CRYOPRESERVATION OF RICE CALLUS

Abstract

Cryopreservation is a technique that allows maintaining long-term germoplasma using ultra-reduced temperature. The objective of this study was to evaluate the regeneration seed´s callus of rice cryopreservated. Seeds of rice BRS-7 TAIM, were peeled and desinfested for establishment in vitro, distributed in flasks containing MS (Murashige & Skoog, 1962) 2,5 mg dm^-3 of 2,4 D for induction of callus and maintained the temperature of ±25 ºC in the darkness. After twelve days the calluses were cryopreservated in liquid nitrogen for one hour, thawed 37º C and put back in the middle of cultivation for proliferation. It was used fifty callus by treatment: Test, Test cryopreservated, Glycerol 500 g dm^-3 and Glycerol 500 g dm^-3 cryopreservated. The evaluation of the proliferation was accomplished to the thirty days being observed the size and coloration of the callus. The material was transferred for middle of regeneration MS 10 mg dm^–3 sucrose, 0,5 mg dm^-3 of ANA and 2,0 mg dm^-3 of BAP and it was incubated in fotoperíodo of 16 h. The evaluation of the regeneration was accomplished to the thirty and forty five days of incubation, the parameters were: growth of the callus, sprout and callus number, number of callus with sprout and sprout/callus number. In the proliferation the callus of the treatment Test cryopreservated rusted, however it was observed in the regeneration, to the thirty days, that the same ones presented such adult and number of sprout, and to the forty five days adult number of sprouts than the other treatments. It is ended that the cryopreservation technique can be used in callus of seeds of rice, not affecting the regenerative capacity.