Current issue

• 2020 Vol.36 No.18 Published:25 June 2020

  Effects on Leaf Physiological Characteristics, Yield and Quality of Dry Seeding Rice: Water-saving Irrigation and Conventional Irrigation Yin Chunyuan, Wang Shuyu, Liu Hemei, Sun Jianquan, Hu Xiuming, Wang Hele, Tian Fanghui, Ma Chaoyang, Zhang Xu, Zhang Ruiping, Ma Xiaohong 2020, 36 (18):  1-9.  DOI: 10.11924/j.issn.1000-6850.casb19030042 Abstract + ( 239 )   HTML ( 7 )   PDF ( 1332KB )   ( 45 ) To study the effects of different irrigation methods on yield and quality of direct seeding rice, three rice cultivars were used as test materials under dry direct seeding field cultivation mode. Two methods of conventional and water-saving irrigation were set up. The indexes of direct seeding rice leaf photosynthesis, grain yield, quality and so on were analyzed. The results showed that compared with conventional irrigation, the water-saving irrigation decreased the chlorophyll content and water content of flag leaf by 3.66% and 4.37%, increased the photosynthetic rate of flag leaf and rice yield at the middle and late stage of grain filling by 5.78% and 5.69%. The effect of different irrigation modes on rice quality was varied among the cultivars. For ‘Xindao567’and ‘Xindao568’, water-saving irrigation reduced the quality of rice processing and taste by 6.21% and 3.84% respectively, increased the chalky grain rate and chalkiness by 18.9% and 5.37% respectively. For ‘Xinkedao31’, water-saving irrigation increased the quality of rice processing by 3.4%, decreased the chalky grain rate and chalkiness by 19.59% and 27.84% respectively. The correlation analysis showed that the relationship between leaf moisture content and photosynthetic rate was positive, the relationship among yield, quality and photosynthetic rate varied with different grain-filling periods. The yield and processing quality of rice could be improved, but the appearance and taste quality of rice decreased as the photosynthetic rate of the middle and late grain filling stage increasing. In conclusion, rice yield could be increased by water-saving irrigation, but the rice quality regulation varied by cultivars. Setting different soil irrigation water potential standards according to cultivar is of significance to the development of water-saving direct seeding rice production and the improvement of water use efficiency in rice field.

  Wheat Varieties in Regional Test in the Middle and Lower Reaches of the Yangtze River: Quality Analysis from 2008 to 2018 Wen Mingxing, Li Dongsheng, Chen Chen, Guo Rui, Lu Panpan, Qu Chaoxi 2020, 36 (18):  10-15.  DOI: 10.11924/j.issn.1000-6850.casb19030026 Abstract + ( 243 )   HTML ( 3 )   PDF ( 1107KB )   ( 37 ) To study the current status of wheat quality breeding in the middle and lower reaches of the Yangtze River, the quality data of 130 varieties (182 samples) in the regional test from 2008 to 2018 were collected and analyzed, and the present situation of wheat quality improvement in the region was evaluated according to different quality classification standards. It turns out that the bulk density is 786±16.07 g/L, the crude protein content is 12.79%±0.93%, the wet gluten content is 26.14%±2.77%, the sedimentation value is 34.65±10.43 mL, the water absorption rate is 56.62%±3.83%, the stability time is 4.03±2.82 min, the Max. resistance is 289.55±123.01 E.U, the extensibility is 154.55±19.11 mm, moreover, the variation coefficient of stabilization time is the highest, it reaches 69.98%; the natural weight is the lowest, it is 2.04%. Through inter-annual comparison, it is found that the bulk density, crude protein and water absorption rate are volatile; the wet gluten content remains stable; sedimentation value, stabilization time, Max. resistance and extensibility first increase and then decrease. According to the national quality evaluation system, there are a large proportion of varieties which show uncoordinated gluten levels among different indices, unable to fit any standard indicators. Strong gluten and medium strong gluten varieties are less; medium gluten and weak gluten varieties are more in standard wheat varieties. In short, the quality breeding of wheat varieties tends to breed medium gluten and weak gluten in the middle and lower reaches of the Yangtze River.

  Effects on Agronomic Traits of Barley in Dongting Lake Area: Sowing Date, Tillage Methods and Fertilization Luo Jinfeng, Xiao Xu, Jie Hongdong, Xing Hucheng, Jie Yucheng, Zhou Jinghua, Tian Zuqing 2020, 36 (18):  16-21.  DOI: 10.11924/j.issn.1000-6850.casb19030065 Abstract + ( 210 )   HTML ( 4 )   PDF ( 1163KB )   ( 48 ) The aims are to promote the cultivation of Hunan Hordeum vulgare L., develop winter fallow field effectively, and explore the cultivation measures of lodging resistance, high yield and cost saving barley around Dongting Lake area. The effects of different sowing dates, tillage methods and fertilization on yield components such as effective panicle number, grain number per panicle and 1000-grain weight of barley were investigated using the split plot design method. The results showed that when the barley was planted in the winter fallow field, different sowing dates, tillage methods and fertilization affected the agronomic traits and yield of barley obviously (P<0.05). Under the condition of not affecting the double cropping rice production, the sowing date should not exceed November 4, and ploughing could significantly improve the yield (P<0.05), while fertilization had a small impact on the yield, so the fertilization could not be considered. In general, the seed yield of ‘huadamai No. 4’ could reach 9.5 kg per plot, which is suitable for planting in Dongting Lake area.

