Caracterização in situ, molecular e morfológica de acessos de Gossypium do Estado de Pernambuco

Abstract

Cotton (G. hirsutum L.) has the most important natural textile fiber in the world. The Gossypium remainders in Pernambuco state are in risk of disappearing due to ecological and agricultural process. The study of species in situ, about they genetic and morphological characteristics gives support in order to find and implement preservation options. The aims of this work was characterize the genetic variability of G. hirsutum e G. barbadense accesses of Sertão, Agreste and Zona da Mata of Pernambuco state by morphological and molecular marks. On the in situ study were evaluated 82 accesses in the 29 counties during expedition in 2005 and 2006 by interview and observation about morphological and phenological characters, and condition of conservation. The identified plants uses were: medical, ornamental and for confection of lamp wick. The genetic erosion risk observed were: change and loss of cultural human habit, animal pastry and environmental depredate. In the molecular study was used fifteen pair of microssatelites primers in order to evaluate the allelic frequency, genetic diversity and genetic distance by Nei statistical. The average of heterozygosis expected (He) that correspond the genetic diversity was 0.321, it was biggest for upland cotton (0.481). For the three studied biomes on the Sertão and the Agreste where predominate of the upland cottonthe He had highest value, 0.548 e 0.444, respectively. The average of inbreeding index was 0.806, highest for G. barbadense (0.968). Cluster shoed an interspecific hybrid between G. barbadense and G. hirsutum (PE 0553). On the morphological characterization ex situ were evaluated 38 morphological characters and nine fiber characters of 72 Gossypium accesses PE0553 (G. barbadense), PE0516 (upland cotton) and PE0524 (moco cotton) were the most morphological divergent and showedmore variability for studied characters. The majority of accesses of three types of cotton shoed good index for fiber being what herbaceous cotton were better about fiber uniformity, reflectance, resistance and percentage of fiber. The information obtained on morphological and molecular cauterization Gossypium genus on Pernambuco state showed high genetic diversity that should be conserving in order gives genes to breeding programs.