Morphological characterization and genetic diversity in Passiflora alata Curtis and P. cincinnata Mast. (Passifloraceae)

Abstract

The genetic variability in accessions of Passiflora alata and P. cincinnata in a Brazilian germplasm collection was inferred using sixteen quantitative and eight qualitative morphological descriptors. The accessions were evaluated with randomized block design, with three repetitions. Among the morphological characteristics, the bract length, and plant height were the traits that presented most variation among the accessions of P. alata, whereas floral pedicel length and internode number presented the largest variation among the accessions of P. cincinnata. By means of multivariate analysis, applying Mahalanobis’s cluster technique by single linkage, Tocher optimization, and canonic variables, a cluster of the genotypes per species was noted, and within each species, there was consistency between the methods for the number of groups formed. The accessions of P. alata were divided in our subgroups and the ones of P. cincinnata in eight subgroups. From the qualitative data, the cluster analysis by means of the nearest neighbor method revealed the formation of nine groups, separating them by species, with cophenetic correlation coefficient of r cof = 86. The traits were not efficient to group the accessions, and the corona diameter was the character that contributed most for the explanation of the interspecific genetic divergence. Genetic variability was observed in and between species, with larger genetic divergence between accessions 363 and 332 of P. alata, and 245 and 211 of P. cincinnata.