Caracterização morfológica, divergência genética e indicação de cruzamentos em pitaya

Abstract

The pitaya germplasm is formed by two genera (Selenicereus spp. and Hylocereus spp.) with potential for human and animal consumption, with differences in the characteristics of th,e cladodes, flowers and fruits. Commercial cultivation in Brazil is recent and, due to the lack of agronomically selected matrices, there is significant phenotypic variation, observed in the production, size and shape of the fruits, as well as in their physical-chemical characteristics, because of the genetic non-uniformity of the plants. The development of varieties adapted to the different agroecosystems, with agronomic potential, is necessary, as it will allow the guarantee of the harvest, the uniformity of production and commercialization. Therefore, this research aimed at the morphological characterization of 14 pitaya genotypes, the estimation of genetic divergence and the indication of intra and interspecific crosses. The research was carried out in Maragogi/AL, using matrices installed in an active germplasm bank located in the Bom Jesus settlement. Nine morphological descriptors of the cladodes and 14 of the fruits were evaluated. Regarding the qualitative descriptors, it was observed that the pitaya genotypes presented wide phenotypic variability, with a predominance of the rough texture of the cladodes (50%), convex margin of the rib (85.7%), dark pink color of the fruit skin (42.8%) and color of the pulp ranging from white to purple. In the quantitative descriptors, wide variation was also observed, both due to the high values of coefficient of variation, reaching 69.1% for the height of the arch, and due to the formation of groups by the Tocher grouping method, in all the variables analyzed, with emphasis on the length of the cladode, with the formation of five divergent groups. From the principal components analysis, using the Gower algorithm, it was possible to form five similarity groups, allowing the indication of crosses between the divergent genotypes ‘Vermelha Colombiana x Boreal Red’, ‘Golden de Israel x Vietnamese White’, ‘Matsuka x Boreal Red’. With this, it will be possible to gain with greater heterosis and superior progenies.