Diversidade genética em populações de canafistula (Peltophorum dubium (Spreng.) Taub.), micropropagação e produção de mudas micorrizadas em Mato Grosso do Sul

Abstract

Brazil is among the megabiodiversity countries, however, currently the Brazilian biomes, Atlantic Forest and Cerrado, are on the list of biodiversity hotspots, making evident the need for conservation and improvement of natural genetic resources. Regionalized studies to broaden the base of native species and potential genetic materials seek greater knowledge of fast-growing native species and high wood productivity; as is the case with canafistula. For research on the genetic diversity of canafistula was installed in Dourados-MS, a progeny and provenances test of 64 genotypes from three regions of MS and the Lavras-MG microregion. The results showed the existence of genetic variability between and within populations for the dendrometric characteristics and grouped the progenies in 03 groups due to genetic divergence. In vitro micropropagation experiments were also performed with the species. Explant type and disinfestation time for in vitro establishment were tested; concentrations of Zeatina (ZEA) 0; 2.5 and 5.0 mg L-1 in the multiplication phase of apical segments and indolbutyric acid (IBA) concentrations: 0; 0.5 and 1.0 mg L-1 for rooting of the nodal segments. In vitro establishment, superiority was verified of stem apex over nodal segments, with high establishment percentage without influence of the disinfestation time. The zeatin concentration tested were not efficient in vitro multiplication of canafistula. It was not possible to establish protocol for multiplication and rhizogenesis, suggesting possible recalcitrance (callus formation) of the species. Effects of inoculation with arbuscular mycorrhizal fungi (Glomus clarum, Gigaspora margarita, Gigaspora albida, Clareoideoglomus etunicatum and control without AMF) and phosphorus doses (0, 60, 120, 180 and 240 mg kg-1) on canafistula seedlings production, were also the object of study, where it was found that G. albida and C. etunicatum were the most promising fungi for the growth and development of canafistula seedlings and that excess P was detrimental to mycorrhization.