Current issue

• 2022 Vol.12 No.8 Published:20 August 2022

  The Relationship Between Leaf Area Index and Yield of Rice: Research Progress HE Mi, LI Xiaobo, HUANG Jing, HUANG Guangfu 2022, 12 (8):  1-5.  DOI: 10.11923/j.issn.2095-4050.cjas2020-0269 Abstract + ( 795 )   HTML ( 49 )   PDF ( 963KB )   ( 717 ) Leaf, as the material basis for constructing the rice organs, is closely related to the quality of the light environment and the utilization rate of light energy. The leaf area index (LAI) is an important indicator related to rice yield, and is significantly correlated with the light and effective radiation absorption coefficient in rice canopy. In this paper, we reviewed the relationship between the LAI in different growth periods of rice and the yield, and pointed out that the optimal LAI could be increased based on variety selection and cultivation measures, to achieve the high yield. The study could provide a theoretical basis for developing a predicting system of the optimal LAI and for regulating the rational canopy structure of rice.

  Correlation Degree Between Water Stress and Wheat Yield Traits and Grain Bulk Density NIU Liya, YU Liang, ZHANG Yujie, ZOU Jingwei, LU Li, WANG Fengzhi, WANG Weiwei 2022, 12 (8):  6-9.  DOI: 10.11923/j.issn.2095-4050.cjas2020-0265 Abstract + ( 335 )   HTML ( 9 )   PDF ( 1110KB )   ( 203 ) This study used correlation analysis and grey correlation analysis to analyze 7 main characters of 10 new wheat varieties, including yield and bulk density. The research showed that the yield traits and bulk density of wheat were affected by water content, and different traits had different degrees of reduction. The results of grey correlation analysis showed that under dry and water land condition, the correlations between the yield traits and the yield per plant and bulk density were not consistent and varied in degrees. According to the analysis, when selecting wheat varieties in Cangzhou, the tillering ability and the rate of spike formation should be the most important factors, and the number of grains per spike should also be taken into consideration. Wheat grain yield and grain bulk density are complex comprehensive characters, which are combined and interacted with many factors. Therefore, it is objective and feasible to evaluate the influence degree among the characters by grey correlation analysis method, which could be used in breeding practice in the future.

  Nitrogen Application Rate: Effects on Photosynthetic Characteristics and Grain Filling Characteristics of Maize MENG Yanyu, JING Yanjie, ZHOU Yinfu 2022, 12 (8):  10-15.  DOI: 10.11923/j.issn.2095-4050.cjas2020-0215 Abstract + ( 303 )   HTML ( 10 )   PDF ( 1293KB )   ( 187 ) To apply nitrogen fertilizer more reasonably and improve nitrogen use efficiency in planting high-efficiency maize varieties, low-nitrogen and high-efficiency type maize variety ‘Jingnongke 728’ and high-nitrogen and high-efficiency type maize variety ‘Xianyu 335’ were used as materials, five nitrogen treatments were set up: N1(120 kg/hm2), N2(180 kg/hm2), N3(240 kg/hm2), N4(300 kg/hm2), and NCK (360 kg/hm2, nitrogen application rate in local field production). The photosynthetic characteristics and grain filling characteristics of the two maize varieties were measured in this experiment. The results showed that the photosynthetic rate of ‘Jingnongke 728’ under N2 treatment at jointing stage and filling stage was significantly higher than that under NCK, and the transpiration rate at jointing stage was significantly higher than that under NCK, the intercellular carbon dioxide concentration at the tasseling stage was lower than that under NCK, and the difference was significant. The photosynthetic rate, transpiration rate and stomatal conductance of ‘Xianyu 335’ under N4 treatment were significantly higher than those under NCK at the silking stage, and the photosynthetic rate was significantly higher than that under NCK at the filling stage. The intercellular carbon dioxide concentration during tasseling and filling stage was significantly lower than that under NCK. The grain-filling rate of ‘Xianyu 335’ under N4 treatment was significantly higher than that under NCK. Therefore, the optimum nitrogen application rate of ‘Jingnongke 728’ is about 180 kg/hm2 (N2), and that of ‘Xianyu 335’ is about 300 kg/hm2 (N4).

