Morphological characterization and genetic parameter estimation in backcrossed progenies of Passiflora L. for ornamental use

Abstract

Morphological characterization and genetic parameter estimation were performed in four progenies obtained by backcrossing the donor genitor Passiflora sublanceolata and four recurrent genitor F1 HD13 hybrids (P. sublanceolata vs. P. foetida). The use of two different germination methodologies showed the existence of significant differences between the germination potential of two-way crossing, indicating time differences to overcome seed dormancy. SSR and ISSR molecular markers allowed the backcrossed character to be confirmed in most plants within progenies, discarding the hypothesis of self-pollination in the origin of backcrossed germplasm. Broad qualitative variation was observed, reflecting 30 different floral patterns in the backcrossed population. ANOVA revealed a significant effect between both characterization periods and for most descriptors analyzed separately in the first and second characterization periods. Scott-Knott clustering revealed that most of the features of the progenies showed intermediate values for the mean of the genitors; however, they have similar mean values between them. Generally higher heritability was observed for floral traits, suggesting high genetic control in phenotypic expression. Data indicates the success of the backcrossing for the recovery of ornamental characteristics with broad variability among progenies. Genetic parameters indicate that the selection of progenies should be made based on floral characteristics, yet all progenies showed higher mean values of the recurrent parents for the most important floral descriptor. However, the selection of plants within progeny should be performed after the characterization of individual plants, either for direct use as an ornamental plant, or for use in other breeding programs.