Contribution of male genitors in open-pollination progenies of sour passion fruit

Passion fruit breeding programs often use a single fruit to obtain progeny. Open-pollination progenies are considered half-siblings since they allow the occurrence of a mixture of pollens during pollination. However, there are no studies able to prove that these progenies are, in fact, consequence of a mixture of pollens. The contribution of male genitors to the formation of open-pollinated progenies and genetic diversity were evaluated by means of microsatellite markers. A hybrid test was performed based on the gathered genotypic data, a chi-square test was used to verify the expected and observed frequencies, and the proportion of identical genes by descent (IBD) was estimated. Genetic diversity was studied through descriptive analysis, cluster analysis, and molecular analysis (AMOVA). The hybrid test indicated the participation of more than one male genitor in progeny formation. However, the genotypic composition observed in the progenies differed significantly from that expected when assuming crosses between all individuals of the origin population. The IBD values for the progenies ranged from 0.26 to 0.30, indicating that they are progenies of half-siblings. The progenies showed observed heterozygosity greater than expected and an inbreeding coefficient close to zero. The AMOVA revealed that the greatest genetic variation (81.96%) occurred within progenies. In sour passion fruit, open-pollinated progenies obtained from a single fruit do not present genotypic composition representative of their population of origin since the greatest genetic diversity was observed within the progenies.