Assessing the genetic structure of teak from Southeast Sulawesi and its implication for genetic conservation and utilization in Indonesia

Genetic relationships among teak (Tectona grandis) seed sources have been found to be low, thus genetic materials from other sources are required to maintain broad genetic diversity. This study here is therefore aimed to assess the potency of teak genetic structure in Southeast Sulawesi, Indonesia. Leaf materials were sampled from six populations: the villages of Angondara, Anduna (Konawe), Napabalano, Matakidi, Wakuru (Muna) and Wakonti (Buton). One population from Java Island (Kepek) was used as an outgroup. Genetic structures were assessed by using six microsatellite markers. The genetic diversity within populations was moderate (mean expected heterozygosity = 0.544; mean allelic richness = 3.752) as well as the genetic differentiation among the populations (mean FST = 0.085). Dendrogram analysis revealed that the populations were separated into two clusters; the first is Kepek-Angondara, Anduna-Napabalano-Matakidi, Wakuru, and the second is Wakonti. AMOVA showed that the genetic variation was insignificant between regions, but significant among populations. The structural analysis demonstrates the division of populations into two lineages (Java and Southeast Sulawesi populations). Differences in genetic structures indicated that the teak from Southeast Sulawesi may have originated from other sources. Thus, those populations are promising for broadening the genetic base of commercial teak in Java.