冬小麦持绿和灌浆特征及其抗早衰特性评价

Characteristics of Stay-green and Grain-filling and the Evaluation of Anti-senescence Properties of Winter Wheat

选择23个小麦品种(系),在大田条件下测定了小麦花后旗叶叶绿素含量、颖壳叶绿素含量、籽粒重量、籽粒饱满度等与早衰有关的形态和生理指标,并分别对其花后旗叶叶绿素含量、花后旗叶与颖壳的叶绿素含量比值、粒重比和饱满度以及综合4项指标进行聚类分析,以建立科学的早衰鉴定指标。结果显示:(1)23份小麦材料以花后旗叶叶绿素含量变化可分为4个类型:下降迟且幅度小型、下降早而幅度较大型、下降早且幅度小型、下降早且幅度大型,除第2类型外,其花后旗叶叶绿素含量下降幅度依次增大。(2)以花后旗叶和颖壳叶绿素含量比值变化将其分为3种类型:穗黄叶绿型、同步转黄型、穗绿叶黄型,其比值依次减小。(3)以粒重比可分为3种类型:灌浆充实型、灌浆相对不充实型、灌浆不充实型,其比值依次减小。(4)以饱满度可分为4个类型:饱满型、相对饱满型、相对瘪瘦型和瘪瘦型,其饱满度依次减小。(5)综合以上4项指标可分为4种类型:穗黄叶绿型、正常落黄成熟型、轻度早衰型和典型早衰型;而以饱满度为鉴定指标最接近综合鉴定分析结果。研究发现,籽粒饱满度(干籽粒体积与其充分吸涨后的体积的比值)可作为鉴定小麦早衰的简单、快捷指标,旗叶和颖壳叶绿素含量比较分析可作为田间的初步鉴定指标。

Senescence resistance is an important object of wheat breeding,so it is necessary to find index of wheat senescence.In this paper,the morphological and physiological indices correlating with senescence including flag leaf and hull chlorophyll contents,the weight and volume of seeds and grain plumpness were determined under the condition of the fields after anthesis for 23 wheat varieties.These indices were analyzed respectively by the cluster analysis and all these combined indices were analyzed.The results showed that the cluster analysis of the chlorophyll content of their flag leaf divided these materials into four types.They are delayed and little decreased,early and a little large decreased,early but little decreased,early and large decreased,and except the type of early and a little large decreased,their chlorophyll content declined in turn.The cluster analysis of the ratio of chlorophyll contents of their flag leaf to their hull divided these materials into three types.They are ear yellow but green flag leaf,turn yellow simultaneously,ear green but yellow flag leaf,and the value of their ratio declined in turn.The cluster analysis of the ratio of the grain weight divided them into three types.They are well grained,a little worse grained,worse grained,and their ratio of the grain weight declined in turn.The cluster analysis of the grain plumpness divided them into four types.They are full plumpness,a little full plumpness,a little thin plumpness,thin plumpness,and their plumpness declined in turn.The cluster analysis of all these combining indices divided them into four types,and they are ear yellow but green flag leaf,good mature,slightly senescence,typical senescence.The cluster result of grain plumpness in accordance with that of all combining indices mostly.It indicated that grain plumpness could be considered as the easy and fast identification index of senescence in wheat varieties and the flag leaf chlorophyll and hull content could be considered as the preliminary index in the fields.