基于小麦产量三要素的产量条件QTL分析

Conditional QTL Analysis of Three Yield Components in Wheat(Triticum aestivum L.)

为了从单个QTL水平上解析产量与产量三要素的遗传基础,利用花培3号和豫麦57杂交获得的168个家系的DH群体及其遗传图谱,在5个环境下对产量进行了非条件QTL分析和基于产量三要素(穗粒数、千粒重和单位面积穗数)的条件QTL分析,共检测到9个非条件QTL和28个条件QTL。其中,检测到2个主效QTL(QY.sdau-4D和QY.sdau-6D.2),它们可分别解释15.77%和10.16%的表型变异。分别检测到6个"一因多效"QTL和11个微效QTL;其中,QYsdau-4D.2通过影响单位面积穗数、穗粒数和千粒重而影响产量,QYsdau-2D.1和QYsdau-3A.1能提高单位面积产量但不影响穗粒数,即单位面积产量和穗粒数在该位点上几乎没有关联。本研究结果为通过分子设计聚合高产有利基因提供了理论基础,对培育单位面积产量大幅度提高的小麦新品种具有重要意义。

Kernel number per spike(KNPS),thousand-kernel weight(TKW)and spike number(SN)are three main components of yield.A doubled haploid(DH)population including 168 lines,derived from Huapei 3×Yumai 57,was analyzed under five environments in this study.Conditional QTL mapping for three yield components and unconditional QTL mapping were conducted using software IciMapping 3.3.Nine unconditional and 28 conditional QTLs were detected,among which two(QY.sdau-4D and QY.sdau-6D.2,accounting for 15.77%and 10.16%of the phenotypic variance,respectively)were major QTLs.Six QTLs showed pleiotropic effects.One QTLs(QYsdau-4D.2 affected yield by influencing SN,KNPS and TKW;while QYsdau-2D.1 and QYsdau-3A.1 improved yield without influence on KNPS.Combined conditional and unconditional QTL mapping,the genetic relationship between yield and its components were dissected on single QTL level.These results provide useful information for pyramiding favorable genes for marker assisted selection(MAS)and can be valuable to improve wheat yield in breeding program.