  Regional Trials of Mid-Late Maturing Potato Varieties in the North China Group 2019-2020 LIN Tuanrong, WANG Yufeng, WANG Zhen, FAN Longqiu, ZHANG Zhicheng, WANG Wei, HUANG Wenjuan, JIAO Xinlei, WANG Yiqian, XING Jin, YIN Yuhe 2022, 12 (8):  16-21.  DOI: 10.11923/j.issn.2095-4050.cjas2021-0054 Abstract + ( 315 )   HTML ( 5 )   PDF ( 1090KB )   ( 230 ) To better adapt to the development of spring potato production in China, and select new potato varieties suitable for planting in north China, the national potato variety regional trials were carried out in Ulanqab of Inner Mongolia from 2019 to 2020. The results showed that among the 8 tested varieties, ‘YL1106-67’ had the highest yield of 54810 kg/hm2, followed by the yield of ‘Jin 12-13-9’ of 47760 kg/hm2, and the third was the yield of ‘Zhongshu 928’ of 46035 kg/hm2. All the three varieties had higher yield than that of the control ‘Zihuabai’, the yield increase rate was 26.32%, 10% and 6.12%, respectively. The yield of ‘YL1106-67’ was extremely different from that of the control ‘Zihuabai’, and the yield difference between ‘Jin 12-13-9’, ‘Zhongshu 928’ and that of the control was not significant. Therefore, ‘YL1106-67’ and ‘Zhongshu 928’ are new potato varieties suitable for planting in north China.

  Research Progress of Alternative Splicing in Plants XU Yue, WANG Xi, SHEN Zimeng 2022, 12 (8):  22-26.  DOI: 10.11923/j.issn.2095-4050.cjas2020-0190 Abstract + ( 768 )   HTML ( 15 )   PDF ( 1131KB )   ( 418 ) Alternative splicing is widespread in plants and is the main source of transcriptome and proteome diversity in organisms. With the development of science and technology, the research methods of alternative splicing have gradually become simple, convenient and efficient, and more and more alternative splicing events have been discovered in plants. The article mainly introduces the mechanism and research methods of alternative splicing in plants, as well as the latest research progress of alternative splicing in several plants, and puts forward suggestions on the research direction in the future.

  The Agronomic Traits of 24 Broomcorn Millet Materials: Principal Component Analysis and Cluster Analysis YANG Fang, LIANG Haiyan, LIN Fengxian, SONG Xiaoqiang, DENG Yarui, LI Hai 2022, 12 (8):  27-34.  DOI: 10.11923/j.issn.2095-4050.cjas2021-0099 Abstract + ( 307 )   HTML ( 8 )   PDF ( 1175KB )   ( 353 ) To screen excellent breeding materials for broomcorn millet and provide reference for its local breeding, the agronomic traits of 24 broomcorn millet materials were analyzed by principal component analysis and cluster analysis, and a comprehensive evaluation was conducted in this experiment. The results showed that the cumulative variance contribution rate of the four extracted principal components was 84.9%, which reflected most of the information of the original indexes. ‘201-8’ and ‘06-D69’ had the highest comprehensive scores among the 24 materials. The test materials were grouped into four categories, the score and yield of the first and second categories were better, the average score was 41.78 and 38.48, respectively, and the average yield was 251.1 kg/hm2 and 210.6 kg/hm2, respectively. These materials can be given priority in variety breeding. The score and yield of the third category was poor, 37.69 and 185.1 kg/hm2, respectively, but the plant height, spike length, basal stem diameter and other indicators were better, which could be considered in breeding lodging-resistant varieties. The materials of the fourth category scored the least and had the lowest yield, 33 and 169 kg/hm2, respectively, and other indexes were not ideal too. Therefore, the materials of the fourth category are not recommended.

  Wild Wheat Seedlings in Field: The Determination of Pre-harvest Sprouting Resistance and Genetic Analysis ZHANG Xitai, XIAO Lei, DONG Ce, XIE Shuqin, LIN Guifen 2022, 12 (8):  35-42.  DOI: 10.11923/j.issn.2095-4050.cjas2021-0006 Abstract + ( 367 )   HTML ( 7 )   PDF ( 2241KB )   ( 124 ) The aims are to obtain the wheat germplasm resources with high resistance to pre-harvest sprouting (PHS) and to clarify the genetic background. After autumn harvest before winter wheat planting, the newly emerged wild wheat seedlings in field were used as test materials. The centralized transplanting cultivation, and growth consistency and genetic stability observation were used to eliminate the strains with unstable inheritance. The comprehensive agronomic characters of 118 wild wheat seedlings with genetic stability were investigated, and the PHS resistance was determined. 4 germplasm lines with good comprehensive agronomic characters and high resistance to PHS were selected. SSR molecular markers were used to analyze the genomic DNA of the 4 germplasm lines, Aegilops tauschii Coss. and local main wheat varieties planted in 5-10 years before wild wheat seedlings. The results showed that 78.8% of the wild wheat seedling lines were highly resistant to PHS, and 19.5% of the wild wheat seedling lines had a PHS rate of 0. The 4 germplasm lines with high resistance to PHS were found to be the hybrids of Aegilops tauschii Coss. and the former main wheat varieties by SSR molecular marker analysis. Collecting, transplanting and identifying wild wheat seedlings in field after autumn could be a new way to obtain wheat germplasm resources resistant to PHS.

