Intraspecific classification of Ficus deltoidea Jack subsp. deltoidea (Moraceae) in Peninsular Malaysia based on morphological and molecular variations

• Sixteen nuclear Simple Sequence Repeat (nSSR) markers of Ficus deltoidea subsp. deltoidea were developed and characterized.
• The intraspecific variation of the species in Peninsular Malaysia was studied using morphological and molecular approaches.
• The nSSR cluster analysis is congruent with the morphological classification, dividing the species into four main varieties.
• The study demonstrates the applicability of molecular approach in complementing the conventional taxonomic classification.

Taxonomic classification of the important medicinal plant, Ficus deltoidea (Moraceae), is challenging because of the variability of its leaves and fig forms that occur within the species. We developed 16 nuclear Simple Sequence Repeat (nSSR) markers, and characterized them using 24 individuals from a natural population. We then studied the intraspecific variation of F. deltoidea subsp. deltoidea in Peninsular Malaysia using morphological and molecular approaches. Based on the morphological variations, we further determined the varieties that occur regionally under the above subspecies based on the leaf characteristics. As for molecular data sets, we used both chloroplast DNA (cpDNA) and nSSR markers to elucidate the phylogenetic relationship among the varieties. The cpDNA dendrogram yielded poorer resolution where most of the clades were forming paraphyletic complex. The cluster analysis based on nSSR is largely congruent with the morphological classification, with F. deltoidea subsp. deltoidea classified into four main varieties, namely var. deltoidea, var. angustifolia, var. kunstleri and var. lutescens. Our study demonstrates the applicability of molecular approach in complementing the conventional taxonomic classification.