Genetic diversity in Passiflora L. species based on pollen and seed morphology and nuclear DNA content

Abstract

Characterizing and predicting genetic diversity within the genus Passiflora is critical for promoting diversified strategies in genetic improvement programs. The present study aimed to characterize the morphology of pollen grains and seeds, and to infer the 2C DNA content using flow cytometry in species of the genus Passiflora with ornamental potential. For the morphological characterization of pollen grains and seeds, 11 and 12 descriptors were used, respectively. The data obtained were analyzed using ANOVA and grouped according to the Scott-Knott method. To study genetic diversity, the Mahalanobis distance matrix, and the UPGMA agglomerative method were used. For the morphological characterization of pollen and seeds, the results indicated significant differences across all descriptors. Four descriptors were particularly remarkably divergent: colpus width, equatorial axis, polar axis length, and the number of ornaments on the seeds. The species were grouped into three clusters in the dendrogram using the clustering method. 2C DNA content values demonstrated high interspecific variability, possibly due to chromosomal number and size. These results enabled the detection of genetic diversity, the significance of the biological trait values, and a better knowledge of interspecific gene interactions, all of which aid the selection of ornamental parent plants. © 2025, Federal University of Lavras. All rights reserved.