利用选择导入系QTL聚合设计方法改良水稻产量相关性状

The Improvement of Yield-Related Traits in Rice(Oryza sativa L.) Using QTL Designed Pyramiding between Selected Introgressed Lines

培育和种植高产水稻品种是解决粮食短缺危机最有效的方法之一。利用轮回亲本明恢86和供体亲本ZDZ057、辐恢838和特青构建了3个BC2F4高产选择导入系群体,从中选择5个稳定的高产导入系培育了4个聚合群体WD135/WD190、WD190/WD250、WD208/WD258、WD135/WD258。通过对4个F4聚合群体进行大田表型鉴定,考察产量及其相关性状。选取55个SSR多态性标记对聚合群体进行基因型鉴定,并利用性状-标记间的单项方差分析进行产量及相关性状的QTL检测和根据遗传搭车理论对增产的聚合系基因型的分析结果进行卡方检测。方差分析结果表明,穗长和单株产量在所有4个聚合群体中都存在显著或者极显著基因型差异,抽穗期没有差异,其余性状在不同群体中表现不尽一致。在4个聚合群体中,一共有57个聚合系产量高于轮回亲本,增产幅度从0.36%～72.7%,其中有40个聚合系高于其各自的聚合亲本。与轮回亲本和导入系亲本相比,高产聚合系的单株有效穗数、每穗实粒数和每穗颖花数有了一定程度的提高。高产聚合系增产的主要原因是由于单株有效穗数、每穗实粒数和每穗颖花数得到了改良。利用卡方检验和单项方差分析分别检测到22和20个与产量及相关性状有关的QTLs,其中10个QTL与前人定位的结果一致。聚合亲本携带的QTL在聚合群体的效应与导入系群体估算的不完全一致。说明利用选择回交导入系进行复杂性状聚合改良虽然可以部分消除QTL与遗传背景的互作,但是QTL之间的上位性互作可能仍然起着一定的作用。本研究采取的产量聚合系定位方法可靠性较好,为复杂性状的聚合系定位提供了一个新途径。

Developing and growing high yield rice varieties is one of the effectiVe approaches to solve the crisis of food shortage. The QTL detection and pyramiding of rice yield will lay a good foundation for the improvement of complicated targeted traits of main crops. In the present study, a total of 5 selected introgression lines from the population between recurrent parent （Minghui86） and donor parents （ZDZ057, Fuhui838 and Teqing） were used to develop 4 pyramiding populations： WD135/WD190, WD190/WD250, WD208/WD258 and WD135/WD258. Yield and its related traits of pyramiding F4s were evaluated in the normal paddy field. The pyramiding populations were genotyped by using 55 polymorphic SSR markers. One-way ANOVA and Chi-square Test were applied to identify QTLs in pyramiding populations. The significant variation among genotypes for panicle length and yield were observed in all four pyramiding populations. For heading date, no significant variation was observed in any populations. The genotypes for other traits vary among populations. In the 4 pyramiding populations, there were 57 higher yield pyramiding lines with 0.36%-72.7% increased yield, and about 44 pyramiding lines showed higher yield than better pyramiding parents. Compared with recurrent parent and pyramiding parents, panicle numbers, filled grain number per panicle and spikelet number per panicle were increased significantly. Spikelet fertility and 1 000-grain weight were also improved in some high yield pyramiding lines. The detection of QTL showed that 20 loci were identified by one-way ANOVA and 22 loci were detected by Chi-square test. Compared with the better parents of pyramiding populations, panicle numbers, filled grain number per panicle and spikelet number per panicle were improved significantly in higher yield pyramiding lines. The QTL effects estimated in introgressed populations and pyramiding populations were not coincident completely, which indicated that even though pyramiding by using introgressed lines with same genetic background could remove some interaction between QTL and genetic background, epistatic interaction between QTLs which may also play a role in the pyramiding lines. This study will laya good foundation for the improvement of complicated targeted traits of main crops.