基于文献计量学的中国作物富硒研究现状分析

为全面了解中国作物富硒研究现状与发展趋势,采用文献计量学方法,对CNKI和SCI-E数据库收录的中国作物富硒研究文献进行统计分析。结果表明,1992—2020年中国作物富硒研究总发文量1085篇,年发文量总体呈上升趋势,2010—2020年发文量占67.0%,SCI文献逐年增多。华中农业大学、南京农业大学、西北农林科技大学、中国农业大学和中国农业科学院的科研实力和学术影响力较强。中国作物富硒研究主要集中在8个方面,包括硒对作物的生长、产量和品质的效应研究,作物对硒的吸收、转运及分配研究,硒对作物吸收镉、铅和汞等有害元素的拮抗作用研究,硒对作物的抗氧化效应研究,硒对作物光合特性效应研究,富硒作物的硒种类和含量研究,硒与锌、钼和硫等元素的相互作用研究,作物富硒效应的分子机制研究。中国作物富硒研究SCI文献逐年增多,学术影响力不断提升,中国作物富硒研究已由生理生化水平深入到分子生物学研究水平。     

Production of Xylose from Sorghum Straw Using Hydrochloric Acid

Xylose is a hemicellulosic sugar mainly used for its bioconversion to xylitol. Sorghum straw is a raw material for xylose production that has been studied scarcely. The objective of this work was to study the xylose production by hydrolysis of sorghum straw with hydrochloric acid at 122 °C. Several concentrations of HCl (2–6%) and reaction time (0–300 min) were evaluated. Kinetic parameters of mathematical models for predicting the concentration of xylose, glucose, acetic acid and furfural in the hydrolysates were found. Optimal conditions for hydrolysis were 6% HCl at 122 °C for 70 min, which yielded a solution with 16·2 g xylose/L, 3·8 g glucose/L, 2·0 g furfural/L and 1·9 g acetic acid/L.     

Variation in avenanthramide content in spring oat over multiple environments

Avenanthramides (AVNs), a group of phytochemicals which are unique to oats, provide health benefits through antioxidant activity and other bioactivities. In this study, we explored genotype-by-environment interactions and heritability for AVN concentrations in oats. Avenanthramide concentrations were quantified for 100 breeding lines and cultivars at three locations over two years. While year and environment had an influence on AVN concentrations, with the influence of year being more apparent than that of environment within a year, genotype had the largest impact on AVN concentration. All three major AVNs were found to be heritable. Two methods of calculating heritability on a line mean basis were used. The statistical method yielded heritability estimates of 0.34, 0.39, and 0.41 for AVN 2c, AVN 2p, and AVN 2f, respectively. By comparison the traditional plant breeding method yielded heritability estimates of 0.82, 0.88, and 0.89 for AVN 2c, AVN 2p, and AVN 2f, respectively, indicating that expected gains will be dependent on the scale of the breeding program, the number of target environments, and climate variability. The estimated heritabilities and the 11-fold range in AVN concentrations in the 100 genotypes studied provided evidence that variability for AVN concentration should allow breeding progress for higher AVN concentration.     

Analysis of yield-attributing traits for high-yielding wheat lines in southwestern Japan

Development of wheat cultivars that achieve high yields despite the short growing season is essential for increasing wheat production in southwestern Japan. The objectives of this study were to assess the genetic progress in grain yield and to clarify yield-attributing traits of high-yielding wheat lines in southwestern Japan. We conducted field experiments for two growing seasons (2012–2013 and 2013–2014) using three commercial wheat cultivars (Shiroganekomugi, Chikugoizumi, and Iwainodaichi) and four high-yielding wheat lines including Hakei W1380 developed in southwestern Japan. In an ancillary field experiment, we compared a commercial cultivar, Shiroganekomugi, and a high-yielding line, Hakei W1380, in the 2014–2015 season. Across the two seasons, grain yield of high-yielding lines was generally higher than commercial cultivars. Hakei W1380 achieved the highest grain yield across the two seasons, and successfully produced more than 900 g m^?2 in the 2013–2014 season. Correlation analysis showed that recent yield progress of wheat lines in southwestern Japan was derived from enhanced biomass production and grain number m^?2. Larger numbers of grains m^?2 in high-yielding lines than in commercial cultivars were associated with higher crop growth rate at the pre-anthesis stage, and therefore higher spike dry weight m^?2 at anthesis. Genotypic differences in crop growth rate from jointing to anthesis resulted mainly from differences in leaf area index. These results indicate that further improvements in grain yield in southwestern Japan could be achieved by increasing the amount of radiation intercepted at the pre-anthesis stage and grain number m^?2.     

Long-term trends in intersectoral water allocation and crop water productivity in Zhanghe and Kaifeng,China

This paper examines the trends in water allocation among sectors, water use by source, cropped area, crop production and water productivity. The study was undertaken at two sites in China: the Zhanghe Irrigation District in the Yangtze River Basin approximately 200 km west of Wuhan and Kaifeng City Prefecture located just south of the Yellow River in Henan Province. In both areas, water demand for purposes other than irrigation has grown. In the Zhanghe Irrigation District this resulted in a sharp reduction of water availability for irrigation. The decline of water availability for irrigation resulted in adoption of water saving practices and policies that led to a significant gain in water productivity per unit of irrigation water. In the Kaifeng City Prefecture the increased demand from other uses was met by an increase in groundwater extraction without the dramatic cuts in supplies for agriculture as in the Zhanghe Irrigation District. Gains in water productivity were due almost exclusively to higher crop yields. There will be continuing pressure to further reduce diversions to agriculture from the Zhanghe main reservoir in the Zhanghe Irrigation District and from the Yellow River in Kaifeng. Research continues on testing practices that have the potential for further increasing water productivity, some of the results of which are reported in other papers in this volume.     

