Avaliação da ocorrência e dos padrões de fluxo gênico contemporâneo em uma coleção de germoplasma de Hancornía specíosa Gomes (Apocynaceae)
Nenhuma Miniatura disponível
Data
2013-03-22
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
Hancornia speciosa Gomes is a fruit species inhabiting different regions of Brazil. It's kind of great importance for the fauna of the regions in which it occurs and has a high economic potential. Toe species is divided into six botanical varieties and to distinguish these varieties are mainly morphological characteristics. However, no further work was done to identify genetic differences between these varieties. Furthermore, little is known about the mating system and pollen flow pattems ofthis species. Accordingly, the general objective of the study was to evaluate the contemporary gene flow and the reproductive system in a reproductive station in the germplasm collection in vivo and ex situ of H. speciosa, maintained by the Escola de Agronomia, Universidade Federal de Goiás. It sampled every 274 adults in the collection, 28 trees (matrices) were selected and each of these 20 fruits was collected. A seed of each fruit was planted in a greenhouse, totaling 560 seeds, 57% of the seeds germinated and these leaves were collected for analyzes of patemity. All subjects were genotyped with seven microsatellite loci developed for the species. For the set of loci analyzed was possible to find an average of 18.6 alleles per locus in adults and 15.7 for the progenies. There was no significant difference between the observed and expected heterozygosity found in adults and progenies. When the botanical varieties were evaluated separately, we could not find significant differences between the number of alleles, and observed and expected heterozygosity for each variety. The battery of loci used is capable to discriminating individuais and exclude the patemity of a false pollen donor (CI = 3.34 x10-11 and QC = 0.9999). Multilocus outcrossing rates (tm) and single locus outcrossing (ts) were high and equal to 0.990 and 0.899, respectively. Toe difference of multilocus outcrossing rate and single locus outcrossing combined for all families analyzed was significant, indicating the occurrence of 9 .1 % crossover between related individuais. The correlation of selfing was negative indicating no occurrence of the formation of seeds produced by selfing and this corroborates the hypothesis be selfincompatible species. The patemity correlation was very low, 0.076, and this means that only 7.6% ofthe seeds of each mother are daughters of the sarne pollen donor. Patemity was determined for 71.56% (229) of the analyzed seeds, all botanical varieties of H speciosa contributed to the events of crossing, without thereby restricting the gene flow between varieties. The pollen dispersai distance varied from 5 m between neighbors, 165.6 m, averaging 53 m and 64% ofpollination events occurred at distances of60 m. Toe effective neighborhood area of pollination, considering all patemity assignments, was equal to 8702 m. Among the events crossing, 29% involved pollen donors that are not in the collection, showing that there is contamination of pollen in germplasm collection.
Descrição
Citação
OLIVATTI, A. M. Avaliação da ocorrência e dos padrões de fluxo gênico contemporâneo em uma coleção de germoplasma de Hancornía specíosa Gomes (Apocynaceae). 2013. 92 f. Dissertação (Mestrado em Genética e Melhoramento de Plantas) - Universidade Federal de Goiás, Goiânia, 2013.