Mitochondrial DNA variations and nuclear RFLPs reflect different genetic similarities among 23 Arabidopsis thaliana ecotypes.

摘要

The mitochondrial genome of 23 Arabidopsis thaliana ecotypes was analysed by Southern hybridization in total cellular DNA. The extent of divergence between the mitochondrial genomes in closely related lines of one plant species, and the use of mitochondrial versus nuclear RFLPs to determine evolutionary relationships between Arabidopsis ecotype isolates, were investigated. Highly divergent stoichiometries of alternative mitochondrial genome arrangements characterize individual ecotypes including the complete loss of a 5 kb region from ecotype Landsberg without apparent effect on plant viability. The genetic similarities between ecotypes suggested by mitochondrial genome arrangements differed from those deduced from the nuclear RFLP patterns produced using a set of 18 CAPS (cleaved amplified polymorphic sequences) markers. Similarity of nuclear RFLP patterns among the 23 Arabidopsis ecotypes was not correlated with either their geographic origin or with the observed mitochondrial genome arrangements. A promiscuous mitochondrial sequence insertion previously identified in ecotype Columbia was also found in the nuclear genomes of ecotypes Eifel, Enkheim and Hilversum. Two ecotypes (Eifel and Tabor) displaying identical RFLP patterns at all 18 nuclear loci showed differences in both this sequence transfer and a mitochondrial DNA recombination event.