探讨不同浓度核黄素对棉花枯萎菌生长的影响，找出影响枯萎菌生长的最佳浓度。采用PDA培养基中加入不同浓度的核黄素，观察棉花枯萎病菌菌丝、菌落及孢子的生长变化。结果表明：菌丝生长、菌落形态及孢子形态均有不同程度变化，当核黄素浓度大于0.5 mg/mL的核黄素能明显抑制菌丝生长，而且抑制效果随着处理浓度的增大而增强；当核黄素浓度大于1 mg/mL的核黄素处理可诱导初生菌丝发生肿胀，分枝增多且菌体分隔增加及体细胞发生畸形等形态变化；当核黄素浓度大于1 mg/mL时，孢子发生畸形。利用核黄素可以抑制棉花枯萎病病菌的生长，对开拓植物病害新的防治方法有一定的参考价值。

To investigate the potentia1 effect of riboflavin on the growth of cotton Fusarium wilt for looking for optimal concentration. By means of PDA medium consisting of 9 riboflavin concentration gradients, the result is that radial growth and sporogensis of cotton Fusarium wilt was affected. In the test, PDA 2% sterile NaOH solution was designed as controls. The results showed when the riboflavin concentration was higher than 0.5 mg/mL, riboflavin can inhibit the growth of mycelia, and the inhibiting activity of riboflavin was increased when its concentration increased. When the riboflavin concentration is more than 1 mg/mL, the riboflavin treatment could induce the primary hyphae swelling, branch and thallus separation increasing and somatic cell defects and other morphological changes. When the riboflavin concentration was higher than 1 mg/ml, the microsporogenesis emerge deformity. Riboflavin was effective in inhibiting radial growth and sporogensis of cotton Fusarium wilt.