Mangaba (Hancornia speciose Gomes—Apocynaceae) is an important fruit tree in Brazil and has an unexplored stock germplasm collection. Commercial varieties are unavailable and little is known about its potential as a ...Mangaba (Hancornia speciose Gomes—Apocynaceae) is an important fruit tree in Brazil and has an unexplored stock germplasm collection. Commercial varieties are unavailable and little is known about its potential as a source of genetic diversity for molecular breeding programs. Progeny tests may improve studies on commercial variability and facilitate genetic improvement of the species. Our aim was to evaluate the genetic diversity and structure of accessions and progeny from the Mangaba Genebank of Embrapa Coastal Tablelands. We estimated the genetic diversity of 96 individuals using 4 SSR markers. The mean observed heterozygosity was lower than expected, showing an excess of homozygotes, corroborated by the positive coefficient of endogamy. The genetic diversity indexes (Fst) and Nei’s unbiased genetic identity (GI) revealed, in general, moderate genetic diversity between accessions. The relationship between matrices and progenies showed that there may be a greater degree of genetic information sharing between the ABP1 and ABP2 accessions. The Bayesian analysis suggested the presence of two distinct groups of genotypes (K = 2). These results will assist future breeding programs and facilitate the conservation of mangaba.展开更多
文摘Mangaba (Hancornia speciose Gomes—Apocynaceae) is an important fruit tree in Brazil and has an unexplored stock germplasm collection. Commercial varieties are unavailable and little is known about its potential as a source of genetic diversity for molecular breeding programs. Progeny tests may improve studies on commercial variability and facilitate genetic improvement of the species. Our aim was to evaluate the genetic diversity and structure of accessions and progeny from the Mangaba Genebank of Embrapa Coastal Tablelands. We estimated the genetic diversity of 96 individuals using 4 SSR markers. The mean observed heterozygosity was lower than expected, showing an excess of homozygotes, corroborated by the positive coefficient of endogamy. The genetic diversity indexes (Fst) and Nei’s unbiased genetic identity (GI) revealed, in general, moderate genetic diversity between accessions. The relationship between matrices and progenies showed that there may be a greater degree of genetic information sharing between the ABP1 and ABP2 accessions. The Bayesian analysis suggested the presence of two distinct groups of genotypes (K = 2). These results will assist future breeding programs and facilitate the conservation of mangaba.