  High Temperature Affects Agronomic Characters and Yield Related Traits of Maize Hybrid ‘Xindan 68’ Wei Xiaoyi, Wei Feng, Hong Defeng, Ma Yi, Ma Junfeng, Wang Jiamu, Zhang Xueshun 2020, 36 (18):  22-26.  DOI: 10.11924/j.issn.1000-6850.casb19030027 Abstract + ( 734 )   HTML ( 4 )   PDF ( 1089KB )   ( 35 ) In the study, ‘Xindan 68’ was used as materials and ‘Zhengdan 958’ was used as control, the effects of high temperature on the growth period, agronomic characters and yield related traits were studied in 2016 and 2018. The results showed that under the high temperature in 2018, the maturity period of ‘Xindan 68’ and ‘Zhengdan 958’ was ahead of time, and anthesis-to-silking interval was extended. The plant height, ear height, and tassel main axis length of ‘Xindan 68’ and ‘Zhengdan 958’ all increased significantly, but the effect on the total leaf number and tassel branch number was not obvious. Under high temperature, the yield of ‘Zhengdan 958’ decreased, its yield related traits such as 100-kernel weight and kernel number per row were reduced, and its bare ear length increased. The high temperature also had some effects on the yield and yield-related traits of ‘Xindan 68’, but the difference was not significant, indicating that ‘Xindan 68’ had a certain degree of high temperature resistance compared with ‘Zhengdan 958’.

  Effects of Different Boron Deficiency Treatments on Leaf Growth and Photosynthetic Characteristics of Sugar Beet Seedlings Hao Xueming, Wang Xiangling, Wu Zhenzhen, Song Baiquan, Zhou Jianchao 2020, 36 (18):  27-32.  DOI: 10.11924/j.issn.1000-6850.casb19030017 Abstract + ( 214 )   HTML ( 3 )   PDF ( 1443KB )   ( 30 ) The effects of different boron deficiency treatments on the growth and photosynthesis of sugar beet leaves were discussed, aiming to provide a theoretical basis for production practice. In the present research, a hydroponic experiment was conducted to measure the leaf morphological parameters and photosynthetic performance of sugar beet seedlings under different boron concentrations of 0 μmol/L (B1), 0.5 μmol/L (B2), 5 μmol/L (B3) and 50 μmol/L (B4, CK) after 21 days. The results showed that boron deficiency significantly inhibited the growth and development of sugar beet leaves, and the inhibition degrees were related with the intensity of the stress. The specific performance was: boron deficiency significantly reduced leaf area, fresh and dry weight, increased leaf thickness and leaf color value; decreased leaf chlorophyll a and chlorophyll b by 22.3%-51.5% and 23.3%-42.3%, respectively; the photosynthetic parameters decreased by 0.6%-28.4% compared with the control in the treatment of boron deficiency. Correlation analysis showed that the correlation between leaf area and photosynthetic pigment, photosynthetic rate, transpiration rate and intercellular CO2 concentration under boron deficiency reached very significant level (P<0.01). In conclusion, boron deficiency affects the leaf morphology of plants, inhibits the formation of photosynthetic pigments, significantly reduces the photosynthetic characteristics of leaves, and further reduces the biomass accumulation of sugar beet seedlings, leading to abnormal growth and development of leaves.

  Compact Rapeseed Under Different Densities: Sink-source Characteristics and Their Correlation with Harvest Index Wang Xuefang, Tian Jianhua, Dong Yuhong, Guan Zhoubo, Yang Li 2020, 36 (18):  33-38.  DOI: 10.11924/j.issn.1000-6850.casb19040030 Abstract + ( 330 )   HTML ( 11 )   PDF ( 1100KB )   ( 40 ) The aim is to provide the theoretical and technical support for plant-type breeding and mechanized cultivation of rapeseed. 3 different conventional compact varieties and a hybrid loose variety ‘Qinyou 7’ (as control) were studied under varying planting densities (15×10 4, 30×104, 45×104, 60×104, 75×104 and 90×104 plants/hm2). The sink-source characteristics and their relationship with harvest index of compact rapeseed were explored. The results showed that the sink-source characteristics of compact rapeseed single plant were similar with the control. Root, stem dry weight, branches dry weight and shell dry weight, number of siliques, siliques number per plant decreased significantly with the increasing density, and were higher under the low density than under the high density. While thousand-seed weight changed a little along with the densities. The biological yield and economic yield of compact rapeseed increased with the increasing density, while those of the loose rapeseed decreased along with the increasing density, which indicated that compact rapeseed was suitable for compact density and mechanized harvesting. Response of harvest index to different densities was the same between compact and loose types. The highest harvest index was obtained with density increasing from 15×104 plants/hm2 to 30×104 plants/hm2, and it decreased with density increasing continuously. Correlation analysis showed that there was a significantly positive correlation between harvest index and stem+branches+shell dry weight, number of siliques, siliques number per plant, thousand-seed weight, yield per plant, yield per plant/root dry weight, yield per plant/ stem dry weight, yield per plant/branches dry weight and yield per plant/shell dry weight. Thus, the increase of harvest index of rapeseed needs increasing sink and source, and keeping a rational proportion between sink and source.

