally at the level of medium potential ecological risk. Hg contributed the most to RI and was the most important ecological risk element.

  Improvement Effects of Different Soil Amendments on Secondary Salinized Soil in Protected Field Li Bin, Li Yuefei, Tao Jiale, Wang Weijin, Qi Shigang, Gao Xueshuang 2021, 37 (32):  116-119.  DOI: 10.11924/j.issn.1000-6850.casb2021-0596 Abstract + ( 276 )   HTML ( 1 )   PDF ( 1126KB )   ( 32 ) To improve the fertility of the secondary salinized soil in the protected field and establish a suitable secondary salinized soil improvement model, the effects of applying organic fertilizer, soil conditioner and rice bran on soil organic matter, available nitrogen, available phosphorus and water-soluble salt were studied in Suyu. The results showed that all treatments could improve the secondary salinized soil and increase soil nutrients and reduce soil salt content. Compared with the control, the organic matter, available phosphorus and available potassium in the treatment of organic fertilizer were increased by 41.6%, 68.3% and 121.6%; the organic matter and available potassium in the treatment of rice bran were significantly increased by 41.4% and 48.6%; the organic matter, available nitrogen and available potassium were also increased in the treatment of soil conditioner. In addition, the treatments reduced the water-soluble salinity of soil as well. Compared with the control, the soil conductivity, total water-soluble salt, water-soluble calcium, water-soluble magnesium and sulfate ion in the treatment of rice bran were significantly reduced by 43.3%, 23.5%, 28.9%, 34.6% and 23.2%, respectively. The improvement effects of rice bran, organic fertilizer and soil conditioner on secondary salinized soil decrease successively, and the improvement effect of rice bran is more significant.

  Oil Peony Flowering Season Forecast Zhang Cuiying, Fan Xianzheng, Li Ruiying 2021, 37 (32):  120-126.  DOI: 10.11924/j.issn.1000-6850.casb2021-0099 Abstract + ( 180 )   HTML ( 2 )   PDF ( 1303KB )   ( 41 ) According to the observation data of flowering period of oil peony in Heze City from 2008 to 2019 and the corresponding meteorological elements, the main meteorological factors affecting the flowering period of oil peony in Heze City were analyzed by using the mathematical statistical methods of moving average, correlation analysis and stepwise regression. The results showed that temperature was one of the main meteorological factors affecting the first flowering period of oil peony, and had a significant negative correlation with the flowering period; sunshine, precipitation and daily range had no significant correlation with the first flowering period of oil peony. Based on the meteorological factors that had great influence on the flowering period of peony from 2008 to 2018, a forecasting model for the first flowering period of oil peony was established by using the stepwise regression method, which could release the flowering forecast on March 21 and April 1 respectively. The accuracy of the model was 100% in 2019 and 2020, and the fitting degree was ideal. The model has a good forecasting effect and could meet the needs of meteorological services.

  Effects of Two Inducers on Induced Resistance to Grapevine Downy Mildew Wang Xiaolin, Wu Qinyan, Peng Yanqiong, Wu Jie, Huang Jiexue, Mao Nini, Ji Muxiang 2021, 37 (32):  127-131.  DOI: 10.11924/j.issn.1000-6850.casb2021-0034 Abstract + ( 319 )   HTML ( 1 )   PDF ( 1355KB )   ( 37 ) In order to provide references for resistance inducing agent for grapevine downy mildew control, the resistance effects of different inducers applied on grapevine downy mildew were evaluated, furthermore the physiological mechanism of resistance were explored. In this paper, the leaf spray method was used to investigate the resistance inducing effect of 2 kinds of inducers on grapevine downy mildew. The results showed that the two resistance inducers had better control effect on grapevine downy mildew, and β-1,3-glucooligosaccharides with 10 times dilution had the best control efficiency (65.44%). Compared with the control group, β-1,3-glucooligosaccharides with 10 times dilution could significantly increase the activities of superoxide dismutase (SOD), peroxidase (POD) and chitinase (CHI), phenylalanine ammonia-lyase (PAL) in grape leaves at 3-day and 7-day after treatment. Taken together, this study confirms that β-1,3-glucooligosaccharides with 10 times dilution can induce grape leaves to produce systemic resistance through enhancing the activities of defense enzymes and resistance related protein, and sever as a resistance inducer applying for grapevine downy mildew control.

  Nutrient Component of Seed-case of Buckwheat Cultivars Zhang Jin, Liu Sichen, Cao Xiaoning 2021, 37 (32):  132-138.  DOI: 10.11924/j.issn.1000-6850.casb2021-0247 Abstract + ( 522 )   HTML ( 3 )   PDF ( 1292KB )   ( 27 ) Buckwheat is an important medicinal and edible minor cereal crop, which has good medicinal and nutritional value. In this paper, 20 buckwheat cultivars were used as trial materials to analyze the differences of nutritional and functional components in seed-case of different buckwheat cultivars. Results showed that there were significant differences in nutritional components of different buckwheat cultivars. The flavonoid content of ‘Zhengning Honghua’, ‘Xuanwei buckwheat’ and ‘miqiao 1’ were the highest among all the cultivars, being 12.8, 12.5 and 10.6 mg/g, respectively, which was 66.2%, 62.3% and 37.7% higher than that of ‘Dingtian 2’. The rutin content of ‘Miqiao’ (3.66 mg/g) was the highest among all cultivars. Also, the lignin content of ‘Miqiao’ was the highest (34.6%), which was 58.1% higher than that of ‘Kuciqiao’ (21.9%), while the change trend of cellulose content was the opposite. The soluble sugar and protein content had no obvious change trend among the cultivars. It can be concluded that the seed-case of ‘Miqiao 1’ has relatively high nutritional value, which is worthy of further promotion in the development of buckwheat seed-case products.