  Heterogeneity of Available Phosphorus in Regional Farmland Soil and Its Causes ZHANG Jian, ZHANG Mingkui 2022, 12 (8):  43-47.  DOI: 10.11923/j.issn.2095-4050.cjas2021-0153 Abstract + ( 327 )   HTML ( 10 )   PDF ( 1067KB )   ( 148 ) The application of phosphorus (P) fertilizer is an important means to regulate soil available P and obtain high yield of crops. Therefore, the regional soil available P status can reflect the rationality of P fertilizer application in the area on a long time scale. Taking Zhejiang Province as an example, through the statistical analysis of the collected data of soil available P measured from 2015 to 2020, we discussed the change and spatial differentiation characteristics of farmland soil available P, analyzed the problems existing in the application of P fertilizer, and put forward countermeasures and suggestions of P application. The average level of soil available P in farmland soil in Zhejiang increased significantly, with an overall increase of about 85.0%. However, the distribution of available P in farmland soil in different regions of Zhejiang was extremely unbalanced. Available P in soil showed significantly spatial heterogeneity in both large and small spatial scales. Soil available P data showed a skewed distribution, which was reflected in the low proportion of soil with available P of 10-30 mg/kg, the high proportion of P deficiency soil with available P of <10 mg/kg, and the excessive accumulation of P in soil with available P of > 50 mg/kg. The reason was that the application of P fertilizer in many areas focused on cash crops rather than on food crops, and the implementation of compound fertilizer exacerbated this trend to a certain extent. Landform, soil texture and soil type also had a certain impact on the level of soil available P. The analysis shows that it is necessary to strengthen the work of soil testing formula in the application of P fertilizer, and implement classified P application based on the level of tested soil available P. The results also show that the geometric average could better reflect the real situation of regional available P than the arithmetic average.

  Research Progress of Phytoremediation of Farmland with Excessive Heavy Metals NIE Xiongfeng, HUANG Yanfei, CHEN Guifen, HUANG Yuyi, LIU Bin, LIU Yongxian 2022, 12 (8):  48-54.  DOI: 10.11923/j.issn.2095-4050.cjas2021-0100 Abstract + ( 498 )   HTML ( 9 )   PDF ( 1108KB )   ( 464 ) This paper briefly analyzed the characteristics of the control technologies of heavy metal pollution in farmland in southern China. 40 species of hyperaccumulators for cadmium, arsenic, copper and lead in China were collected, classified and summarized. Based on the existing heavy metal hyperaccumulators in China, the selection and cultivation direction of remediation plants in farmland with excessive heavy metals in southern China were discussed. Suggestions for the application of hyperaccumulators in the remediation of farmland with heavy metal cadmium, arsenic, copper and lead pollution were put forward.

  Polyploidy Induction by Colchicine in Forest Trees: Research Progress LI Yuling, YAN Shaobo, MAO Xiuhong, WANG Cuiyan, WANG Jinna, LIU Cuilan, ZHANG Qian, QIAO Yanhui 2022, 12 (8):  55-61.  DOI: 10.11923/j.issn.2095-4050.cjas2021-0077 Abstract + ( 577 )   HTML ( 7 )   PDF ( 1205KB )   ( 1271 ) Polyploid breeding is an important way to create and select new varieties of plants. Colchicine is the most widely used and effective reagent for plant polyploidy induction at present. In this paper, the research progress of colchicine in forest polyploidy induction in recent years is reviewed, and the influencing factors such as colchicine concentration, induction time, treatment methods and the methods for identifying polyploidy are summarized. It is pointed out that there are some problems in forest polyploidy, such as tedious and slow separation and purification of chimeras, urgent development requirement of new inducers, long evaluation period of forest polyploidy, and insufficient research on molecular mechanism of autopolyploid. Then, corresponding solutions and suggestions are given. The purpose of this review is to provide theoretical reference for forest polyploidy breeding.

