西瓜枯萎病菌致病力与镰刀菌酸和β-1,4葡萄糖苷酶活性的关系研究

Study on the Relationship between the Fusaric Acid, β Glucoseidase Activity and the Pathogenicity of Fusarium oxysporum f.sp. niveum on Watermelon

镰刀菌酸是枯萎病菌产生的一种非寄主特异性致病毒素。β 葡萄糖苷酶在枯萎病病程中起着降解细胞壁纤维素破坏植物细胞组织的作用。为了探索西瓜枯萎病菌的镰刀菌酸产量和β 1,4 葡萄糖苷酶活性与致病力的关系 ,本试验测定了 2 8个采自新疆的菌株 ,发现其镰刀菌酸的产量极不稳定 ,且与致病力强弱无关 ,而 β 1。

The production of fusaric acid (5 n butyl picolinic acid) and glucosidase activity in 28 isolates of Fusarium oxysporum f.sp. niveum collected in Xinjiang and their pathogenicity against watermelon were tested. A positive correlation(r=0.836) was found between the β glucosidase activity of F. oxysporum f.sp. niveum cultured in Armstrong's medium and the pathogenicity as expressed in the wilt rate of watermelon seedlings. There was no clear relationship between the production of fusaric acid and the physiological races and the virulence of this fungus. It was suggested that pathogenesis of fusarium wilt depended not only on the pathotoxins it produced but also on its cellulolytic enzyme activities.