Genetic parameters and prediction of genotypic values in a segregating population of Passiflora BC3 [(P. edulis x P. cincinnata) x P. edulis] for fruit quality and resistance to cowpea aphid-borne mosaic virus using REML/BLUP

Passion fruit woodiness caused by the cowpea aphid-borne mosaic virus (CABMV) has the greatest economic impact on Brazilian passiculture. Therefore, obtaining more productive materials, with better fruit quality and greater resistance to CABMV through the use of interspecific hybridization, is essential in passion fruit genetic improvement programs. The objective of this study was to evaluate the genetic parameters and predicted genotypic values in a segregating population of interspecific hybrids of passion fruit from the third backcross generation (BC3) regarding fruit traits and resistance to CABMV, using REML/BLUP. We evaluated 366 BC3 progenies belonging to 22 families regarding production, physical and chemical fruit traits and resistance to CABMV. Estimates of genetic parameters via REML revealed high variability in the BC3 population, with σf2being explained in most characters by σa2 and the highest ha2 ranging from 0.55 to 0.90 for peel thickness, fruit weight and length, peel weight, pulp weight with seeds and fruit diameter. The genetic variance and heritability for passion fruit woodiness virus were low in the population. The predicted genotypic values of µ+g obtained by BLUP exhibited wide variation for the evaluated traits. Twelve progenies stood out for fruit quality and productivity, followed by one progeny that had a combination of high fruit quality, production and productivity along with lower severity of CABMV. The BC3.C and BC3.D families and their progenies stood out especially in relation to variables associated with fruit quality. In general, the BC3 families and progenies were classified as moderately resistant or susceptible to the virus, with emphasis on the BC3.A, BC3.B and BC3.G families, which included 43 progenies with moderate resistance to CABMV. The results obtained in this study provide useful information for the improvement of passion fruit, since the REML/BLUP procedure allowed accurately selecting progenies with predicted genetic gains based on fruit traits and resistance to CABMV.