  Effects Induced by Alicylic Acid on Defense Enzyme Activities in Apple Hou Hui, Zhou Zengqiang, Wang Li, Wang Shengrong 2020, 36 (18):  39-43.  DOI: 10.11924/j.issn.1000-6850.casb19030018 Abstract + ( 248 )   HTML ( 2 )   PDF ( 1149KB )   ( 42 ) To study the activities of defense enzymes in apple by leaf-spraying salicylic acid (SA), the resistant variety ‘Kitanosach’ and the susceptible variety ‘Liquanduanfu’ were used as materials, the activities of defense enzymes in the leaves were detected before and after different-concentration SA treatments. The results showed that after treated by salicylic acid, the β-1,3-glucosidase, POD, PAL and PPO activities of ‘Kitanosach’ and ‘Liquanduanfu’ increased and were higher than those of the control. The activity of β-1,3-glucanase, POD, PAL and PPO in ‘Kitanosach’ was 2.04 times, 6.19 times, 2.73 times and 2.32 times of those of the control, respectively. The activity of β-1,3-glucanase, PAL POD and PPO in ‘Liquanduanfu’ was 1.82 times, 1.70 times, 5.68 times and 4.00 times of those of the control, respectively. Therefore, the activities of defense enzymes can be increased by different degrees after treated by salicylic acid, but the resistance of different varieties was different.

  Amaranthus spp. Germplasm Resources in Yunnan: Phenotypic Diversity Analysis Wang Yanqing, Lu Wenjie, Li Chunhua, Yin Guifang, Sun Daowang, Hong Bo, Wang Lihua 2020, 36 (18):  44-54.  DOI: 10.11924/j.issn.1000-6850.casb19030111 Abstract + ( 261 )   HTML ( 3 )   PDF ( 1231KB )   ( 33 ) The paper aims to analyze the phenotypic genetic diversity of Amaranthus spp. gerplasm resources in Yunnan. We studied 30 phenotypic traits of 104 Amaranthus spp. germplasm resources in Yunnan by using the genetic diversity index, principal component analysis, correlation analysis and cluster analysis. The results showed that: the highest quality and quantitative traits of genetic diversity index were main inflorescence shape (1.68) and main inflorescence length (2.07), respectively; the cumulative contribution rate of the first 10 principal components reached 73.944%; the fresh weight per plant was positively correlated with the third, sixth and ninth principal component, and the grain weight per plant was positively correlated with the ninth principal component. According to cluster analysis, the 104 germplasms were divided into 5 groups; group Ⅰ could be used as interplanting parent material, group Ⅱ and Ⅲ could be used as large grain parent material, and group Ⅳ could be used as high quality forage parent material, group Ⅴ could be used as ornamental parent material. The phenotypic traits of Amaranthus spp. germplasm resources in Yunnan are rich in genetic diversity and have great potential for exploitation and utilization.

  Informaion Entropy Osculating Method: The Assessment of Eutrophic Status in Suyahu Reservoir Wang Guozhong, Li Zhongyuan, Zhang Jiyu, Zuo Qiting, Cheng Huanling 2020, 36 (18):  55-59.  DOI: 10.11924/j.issn.1000-6850.casb19030054 Abstract + ( 249 )   HTML ( 4 )   PDF ( 1140KB )   ( 56 ) To grasp the nutritional situation of Suyahu reservoir, combining with the evaluation criteria of the eutrophication of lake and reservoir, the eutrophic status was analyzed based on information entropy osculating method from 2009 to 2015. The results showed that the reservoir had mild eutrophication in 2012, and moderate eutrophication in the other years. By nutritional degree, the order of each year from light to heavy was 2012<2013<2015<2009<2010<2014<2011; from the perspective of linear interpolation method, the order of its nutritional degree was 2012<2015<2013<2011<2010<2009<2014; there were differences in the sorting though the outcome from the two methods were consistent, the subjectivity of linear interpolation method was more due to the discrepancy of evaluation principle and approach of index weight, information entropy osculating method could reduce the subjectivity and identify the major influencing factors, which made the evaluation result more accord with the reality. Information entropy osculating method can be used as a common method to analyze water quality of reservoirs and lakes.

