Cytological effects of ~(60)Coγ-rays irradiation on seeds of Medicago sative L.

Seeds of three genotypes Medicago sative.L were irradiated by 0Gy,1000Gy,1500Gy,2000Gy 60Coγ-rays,then we compare irradiated states of two different conditions,one is the same dosage of different genotype,the other is the same genotype of different dosage,and the genetics effects on root tip cell in Medicago sative L were studied.The results showed that the irradiation of γ-rays inhibited mitoses and produced various aberrations,such as single micronucleus,double micronucleus,multi-micronucleus,small micronucleus,chromosome fragment,chromosome conglutination,single bridge,double bridge,multi-bridge,dissociative chromosome,lagging bridge in root tip cells of Medicago sative L.Under the same irradiation dosage,sensitivity of Longmu803 genotype is most.The larger the γ-rays irradiation dosages,the higher the rate of aberration in 0 to 2000Gy,at 2000Gy irradiation dosage,all the aberration rates reach the top,resulting in the relative higher biological effects of γ-rays irradiation of high dosage.