Mating system in Pterocarpus macrocarpus Kurz in Thailand

Abstract

The mating system in 11 natural populations of Pterocarpus macrocarpus Kurz in Thailand was investigated based Oh the mixed mating model using 16 isozyme markers. Single-locus outcrossing rates (t(s)) averaged from 0.620 to 0.931 among populations while multilocus outcrossing rates (t(m)) ranged from 0.719 to 0.959. Both t(s) and t(m) revealed a geographic with western populations exhibiting higher outcrossing than eastern populations. Low estimates of outcrossing rates in eastern populations could be attributed to habitat characteristics, degree of disturbance, density, and distribution of flowering mature trees. Individual tree outcrossing rates (t(mi)) indicated that reduced population density associated with disturbance could result in low t(m) in some eastern populations.