烟草及向日葵上列当Orobanche cumana的发生及其生物防治

Occurrence and biocontrol of Orobanche cumana on tobacco and sunflower

近年,在河北省部分烟草和向日葵种植地发现大量寄生性杂草列当发生并造成严重为害。经鉴定为向日葵列当O robanche cumanaW allr.。向日葵、烟草、番茄和黄瓜等作物的根分泌物能够刺激向日葵列当O.cumana种子萌发,而油葵根的分泌物则不能刺激向日葵列当种子萌发。利用列当致病镰刀菌L2菌株进行田间生物防治,防治效果达到92.4%。L2菌株对小麦、玉米、棉花、烟草和向日葵等作物生长无影响,L2菌株粗毒素能够抑制列当种子萌发,并造成列当种子萌芽管损伤。

Broomrape, Orobanche cumana Wallr., caused a severe damage on tobacco and sunflower in Hebei province. Studies showed that the root secretions of sunflower, tobacco, tomato and cucumber could stimulate seed germination of O. cumana, but not of oil sunflower. Fusarium sp. strain L2, a pathogenic strain isolated from diseased broomrape, was used to control broomrape in tobacco field and showed a high efficacy of 92.4%. Strain L2 was safe to wheat, corn, cotton, tobacco and sunflower. The toxin produced in liquid culture by strain L2 could inhibit seed germination of O. cumana and injure the haustorium.