Variation of plastid and mitochondrial DNAs in the genus Hedysarum.

Plastid and mitochondrial DNAs from Hedysarum species of the western Mediterranean basin, H. spinosissimum ssp eu-spinosissimum, H. spinosissimum ssp capitatum, H. carnosum, H. coronarium and H. flexuosum, were compared by restriction endonuclease fragment analysis. ctDNA fragment patterns for ssp eu-spinosissimum and ssp capitatum were indistinguishable in different enzyme digests. An identical ctDNA variation was found in Hpa II digests with two Sardinian populations of ssp capitatum. Each of the two subspecies was characterized by specific mt DNA patterns with Pst I, Bam HI, Sma I and EcoRI. No variation was detected in populations of different geographical origins for a given subspecies. H. carnosum, H. coronarium and H. flexuosum generated specific ct and mt DNA patterns. Comparison of mitochondrial fragments indicated: - a strong homology between the two subspecies, - a closer homology among the three other diploids, each being closer to the other two than to H. spinosissimum subspecies - as was also the case for the plastid genomes.