  Stagnic Anthrosols in Shaoxing Water-network Plain: Development and Synergistic Variation of Genetic Characteristics Zhang Mingkui 2020, 36 (18):  60-66.  DOI: 10.11924/j.issn.1000-6850.casb19030028 Abstract + ( 334 )   HTML ( 3 )   PDF ( 1186KB )   ( 23 ) To understand the spatial variability of genetic characteristics of the stagnic anthrosols in water-network plain, by selecting Shaoxing plain of Zhejiang as the study area, the author investigated the spatial variability of the genetic characteristics, such as diagnostic horizon and diagnostic characteristics of different kinds of stagnic anthrosols in the plain, and the correlations between various genetic characteristics and the soil-forming environments. The results showed that: gleyi-, Fe-accumuli-, and hapli- stagnic anthrosols were the main types of the stagnic anthrosols in the study area, and the distribution of endogleyic hapli- stagnic anthrosols was the most concentrated in the area; in the water-network plain, endogleyic hapli-stagnic anthrosols and typic gleyi-stagnic anthrosols mostly distributed as interlaced zones; all soil genetic characteristics in the study area varied in different degrees; among them, the variations of the numbers of spots and gray film on structure surface of the hydragric horizon, the activation degree of iron oxide in the hydragric horizon, and the color of the anthrostagnic epipedon were greater, while those of the thickness of the anthrostagnic epipedon, bulk density ratio of plow pan to plow layer, and the organic matter content of the topsoil were relatively smaller. In the course of the evolution of the stagnic anthrosols in the area, there were synergistic changes in the main genetic characteristics, which were mainly affected by the winter groundwater level and clay content. The main direction of soil evolution of the stagnic anthrosols is transformed from gleyi-stagnic anthrosols to hapli-, and Fe-accumuli-stagnic anthrosols.

  Soil Environmental Criteria: Research and Prospect Qiu Huiyuan, Li Bo, Zu Yanqun 2020, 36 (18):  67-72.  DOI: 10.11924/j.issn.1000-6850.casb19030098 Abstract + ( 263 )   HTML ( 5 )   PDF ( 1088KB )   ( 37 ) Soil environmental criteria are the basis of soil environmental quality standard, and can be used to evaluate environmental risks. In this study, the environmental criteria were classified and the research status of soil environmental criteria at home and abroad in recent 25 years was reviewed. This paper summarized the differences in the derivation of soil environmental criteria in different countries, and analyzed the advantages and disadvantages of the methods used in developing soil environmental criteria in some areas of China. It is found that: most of the criteria are derived from the sensitivity of soil plants and soil animals to heavy metals, or by collecting a large number of soil background values; the criteria still have deficiencies compared with foreign criteria, such as no uniform criteria method, unclear protection targets, and incomplete types of ecological receptors considered in the development. In the future, it is necessary to strengthen soil diversity research in different regions, standardize criteria developing methods and further improve the toxicology database so as to provide references for the revision of soil environmental quality standard.

  Measuring Methods of Exchangeable Calcium and Magnesium in Acid and Neutral Soil of Rubber Plantation Xu Muguo, Ding Huaping, Liu Zhongmei, Chen Guiliang, Chen Yongchuan, Li Xiaoqing 2020, 36 (18):  73-79.  DOI: 10.11924/j.issn.1000-6850.casb20191100871 Abstract + ( 259 )   HTML ( 4 )   PDF ( 1767KB )   ( 27 ) To obtain a simple and easy to operate method with high accuracy to determine exchangeable calcium and magnesium in acid and neutral soil of rubber plantation, through the response surface optimization test, a mathematical model was established between the sample size, the liquid volume, the extraction method and the results of exchangeable calcium. The study showed that: under the condition of 25 ℃, 1 mol/L ammonium acetate was taken as the soil extract, the sample volume was 2 g, the extracted liquid was 175 mL, and the oscillation was 36 min, which was the best extraction condition for acidic and neutral soil in rubber plantation. The results obtained under the above condition were consistent with those of the standard method, and the relative errors ranged from 1.25 to 3.04, which were all within a reasonable range. The optimized method was tested and verified with standard samples, and the results were consistent with the recommended values. The improved method has the advantages of low cost, simple operation, accurate measurement results and good stability, which can be applied to the determination of exchangeable calcium and magnesium in acid and neutral soil of rubber plantation.

