Diversidade fenotípica de (Opuntia ficus-indica (L.) Mill., acessada por marcadores morfológicos e bromatológicos

Abstract

The forage cactus is the popular name for the species Opuntia ficus-indica (L.) Mill. The plant has adaptations to arid and semiarid regions, being a cosmopolitan species. The forage cactus has agronomic, medicinal and ecological properties, and there is a wide diversity of shapes and colors of cladodes and fruits. This work provides an overview of the morphological and bromatological diversity of 30 accessions of O. ficus-indica (L.) Mill. Quantitative and qualitative, morphological and bromatological characteristics were evaluated. Data were subjected to analysis of variance (ANOVA), and from the means, broad heritability, variances and phenotypic and genotypic correlations were estimated. In addition, accesses were grouped using the modified Tocher and the UPGMA hierarchical method. The relative importance of the characters for the diversity and analysis of the principal components was also determined. Although the populations of O. ficus-indica (L.) Mill. are mostly derived from clones through the vegetative propagation of their cladodes, it was observed that there is genetic diversity among the studied accessions. Higher heritability estimates were found in bromatological markers, when compared to morphological ones, suggesting greater influence of genetic control than environmental. The phenotypic and genotypic correlations were high and positive for all cladode variables. The Tocher grouping gathered accessions into 3 distinct groups, while the dendrogram organized accessions into 4 groups. The first two Principal Components (PCA) explained 74% of the variability. It was found that the descriptors cladode color, spine distribution and spine length were the variables that most contributed to the diversity of accessions. There is genetic variability within Opuntia ficus-indica, and the accessions that stood out were the accessions 4, 5, 7, 8, 12, 13 and 30, being the same promising for the improvement programs of cactus forage.