长江中下游稻茬小麦高光效群体构建机理与调控途径研究

长江中下游麦区温光水资源丰富、土壤肥力高，以稻茬小麦为主，由于稻茬小麦受前茬水稻成熟期迟、土壤耕种难、灾害频发等因素的制约，稻茬小麦产量潜力难以发挥。本项目选用小麦优良品种，重点研究：一、稻茬小麦高光效群体（子粒产量≥9000kg/hm2）产量形成特点；二、稻茬小麦高光效群体源库流特征，从叶源、非叶源（茎鞘源、穗源）的结构配置、功能强度与持续期和最佳穗数与穗粒重配置明确高光效群体的源库特征；从物质生产与输配、蔗糖源向库的运转与转化、库贮藏物的转化效率与持续期以及相关酶活性变化明确高光效群体的流特征；提出源库流协调的群体诊断指标；三、稻茬小麦土壤供肥和高光效群体的需肥特性；应用13C, 15N示踪分析高产群体碳高效输配与氮高效利用的生理基础；四、冬前控旺促壮提高抗寒能力、生育中期壮秆防倒、后期防早衰的高光效群体构建与调控技术途径，为提升长江中下游稻茬小麦生产能力提供理论与技术指导。

Yield-increasing potential of wheat following rice in the middle and lower Yangtze region is great due to water availability, high soil fertility, and adequate light. However, wheat production might be restricted by late maturity of rice, poor soil tillage quality, frequent natural disaster, and so on. This project will choose wheat varieties with good resistance in this region as test material, and will analyze the grain yield formation characteristics of high photosynthetic efficiency population with grain yield ≥9000kg/hm2 (HPEP) in wheat. The characteristics of the source and sink in HPEP will be studied from the structure configurations of leaf and non-leaf (stem, sheath and spike) source, the intensity and lasting duration of leaf photosynthetic function, as well as from the best configurations of the optimum number of spikes and the kernel weight. The characteristics of translocation will also be analyzed from the production and distribution of photosynthetic matter, the conversion efficiency from sucrose into starch. The diagnostic indices of the source, sink and translocation in HPEP will be suggested. This project will also definite the features of the fertilizer requirement for the HPEP and soil fertilizer supply during wheat growth. The feature of carbon assimilates exporting and partitioning and nigtrogen efficient utilization in HPEP will be ivestigated by using 13 C and 15N isotope. The cultivation approach to control vigorous growth, promote strong seedling and improve cold-hardiness before winter, strengthen stem and prevent lodging at the middle growth stage, and prevent premature senescence at the late stage will be suggested. It is beneficial to provide the theoretic basis and technical guide for improving wheat yield and output in the middle and lower Yangtze region.