Abstract:

The aim was to clarify the pathogenic mechanism of Bipolaris sorghicola in sorghum. The seeds of L407B and Tx622B were treated by different concentrations of Bipolaris sorghicola crude toxins. And the radical growth inhibition rate as well as the electrical conductivity and malondialdehyde (MDA) content were detected to study the effect of crude toxins of Bipolaris sorghicola on the growth and membrane permeability of different varieties of sorghum radicle. The results showed that crude toxin could obviously inhibit growth of sorghum radical. The electrical conductivity and MDA content were all higher in the group which was treated by Bipolaris sorghicola crude toxins with same concentration two days before than in control group. The electrical conductivity and MDA content were also higher in the group which was treated by Bipolaris sorghicola crude toxins with different concentration on the same treated time. It demonstrated that Bipolaris sorghicola crude toxins could reduce membrane permeability of sorghum radicle and there was significant difference among the different varieties of sorghum.