Diversidade genética em populações de plantas nativas acessada por RAPD e qualidade fisiológica de diásporos de Myracrodruon urundeuva Fr. All.

Abstract

The Caatinga is characterized by a diversity of plant species with important ecophysiological adaptations for survival in semiarid regions. However, several species are threatened with extinction due to human actions that compromise the ecosystems present in this biome. In this sense, are necessary studies on the various aspects that enhance the development of recovery strategies and conservation of degraded areas. The aim of the studies was to evaluate the genetic diversity among 20 individuals of Poincianella pyramidalis and Myracrodruon urundeuva occurring in populations located in Caatinga of Paraiba, using molecular markers. The objective also identify the most appropriate substrates and temperatures to evaluate the physiological quality of M. urundeuva diasporas. The genetic diversity of experiments were performed through DNA extraction using young shoots of individuals and amplification with 20 primers for P. pyramidalis (OPAT-01 to OPAT-20) and 28 primers for M. urundeuva (OPAT-01 to OPAT 20; MEP-01 to-08 MEP). The obtained labels were converted into a binary matrix, from which it is constructed the genetic dissimilarity matrix using complement arithmetic of Jaccard’s coefficient and construction of dendrogram, using the UPGMA method. The physiological quality of M. urundeuva diasporas was evaluated using different substrates (between and over): sand, vermiculite, basaplant® , mata-borrão® paper and scroll germitest® paper combined with constant temperatures of 20, 25, 30, 35, 40 °C and alternate 20-30 °C. The variables analyzed were: water content, germination, main root and shoot length, dry weight of roots and shoots. Based on the results, P. pyramidalis subjects 09 and 17, as well as 04 and 09, 13 and 16 of M. urundeuva are important for suppliers of plant material to the physiologicalseed assessment; the most divergent individuals genetically found in both species should be used in conservation projects and/or restoration. M. urundeuva germination test should be conducted on paper at 30 °C; in a roll of paper, at any temperature other than 20 °C and 40 °C; on any substrate except between sand and vermiculite at 35 °C; more vigorous seedlings are obtained when the diasporas are grown on sand at 25 °C.