Parental selection in Portulaca umbraticola Kunth for ornamental purposes

ABSTRACT Purslane (Portulaca umbraticola Kunth) is used as a food, medicinal, and ornamental plant. Its ornamental use is associated with the wide genetic variability in phenotypic traits, which is fundamental in breeding programs. The objective of this study was to select parents of P. umbraticola Kunth, based on genetic divergence of ornamental purposes. Twenty-two accessions were collected in the states of Ceará, Rio Grande do Norte, and Paraíba, Brazil. The experiment was conducted in a completely randomized design, with twenty-two treatments and three replicates. Plants were evaluated 40 days after planting, at full bloom. The evaluated traits were: plant height, stem diameter, crown diameter, leaf length, leaf width, flower diameter, petal length, number of flowers per plant, chlorophyll a, and chlorophyll b, and flower color. Data were subjected to analysis of variance and Scott-Knott test (p ≤ 0.05). Heritability and the ratio between coefficient of genetic variation and coefficient of environmental variation were estimated. The genotypes were grouped by Tocher’s method, and the importance of traits by Singh’s method. The accessions were grouped into seven clusters, demonstrating genetic variability, with greater importance of the traits crown diameter, plant height, and number of flowers per plant. Eight phenotypic classes were found for flower color, demonstrating the potential of these accessions for use in breeding programs. Based on intergroup distance and considering the key traits for ornamental purposes, the accessions Ac2, Ac4, Ac6, Ac16, Ac18, and Ac19 should be selected as parents. The use of selection index should improve the choice of the parents.