  Change of Soil Nitrogen Component and Content in Different Growth Periods of Winter Rapeseed Wang Zhijiang, Xu Yaozhao, Zeng Xiucun, Wang Fan 2020, 36 (18):  80-86.  DOI: 10.11924/j.issn.1000-6850.casb20191200971 Abstract + ( 416 )   HTML ( 12 )   PDF ( 1187KB )   ( 90 ) To evaluate changes of soil nitrogen component and content of winter rapeseed in different growth periods, winter rapeseed varieties were planted under field growth condition, contents of total nitrogen, ammonium nitrogen, nitrate nitrogen, alkali-hydrolyzed nitrogen, mineralized nitrogen, acid-hydrolyzed nitrogen, amino sugar nitrogen, amino acid nitrogen, non-acid-hydrolyzed nitrogen and unknown nitrogen were tested. The results showed that the content of total nitrogen, acid-dissociated nitrogen and unknown nitrogen in perish period were the highest, 1.24 g/kg, 694.52 mg/kg and 539.50 mg/kg, respectively. The content of nitrate nitrogen at seedling stage was the highest, 33.04 mg/kg. The content of alkali-hydrolyzed nitrogen and ammonium nitrogen were the highest at the turning green stage, 40.68 mg/kg and 21.55 mg/kg, respectively. The content of mineralized nitrogen and amino acid nitrogen were the highest at harvesting stage, 1583.25 mg/kg and 63.45 mg/kg, respectively. The content of nitrogen in perish and turning green stage were significantly different from that at seedling and flowering stage. The “up-down” trend of content of total nitrogen, ammonium nitrogen and non-acidic nitrogen was observed in winter rapeseed during different growth periods, the “down-up” trend was showed in the content of nitrate nitrogen and amino acid nitrogen, the “down-up-down” trend was found in the content of alkali-hydrolyzed nitrogen and aminoglycosaccharide nitrogen, and the “up-down-up” trend was observed in the content of mineralized nitrogen, acidolysis nitrogen and unknown nitrogen.

  Loess Slope Crust: Effects on the Stability and Erodibility of Soil Water-stable Aggregates Chen Lin, Wang Jian, Song Pengshuai, Zhao Yu, Ma Yuhong 2020, 36 (18):  87-92.  DOI: 10.11924/j.issn.1000-6850.casb19030062 Abstract + ( 280 )   HTML ( 3 )   PDF ( 1367KB )   ( 27 ) The paper aims to explore the crust types and the aggregates composition differences in micro-topographic soil attacked by raindrops. We studied the distribution characteristics, stability and soil erodibility of crust soil water-stable aggregates at different locations on slopes by simulated rainfall. The results showed that: (1) the water-stable aggregates of undisturbed soil, structural crust, sedimentary crust, transitional zone crust>0.25 mm were 37.28%, 43.58%, 36.69% and 40.34%, respectively; (2) taking the rainfall for 5 min as an example, the PAD of water-stable aggregates of undisturbed soil, structural crust, sedimentary crust and transitional zone crust were 51.49%, 46.00%, 62.76%, 51.02%, respectively; (3) the MWD of water-stable aggregates of undisturbed soil, structural crust, sedimentary crust and transitional zone crust were 0.15, 0.20, 0.14, 0.17 mm, respectively; (4) the erodibility K values of undisturbed soil, structural crust, sedimentary crust and transitional zone crust were 0.223, 0.200, 0.229, 0.205, respectively. The crust differences under micro-topography make the distribution of water-stable aggregates different, so the stability and erodibility of soil water-stable aggregates are different.

  Humic Acid and Biochar Application: Effects on Nitrogen Absorption of Feeding Sweet Sorghum and Soil Nitrogen Change Zhao Siwen, Wang Xi, Lu Shuchang, Zhang Yu 2020, 36 (18):  93-96.  DOI: 10.11924/j.issn.1000-6850.casb19030100 Abstract + ( 170 )   HTML ( 3 )   PDF ( 1174KB )   ( 29 ) The paper aims to improve soil nitrogen utilization and reduce nitrogen accumulation in greenhouse soil. Taking feeding sweet sorghum as a test crop and the humic acid and biochar as the test materials for pot experiment, the effects of humic acid and biochar application with different proportions on nitrogen absorption and soil nitrogen change of feeding sweet sorghum were studied. The experiment set 6 treatments, i.e., CK, biochar, humic acid, humic acid+biochar, humic acid+1/2 biochar, 1/2 humic acid+biochar.The results showed that: feeding sweet sorghum under the treatment of the 1/2 humic acid+biochar treatment had the largest nitrogen absorption in shoots, indicating the treatment could increase the proportion of nitrogen to the shoots, and improved the nitrogen absorption of feeding sweet sorghum; humic acid+biochar treatment could reduce soil nitrogen content and was good for soil nitrogen transformation. Therefore, the combination of humic acid and biochar with a suitable ratio has a positive effect on increasing nitrogen utilization rate, promoting soil nitrogen transformation and reducing soil nitrogen accumulation.

