Genetic variability of Dipteryx alata Vog. (Fabaceae) in a provenance and progeny trial

Abstract

Cerrado is the second largest biome in Brazil and one of the most biodiverse regions in the world, being highlighted as a hotspot for biodiversity conservation. The accelerated pace of deforestation of Cerrado, mostly due to the expansion of agricultural activities, intensifies the process of habitat fragmentation and, consequently, in ecological and genetic aspects of the indigenous species. This work aims to study the genetic variability and reproductive system of Dipteryx alata in a provenance and progeny trial. This is a tree species native from Cerrado regions widely used by traditional peoples, provider of food and wood for multiple purposes. The trial consists of 66 families of half-siblings, 25 families coming from extreme west, 25 from the northwest and 16 from the mid-north regions of the state of Minas Gerais in the southeast of Brazil. Isozymes extracted from leaf samples were run in polyacrylamide gel electrophoresis and stained with several enzymatic solutions, among which the best revealing enzymatic systems were chosen for analysis. It can be inferred that D. alata has a low divergence among the three provenances analyzed based on the similarity in the allele frequencies of populations, along with similar proportions of genetic equity. It is reported that the history of fragmentation in the Cerrado region of Minas Gerais is relatively recent and because of that we hypothyse that not enough time has elapsed for natural populations of D. alata occurring in these localities to express genetic changes. The results showed high genetic variability in the three provenances indicating high potential to be employed in genetic improvement, mainly due to the wide variability with in populations. In accordance with previous studies we detected a mixed reproduction system with predominance of outcrossing.