Selênio e substâncias húmicas em pitaias durante o cultivo in vitro e após aclimatização

Abstract

Fruit producers have invested on fruits such as pitaya, witch besides having an attractive economic value, awakens interest to consumers who seek a healthy and quality diet, combined with the prevention of diseases, thus emphasizing the importance of its cultivation. In this context, the aim of this study was to promote a micropropagation process and obtain seedlings from red fleshed pitaya (Hylocereus polyrizus) under addition of selenium and humic substances. The effect of different Selenium sources (selenite and sodium selenite) and concentrations (0, 12, 24, 36, 48 e 60 μmol L-1) on seedlings cultivated in vitro and acclimatized was verified, in order to evaluate their accumulation and physiological characteristics in red fleshed pitayas and also the viability of biofortification by tissue culture. A completely randomized design (CRD) was used, with five replications per treatment, containing six tubes per replication. On the other hand, for the study of humic substances, humic and fulvic acids and concentations (0, 5, 10, 20 e 40 mg L-1) and their effects on growth, physiological and anatomical variables in in vitro and acclimatized cultivated plants were evaluated, aiming better performance and tolerance in red pitayas. Five replications (10 tubes/replications) were used in a factorial design. Therefore, it is concluded that the concentration 36 μmol L-1 of selenate was the most efficient to obtain plants with higher accumulations of selenium after acclimatization, without causing losses int phytotechnical characters, enzymatic and photosynthesis complexes and tissue culture is viable for the biofortification of pitaya. In addition, the concentration of 20 mg L-1 of fulvic enhanced its rooting characteristics and anatomical variables of pitaya plants.