Como selecionar indivíduos de Handroanthus impetiginosus (Mart. ex. DC.) para subsidiar áreas de coleta de sementes na Caatinga?

Abstract

Handroanthus impetiginosus (Mart. ex DC.) Mattos (Bignoniaceae) is a native Brazilian tree threatened by illegal logging. In addition to the full protection of the remaining populations, other strategies capable of increasing the survival prospects of this species in nature are the reintroduction and commercial cultivation for wood purposes. As projects of this nature need a supply of seeds of high genetic and physiological quality, the objective of this study was to define criteria for selection of matrix trees, aiming at installing H. impetiginosus Seed Collection Areas. Therefore, the genetic diversity and physiological quality of seeds of 63 individuals of a natural population of H. impetiginosus located in the state of Rio Grande do Norte, Brazil, were evaluated. Initially, the ability to detect genetic polymorphism of Inter Simple Sequence Repeat (ISSR) molecular marker primers was evaluated. Of the 30 primers tested, eight were selected for having higher rates of polymorphism (4-18 loci per primer) and amplification pattern. This set of markers revealed that the studied population has an intermediate degree of intrapopulational genetic diversity (genetic diversity of Nei = 0.35; and Shannon's index = 0.52). Subsequently, the physiological quality of seeds from 63 trees was evaluated using germination testicles and seed vigor. Of this total, 45 produce seeds of high and intermediate physiological quality. Therefore, visitors of H. impetiginosus with genetic distance of Nei <0.72 and germination greater than 50% can be selected as parent trees in Seed Collection Areas.