利用“永久F2”群体剖析玉米产量及其相关性状的遗传机制

利用RIL群体构建了一套包含441个杂交组合的玉米“永久F₂”群体，通过253个SSR标记的等位基因频率分析，发现“永久F₂”群体的遗传组成与基因频率与F₂群体相似，理论上可以代替F₂群体进行相关遗传研究。通过两年一点的田间试验，利用复合区间作图法对玉米产量及其3个主要构成因子进行了遗传分析。结果表明，玉米产量与穗长、穗行数及百粒重呈显著或极显著正相关，而穗长与穗行数和百粒重显著负相关。共定位3个产量QTL、8个穗长QTL，11个穗行数QTL和5个百粒重QTL。

Genetic Dissection for Grain Yield and Its Components Using an "Immortalized F2 Population" in Maize

Genetic dissection for grain yield and its components can provide a new strategy for crop breeding,and it plays an important role in improving agricultural production.For dissecting the genetic basis of grain yield and its components,a set of recombinant inbred line(RIL)derived from an elite maize hybrid Yuyu 22,which is planted broadly in China,was used to constructed an "immortalized F2"(IF2)maize(Zea mays L.)populations including 441 single crosses.The frequency of molecular marker loci for the IF2 population was analyzed using 253 different SSR markers.The results demonstrated that the genetic components and gene frequency of the IF2 population was similar to its F2 population in molecular maker level,theoretically it could replace F2 population in related genetic analyses.The IF2 population was evaluated in one environment over two years,and the genetic mechanism of grain yield and its components was dissected through QTL analysis using composite interval mapping(CIM)method.These results showed that grain yield had positive significant correlation with its three components at P<0.01 or P<0.05 level,and in the three components,ear length had negative significant correlation with row number and 100-grian weight at P<0.05 level.A total of 8 QTL were detected for grain yield,8 for ear length,11 for row number and 5 for 100-grain weight.