玉米胚乳突变基因ae连锁累赘的SSR分析

本研究通过与玉米胚乳突变基因ae连锁的SSR标记对轮回亲本不同的2个回交一代群体amylose extender(ae)基因两侧的连锁累赘进行了SSR分析,通过均匀分布在ae基因所在的Chr5连锁群上的SSR标记对这2个回交群体的染色体遗传背景回复率开展研究,结果表明,通过MAS可以将回交群体CHBC₁F₂染色体两侧的连锁累赘分别限定到13.2和17.2 cM,将另一回交群体DHBC₁F₂的染色体的单侧连锁累赘限定到13.9 cM。背景选择的结果表明,通过基因组的负选择可以使CHBC₁F₂群体中某些植株的5号染色体的遗传背景回复率达到85.7%,使DHBC₁F₂群体的染色体的遗传背景回复率达到87.5%。通过高密度的遗传连锁图谱(比如10~20 cM)就可以直接选择在目的基因附近发生重组的个体,减少不需要的染色体片段,降低目标基因附近的搭载效应。

SSR analysis of the linkage drag of endosperm mutation gene ae

Molecular assisted selection was used to analyse linkage drag of different recurrent parents on two flanks of two populations and for restoring the ratio of two populations by SSR markers for ae.These are evenly distributed on chromosome 5.Linkage drags at the two flanks were controlled in 13.2 and 17.2 cM of CHBC1F2 populations by SSR markers and the linkage drag at one flank was controlled in 13.9 cM of DHBC1F2 populations.Genetic background resemblance of individuals of the CHBC1F2 population to the recurrent parent’s was 85.7%.Genetic background resemblance of individuals of the DHBC1F2 population to the recurrent parent’s was 87.5%.It is possible to identify recombination individuals with the targeted gene through a high density(10-20 cM per marker) map.This reduced unnecessary fragmentation of chromosomes and eliminated linkage drag of the targeted gene in backcross breeding.The hitchhiking effect may have been reduced.