杂交狼尾草重离子辐射诱变体系及耐寒种质筛选OA

Hybrid Pennisetum(Pennisetum glaucum×P.purpureum)is an important high-yield and high-quality forage grass;however,its poor cold tolerance restricts its cultivation and utilization in northern and high-latitude regions.Heavy-ion irradiation is a relatively new mutagenic approach and has been rarely applied in forage breed-ing.In this study,seeds of the hybrid Pennisetum cultivar'Bangde No.1'were treated with heavy-ion irradiation at doses of 50,100,150,200,and 300 Gy.Seedling growth traits and physiological responses under low-tempera-ture stress were systematically evaluated to investigate the mutagenic effects of heavy-ion irradiation,establish a heavy-ion mutagenesis system for hybrid Pennisetum seeds,and develop novel cold-tolerant germplasm.The results showed that heavy-ion irradiation exerted a clear dose-dependent effect on hybrid Pennisetum.Among the treatments,100 Gy not only maintained a high seedling establishment rate but also significantly increased soluble sugar content and the activities of superoxide dismutase(SOD)and peroxidase(POD),reduced membrane damage,and resulted in the lowest semi-lethal temperature(LT50)of plant mutants,indicating the strongest cold tolerance and relatively high mutagenic efficiency.Based on a comprehensive evaluation integrating laboratory and field assessments,principal component analysis,membership function analysis,field survival rate,and field over-wintering rate,three potential cold-tolerant mutants were identified from the M₁ generation.