北京地区高产小麦冠层形成和结构及其生理基础的研究

 1980-1989年，以改善北京地区高产小麦产量潜力为目标，对冠层形成和结构以及与高产有关的几个生理问题进行了系统研究。首先确定了选用中间类型叶型的品种、在20cm行距和基本苗15-20万/亩对产量最有利的基础上，提出了一整套包括形态和生理在内的冠层性状指标，为亩产450kg水平的小麦确定了一个框架结构和形成模式。还研究了叶面积指数变化与光透射、生育阶段持续期与粒数和粒重、育性与脱落酸水平变化等之间的关系，高温和水分胁迫的影响，以及不同衰老类型在衰老过程中的形态和生理变化。为制定育种目标和方案、高产栽培措施，提供了生理方面的依据。最后对北京地区高产小麦品种的叶型和株型、粒数和粒重、源和库在决定产量上的相对重要性等问题进行了讨论。本研究在生理与育种、栽培等学科结合的研究上取得了有益的进展。

STUDIES ON CANOPY DEVELOPMENT AND STRUCTURE AND PHYSIOLOGICAL BASIS OF HIGH-YIELDING WHEAT VARIETIES IN BELJING DISTRICT

During 1980-1989,a serial researches aimed at improving yield potential of high-yielding wheat varieties and focussed on the canopy development and structure and several aspects related to physiological basis,were conducted. Firstly, intermediate or slightly lax-leaved cultivars planted with 20 cm of row space and 225-300 plants/m2 were determined, which were beneficial to obtaining high yield. Secondly,a number of canopy characteristic criteria including morphological and physiological ones were proposed,which established a frame structure and development model for the high-yielding cultivars at the level of 450 kg/mu grain yield.Thirdly, results relevant to physiological basis are as follows:light attenuation coefficients from regrowth in spring to flowering and from the top of the canopy to ground at anthesis, and the LAD from anthesis to maturity were determined as the most important factors for the grain yield (R2=0.912);a new approach for kernel number and weight improvement were proposed,i. e. the adjustment of the relative length of developmental stages and their recombination; the association of the sterility of the nuclear male sterile plants with high level of endogenous ABA were demonstrated; high temperature at meiosis and water stress at the stage of cell division of leaf dramatically inhibited the grain set and leaf area respectively; the length of the induced senescent period and the amount of total nitrogen remobilized from leaf blade and sheath and stem to the filling grain of the normal senescent pattern were longer and munch more than those of the early senescent ones. Finally,the leaf posture and plant type, grain number or weight,source or sink, which possess the relatively importance to the grain yield in Beijing district are discussed.