小麦籽粒产量及穗部相关性状的QTL定位

QTL Mapping for Grain Yield and Spike Related Traits in Common Wheat

由小麦品种花培3号和豫麦57杂交获得DH群体168个株系,种植于3个环境中,利用305个SSR标记对籽粒产量和穗部相关性状(穗长、穗粒数、总小穗数、可育小穗数、小穗着生密度、千粒重和粒径)进行了QTL定位。利用基于混合线性模型的QTLNetwork2.0软件,共检测到27个加性效应和13对上位效应位点,其中8个加性效应位点具有环境互作效应。相关性高的性状间有一些共同的QTL位点,表现出一因多效或紧密连锁效应。5D染色体区段Xwmc215–Xgdm63,检测到控制籽粒产量、穗粒数、总小穗数、可育小穗数和小穗着生密度5个性状的QTL位点,各位点的遗传贡献率较大且遗传效应方向相同,增效等位基因均来源于豫麦57,适用于分子标记辅助育种和聚合育种。控制千粒重与穗粒数的QTL位于染色体不同区段,有利于实现穗粒数与粒重的遗传重组。

Grain yield and spike related traits are complex traits in wheat （Triticum aestivum L.）. They are often influenced by environmental factors and show a high genotype-environment interaction. Thus, determination of the number, locations, and ef- fects of these polygenes is desired for obtaining optimal genotypes in breeding practice. To detect QTLs associated with wheat yield, such as grain yield, spike length, grains per spike, spikelets per spike, compactness, fertile spikelets per spike, 1000-grain weight, and grain diameter a set of 168 doubled haploid （DH） lines derived from the cross between Huapei 3 and Yumai 57 were used with 305 SSR markers covering the whole wheat genome. The DH population and the parents were evaluated for grain yield and spike related traits in 2005 and 2006 cropping seasons in Tai＇an, Shandong province and in 2006 cropping season in Suzhou, Anhui province. QTL analyses were performed using the software of QTLNetwork version 2.0 based on the mixed linear model. A total of 27 additive QTLs and 13 pairs of epistatic QTLs were detected for grain yield and spike related traits. Of these, eight additive QTLs had significant interactions with environments. Many of the traits shared the same QTL, which was consistent with its high phenotypic correlations and showed tight linkages or pleiotropisms. The Xwmc215-Xgdm63 interval on chromosome 5D had the same direction of additive effects on grain yield, grains pr spike, spikelets per spike, compactness, and fertile spikelets per spike with high contribution, which showed pleiotropisms and could be used in marker-assisted selection. And the favorable al- leles were contributed by Yumai 57. The QTLs for 1000-grain weight were located on different intervals from the QTLs for grains per spike, which was beneficial to genetic recombinant for them in wheat breeding programs.