⁶⁰Co-γ mutagenic effect of irradiation on Chinese rose variety Dragonfly and analysis of mutant ISSR

In order to cultivate a new type of blue rose with unique flower color and excellent cultivation quality, the radiation of 60Co-γ was used irradiating the Chinese rose variety Dragonfly, and three doses of 40, 50 and 60 Gy were set. The study found that the mutagenesis caused by the irradiation of Chinese rose Dragonfly is reflected in： firstly, the irradiation treatment has a certain damage and growth inhibition effect on the plants, and the growth points or old leaf tips of the plants treated with high-dose irradiation die during the growth process, the new leaves grow slowly, the new buds do not germinate again, and the plant roots wilt and rot and blacken. Secondly, the mutant has great differences with control check（CK） in flower shape, flower color, flowering period, petal and so on, which is specifically reflected in the increase or decrease of the maximum flower diameter, the change of flower color, the shortening of flowering period, the change of petal number and petal morphological characteristics. The genetic diversity and genetic relationship of irradiated the Dragonfly were analyzed by inter-simple sequence repeat （ISSR） molecular marker and unweighted pair-group method with airthmetic（UPGMA） cluster analysis. It was found that the genetic material of the Dragonfly had different degrees of mutation after mutational irradiations. The results laid a foundation for cultivating high-quality blue rose varieties.