The use of mitochondrial DNA polymorphisms to distinguish commercial cultivars of the broad bean, Vicia faba L.

Abstract

Restriction fragment length polymorphisms (RFLPs) have been used to detect mitochondrial DNA (mtDNA) variation among 9 commercial cultivars of Vicia faba L. The mitochondrial DNA was initially digested with 8 restriction endonucleases revealing complex banding patterns on ethidium bromide (EtBr) stained gels. However, no RFLPs were visualised from these complex profiles. Southern hybridisation using total digested mtDNA as a probe against mtDNA digested with the same restriction enzymes revealed a limited number of RFLPs which allowed the 9 cultivars to be consistently distinguished into two main cytoplasmic types. Southern hybridisation with 23 random mitochondrial clones covering 56 kb of the mitochondrial genome revealed considerable levels of polymorphisms. Of the 23 clones analysed, 12 detected at least 22 polymorphisms using 3 restriction enzymes among the cultivars analysed. These RFLPs allowed the 9 commercial cultivars analysed in this study to be distinguished into at least 6 separate groups. Most polymorphisms distinguished the cultivars into two main cytoplasmic groups.