Evaluation of descontamination, germination and morphogenetic responses of papaya cultived in vitro (Carica papaya L.)

Abstract

The tissue culture has assisted enough in genetic improvement and propagation of materials that offered resistance to pest and disease. This work aimed to study the descontamination, germination and types of morphogenetic responses induced in different explants of papaya (Carica papaya L.) by different plant regulators. Two experiments were led in laboratory, using as source of explant: seedlings from in vitro germination.  The first experiment evaluated different treatments to reduce the contamination by fungus and bacteria. The second one evaluated the germination of seeds and embryos in culture environment supplemented with different plant regulators (NAA, BAP and TDZ) at 1 ìM. Later it was observed the behavior and the morphogenetic responses of differents explants (intact seeds and immature embryos) by plant regulators. The results indicated that the scarification of seeds, then ten minutes in immersion in H2SO4, ten minutes in alcohol 70% with 23 beads of Tween 80, 20 minutes in CaOCl 20% and five times in sterile water during 19 days in freezer, presented the lowest percentage of seeds contamination. The best results for germination were obtained with embryos in culture environment supplemented with TDZ. It was observed friable calluses in large quantity and regenerated microshoots countless.