  Combined Application of Biochar and Alum in Winter Wheat-Summer Maize Multiple Cropping Area in North China: Effects on Soil Carbon and Nitrogen Status Li Chenyu, Lu Shuchang 2020, 36 (18):  97-103.  DOI: 10.11924/j.issn.1000-6850.casb19030132 Abstract + ( 217 )   HTML ( 3 )   PDF ( 1183KB )   ( 29 ) The study aims to provide a basis for the application of soil conditioners in field to improve soil carbon and nitrogen condition. In the winter wheat-summer maize multiple cropping area of north China, biochar and alum were used as soil conditioners, a two-planting season experiment was conducted with four treatments, T1 (the control), T2 (biochar), T3 (alum) and T4 (biochar+alum). The results showed that T2 (biochar) and T4 (biochar+alum) had better effects on improving soil carbon and nitrogen, increasing crop yield and nitrogen nutrient uptake compared with the control. After two planting seasons, the content of organic carbon in soil treated with T4 (biochar+alum) increased by 15.82 g/kg, and the C/N of surface soil increased to 10.88. Furthermore, T4 (biochar+alum) treatment was efficient to reduce soil nitrate in 0-90 cm soil horizon. It was found that soil nitrate in the soil layers of 0-30, 30-60 and 60-90 cm were reduced by 86.96%, 86.82% and 60.41%, respectively, compared to the control. For the crop yield, the highest crop grain (11.34 t/hm2) was found in T2 (biochar). However, the highest yield of wheat (10.28 t/hm2) was found in T4 (biochar+alum). The nitrogen uptake of summer maize and winter wheat treated by T4 (biochar+alum) were the highest, which reached 168.32 kg/hm2 and 35.49 kg/hm2. Overall, T4 (biochar+alum) has better effect on improving soil carbon and nitrogen status in farmland.

  Upper Ocean Thermal State in the South China Sea: Analysis of Climate Change Characteristics Based on GODAS Dataset Ke Yuanhui, Fu Chuanbo, Ma Mingming 2020, 36 (18):  104-112.  DOI: 10.11924/j.issn.1000-6850.casb19030048 Abstract + ( 300 )   HTML ( 8 )   PDF ( 1745KB )   ( 86 ) To understand the change rules of the upper ocean thermal state in the South China Sea (SCS), the vertical mean sea temperature of 5-366 m was characterized by the thermal content (HC) of the upper ocean in the South China Sea, the horizontal and vertical distribution characteristics and seasonal and interannual variability of upper thermal state in the South China Sea was analyzed based on the monthly subsurface sea temperature data of GODAS from 1980 to 2015. The results showed that: the horizontal distribution of annual mean HC in the SCS was characterized by high in east and low in west, the vertical zonal mean distribution was characterized by warm pool thickness and thermocline depth was thick (deep) in east and thin (shallow) in west; the vertical meridional mean performance was that the warm pool thickness was thick in the south and thin in the north, and the depth of the thermocline was shallower in the middle and deep on both sides; the biggest change of the sea temperature was kept in the subsurface (75-200 m) over the SCS, and the anomaly of the temperature in different depths had obvious interannual and interdecadal variability; the average HC in the SCS region was the highest in autumn, followed by that in spring and summer, and the lowest was in winter and the interannual variability of HC was obvious, and there was a significant mutation after 1998, which changed from negative to positive, showing an obviously warming trend; the spatial distribution of the first mode of S-EOF in the HC revealed high in east and low in west, the corresponding time series had interdecadal transitions in the late 1990s, which were mainly negative values transformed into positive values, in terms of spatial distribution, the HC was transformed from the west high and east low type to the east high and west low type.

  Negative Accumulated Temperature from 1961 to 2018 in Shouguang: Variation Characteristics and Its Effect Xu Fengxia, , Zhang Shan, Chang Cheng, Gao Xueqin 2020, 36 (18):  113-118.  DOI: 10.11924/j.issn.1000-6850.casb19030050 Abstract + ( 360 )   HTML ( 2 )   PDF ( 1275KB )   ( 42 ) The paper aims to reveal the variation regularity of negative accumulated temperature in winter in Shouguang, and make rational use of climate resources. Based on the daily mean temperature observation data of Shouguang from 1960 to 2018, the paper counted the negative accumulated temperature and the maximum duration of days, and analyzed the variation characteristic of them and their effects by using the method of modern climate diagnostic analysis, so as to provide a basis for industrial and agricultural production in Shouguang. The results showed that: (1) the negative accumulated temperature showed a decreasing trend from 1961 to 2018 in Shouguang with the climate tendency rate of -32.8℃/10 a; the variation of negative accumulated temperature in winter showed a decreasing trend, and January contributed the most to winter warming; the negative accumulated temperature had a mutation in 1989; (2) the maximum duration of days of negative accumulated temperature in winter showed a decreasing trend in Shouguang with the climatic tendency rate of -5.0 d/10 a; the mean first day of the maximum duration of negative accumulated temperature was delayed by 12 days; in 2010s, the winter cold began late and ended early, showing 18 days shorter than the average of previous years; (3) negative accumulated temperature variation had both advantages and disadvantages on agriculture; (4) negative accumulated temperature had more advantages than disadvantages on industry.

