Genetic diversity and population restructuring of Astronium fraxinifolium Schott. (Anacardiaceae) in a heavily impacted Brazilian Savanna (Cerrado) anthropic area

Brazil is a characteristic country for having an energy matrix essentially linked to its river courses and the forest fragmentation resulting from these impacts causes a decrease in the number of individuals in a population, favoring the loss of genetic variation. Therefore, preserving the diversity of native plant populations in these impacted ecosystems is extremely important, such as Astronium fraxinifolium Schott (Anacardiaceae), a dioecious and an endangered species typical of the Cerrado. In this context, from a natural population of A. fraxinifolium, located in a highly degraded area of Cerrado, the present work aimed to: i) estimate the genetic variation from the measurement of silvicultural characters; ii) determine the sex ratio; iii) investigate genetic diversity and structure using eight microsatellite loci. All growth characters were significant, with average height and diameter at breast height of 10.99 m and 21.30 cm, respectively, with females being more developed than males. The coefficient of genetic variability was above 25% in all traits. The sex ratio of the population is close to balance from 1:1 to 5% of significance. The population has a total of 101 alleles from 384 individuals analyzed with 8 microsatellite loci, resulting in an average of 12.5 allelic richness, 0.706 observed heterozygosity, 0.793 expected heterozygosity and 0.111 fixation index. The results of this work show the presence of genetic variation and diversity in the quantitative and molecular analyses, with use for mother trees to collect seeds for use in conservation programs, recovery of degraded areas and breeding.