Department of Agronomy, Agronomy Hall, Iowa State University, Ames, IA 50011, USA.
Department of Plant Production, Faculty of Agriculture, Mu'tah University, P.O. Box 7, Karak, Jordan.
Plant Sci. 2014 Jul;224:9-19. doi: 10.1016/j.plantsci.2014.03.019. Epub 2014 Apr 3.
Several genes involved in maize root development have been isolated. Identification of SNPs associated with root traits would enable the selection of maize lines with better root architecture that might help to improve N uptake, and consequently plant growth particularly under N deficient conditions. In the present study, an association study (AS) panel consisting of 74 maize inbred lines was screened for seedling root traits in 6, 10, and 14-day-old seedlings. Allele re-sequencing of candidate root genes Rtcl, Rth3, Rum1, and Rul1 was also carried out in the same AS panel lines. All four candidate genes displayed different levels of nucleotide diversity, haplotype diversity and linkage disequilibrium. Gene based association analyses were carried out between individual polymorphisms in candidate genes, and root traits measured in 6, 10, and 14-day-old maize seedlings. Association analyses revealed several polymorphisms within the Rtcl, Rth3, Rum1, and Rul1 genes associated with seedling root traits. Several nucleotide polymorphisms in Rtcl, Rth3, Rum1, and Rul1 were significantly (P<0.05) associated with seedling root traits in maize suggesting that all four tested genes are involved in the maize root development. Thus considerable allelic variation present in these root genes can be exploited for improving maize root characteristics.
已经分离出了几个参与玉米根系发育的基因。鉴定与根系性状相关的 SNP ，将有助于选择具有更好根系结构的玉米株系，这可能有助于提高氮素吸收，进而在氮素缺乏的条件下促进植物生长。在本研究中，对由 74 个玉米自交系组成的关联研究（AS）面板进行了筛选，以检测 6、10 和 14 日龄幼苗的根系性状。还在同一 AS 面板系中对候选根基因 Rtcl、Rth3、Rum1 和 Rul1 的等位基因重测序进行了分析。这四个候选基因显示出不同水平的核苷酸多样性、单倍型多样性和连锁不平衡。在候选基因的个体多态性和在 6、10 和 14 日龄玉米幼苗中测量的根系性状之间进行了基于基因的关联分析。关联分析显示，Rtcl、Rth3、Rum1 和 Rul1 基因中的几个多态性与幼苗根系性状有关。Rtcl、Rth3、Rum1 和 Rul1 中的几个核苷酸多态性与玉米幼苗根系性状显著相关（P<0.05），这表明所有四个测试基因都参与了玉米根系发育。因此，这些根基因中存在的大量等位基因变异可以被利用来改善玉米根特性。
