Microenxertia de Selenicereus megalanthus em diferentes porta-enxertos de pitaia

Abstract

Pitaia has aroused the planting interest of Brazilian producers and the researchers' interest in improving their production system, due to their rusticity, precocity of production and high economic returns. The objective of this research was to evaluate the viability of yellow pitaia (Selenicereus megalanthus) micrografting on differents rootstocks. Five treatments were used, consisting of white pitaia rootstocks (Hylocereus undatus), red pitaias (Hylocereus polyrhizus) Cebra and Orejana varieties and yellow pitaia (Selenicereus megalanthus), four replicates of five plants, in a total of 100 plants. For evaluation, after 30 days of cultivation, ten plants of each treatment were evaluated for the length and diameter of scions and rootstocks, root length, percentage of "glue" of the micrografts, as well as the fresh mass of the plants. Subsequently, the micrografted plants were taken to the greenhouse to be acclimatized and at 90 days, phytotechnical analyzes were performed, measuring the length and diameter of the scion and rootstock. Flow cytometric analyzes were also performed, which were conducted before and after the micrografting procedure. Before micrografting, 4 plants (cladodes) of each pitaias established in vitro were sampled and after micrografting, 3 plants per treatment of both the scion and the rootstock were evaluated to verify possible changes in their DNA index. After 30 days of in vitro culture of the micrografted plants, longitudinal cuts were also made in the region of insertion of the scion with the rootstock, aiming to verify the presence of the connections of vessels and tissues between them, through histological cuts. Comparing the DNA indices, there was endoreduplication in all treatments and when the yellow pitaia was grafted onto the red Orejana variety rootstock, the genetic material index of the scion was not affected. Considering phytotechnical, genetic and anatomical characteristics, it is feasible the micrografting of yellow pitaia.