Leaf morphometric and genetic variation of Butea superba in Thailand

摘要

Red kwao krua, Butea superba Roxb., is a herbal leguminous plant endemic in Thailand whose tuberous roots are used for male rejuvenation and the prevention of erectile dysfunction. Different populations from different provinces vary in their bioactivities, raising the need to evaluate the causes prior to optimal population selection and growth. Morphometric analysis of leaves collected from 34 populations from 24 provinces throughout Thailand using nine parameters for factor and cluster analyses were correlated with latitude and longitude revealing a clinal pattern. From the North to the South, leaf length increased in size in factor 1 but decreased in size in factor 2. Genetic analysis on the same samples, using DNA sequence analysis from the chloroplast rbcL, trnLF-cd, and trnLF-cf regions and maximum parsimony and neighbourjoining phylogenetic analysis, revealed essentially no genetic variation in the rbcL region, as expected. However, some between-population genetic variation was revealed by trnLF-cd and trnLF-cf sequences, suggesting potentially considerable genetic polymorphism. This was supported by preliminary RAPD analyses using five primers which indicated high genetic variation within and between populations.