Short communication: Variations in leaf morphological characters of Shorea leprosula in progeny trial stand of a logging concession in Kalimantan, Indonesia

Indonesia has the largest diversity and highest distribution of Dipterocarpaceae members, and Shorea leprosula is one of the species that has a natural hybrid in its habitat. This species has intermediate morphological characters with the neighboring species Shorea curtisii, suggesting there might be a possibility of outbreeding across dipterocarps species. This study aimed to investigate the morphological variations of the leaf of Shorea leprosula Miq. progeny trial in a logging concession in Kalimantan, Indonesia. The morphological characters of 72 S. leprosula individuals in the progeny trial stand were identified through sampling. Macroscopic and microscopic observations were conducted, and the measurement data of 22 characters were analyzed using clustering and principal component analyses to explain the similarity pattern and the contribution of each morphological character. The results showed variations in four characters, namely laminar shape, apex shape, base shape and midrib thickness. The cluster analysis classified the samples into four cluster groups, namely (i) a notophyll leaf size category with a rounded base; (ii) a laminar ellipse shape with medium midrib thickness; (iii) an oblong laminar with an obtuse apex shape; (iv) a notophyll leaf size category with an obtuse base. The principal component analysis showed that the base shape had the highest contribution to the variation of the samples. © 2021, Society for Indonesian Biodiversity. All rights reserved.