Effects of Sclerotinia sclerotiorum toxin on sunflower physiology and biochemistry

To better understand the physiology and biochemistry resistance mechanism of sunflower on Sclerotinia sclerotiorum toxin,changes of β- 1,3- glucanase and MDA,soluble sugar,free proline,lignin and cell membrane permeability of sunflower leaves were investigated. 2 sunflower varieties Fengkuiza 1( FKZ1) and 7101 with different resistance were treated with crude toxin from S. sclerotiorum. The above indexes( except MDA) were significantly changed after toxin treatment especially in resistant cultivar. Cell membrane permeability was significantly damaged by toxin. Resistant FKZ1 had higher ability of damage- resistance than 7101( susceptible). Results showed that sunflower resistance to S. sclerotiorum had positive correlation with chitinase,β- 1,3- glucanase activity,soluble sugar,free proline,lignin content and cell membrane permeability. MDA was negatively correlated with the resistance.