作物长势信息空间分析系统设计

为了满足作物长势动态测量的要求,设计了作物长势信息空间分析系统,针对作物冠层信息获取手段及其数据特点设计相应的功能模块。系统主要由光谱文件管理、定点作物光谱分析、动态采集监测、空间数据分析等功能模块组成。系统能够兼容多种光谱文件格式,具有两种空间数据分析方法,配有专家数据库接口,具有较强的二次开发潜力。该系统配合车载作物长势检测平台,对玉米的长势空间分析进行了应用效果验证,结果证明：该系统能够实时读取和分析车载式作物长势检测平台的动态数据,通过不同的空间插值方法能够掌握冠层生物信息空间分布状况。该系统为车载动态测量提供了良好的技术支持,可为制定相应的精准管理决策提供理论依据。     

System of rice intensification in short duration rice hybrids under varying bio-physical regimes: New opportunities to enhance rice productivity and rural livelihoods in North-Western Himalayas under a participatory-mode technology transfer program

Abstract

To harness the benefits of system of rice intensification (SRI) coupled with short-duration rice-hybrids, 10 multi-location “On-Farm-Trials” were conducted during 2007–2012 in Himachal Pradesh, India. The study revealed that rice-hybrids were more productive with higher resource-use-efficiency than high-yielding-varieties (HYVs) both under conventional-transplanting (CT) and SRI. The Arize-6129 rice-hybrid exhibited wider adaptability for CT and SRI under varying bio-physical regimes. Arize-6129 rice-hybrid under SRI in rainfed medium-fertility, irrigated medium-fertility and irrigated high-fertility situations yielded about 6.75–6.88, 7.00–7.86, and 7.58-8.32 t grains ha^?1, respectively; with respective net returns of INR 48,517–49,761, 57,240–62,603 and 64,333–66,748?ha^?1. After Arize-6129, “Swift,” “US-312,” and “PAC-801” are the alternate options for SRI-cultivation. Adoption of SRI using short-duration rice-hybrids under participator-mode technology-transfer program, led to higher net income gains by 29.4% over CT in study area. Overall, SRI using short-duration rice-hybrids has provided new opportunities to enhance rice productivity and profitability to transform rural-livelihoods in wet-temperate NW Himalayas.     

Effect of Incorporation of Crop Residues on a Maize–Groundnut Sequence in the Humid Tropics. II. Soil Physical and Chemical Properties

Abstract

A two‐year study (1997–1999) was conducted on a sandy clay loam (Typic Paleudult) at the experimental farm of the Universiti Putra to determine the effects of application of crop residues on changes of some soil properties in a maize (Zea mays L.)–groundnut (Arachis hypogaea) crop rotation system. Five crops of a rotation of sweet corn–groundnut–sweet corn–groundnut–sweet corn were sown with three treatments: recommended inorganic fertilizer [nitrogen (N), phosphorus (P), and potassium (K)] with crop residue (T1), recommended inorganic fertilizer without crop residues (T2) or one‐half of the recommended inorganic fertilizer with crop residues combined with 10 t ha^?1 of chicken manure (T3). Soil organic carbon (OC), soil water content and soil bulk density were not significantly changed. Application of crop residues for two years increased cation exchange capacity (CEC) whereas supplementing crop residues with CM had significantly increased soil pH of the topsoil. Phosphorous in manure treatment had moved down the soil profile, which might cause eutriphication of under ground water, particularly during the rainy season. Based on this work, incorporation of crop residues could be a beneficial practice for improving the fertility of acid soils.     

A model to predict the dry matter and yield of rapeseed under salinity and deficit irrigation

In this investigation, a model was developed to predict dry matter, seed yield and other crop parameters of rapeseed under deficit irrigation and salinity by using soil water and salt budget and other simple plant physiological relationships. Two-year experimental data were used. In calibration and validation of the presented model, results indicated that the model was able to estimate evapotranspiration, soil water content, leaf area index, evaporation, crop transpiration, dry matter and seed yield of rapeseed properly. The advantage of this model is its simplicity and easy calibration in other areas and climate conditions and it can be used to estimate yield and other crop parameters with common measurable data in the field. Prediction of crop yield by this model can be used for better management of agronomic systems to reduce administrative costs and in different environmental conditions. Finally, under scarce data, arid and semi-arid environments, this model is proposed to be used by irrigation managers and agricultural advisors.     

Role of crop diversification and integrated nutrient management in resilience of soil fertility under rice-wheat cropping system

A field study conducted for two crop cycles of five cropping systems supplied with six nutrient combinations at the Indian Agricultural Research Institute, New Delhi indicated that the cropping systems having a legume increased organic C content over initial level by 0.02?–?0.05%, available N by 3.5?–?14.1?kg ha^???1, whereas the rice-wheat cropping system resulted in a reduction in organic C and available N over initial level by 0.05% and 1.5?kg ha^???1, respectively after 2 years of study. Rice-potato-mungbean cropping system resulted in a negative balance of available P and rice-clover cropping system had a negative balance of both available P and available K content in soil and thus call for adequate P and K fertilization. Application of P and K helped in building up their content in soil; NPK?+?FYM showed the highest increase in organic C, available N, available P and available K content in soil. These results suggest the inclusion of a legume in a cropping system for maintaining organic C and available N in soil and adequate P and K fertilization for arresting the depletion of available P and K content in soil. Integrated nutrient management is one of the best methods for resilience of soil fertility under rice-wheat cropping system.