Abstract:

To select new variety resistant to Taizishen leaf spot, in vitro screening of resistant mutants of taizishen to Phyllosticta commonsii was cultured in crude Phyllosticta commonsii toxin by gradually increase the concentration of toxin. The results indicated that crude Phyllosticta commonsii toxin showed signifisant inhibitory effects on callus induction and growth, adventitious buds differentiation. The resistance of callus to Phyllosticta commonsii toxin could be improved by increasing the concentration gradually. The toxin concentration of 25% was considered as the selection pressure of resistant mutants of callus to Phyllosticta commonsii, and up to 15.5% of survival-rate of callus. To reduce the toxin concentration to 10%~20% appropriately is more advantageous for adventitious bud differentiation, and up to 54%~40% of differentiating-rate. The toxin concentration of 60%~70% was considered as the selection pressure of resistant mutants of regenerated-plantlets to Phyllosticta commonsii, and up to 8.3% of survival-rate of plantlets. There were 46 regenerated plants to be high resistance to crude Phyllosticta commonsii toxin by detached leaves resistance identification, and its resistance to the toxin was significantly higher than the control.