Conservation genetics of Annamocarya sinensis (Dode) Leroy, an endangered endemic species.

The endangered perennial plant Annamocarya sinensis (Dode) Leroy is a tertiary relict tree restricted to southeastern China and northern Vietnam. To explore endangerment mechanisms, develop protection strategies, and guide reintroduction efforts for this species, we investigated genetic diversity and population structure by surveying 70 individuals from three distinct populations using 12 polymorphic microsatellite markers. We found high genetic diversity for A. sinensis as indicated by high allelic diversity (allelic number = 4.667 ± 0.436, effective number of alleles = 2.913 ± 0.249), excess heterozygosity (observed heterozygosity = 0.586 ± 0.039, expected heterozygosity = 0.582 ± 0.029), and low fixation index (-0.028 ± 0.057). Our research revealed low genetic differentiation (FST = 0.066 ± 0.011) and no correlation between genetic distance and geographic distance. Analysis of molecular variance attributed 87% of the variance to differences within the population, whereas 13% was distributed among populations. The protection strategy should aim to protect as many populations as possible. Promoting sexual reproduction among various genotypes and establishing an outcrossing program are advisable for A. sinensis.