小麦K型及V型细胞质雄性不育系线粒体DNA的比较分析

Mitochondrial DNAs of Cytoplsamic Male Sterile Lines of K-and V-Type in Wheat

采用RFLP（restrictionfragmentlengthpolymorphism）和RAPD（radomlyamplifiedpolymorphicDNA）技术对具有相同核遗传背景的小麦K型不育系K149A、V型不育系V149A及相应保持系149B的线粒体DNA进行了比较分析。结果表明它们之间线粒体DNA的结构显著不同，atpA，atp9，coxII，cob等线粒体功能基因有组织结构上的差异。推测线粒体DNA是小麦K、V型雄性不育系胞质不育困子的载体。但由于不育系与保持系间线粒体DNA差异甚大，难以确定究竞哪些差异确与雄性不育有关。仅仅比较不育系和保持系间线粒体DNA的差异是限制本领域取得突破性进展的症结所在。基于“核质工作”的思路，把“雄性不育-育性恢复”作为一个整体来考虑，并重视比较不育系和杂种F1代之间线粒体DNA的结构和表达的差异，所得结果对寻找和鉴定cms因子，进而阐明cms的形成机理有积极意义。

The mitochondrial DNAs(mtDNAs) of cytoplasmic male sterile(cms) lines of K- and V-type with thesame nuclear background were comparedwith that of their maintainer line byRFLP and RAPD analyses. Distinctpolymorphisms were identified among themtDNAs of cms-K, cms-V and theirmaintainer line (Figs. 1 ~ 4; Table 1),the orgniation and structure of mitochondrial genes such as atp9, atpA,coxII and cob were different remarkably among the hoe lines (Figs. 1 ~ 3;Table 1 ), which means that mtDNAsmay be responsible for the formation ofcms in wheat. However, it is difficult toidentify which mtDNA fragment is definitely responsible for cms becuse thereare so many differences between themtDNAs of cms line and its maintainerline. Both the formation of cms and thefertility restoration are the results of nucleo-cytoplasmic interaction, 'cms - fertility restoration'is an ideal model systemto stuty the mechanism of cms. Comparing the structural as well as the restoration of differences of mtDNAs betweencms line and its FI hybrid with therestoration line will advance the identifyof cms-inducing factors.