Genetic variation of Pinus merkusii based on microsatellite markers to support the breeding of high-resin-yield
Abstract
Superior genetic materials for developing high-resin-yield pine were derived from Pinus merkusii mother trees, which were selected through the breeding of subline populations originating from seedling seed orchards and pine plantations in East Java and Sulawesi, Indonesia. Although selection processes have been shown to reduce genetic variation, subline populations are expected to manage kinship relationships. Genetic variation in progeny-tested subline populations of high-resin-yield P. merkusii was evaluated using four microsatellite markers. The results demonstrated high genetic variation within each subline population (mean H e =0.409; range=0.392–0.425). However, the Sumedang, East Java, and Sulawesi subline populations exhibited high inbreeding potential, as indicated by elevated Fis values (0.133–0.332). Genetic differentiation among the observed populations was low (F ST 0.011), suggesting close relatedness among populations. Progeny-tested subline populations of high-resin-yield P. merkusii can maintain genetic diversity and possess potential for development as ortets for vegetative propagation. Following evaluation and final roguing, conversion of the progeny test into a seed orchard can yield genetically improved seeds. To maintain genetic resources and broaden the genetic base, it is essential to increase outcrossing rates in subline populations and introduce genetic material from other populations.