SISTEM PERKAWINAN BAKAU BANDUL (Rhizophora mucronata Lamk) BERDASARKAN ANALISIS ISOZIM

Abstract

Mating system of bakau bandul (Rhizophora mucronata Lamk.) was studied from progenies of selected mother trees of several natural populations in Sumatra and Java, i.e. North Sumatra, Riau, Jambi, Muara Angke, and Ujung Kulon, using isozymes. Isozyme analysis was performed using six enzyme systems, i.e. AAT, ADH, EST, IDH, MDH, and PER. The result showed that bakau bandul has mix mating systems, with predominantly selfing due to lower outcrossing rates (6-32%). Mother trees from relatively better forest condition (North Sumatra, Jambi, and Ujung Kulon) have higher outcrossing rate (32%, 17%, and 19%) compare to mother tress at degraded forests (Riau and Muara Angke) at 13% and 6%, respectively. Polen ovule ratios vary among loci and alleles, but showed relatively balance formation of male and female gametes. Although predominatly selfing bakau bandul does not have preferential mating (F =-0,197), because of random association of alleles from ovule and pollen from various trees. Wind and insects seemed to play important role on random mating among trees.