Poisoning Effects of Crude Toxin by Sclerotinia Sclerotiorum onSeed and Seedling of Sunflower

Poisoning effects of crude toxin by Sclerotinia sclerotiorum on seed and seedling of sunflower were studied.The results showed that crude toxin could inhibit seed germination,plumular axis growth and seedling growth and also induce lesions of sunflower leaves in vitro.Crude toxin produced the same symptoms with culture filtrate of Sclerotinia sclerotiorum.After being treated with crude toxin in sunflower leaves,the permeability of cell membrane was examined by the electrical conductivity method.The results showed that the permeability of cell membrane was increasing gradually after being treated with crude toxin.The function of cell membrane was damaged in sunflower leaves.