RAPD Analysis on Variation of Mitochondrial DNA for Cytoplasmic-Nuclear Male Sterile Lines in Wheat

Abstract

In order to produce a good F1 hybrid variety in wheat, it is necessary to explore a new male-sterile cytoplasm and its nuclear restore gene(s). Four alloplasmic male sterile lines of wheat with Aegilops cytoplasm were developed to identify mitochondrial DNA (mtDNA) variation that could potentially be associated with cytoplasmic male sterility (CMS). mtDNA isolated from the Aegilops species, the respective male sterile lines and F1 hybrids were analyzed by RAPD markers. Reproducible polymorphisms were detected between the Aegilops species and male sterile lines. Above results indicated that mtDNA variation existed in the cytoplasm donors and male sterile lines resulted from genetic interactions between common wheat nucleus and Aegilops cytoplasm, and have affected the structure of the mitochondrial genome. Similar results were also obtained in male sterile lines and fertility-restored F1 hybrids. These demonstrated the variation of mtDNA in fertility restoration by the combination of the fertility restorer gene(s), and fertility restoration involved a strong influence of nuclear restorer genes on mtDNA organization. The variation of mtDNA in Aegilops species, their respective CMS lines and fertility-restored F1 hybrids may reflect the fertility divergence.