Callus induction, embryogenic potential and genetic stability in red pitaya

Abstract

The red pitaya with white pulp (Hilocereus undatus) is a cactus belonging to the group of tropical fruit, considered promising for cultivation. This study aims to induce callus and embryogenic potential and determine the genetic stability in pitaya. The study was divided into four steps: 1ª) Callus induction using doses of 2,4-D (2.0 and 4.0 mg L-1) and with doses of glutamine (100 and 200 mg L-1); 2ª) callus growth curve for various time periods (0, 7, 14, 21 , 28, 35, 42 , 49, 56, 63 , 70, 77, 84 , 91, 98, 105 and 112 days); 3ª) Cytochemical analysis to assess the potential of embryogenic callus (samples consisting of 100 mg of callus) and 4ª) Analysis of flow cytometry to assess the genetic stability of the callus (compared with a seedling in vitro - control). The conclusion is that the 4.0 mg L-1 2,4-D is the best concentration for callus induction in explants shoots of pitaya; the glutamine does not influence the callus formation. The callus has higher embryogenic potential at 49 days, therefore must be spiked in this period. By flow cytometric was detected endoreduplication in the material analyzed.