Effect of ~(60)Co γ-ray radiation on mutation of Chinese pear cultivar Dangshansuli and its detection by RAPD marker

To study the effect of irradiation on the shoot growth and mutation of pear and discuss the technology of the molecular marker-assisted mutagenic breeding,the dormant branch of Chinese pear cultivar Dangshansuli was treated with 60Co γ-ray irradiation and than grafted.The survival rate of treated bud and the length of shoot growth were investigated.The relationship between different treatment doses and the mutagenic rates detected in level of genomic DNA,which were extracted from the leaves by CTAB method,was also analyzed by RAPD marker.The results showed that the survival rates of bud treated with the dose of 30 Gy,40 Gy and 50 Gy were 0.7257,0.5427,0.1940,of which the length of shoot growth was 48.21,35.47 and 25.67 cm,respectively.Ten suitable random primers were screened out from 42 ones.Therefore,it was proposed that the survival rate of bud and the length of shoot growth were decreased as the irradiation dose increased.The degree of variation was increased as the irradiation dose increased.