春小麦千粒重相关性状的QTL定位及其耐热性分析

QTL Mapping for the Traits Related to Thousand-kernel Weight and Analysis for Its Heat Tolerance in Spring Wheat

春小麦灌浆中后期正逢高温天气,适于发掘与耐高温相关的QTL。本研究利用春小麦Avocet/Sujata重组自交系群体,自2016-2018年在石家庄藁城区和天津两地4个环境下种植,进行千粒重(TKW)、粒长(KL)和粒宽(KW)等性状QTL定位,探讨这些QTL与灌浆期高温和品种适应性的关系。结果显示:在4个环境下共检测到20个QTL。其中,5个与粒长相关,4个与粒宽相关,11个与千粒重相关。在千粒重相关QTL中,有1个兼控粒长(QTkw-5A.1/QKl-5A),3个兼控粒宽(QTkw-2A.1/QKw-2A.2、QTkw-3B.2/QKw-3B和QTkw-6A/QKw-6A);3个QTL(QTkw-2A.1、QTkw-4B和QTkw-5A.1)可在不同环境下重复检测到。在2017年(持续高温环境)和2018年(高温+超高温环境)石家庄试点共检测到7个千粒重QTL,可能与耐高温有关。其中,有2个主效QTL(QTkw-2A.1和QTkw-5A.1),分别解释13.8%和17.3%的表型变异,5个微效QTL(QTkw-2A.2、QTkw-3B.1、QTkw-3B.2,QTkw-4A.2和QTkw-6A),解释7.4%~9.9%的表型变异。这些QTL可能在今后的抗干热风育种中发挥重要作用。在石家庄试点共检测9个千粒重QTL,其中6个加性效应来自Sujata(5个可在2017年和2018年高温环境下被检测到),3个来自Avocet(2个可在高温环境下被检测到)。可见,聚合了多个优异位点可能是Sujata具有高千粒重和广泛适应性的遗传基础。

The high temperature at the grain filling stage of spring wheat is harmful to the yield production and exploration of the quantitative loci with elevated high-temperature tolerance becomes of interest in wheat breeding.In this study,a recombinant inbred line population derived from the cross of two spring wheat lines‘Avocet’and‘Sujata’was used for the quantitative mapping of the genetic loci that associated with TKW(thousand kernel weight),KL(Kernel length)and KW(Kernel width)as well as analyzing the interaction pattern of QTLs responding to high temperature at the grain-filling stage.The field trails were conducted at four environments(Gaocheng,Shijiazhuang,2016-2018;Tianjin,2017).Twenty quantitative loci were detected at all of four environments,including five QTLs associated with KL,four with KW and eleven with TKW.Four loci QTkw-5A.1/QKl-5A,QTkw-2A.1/QKw-2A.2,QTkw-3B.2/QKw-3B and QTkw-6A/QKw-6A were found with double functions.Three TKW-QTLs(QTkw-2A.1,QTkw-4B and QTkw-5A.1)were detected specifically at different environments.Seven TKW-QTLs were detected at Shijiazhuang,where high-and/or super-high temperature was observed in two calendar years of 2017 and 2018.Two major QTLs(QTkw-2A.1 and QTkw-5A.1)explained 13.8%and 17.3%of phenotypic variation,respectively,whereas five minor QTLs(QTkw-2A.2,QTkw-3B.1,QTkw-3B.2,QTkw-4A.2 and QTkw-6A)contributed to 7.4%-9.9%of phenotypic variation.Out of nine TKW-QTLs detected in Shijiazhuang,six and three represented additive effects from Sujata and Avocet,respectively.Thus,the parental line‘Sujata’represented more elite alleles causing higher TKW and wider adaptability.