玉米自交系K10白色叶鞘遗传机理研究

玉米白色叶鞘是重要的遗传研究材料。本研究以玉米白色叶鞘自交系K10为研究材料,对白色叶鞘性状进行了遗传机理初探和基因初步定位。以白色叶鞘自交系K10与多个自交系进行正反交,F1均表现为绿色叶鞘,表明该白色叶鞘性状与细胞质遗传无关,由隐性核基因控制。而F2分离比例均不符合孟德尔遗传分离定律,证明该性状受多基因控制。在拔节期利用透射电镜对F2分离群体中白色叶鞘和绿色叶鞘植株的叶绿体超微结构观察发现,白色叶鞘细胞中完整的叶绿体结构较少,且大多数没有类囊体片层及基粒。绿色叶鞘植株和白鞘植株叶片中叶绿素a、叶绿素b以及总叶绿素含量并不存在显著差异,而K10白色叶鞘中三者含量均低于正常植株叶鞘。利用SSR分子标记技术对白色叶鞘性状进行初步定位,共定位到2个基因位点,分别位于第8(qws8)和第9(qws9)染色体。

Research on Genetic Mechanism of White Sheath in Maize inbred line K10

Maize with white sheath is one of important materials for genetic research. In this study, the genetic mechanism and gene loci of the white sheath of maize inbred line k10 were studied. The phenotype of F1 generations produced by reciprocal cross of K10 and other lines showed that white sheath was a recessive trait and controlled by nuclear genes. The segregation ratios of F2 generations were not consistent with Mendel's regulavity of segregation, indicating white sheath was controlled by multiple genes. The chloroplast ultrastructure of the white sheath and the green sheath was detected by Transmission Electron Microscope in F2 generation group. The results indicated that complete structure of chloroplast was fewer than the green sheath and grana as well as thylakoid was absent in most of the white sheaths. There was no significant difference of chla, chlb and total chlorophyll contents between the white sheaths and the green ones. However, all of them were found to be more in the green leaves than white leaves. By the method of SSR technology, the genes controlling the trait of white sheath in maize were mapped on the chromosome 8 and 9, respectively.