EFFECTS OF ~(60)Coγ-RAYS IRRADIATION ON Iris hollandica

The bulblets of Iris hollandica'Zhan chi' were irradiated by ~(60)Coγ-rays in this study,using group indexes of damages to the growth and development for statistical investigation,such as emergence rate of seedlings,survival rate and plant height,morphological changes and so on.The results showed that the damaging effects of irradiation on plant were gradually strengthened as the doses increased within the range from 3Gy to 10Gy.Moreover,the sensitivity to irradiation of the small bulblets was stronger than those of big ones.Besides,the irradiation still had great effects on the blossom of regenerated plants from M_2 generation,and those under 7Gy presented highest variation rate and survival rate,with excellent single mutant obtained.According to these results,the suitable irradiation dose to the young bulblets of Iris hollandica 'Zhan chi' could be determined within the range from 7Gy to 8Gy.