Leaf morphometry, genetic variation and phylogeny of Red Kwao Krua Butea superba in Thailand

Abstract

Butea superb (Red Kwao Krua) are Thai herbal leguminous pants. Its tuberous roots are widely used for estrogen replacement therapy. It reported that Kwao Krua from different localities performed different estrogenic activity. Morphometric and genetic analyses were used in this research. Leaves of B. superba were collected from 29 locaities throughout Thailand for morphometric analysis and from 34 localities for genetic analysis. In morphometric analysis 9 parameters [petiole length (PL), petiole diameter (PD), rachis length (RL), petiolet length (PLL), terminal leaflet length (TLL), terminal leaflet breadth (TLL), terminal leaflet breadth(TLB), stipule length (SPL), angle of first leaf border (AB), and number of pairs of primary veins (NPV)] were used for factor and cluster analyses. For factor analysis, 7 out of 9 morphometric characters were selected as new variable and could be grouped into 3 new factors. Due to graph plotting of factor scores, no cultivars could be separated from each others. Moreover, a dendrogram generated by cluster analysis supported the graph of factor score that B. superba cultivars could not separate into groups. However, result on correlation analysis of factor scores against latitude and longitude shows clinal patterns in morphometric characters of B. superb leaf in Thailand. From the North to the South, leaf length increase in size in factor l but decreases in size in factor 2. In genetic analysis variation of rbcL, trnLF-cd, and trnLF-cf regions was determined. Amplified PCR products of 300, 550 and 1,000 bp by PCR were obtained, respectively. After direct sequencing nucleotide base were obtained and clustered by using maximum parsimony (MP) and neighbor-joining (NJ) method. Considering a phylogenetic tree of rbcL, low genetic variation was obtained but not 2 phylogenetic trees of trnLF-cd and trnLF-cf. furthermore, RAPD was used to investigate genetic variation. The obtained result also supported the result by direct sequencing method in both trnLF-cd and trnLF-cf region. It can summarize that B. superba cultivars had high genetic variation.