小麦旗叶大小及穗部相关性状的QTL定位

为了发掘更多控制小麦旗叶大小及穗部相关性状的QTL,以兰考906和小偃81创制的133个F6~F7重组自交系为试验材料,在6个环境下利用SSR标记对旗叶大小及穗部相关性状进行QTL定位。结果表明,有202对SSR标记被用于构建遗传连锁图谱,图谱覆盖小麦21条染色体,全长1 678.93cM,标记间平均距离8.30cM。采用完备区间作图法共检测到30个QTL,分布在1B、2A、3D、4A、4B、4D、5D、6A、6B、6D和7D染色体上。其中,旗叶宽QTL有7个,穗长QTL有9个,小穗数QTL有5个,穗粒数QTL有5个,小穗着生密度QTL有4个,不同环境下单个QTL可解释的表型变异率为4.94%~23.14%,有14个QTL的表型贡献率大于10%,有8个QTL可在2个或2个以上环境中被检测到。其中,Qflw-4A在3个环境中被检测到,贡献率为10.13%~20.77%,是控制旗叶宽的稳定主效QTL;Qsl-4D.2在4个环境中被检测到,贡献率为12.58%~23.14%,是控制穗长的稳定主效QTL;Qker-5D在2个环境中被检测到,贡献率为11.44%~14.32%,是控制穗粒数的稳定主效QTL。这3个稳定主效QTL可作为改良叶宽和增加穗粒数的功能QTL作进一步研究。

QTL Mapping for Flag Leaf Size and Spike Related Traits in Wheat(Triticum aestivum L.)

In order to explore more QTLs that control flag leaf size and spike related traits in wheat,a population of 133 F6:7 recombinant inbred lines(RILs) derived from a cross between Lankao 906 and Xiaoyan 81 was used to detect the QTLs for flag leaf size and spike related traits in six environments.The results showed that 202 SSR markers were used to construct genetic linkage maps,covering 21 wheat chromosomes,with the full mapping length of 1 678.93 cM and an average genetic distance of 8.30 cM between the markers.A total of 30 QTLs were detected on 1B,2A,3D,4A,4B,4D,5D,6A,6B,6D and 7D chromosomes by Inclusive Composite Interval Mapping(ICIM,LOD>2.5).There were seven QTLs for flag leaf width(FLW),nine QTLs for spike length(SL),five QTLs for spikelets per spike(SPS),five QTLs for kernels per spike(KER),and four QTLs for spike compactness(SC),with the phenotypic variations ranging from 4.94% to 23.14% in different environments.Among these QTLs, Qflw-4A was detected in three environments with phenotypic variations ranging from 10.13% to 20.77%,which was a stable and major QTL associated with FLW.Qsl-4D.2 was detected in four environments with phenotypic variations ranging from 12.58% to 23.14%,which was a stable and major QTL associated with SL.Qker-5D was detected in two environments with phenotypic variations ranging from 11.44% to 14.32%,which was a stable and major QTL associated with KER.The three stable and major QTLs on chromosomes 4A,4D and 5D identified in this study might be useful for marker-assisted selection of flag leaf size and spike traits in wheat breeding.