Genotype × environment interaction for yield and reaction to leaf spot infections in groundnut in semiarid West Africa

Capitalizing on the yield potential in available groundnut germplasm, and high stability of kernel yield are important requirements for groundnut producers in semiarid environments. Forty-seven groundnut genotypes were evaluated from 2003 to 2005 at 4 locations representative of the Guinea and Sudan savanna ecologies in Ghana. The objectives were to assess genotypic differences in reaction to early and late leaf spot infections under natural field conditions, assess the extent of genotype × environment (G × E) interaction for kernel yield, and determine the relationship between yield potential and yield stability. Genotypes differed significantly in their reaction to leaf spot infections indicated by the area under disease progress curve (AUDPC). Genotypic AUDPC was negatively correlated with maturity period (P < 0.01), with kernel yield (P < 0.05) at each of the 3 locations in the Guinea savanna ecology but not in the Sudan savanna ecology and with each of four stability parameters (P < 0.05). High or low yielding genotypes were grouped based on Dunnett’s test at P < 0.10. High yielding groups had significantly low AUDPC, high biomass, high partitioning of dry matter for kernel growth, and were later in maturity compared to low yielding genotypes. Significant G × E interaction effect for kernel yield was dominated mainly by the lack of correlation among environments variance (76–78%) relative to the heterogeneity of genotypic variance component (22–24%). Stability of yield assessed through the among-environment variance, Wricke’s ecovalence, and Finlay-Wilkinson regression coefficient revealed that genotypes in the higher yielding group were relatively unstable compared to the low yielding group. Indicated by the Kataoka’s index of yield reliability, however, relatively unstable genotypes in the high yielding group are expected to be more productive even under assumptions of high risk aversion (P = 0.75–0.95) compared to the more stable, low yielding genotypes. The findings indicate that deploying these recently developed germplasm in semiarid regions in West Africa provides a better match to farmers’ risk-averse strategies compared with the use of existing earlier maturing cultivars.     

风作用甘蔗的动力学仿真模型

针对目前台风作用甘蔗动力学仿真研究中,风作用甘蔗的动力学仿真研究匮乏的问题,对甘蔗进行简化研究,利用测定的几何参数和CREO三维软件建立甘蔗几何模型,测定甘蔗物理力学特性参数,并建立了甘蔗材料模型。同时,建立了流场几何模型和材料模型,采用Hyper Mesh和LS-PrePost软件分别对甘蔗和流场模型进行网格划分,并定义边界条件和流固耦合控制参数;最后,利用LS-DYNA不可压缩流ICFD求解器和强耦合计算方法,考虑大涡模拟湍流模型,实现风与甘蔗的双向流固耦合作用,并对仿真模型精度进行物理验证。结果表明:该仿真模型的构建方法合理,可用于模拟风作用甘蔗的动力学过程,为台风-甘蔗和自然风-作物流固耦合系统动力学仿真建模提供依据。     

Parasitoid wasps as effective biological control agents

Biological control (biocontrol) is a safe, sustainable approach that takes advantage of natural enemies such as predators, parasitic insects or pathogens to manage pests in agroecosystems. Parasitoid wasps, a very large evolutionary group of hymenopteran insects, are well-known biological control agents for arthropod pests in agricultural and forest ecosystems. Here, we summarize the recent progress on the application of parasitoid wasps in biocontrol in China for the last five years. These include species diversity of parasitoid wasps, identification of dominant parasitoid wasps associated with insect pests and biocontrol practices (three types of biological control, i.e., classical, augmentative and conservation biological control) in several Chinese agroecosystems. We then treat different mass-rearing and release technologies and the commercialization of several parasitoid wasp species. We also summarize other work that may have a potential use in biocontrol, including the effect of plant volatiles on parasitoids and recent advance in the molecular mechanisms underlying the host regulation by parasitoid wasps. Future research area and applied perspectives are also discussed, noting that advances in biocontrol technologies in Chinese agriculture informs research at the global level.     

淡紫拟青霉A10的促生特性及其发酵液对印度芥菜幼苗蓄积Cs+的影响

从种植印度芥菜的盆栽土壤(ρ[Cs~+]为10 mmol·kg-1)中筛选出淡紫拟青霉(A10),通过测试分析A10溶磷、解钾、分泌植物生长素(IAA)类似物及其发酵液对印度芥菜幼苗蓄积Cs~+的影响,研究A10的植物促生特性及其发酵液在印度芥菜蓄积Cs~+过程中的作用,为植物-微生物互作在Cs~+污染环境修复中的应用及其互作机制研究提供实验依据。结果显示:A10对Cs~+的耐受性和富集能力强,ρ(Cs~+)为50～100 mg·L~(-1)时A10的溶磷能力被显著抑制(P0.05);Cs~+处理及外源色氨酸均可显著诱导A10分泌IAA类似物;用1/2 Hoagland营养液稀释A10发酵液后再配制ρ(Cs~+)为25～100 mg·L~(-1)的处理液,用其培养印度芥菜,ρ(Cs~+)为0 mg·L~(-1)(CK)时A10发酵液对印度芥菜幼苗根的生长呈现"低促高抑"的生长素效应,稀释35倍时的促根效果最佳;A10发酵液稀释5、35倍和55倍条件下,ρ(Cs~+)为100 mg·L~(-1)时幼苗地上部Cs~+蓄积量均显著升高,其中稀释35倍时Cs~+蓄积量达最大值,地上部为8.86 mg·g-1DW,地下部为16.76 mg·g-1DW,印度芥菜幼苗蓄积Cs~+与其吸收K+呈显著的负相关性。研究表明,淡紫拟青霉A10具有显著的植物促生特性,A10发酵液有利于提高印度芥菜幼苗对外源Cs~+的蓄积。     

