Abstract:

This study aims to enrich the germplasm resources of Cynanchum bungei Decne. by inducing mutations through radiation mutagenesis. Using seeds of the Cynanchum bungei Decne. cv. Binwu 1 as experimental material, radiation treatments were applied with ⁶⁰Co-γ at doses of 800, 600, 400, 200, and 0 Gy (CK). The optimal irradiation dose was screened by assessing plant phenotypic traits and the content of bioactive compounds in root tuber. Subsequent mutagenesis was conducted at this dose, followed by investigation and analysis of irradiated progenies. Results showed that at 400 Gy, seed germination and seedling emergence rates slightly decreased compared with the control but remained statistically comparable, with no significant change in plant height. However, this dose yielded the highest fresh weight of root tuber per plant and maximized the content of bioactive compounds,including flavonoids, polyphenols, and C21-steroidal glycosides. Thus, 400 Gy was identified as the optimal radiation dose. Using 400 Gy on Binwu 1, two new lines, Yanwu 1603 and Yanwu 1604, were developed through continuous multi-year selection. Compared with Binwu 1, these lines exhibited reduced plant height and fewer branches per plant, while stem and leaf color, flower color, and pest and disease incidence remained unchanged. They also demonstrated increased large root rate, enhanced fresh weight of root tuber per plant, and higher yield per 667 m² in multi-location trials and large-scale demonstration tests. Therefore, radiation mutagenesis technology effectively enriches Cynanchum bungei Decne. germplasm resources.

Key words: radiation mutagenesis, Cynanchum bungei Decne., screening, new germplasm resources