Mutagenic Effect of 60Co- on Aromatic and Soft Rice Variety'Diantun 502'

To identify effect of 60Co- irradiation for high grain quality indica rice irradiation mutation breeding, the effect of different doses of 60Co- irradiation on the main agronomic traits of Yunnan aromatic and soft rice varieties were studied in this experiment. The variety of 'Diantun 502' was tested, and the rice seeds were treated with four different levels of 60Co- irradiation of 100 Gy,200 Gy,300 Gy, 380 Gy. The results showed that, in M1 population, 60Co- dose-dependent significant effect was found on of plant height, tiller number per plant, grain length, grain width,panicle length,1 000-grain weight and seed setting rate. Analysis of correlation showed that there was a highly significant negative correlation between 60Co- irradiation with 300 Gy of dose and grain length(R=-0.323**),seed setting rate(R=-0.309**).Variant coefficient analysis also showed that,in M1 population,the coefficient of variation of the plant height,tiller number per plant, grain length and grain width was higher,they were 21.05%,38.34%,3.15%,3.62%,respectively.These results suggest that mutagenesis using 60Co- had significant effects on rice, and the most appropriate dose was 300 Gy for rice variety 'Diantun 502'.