异源表达玉米ZmWRKY11基因增强拟南芥对盐胁迫的耐受性

从玉米中分离得到响应高盐胁迫的WRKY基因,将其命名为ZmWRKY11。构建过量表达载体pCAMBIA1301-ZmWRKY11,采用花序侵染法转化拟南芥,研究ZmWRKY11基因的生物学功能,扩繁后对T3代转基因植株进行耐盐鉴定试验。结果表明,转基因株系的绿苗率在盐胁迫处理后显著高于野生型拟南芥,同时,野生型株系中丙二醛含量和相对电解质渗透率相较于转基因植株发生了更为显著的上升,但脯氨酸含量的上升幅度则小于转基因株系。结果表明,ZmWRKY11在拟南芥中的异源过表达增强了转基因植物对盐胁迫的耐受性。     

基肥与密度互作对水稻产量构成因素及产量的影响

采用随机区组法,以三江6号和绥粳18号为试验材料,研究基肥与密度互作对产量构成及产量的影响。结果表明:两个品种基肥与密度处理间在穗数、穗粒数、结实率、千粒重及产量上均存在互作关系,A3B3(20 kg/667 m^2基肥,30cm×12 cm)组合有利于水稻产量的提高,A1B1(12 kg/667 m^2基肥,30 cm×16 cm)组合不利于水稻产量的提高。     

基于大数据的化学基础与分析技术在线课程建设

从大数据的视角,以高职食品类专业化学基础与分析技术在线课程建设为切入点,在教学内容、教学模式、考核评价等方面进行改革实践与探索,为建设化学基础与分析技术在线课程打下基础,对同类在线课程建设具有借鉴作用。     

Does the “high sugar” trait of perennial ryegrass cultivars express under temperate climate conditions?

The objective was to evaluate water‐soluble carbohydrate (WSC) and crude protein (CP) concentration of perennial ryegrass (PRG) cultivars with different genetic potential for producing WSC under two contrasting agronomic managements in temperate climate (southern Chile). A 4 × 2 factorial design was randomly allocated to 24 plots (31 m² each, three blocks): four PRG cultivars (diploid standard cultivar, “2nSt”; tetraploid standard cultivar, “4nSt”; diploid high sugar cultivar developed in New Zealand, “2nHSNZ”; and tetraploid high sugar cultivar developed in Europe, “4nHSEU”) and two agronomic managements (“favourable,” defoliations at three leaves per tiller and nitrogen (N) fertilization rate of 83.3 kg N ha^?1 year^?1; “unfavourable,” defoliations at two leaves per tiller and N fertilization rate of 250 kg N ha^?1 year^?1). Herbage samples were collected in early spring, spring, summer and autumn. Concentration of WSC did not differ among cultivars in spring and summer, averaging 194 and 251 g/kg DM, respectively. The cultivar 4nHSEU had the greatest WSC concentration in early spring and autumn (187 and 266 g/kg DM, respectively) and the greatest CP concentration across samplings (average 230 g/kg DM). Favourable management improved WSC concentrations in early spring and summer and decreased CP in spring, summer and autumn. Annual DM yield did not vary with cultivar or management, averaging 8.43 t/ha. Within a 12‐month study at one site in a temperate environment in southern Chile, PRG cultivars have not shown a consistent expression of the “high sugar” trait, where a genetic × environment interaction might be operating.     

水稻高产高效的根-冠互作机制研究进展

为了全面认识水稻高产与水分养分高效利用的过程及其生物学机理,塑造高产高效的冠层和根系,本文归纳了高产高效水稻的根系形态和生理特征,总结了高产高效水稻的群体质量、物质生产特征及叶片光合特性,并分析了高产高效水稻根-冠互作的方式和指标。针对水稻水肥利用率低的问题,本文提出了通过协调根-冠互作机制来协同实现水稻的高产高效,并对水稻高产高效的根-冠互作机制研究进行了展望。     

水氮互作对冬小麦光合生理特性和产量的影响

针对黄淮海地区农业生产中存在的水资源供应短缺,肥料利用率低等问题,设计试验研究水氮互作对冬小麦光合生理特性和产量的影响,为黄淮海地区高效利用水氮资源提供理论依据。2015-2017年以石麦15(SM15)为材料,利用水肥渗漏研究池,设计2个供水量水平(500,250 mm);2个施氮量水平(90,180kg/hm~2);2个氮肥类型(无机肥尿素,有机肥牛粪)。结果表明:2年试验内冬小麦旗叶光合生理特性变化规律相似,各处理的冬小麦旗叶光合速率,蒸腾速率,单叶水分利用效率在生育期内均呈现先上升后下降的趋势。水氮互作对小麦旗叶光合速率影响显著,W1(供水量500mm)处理的旗叶光合速率明显高于W2(供水量250mm)处理,施氮肥180kg/hm~2处理的旗叶光合速率明显高于施氮肥90kg/hm~2的处理,与施用无机肥相比,施用有机肥可保证冬小麦生育后期维持较高的旗叶光合速率。2年试验干物质积累量最多、产量最高的处理为W1M1(供水量500mm,施有机氮肥180kg/hm~2)。综合冬小麦光合生理特性,籽粒产量,本试验条件下有机肥增产效果优于无机肥,冬小麦生育期供水量500mm,施有机氮肥180kg/hm~2时冬小麦旗叶光合生理特性较优,获得较高产量。