Comportamento de cultivares de bananeira (Musa spp) resistentes a doenças no processo de micropropagação.

Abstract

The banana is one of the most consumed fruits in the world and is widely consumed in Brazil, but diseases such as yellow and black Sigatoka have been reducing its production, most of ali because of lack of proper production technology. The tissue culture, specifically the micropropagation, is an alternative for the production of seedlings of banana with phitosanitarium and vegetative quality, but presents factors that difficult its application. Among which stands out contamination by fungi and bactéria, associated with oxidation of the explants by the exudation of phenolic compounds that cause rapid browning and death of apical shoots, resulting in great loss in the initial phase of the explants establishment. The objective of this work was to adapt and/or optimize the behavior of different banana cultivates, resistant to diseases, via micropropagation, adjusting the in vitro culture establishment phases, through the control of oxidation and contamination, proliferation / multiplication of shoots and rooting, for the rapid multiplication of plants with superior quality, as much in the phitosanitarium aspect as in the vegetative. The cultivates Bucaneiro (AAAA), Caipira (AAA), Fhia 18 (AAAB), BRS Garantida (AAAB), Japira (AAAB), Pacovan Ken (AAAB), PA 4244 (AAAB), Preciosa (AAAB), PV 03-76 (AAAB), Thap Maeo (AAB) and Tropical (AAAB) proceeding from the city of Baião in the state of Pará and Caipira (AAA), BRS Caprichosa (AAAB), Pacovan Ken (AAAB), Preciosa (AAAB), PV 03- 76 (AAAB), Thap Maeo (AAB) proceeding from the city of Belém in the state of Pará, were subjected to different micropropagation stages. In the study was used the streptomycin sulfate antibiotic and fungicide to reduce contamination in vitro caused by bactéria and fungi, besides the anti-oxidant PVP (polivinilpirrolidona) to control the oxidation. There was contamination reduction with the use of streptomycin sulfate in the concentration of 100 mg.L1 and of oxidation with PVP at 4 gL1. At the stage of proliferation / multiplication of shoots, the different cultivates showed means ranging from 1,67 to 7,0 shoots / explant, with greater proliferation in the initial culture (2,0 to 7,0 shoots / explant).The cultivate Caipira (AAA) stood out from the others with the highest rate of shoot multiplication after three subcultivations, 65 shoots per initial rhizome average, mostly from the rhizomes proceeding from Baião. The culture médium with half concentration of MS salts was effective in shoots rooting as much for PV 03-76 cultivate as for Pacovan to Ken cultivate.