EVALUATION OF THE GENETIC DIVERSITY OF THE VIETNAMESE BREEDING POPULATION OF Acacia auriculiformis

Abstract

Acacia auriculiformis is an important forestry species in Vietnam due to its wide adaptability, fast growth and its role as a parent in hybrid breeding programs. However, the current breeding population exhibits limited genetic diversity, posing risks of genetic degradation and reduced long-term improvement potential. This study aimed to assess the genetic diversity of 150 A. auriculiformis families (including 100 newly introduced families from Indonesia and 50 existing provenances) using microsatellite markers (SSRs). Results showed that the addition of new genetic materials significantly increased the average number of alleles (Na = 14.3), effective alleles (Ne = 6.4), and observed heterozygosity (Ho = 0.82), while reducing the fixation index (F = -0.05), indicating a notable improvement in genetic diversity and a reduction in inbreeding. Comparison between origin groups revealed that families from Papua New Guinea (PNG) had higher polymorphism (Na = 11.3, Ne = 4.6) than those from Queensland (QLD), suggesting that hybrid breeding strategies should combine internal diversity with wide genetic distances. These findings provide a scientific basis for designing breeding orchards, selecting non-related parents, and supporting the development of effective and sustainable breeding programs for disease-resistant Acacia clones under current and future climate change conditions.