Cytological effect of 60Coγ ray irradiation on Buchloe dactyloides dry seeds.

The irradiation of 60Coγ ray can induce different types of variation and irradiation breeding has been applied to turfgrass variety improvement as one effective method.The cytological effects of 5 kinds of dosages of 60Coγ ray on Buchloe dactyloides(Nutt) Engelm.seeds were evaluated and the results show that the γ ray irradiation inhibited the mitoses of root tip cells.And the mitotic index of root tip cells decreased along with the increased dosage.Furthermore,the γ ray irradiation induced the chromosomal and nuclear aberration,such as bridge,chromosome fragment,chromosome conglutination,chromosome dissociation,draggling chromosome,single micronucleus,double micronucleus,multi-micronucleus,and small micronucleus in root tip cells of B.dactyloides.The higher the γ-rays irradiation dosage,the higher the rate of aberration from the irradiation dosage of 0 to 2000 Gy;all the aberration rates reached to the maximum at 2000 Gy.