  Beet Germplasm Resources: Identification and Genetic Diversity Analysis by SCoT Zhu Shangming, Wu Zedong, Xing Wang, Pi Zhi 2020, 36 (18):  119-123.  DOI: 10.11924/j.issn.1000-6850.casb20200100054 Abstract + ( 168 )   HTML ( 2 )   PDF ( 1320KB )   ( 25 ) To study the feasibility of SCoT molecular marker for identifying beet germplasm resources, we designed 80 SCoT primers to identify 48 beet germplasm resources, and analyzed the genetic diversity and genetic relationship of the germplasm resources. The results showed that 6 of the 80 SCoT primers, namely SCoT1, SCoT12, SCoT13, SCoT14, SCoT17, and SCoT23, amplified clear and highly polymorphic bands. Among them, SCoT1, SCoT12, SCoT14 and SCoT23 could separately identify the 48 beet germplasm resources. The identification of the 48 beet germplasm resources could be distinguished by combining SCoT13 and SCoT17. The cluster analysis results showed that 95.8% of germplasm resources were clustered into the same clade at the genetic distance of 0.15, which indicated that there was close genetic relationship among the 48 beet germplasm resources. The study provided a scientific basis for the identification of beet germplasm resources, hybrid combination parent selection and molecular marker-assisted breeding by SCoT markers.

  Avirulence Genes in Magnaporthe oryzae 007: Cloning, Identification and Expression Analysis Xiong Tiantian, Han Haojie, Lu Yanmei, Zhang Ning, Wang Chuntai, Liu Xingqiong, Cheng Gang 2020, 36 (18):  124-129.  DOI: 10.11924/j.issn.1000-6850.casb20190400047 Abstract + ( 269 )   HTML ( 3 )   PDF ( 1338KB )   ( 120 ) To clarify the avirulence genes contained in the international standard strain Magnaporthe oryzae race 007, and the possible mainly effective avirulence genes, we designed five common avirulence gene-specific primers for cloning and identification. And the expression of five avirulence genes in Magnaporthe oryzae race 007 strain were detected separately in the liquid culture condition and the process of infecting rice. The results showed that Magnaporthe oryzae race 007 strain contained five avirulence genes including PWL2, AvrPiz-t, Avr-pik, Avr-pita and ACE1. The result of cloning and identification indicated that the five avirulent genes did not change much. Compared with that under the liquid culture condition, in the process of infecting rice, the expression of PWL2 was up-regulated, and the expressions of ACE1, AvrPiz-t and Avr-Pik were basically unchanged, while the expression of Avr-Pita gene was down-regulated. Thus, the expression level of PWL2 gene was significantly changed. We further analyzed promoter region sequences of PWL2 gene, and the results showed that there were some cis-acting elements in the promoter region of PWL2 gene to affect the expression of PWL2 gene. This study show that Magnaporthe oryzae race 007 strain contains five common avirulent genes with little sequence variation and the expression of PWL2 gene is regulated and it may play a major pathogenic role in Magnaporthe oryzae race 007.

  A Multifunctional Endophytic Bacillus Fertilizer Improves the Quality of Off-season Fresh Maize Xu Zheng, Qiu Shiming 2020, 36 (18):  130-133.  DOI: 10.11924/j.issn.1000-6850.casb19030099 Abstract + ( 224 )   HTML ( 3 )   PDF ( 1129KB )   ( 59 ) An endogenous and multifunctional bacillus fertilizer has been developed, to study its fertilization efficiency, a simple comparative experiment was conducted with off-season fresh maize growing in the sloping land of red-brown-purple soil. Compared with the control of applying 76.048 kg organic and inorganic compound fertilizer in 210 m2 soil (the normal fertilizer level), after applying 2.94 kg bacillus fertilizer in the 210 m2 soil, the quality of fresh maize was improved obviously. The water-soluble amino acids, water-soluble reducing sugar and vitamin C increased by 40%, 198% and 30%, respectively. At the same time, the crude fiber and starch content decreased by 0.15% and 10.68%, respectively. This bacterial fertilizer is valuable for further research on soil fertility.

  Wheat Quality in Huang-huai Wheat Region from 2011 to 2015 Li Xiaohang, Sheng Kun 2020, 36 (18):  134-140.  DOI: 10.11924/j.issn.1000-6850.casb19030024 Abstract + ( 229 )   HTML ( 3 )   PDF ( 1162KB )   ( 51 ) This experiment explored the fluctuation trend of winter wheat quality index among different years in Huang-huai area, aiming to provide certain reference for the improvement of wheat quality and industrial application of varieties in this area. A total of 317 winter wheat cultivars, originated from the nation wheat regional trial in irrigated land from 2011 to 2015, were taken as the materials to analyze the grain quality index such as crude protein content, wet gluten content and stabilizing time, sedimentation value and maximum resistance. The results showed that the crude protein content and wet gluten content of wheat cultivars in the southern and northern parts of Huang-huai area in 2013 were averagely higher than that in other years, but the stabilization time was not the highest. Comparing these wheat quality traits in different years comprehensively, the variation of the testing weight was the least, but that of the stabilization time was the largest. The variation of protein content and wet gluten content was similar to each other, while the dough stabilization time was up to twenty times as much as the former two. According to these quality indicators, the strong, medium and weak gluten-strength wheat cultivars accounted for 3.15%, 0% and 22.7%, respectively, and the proportion of the remaining unclassified cultivars is as high as 74.14%.

