EFFECTS OF DMSO ON THE INDUCTION AND THE REDIFFERENTIATION OF CALLUS FROM RICE SEEDS

The inductivity of callus in rice seeds was enhanced by soaking with DMSO of 0.2%, 1%, 5% for 1, 3 and 6 hours, and the maximum value of enhancing was at 1 hour-soaking with 5% DMSO. In addition, the soaking of DMSO with various concentrations could also enhance the redifferentiation of callus induced. The highest percentages of callus differentiated and of callus growing roots were at 1 hours-soaking with 5% DMSO, but the highest percentage of callus growing buds was at 3 hours-soaking with 1% DMSO, it indicated that the suitable concentration of DMSO influenced the differentiaton of buds and roots from callus was not same. The soaking of DMSO could also influence some physiological properties of callus induced: ①the soaking with DMSO could influence the cell permeability, and ② influence the changes of peroxidase isozyme pattern and increase the activities of amylase isozymes and so on. It was noticeable that the percentages of callus growing buds treated with DMSO were increased with the increased of the peak height ratio of peroxidase isozyme band 3/band 7 and band 4/ band 10 in corresponding callus, the both appeared to have certain corre lativity. In addition, the relation between the cell permeability of callus induced by DMSO-soaking and the differentiation of callus appeared also to be positive relativity. These correlativities above were very important to the study of mechanism about the effect of DMSO on the efficiency of tissue culture.