MORPHOLOGICAL AND CYTOLOGICAL DIFFERENTIATION OF ENDOSPERMUM DIADENUM AND ENDOSPERMUM QUADRILOCULARE: IMPLICATIONS FOR FOREST PLANTATION SELECTION

Abstract

Endospermum diadenum, locally known as sesenduk, is a promising timber species for forest plantation in Peninsular Malaysia. However, it appears as two morphologically distinct entities—differing in leaf, flower, fruit morphology, and germination rates—yet generally referred to as E. diadenum. This study employed morphological and karyotype analyses to investigate whether these entities, termed Entity A and Entity B, represent separate species. Samples were collected from three locations in Peninsular Malaysia where both entities coexist. Morphological comparisons using Chi-square tests revealed significant differences in leaf, flower, and fruit characteristics. Cytological analysis confirmed that the somatic chromosome numbers were 2n=46 for Entity A and 2n=48 for Entity B, suggesting specieslevel
differences. Consequently, Entity A was identified as Endospermum diadenum and Entity B as Endospermum quadriloculare. Given its higher germination rate, Entity B is recommended for forest plantations.