Evaluation of resistance to Colletotrichum trifolii in seedlings of 40 alfalfa cultivars

Colletotrichum trifolii is an important pathogen that causes anthracnose in alfalfa. In severe cases, it can cause devastating damage to alfalfa crops. A spore suspension spray inoculation method was used to evaluate seedling resistance to C. trifolii in 40 alfalfa cultivars, using incidence and disease index as indicators. Among the tested cultivars, Magnum 2, Vinal, and Algonquin showed high resistance, and WL363HQ, Magnum 7, Ladinuo, 4030, 4010, Rembler, and Liangmu, showed moderate resistance. Fifteen cultivars, including Xinmu No.4, Gannong No.4 and Xunlu showed moderate susceptibility, and 15 cultivars, including Xinjiang Daye, Gannong No.6, and Gannong No.9 showed high susceptibility. Twenty-five percent of tested cultivars displayed resistance. Seventy five percent of cultivars were susceptible. There was a significant difference in resistance between highly resistant and highly susceptible cultivars (P < 0.05).