  Effects of Soil Improvement Materials on Physicochemical Properties of Soil and Yield and Quality of Flue-cured Tobacco GUO Shanhu, ZHOU Zonggui, LIU Min, PAN Wenzheng, ZHANG Lifang, ZHAO Xuetong, ZHANG Qi, XIAO Yongfei 2022, 12 (8):  62-67.  DOI: 10.11923/j.issn.2095-4050.cjas2020-0270 Abstract + ( 362 )   HTML ( 9 )   PDF ( 1184KB )   ( 224 ) To study the effects of different soil improvement materials on soil physicochemical properties and yield and quality of flue-cured tobacco, single factor experiment was used to explore the effects of five soil improvement materials, namely, soil improvement agent, bio-phosphate fertilizer, ferment carbon, soil conditioner and soil fertilizing agent. The results are as follows: (1) The five soil improvement materials could reduce the content of organic matter, hydrolysable nitrogen, available copper, available manganese and available boron, and increase pH, and the content of exchangeable calcium, exchangeable magnesium and available sulfur in tobacco planting soil. (2) Except that soil conditioner could reduce the stem girth, other materials could promote the growth and development of tobacco plants, increase the plant height or stem girth in varying degrees, while all the improvement materials had no significant effect on the maximum leaf length and width. (3) Soil improvement agent could make the chemical compositions of flue-cured tobacco more harmonious, except that the total sugar content was slightly higher than that of high-quality tobacco leaves, other chemical compositions were consistent with the production of high-quality tobacco leaves. (4) Ferment carbon and soil improvement agent were beneficial to improving the physical characteristics of flue-cured tobacco, and had better effect on maintaining the weight per unit area and moisture content respectively. (5) The five soil improvement materials could all increase the output value, and the effect of soil improvement agent was the best with the increase of the tobacco yield by 27 kg/hm2, the output value by 11171.25 yuan/hm2, the proportion of superior tobacco leaves by 5.1%, and the proportion of medium and superior tobacco leaves by 2.95%.

  Sustainable Tobacco Programme (STP) in Yunnan: Promotion Efficiency and Enlightenment SONG Jie, HE Jie, QIN Yifeng, LI Dehua, WU Jiang, ZHAO Sheng, LIANG Yidan, LIU Jingjing, LI Xiangyang, Wang Yuemao 2022, 12 (8):  68-72.  DOI: 10.11923/j.issn.2095-4050.cjas2020-0268 Abstract + ( 414 )   HTML ( 7 )   PDF ( 1052KB )   ( 442 ) Sustainable development is the direction of tobacco industry modernization, as well as an important theme to enhance the core competitiveness of tobacco industry. In this study, the implementation status of Yunnan Sustainable Tobacco Programme (STP) from 2017 to 2020 and its influence on Yunnan tobacco export volume were analyzed. The main practices, including the construction of leadership mechanism and talent team, the building of digital management platform, and flexible use of special funds, were summarized. It is considered that the implementation of STP in Yunnan indirectly affect tobacco production safety, mode and management concept, which has led to the increase of the ratio of Yunnan tobacco export marketability year by year. Based on tobacco production status in Yunnan, the study puts forward that STP industry standards should be established, labor and employment norms should be strengthened, tobacco quality traceability should be promoted, and green (environment-friendly) production should be pulled by green sales.

  Sensitivity Evaluation of the Test Kits for the Determination of the Residual Rate of Five Organophosphorus Pesticides in Agricultural Products LUO Junxia, ZHAO Jianbo, ZHAO Qianqian, ZHANG Gang, WANG Feng, LIU Qing, ZHANG Jie, PAN Ling, ZHAO Limin, MA Lei 2022, 12 (8):  73-80.  DOI: 10.11923/j.issn.2095-4050.cjas2021-0127 Abstract + ( 330 )   HTML ( 4 )   PDF ( 1382KB )   ( 184 ) To evaluate the commercial test kits for pesticide residue rate and understand their quality, the sensitivity of six brands of pesticide residue rapid test kits sold in market to phorate, phoxim, diazinon, parathion and moncrotophos were determined in two cases (2.5 mL and 3 mL of extract). The effect curves of inhibition rate on pesticide concentration of the kits were plotted according to the determination results of the five pesticides at five concentration levels, the logarithm of inhibition rate and pesticide concentration were used for linear fitting, and the correlation coefficient, IC50 and IC10 were calculated, the sensitivity of various kits to each pesticide were compared according to IC10. Then the advantages and disadvantages of the kits were determined. The sensitivity of the same kit to different pesticides and different kits to the same pesticide were different. The kits with better logarithmic correlation between inhibition rate and pesticide concentration had correlation coefficient R2 of 0.4835-1 (2.5 mL of extract) and 0.6602-1 (3 mL of extract); and IC10 was 2.01×10-4-3.78 mg/kg (2.5 mL of extract) and 3.92×10-3-3.36 mg/kg (3 mL of extract) respectively. The six kits were not sensitive to phorate. Except kit A, the inhibition rates of the other kits at five concentration levels were 0. According to the five pesticides tested, the kits are divided into three grades. D kit is the best, followed by C and E, and the third is A, B and F. It is suggested to modify the judgment threshold of 50% or 70% of the national standard and industrial standard.