  Monitoring and Evaluation of Ecological Restoration Effects of Zhenjiang Yangtze Cetacean Provincial Nature Reserve Wang Zhaogen, Pan Jie, Li Hualiang, Luo Hongwei 2021, 37 (32):  139-147.  DOI: 10.11924/j.issn.1000-6850.casb2020-0805 Abstract + ( 183 )   HTML ( 1 )   PDF ( 2755KB )   ( 26 ) Since 2006, the decline of Yangtze cetacean, a critically endangered cetacean species living in the Yangtze River, has attracted widespread attention. To provide a good living environment for the Yangtze finless porpoise in the Zhenjiang Yangtze cetacean provincial nature reserve, a series of ecological restoration projects have been carried out. From 2015 to 2018, ecological floating islands, artificial fish nests and benthic animals release were constructed in the water area of Hechangzhou to carry out ecological restoration. During this period, this study conducted tracking monitoring and effect evaluation for ecological restoration projects. The results show that the construction of ecological floating islands could improve the biodiversity and community structure complexity of phytoplankton and zooplankton in the region. Artificial fish nests have a certain effect on the proliferation of stickiness spawning fish, such as Cyprinus carpio, Carassius auratus, Hemiculter leucisculus and Xenocypris davidi. The construction of ecological floating islands and artificial fish nests has better effects on fish aggregation. The proliferation and release of benthic animals could significantly increase the abundance and biomass of released species and the community biomass of benthic animals in the reserve, and the effect of the proliferation and release is medium. The ecological restoration effect of the nature reserve is remarkable, which provides a scientific basis for the ecological restoration of the aquatic life reserve affected by engineering construction.

  Determination of Residual Arsenic in the Chinese Mitten Crabs (Eriocheir sinensis) by HPLC-ICP-MS Yin Yuting, Wang Qian, Chen Xi, Gui Yuan, Song Chao 2021, 37 (32):  148-156.  DOI: 10.11924/j.issn.1000-6850.casb2020-0731 Abstract + ( 189 )   HTML ( 1 )   PDF ( 1338KB )   ( 24 ) The residues of six arsenic species in edible parts of the Chinese mitten crabs (Eriocheir sinensis) were conducted by the high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS). After pretreatment, extraction and degreasing, optimal separation and detection conditions were obtained by adjusting the suitable chromatographic column, mobile phase, pH and flow rate. The results demonstrate that the linear relationship of the six arsenic species could be observed in the range of 0~50 μg/L, and the R2 of the six arsenic species in the range of 0~50 μg/L is 0.999. The limit of detection is 0.0060~0.0912 μg/kg and limit of quantification is 0.020~0.304 μg/kg. The recovery of this method is 70%~120% and the relative standard deviations (RSDs) are less than 5%. This method establishes a reliable method for the detection of arsenic residues in the Chinese mitten crabs, and could provide a technical support for the rapid detection of the arsenic residuals in aquatic products.

  Effects of Temperature Mutation on the Intestinal and Water Microbial Diversity of Marsupenaeus Japonicus in the Biofloc System Qin Haipeng, Wang Bo, Liao Xuzheng, Hu Shikang, Sun Chengbo 2021, 37 (32):  157-164.  DOI: 10.11924/j.issn.1000-6850.casb2020-0614 Abstract + ( 204 )   HTML ( 2 )   PDF ( 1886KB )   ( 35 ) The bioflocs shrimp culture system was used to culture M. japonicus and investigate the efficiency and stability of nitrogen conversion in the biofloc system during abrupt temperature change. In the experiment, M. japonicus was randomly divided into 2 groups. The control group was disinfected clean seawater with a daily water exchange rate of 20% (semi-closed culture system), and the experimental group was biofloc seawater with an initial volume of 20 mL/L (biofloc floc culture system). After the water quality of the experimental group and the control group remained stable for one week, the temperature mutation stress was applied, and the temperature rose sharply by 10℃. The results showed that there was no significant effect of abrupt temperature change on the nitrogen conversion pathway in the biofloc system during the experiments, and the nitrate nitrogen in the experimental group showed an increase after abrupt temperature change, from 19.65 mg/L on the 5 d of the experiment (before abrupt temperature change) to 31.54 mg/L on the 10 d (after abrupt temperature change), and the cumulative rate was greater in the experimental group than in the control group. High-throughput sequencing revealed that a total of 4219 OTUs were obtained in both experimental and control aqueous organisms. The abundance and diversity indices were greater in the experimental group than those in the control group, and greater before than after abrupt temperature change. Microbial communities in the water and gut after temperature mutation were lower in abundance and diversity than before abrupt temperature change. Bioflocs system performed better than semi-closed culture system in coping with abrupt temperature change, with higher stability in both abundance and diversity of microbial communities.