Genetic diversity and structure of podocarpus lambertii klotzsch ex endl. Populations in the mixed ombrophilous forest of santa catarina state

Abstract

Podocarpus lambertii (Podocarpaceae) is popularly known in Brazil as pinheiro-bravo. It occurs in several forest formations of the Atlantic Rain Forest, mainly in the Ombrophilous Mixed Forest. Due to the high wood exploitation suffered by the species, it is listed as ‘Almost Threatened’ in The IUCN Red List of Threatened Species. In face of this, the objective of the present study was to characterize the genetic diversity and structure of 12 natural populations of Podocarpus lambertii in Santa Catarina state, aiming to generate information for the definition of effective conservation strategies for the species. To access genetic diversity levels and distribution, it was used 10 allozymic systems. Along with the assistance of the software Fstat, the allelic frequencies (A), polymorphic loci percentage (P), observed heterozigosity (H), expected heterozigosity, fixation index (f) and genetic divergence between populations (F ) were calculated. In 11 loci o 32 alleles (A= 1,8) were detected. A low genetic diversity was detected for Podocarpus lambertii ST populations (P = 52,7; H = 0,049; H = 0,079). The mean fixation index obtained (f = 0,374) indicates a deficit of heterozygous 100% individuals. O A high number E of low frequency alleles was detected and together with the high genetic divergence (F = 0,303), it points towards the necessity of in situ conservation of a large number of Podocarpus lambertii populations ST and the need to increase the connectivity among the remnant populations.