  Sanmenxia Red Fuji Apple: Prediction Model of the First Flowering Date JI Zhihong, LIU Xiaoying, ZHANG Yanyan, CAO Suya 2022, 12 (8):  81-86.  DOI: 10.11923/j.issn.2095-4050.cjas2021-0102 Abstract + ( 210 )   HTML ( 11 )   PDF ( 1332KB )   ( 202 ) In order to improve the prediction level of the first flowering date of Red Fuji apple in Sanmenxia and enhance the variety’s tolerance to freezing injury during flowering period, the relationship between meteorological factors and the first flowering date was analyzed in this study. According to different data combinations, four prediction models of the first flowering date were established by regression method. The results showed that the average temperature in mid-March, the average temperature in late March, the average temperature in March, the ≥0℃ accumulated temperature, the ≥3℃ active accumulated temperature and the effective accumulated temperature, the ≥5℃ active accumulated temperature and the effective accumulated temperature were significantly and negatively correlated with the first flowering date. The <0℃ accumulated temperature was positively correlated with the first flowering date. The first flowering date had poor correlation with precipitation and sunshine duration. By verification, the model based on the ≥3℃ active accumulated temperature and the <0℃ accumulated temperature was the optimal one for predicting the first flowering date. The model can provide meteorological service for local Apple Blossom Festival and guidance on preventing the freezing injury during flowering period.

  Problems and Countermeasures of Agricultural Investment Abroad:An Investigation of 25 Typical Enterprises in Hebei Province LIU Yupeng, XIONG Fengshan 2022, 12 (8):  87-91.  DOI: 10.11923/j.issn.2095-4050.cjas2020-0232 Abstract + ( 257 )   HTML ( 8 )   PDF ( 1099KB )   ( 175 ) Through five years’ follow-up investigation of 25 typical agricultural enterprises in Hebei Province which have investment abroad, this paper analyzes the investment scale, the investment region and the characteristics of enterprises based on the investigation data, points out main problems faced by the enterprises in “go global”, and puts forward targeted suggestions from the enterprise and the government level, aiming to provide certain reference for agricultural enterprises to improve their investment and business abroad.

  Study on the Standard System of China’s Leisure Agriculture and Rural Tourism JIA Xinping, MEI Xueying, JIA Junli, LUO Hairong, YI Neng, TANG Ling, LIU Huazhou 2022, 12 (8):  92-100.  DOI: 10.11923/j.issn.2095-4050.cjas2021-0186 Abstract + ( 343 )   HTML ( 17 )   PDF ( 1703KB )   ( 314 ) China’s leisure agriculture and rural tourism have entered a new stage of rapid development, and it is necessary to have standardized guidance for the industrial development in an all-round way. Based on the analysis of current situation of the standardization development of China’s leisure agriculture and rural tourism, we constructed the standard system framework of China’s leisure agriculture and rural tourism by literature review and data analysis, and pointed out major problems that need to be solved urgently. By the end of 2020, there were 18, 10 and 120 standards formulated and implemented at the national, industrial and local level, respectively. Among them, Anhui issued the largest number of local standards (17), followed by Beijing (12) and Sichuan (10). The standard system of leisure agriculture and rural tourism development depends on its construction and perfection, covers nine business types, eleven functions and eight key points, and includes basic standards, general standards and professional standards. At present, we should solve the prominent problems in the construction of leisure agriculture and rural tourism standard system, such as the lack of overall planning, unreasonable structure, the shortage of talents and so on. The construction and improvement of the standard system is of great significance for promoting the standardized and healthy development of China’s leisure agriculture and rural tourism.