Mutator转座子介导的玉米胚大小突变体的遗传分析

Genetic analysis of embryo mutant mediated by mutator in maize

玉米胚大小是由多基因控制的数量性状。本研究以Mutator(Mu)转座子诱变的M5和BC2F2群体为材料,采用数码成像和Photoshop软件相结合的方法测定胚大小,计算胚面积与籽粒面积;以胚面积和籽粒面积的比值(SST)作为胚性状评价标准,对M5和BC2F2诱变材料进行遗传分析。结果表明:在2种世代的诱变群体中共获得了8个胚大小突变体;用MuTail-PCR方法分析突变体材料Mu插入位点的侧翼序列,获得了Mu因子真实性插入的2个靶位点;经Blastn功能分析,该2个靶位点可能与编码鸟嘌呤核苷酸结合蛋白和一种泛素连接酶有关。这些突变体为进一步克隆控制胚大小的基因提供了宝贵的材料。

Maize embryo is the product resulting from double fertilization during seed develop- ment. And the size of maize embryo is a quantitative trait and is under polygenic control. In the present study, mutant populations （M5 and BC2F2） mediated by Mutator were measured the areas of grain and embryo by digital imaging and with Photoshop software; the embryo-to- grain area ratios （SST） were used as standard to evaluate the size of embryo and show the ge- netic analysis of Ms and BC2F2 generations. Eight embryo mutants were screened and two in- serted sites from them were isolated and authentically proved as Mutator-inserted by MuTail- PCR method. Blastn analysis indicated that genes in the target regions may encode the guanine nucleotide-binding protein and an ubiquitin ligase-related protein, respectively. These mutants provide important materials for further cloning genes controlling maize embryo size.