紫外线对非致病尖孢镰刀菌的诱变作用

Mutagenic Effect of UV Light on Nonpathogenic Fusarium oxysporum

以紫外线（λ＝２３０～２６５ｎｍ）照射非致病尖孢镰刀菌３１６菌系，随着照射时间的增加，分生孢子的存活数逐渐减少，照射时间与存活菌株对农抗１２０和速克灵的变异频率间没有一定的相关性。对农抗１２０抗性增加的菌株仍保持３１６定殖西瓜幼苗导管的能力，对瓜苗的促生作用以及非致病性。在药板上用紫外线重复照射存活菌株后，获得的菌株对两种农药的变异频率均有提高，对农抗１２０的抗性有所下降，对速克灵的抗性显著提高。

The strain 316 of nonpathogenic Fusarium oxysporum were irradiated on PDA plate with UV light（230～265 nm）at 32 cm distance. The survival number of conidia decreased as time of irradiation increased．There was no correlativity between the lengths of treated time with UV light and the mutation frequency of survival strain to Agricultural Antibiotic 120（AA 120）and Sumilex. Nonpathogenic AA 120－resistant mutants still remained the colonization in the hypocotylar of watermelon seedlings and promoted the growth of watermelon plant in the greenhouse experiment．The fungicides-re-sistant mutants were repeatedly irradiated on PDA containing AA 120 or sumilex with UV light，the mutation freqtiency to the fungicides were increased．There was a slight decrease in the resistance of mutants to AA 120，while a significant increase in the resistance to sumilex.