Virola surinamensisis an Amazonian tree species commonly found in floodplain areas. The species’ high economic value arises from its several commercial uses, varying from seed oil for cosmetics destinations to woody products. Consequently, virola’s natural populations in Brazil have been intensively exploited, leading the species to a status of endangered. Although characterized as dioecious, a high level of homozygosity was found in Eastern Amazon remaining adult populations, possibly as a result of extensive logging. In order to understand the high level of inbreeding, this study aimed to evaluate seeds sampled in eleven V. surinamensis seed trees in remaining populations located in two areas (Cotijuba and Cametá) in Pará state, Brazil. Offspring from eleven maternal trees (12 to 20 seeds per tree) were sampled in seed traps and genotyped for seven microsatellite loci. Inbreeding coefficients corrected for null alleles were very high, FIS= 0.233 in Cametá and FIS = 0.244 in Cotijuba. This result may reflect the impact of drastic reduction in population sizes, in which few remnant trees effectively mate. The average coancestry coefficient within fruit traps was 0.047 (0.024 - 0.079 range) in Cametá and 0.086 in Cotijuba (0.025 - 0.159 range). Significant spatial genetic structure was detected, with low relatedness occurring in seed trees with distances smaller than 23m in Cotijuba and 47m in Cametá (ρij = 0.093 and 0.052, respectively). Overall, our results suggest that non-random mating pattern might be due to the small number of mating adults, precluding long term persistence of these populations.

01 - Mating patterns of Virola surinamensis trees reveal Amazonian estuary populations might be under risk