Phylogenetic relationships in the genus Nelumbo based on polymorphism and quantitative variations in mitochondrial DNA

Restriction fragment length polymorphisms (RFLPs) of the mitochondrial DNA (mtDNA) of 15 strains of lotus (Nelumbo nucifera and N. pentapetala) were analyzed using 13 rice mtDNA fragments that contained 16 known mitochondrial genes and open reading frames (ORFs) as probes for a DNA gel blot analysis. Five groups appeared as a result of the phylogenetic analysis based on the RFLP data. Ohgahasu (Ohga lotus) and Chuugokukodaibasu (Chinese ancient lotus), strains that were reared from seeds excavated from different ancient deposits were classified into the same group. In the course of this analysis, a unique quantitative variation of mtDNA that indicates a change in the composition of the population of mtDNAs during the evolution of this plant species was detected. In combination with the phylogenetic analysis, the difference in mtDNA composition was found to have generated after the divergence of five strains of N. nucifera from the other seven strains of N. nucifera analyzed in this study.