Morphological characterization, genetic divergence and indication of crossings in dragon fruit

Abstract

Commercial cultivation of dragon fruit in Brazil is recent and, due to the lack of selected matrices, there is wide phenotypic variability, observed in production, size and shape of the fruits and in the physico-chemical traits. The development of varieties adapted to the different agroecosystems, with agronomic potential, will ensure uniformity of production. This research aimed to characterize morphologically 25 dragon fruit genotypes, the estimation of genetic divergence and the indication of biparental crosses. The research was carried out on matrices installed in an active germplasm bank located in Maragogi, Alagoas State, Brazil. The evaluation of cladode variables showed wide phenotypic variability, both in quantitative descriptors, highlighting length, with the formation of nine groups by the Tocher test, with Boreal Red having the highest average (127.0 cm), and in qualitative descriptors, in which the rough texture of the cladode predominated in 68% of the genotypes. In the fruits, the color of the skin and pulp showed six and eight groups of similarity, in which 44 and 68% of the genotypes presented dark pink and reddish/purple colors, respectively. The PCA method revealed that the variables linked to the fruit were the most important for the analysis of genetic divergence, which was of high magnitude, with the formation of seven divergent groups by the UPGMA method, making it possible to indicate the crosses between the genotypes ‘Vermelha Colombiana x Boreal Red’, ‘Golden de Israel x Vietnamese White’, ‘Makisupa x Boreal Red’, allow gains with greater heterosis and superior progenies.