  Alkali Extraction Process of Chondroitin Sulfate in Goose Bone: Optimization Xie Jing, Zhou Yanhong, Yang Yucheng, Yin Yijuan, Jin Chenzhong, Lu Chao 2020, 36 (18):  141-146.  DOI: 10.11924/j.issn.1000-6850.casb19030044 Abstract + ( 308 )   HTML ( 2 )   PDF ( 1275KB )   ( 22 ) To strengthen the development and utilization of goose by-products, improve their added value, and reduce the pressure of untreated by-products on the environment, this study took the bones of Mayang goose as the raw material, and optimized the alkali extraction process of chondroitin sulfate (CS). Single-factor and orthogonal experiments were carried out from four different factors, namely, alkali extraction concentration, solid-liquid ratio, ultrasonic time and ultrasonic temperature. Phloroglucinol spectrophotometric method was used to determine the concentration of CS in the extraction solution, so as to obtain the optimal condition for alkali extraction. The results showed that the extraction rate of chondroitin sulfate reached the maximum of 17.66% when the alkali concentration was 5%, the alkali extraction time was 4 h, the solid-liquid ratio was 1:6, and the alkali extraction temperature was 30℃. The ultrasonic assisted alkali extraction process for extracting CS from goose bone established in this study can improve the production rate and reduce the usage of alkali compared with the existing domestic production methods, so as to reduce the production costs and environmental pollution.

  The Research Progress of Mamestra Brassicae L. Qiao Zhiwen, Wang Jichen, Li Yanli 2020, 36 (18):  147-153.  DOI: 10.11924/j.issn.1000-6850.casb20190600223 Abstract + ( 231 )   HTML ( 2 )   PDF ( 1240KB )   ( 35 ) To provide reference for the control of Mamestra brassicae Linnaeus, this study summarized the research progress of biological characteristics, physiological and biochemical characteristics and control strategies of Mamestra brassicae. In terms of biological characteristics, insect state and development duration, phototaxis, diapause, artificial feeding formula, feeding law, migration law, population growth and decline law, spatial distribution pattern of eggs and species of natural enemies were reviewed. In terms of physiological and biochemical characteristics, five parts of heat shock, sex pheromone, drug resistance gene P450, chitinase gene and digestive enzyme were summarized. In terms of control strategies, the types, dosages and periods of chemical and biological control agents were briefly described. Based on the research, we propose the control strategy of Mamestra brassicae Linnaeus in beet field, which emphasizes the guidance of population dynamics monitoring and drug resistance monitoring, takes chemical pesticide reduction and synergy as the core, and combines chemical control with biological control.

  Metamitron: Growth Inhibition on 2 Freshwater Aquatic Plants Ouyang Wensen, Yu Kuai, Deng Xiaojun, Kong Xuanqing, Li Jianming, Ou Xiaoming 2020, 36 (18):  154-159.  DOI: 10.11924/j.issn.1000-6850.casb19030096 Abstract + ( 288 )   HTML ( 1 )   PDF ( 1177KB )   ( 66 ) To evaluate the aquatic ecological safety of metamitron application, the growth inhibition and toxicity of metamitron on Lemna minor and Myriophyllum spicatum were studied. The number of lobes, fresh weight, plant length and fresh weight were taken as the analysis indexes and the measurement was conducted on the 7 th and 14th day after the exposure treatment under different concentrations of metamitron. The results showed that: ErC50 and EyC50 of Lemna minor was 0.519 mg/L and 0.322 mg/L on lobes and 0.518 mg/L and 0.328 mg/L on fresh weight respectively on the 7 th day, while that of Myriophyllum spicatum was 6.240 mg/L and 4.248 mg/L on plant length and 4.092 mg/L and 2.616 mg/L on fresh weight respectively on the 14 th day. Metamitron had certain toxicity on Lemna minor and Myriophyllum spicatum, and inhibited their growth. In conclusion, the inhibition rate increases with the increase of metamitron concentration in a certain dose range; however, metamitron shows significant taxonomic effects on Lemna minor and Myriophyllum spicatum.

  Agricultural Academic English Reading Course: Curriculum and Teaching Mode Zhao Yijie 2020, 36 (18):  160-164.  DOI: 10.11924/j.issn.1000-6850.casb19040032 Abstract + ( 225 )   HTML ( 1 )   PDF ( 1121KB )   ( 36 ) Academic English reading ability is one of the fundamental abilities of agricultural science and technology personnel in order to obtain information. It is a strategic issue for the development of agricultural science and technology in China, and it is also the primary requirement for agricultural graduate students. In order to further improve the quality and efficiency of academic English reading course for agricultural graduate students, this study proposes a teaching model with the “sociocultural theory” as the guidance, with the “genre teaching method” as the curriculum organization framework and with the “reading circle” cooperative learning as the classroom teaching method. The teaching model is applied to the academic English reading course for master students. The results show that students’ competency is improved significantly in speed and comprehension of English abstract reading. The teaching framework can not only help students gain genre awareness of academic English reading, improve their speed and ability to obtain information in English, but also construct their identity and cognition in academic community. It is one of the feasible plans to teach academic English reading.