Seleção de árvores matrizes de Amburana cearensis (Allemão) A.C.Sm. para produção de sementes e conservação in situ

Abstract

Amburana cearensis (Allemão) A.C.Sm. (Fabaceae) is a native species of the endangered Caatinga. Thus, studying how natural populations remain is imperative to assist in conservation. Thus, it aimed to characterize natural populations of A. cearensis to support the organization of in situ conservation and collection of seeds of this species. Three selected were selected for the study, one in the State of Paraíba (Soledade) and two in Rio Grande do Norte (Caicó and Assu). The quality of seeds produced by trees in the population of Soledade was analyzed with the perspective of selecting matrix trees for seed collection and three sources were genetically characterized to support in situ conservation and seed collection. that produced seeds, only 29% of the requirements meet the requirements of genetic diversity and physical and physiological quality as parent trees with a view to seed production and conservation of the species. By analyzing the amplification profile of 30 ISSR (Inter Simple Sequence Repeat) molecular primers, it was found that only twelve of them revealed loci with good resolution, reproducible and with high polymorphism (83-100%). This set of primers revealed 89 loci with 98.8% polymorphism, this amount being sufficient to detect the genetic polymorphism based on the resampling technique. The genetic diversity indices were polymorphism percentage (% PL), polymorphic information content value (PIC), Nei genetic diversity index (He), Shannon index (I), total heterozygosity (Ht), genetic differentiation (GST) and gene flow. Informative and satisfactory values were found for genetic diversity indices for trees in the Caicó population (% PL = 69.3; He = 0.152; I = 0.232), Soledade (% PL = 80.8; He = 0.225; I = 0.338) and Assu (% PL = 73.7; He = 0.240; I = 0.350). However, Nei genetic diversity (He = 0.364), Shannon index (I = 0.539), total heterozygosity (Ht = 0.371) and genetic differentiation (GST = 0.447) just between as these values were moderately satisfactory. Gene flow was low (Nm = 0.620), indicating isolation or fragmentation of populations. For morphometric characterization of Caicó, Soledade and Assu, there was only difference for height, in which taller tree classes, advanced ontogenetic stage of the trees were observed. From the genetic identity group of Nei of a point of 0.87, it was possible to identify a formation of 28 well-defined groups. Therefore, from the results obtained, it was possible to characterize all sources of A. cearensis as potential seed producers and satisfactory genetic diversity for seed collection and in situ conservation of the species.