Molecular Phylogeny of Native Panchakhan Varieties and Hybrids (Gynostemma pentaphyllum)

Abstract

Morphological diversity of Panchakhan (Thai Jiaogulan) based on its different ecotypes affects the stability of taxonomy nomenclature. This research aimed to study the relationship of 20 native Panchakhan varieties and their hybrids using chloroplast DNA markers of accD, petD, psbB and ycf3 genes and to confirm the botanical name. The evolutionary relationships were generated using maximum likelihood (ML), maximum parsimony (MP) and minimum evolution (ME) methods. The results of ML, MP, and ME analyses showed the concordant clustering of Panchakhan varieties and confirmed their name as Gynostemma pentaphyllum. The phylogenetic tree of the combined datasets of all genes was the most efficient in grouping Panchakhan into 2 formae (f.), f. pentaphyllum and f. dasycarpum. The native Panchakhan, namely Sankampaeng, shared the characteristics of
f. pentaphyllum, with the ovary/fruit surface covered with no hairs and the spherical seeds, ovate shape with regular papillae on surfaces. In addition, hybrid Panchakhan, namely Chiangrai2, also grouped together under this forma according to the genetic characteristics of its mother strain, Sankampaeng. As for the other 9 native Panchakhan varieties; namely Doitung1, Doitung2, Chiangkhong, Phrae1, Wawi2, Wawi4, Wiangkaen1, Wiangkaen2 and Angkhang; showed the characteristics of f. dasycarpum, with the ovary/fruit surface covered with pubescent hairs and flat seeds with slightly triangular to heart-shaped with irregular papillae on the surfaces. Furthermore, a group of hybrids Panchakhan, namely Chiangrai1, isolate Chiangrai1-7, isolate Chiangrai1-9, isolate Chiangrai1-11, isolate Chiangrai1-13, isolate Chiangrai1-19, isolate Chiangrai2-10, and isolate Chinese-Local, formed a group with their mother strain, Sibsongpanna, under f. dasycarpum.