木薯细菌性枯萎病病原菌致病力差异及其胞外酶活性的研究

Study on Pathogenicity and Extracellular Enzyme Activity of Xanthomonas axonopodis pv.manihotis Vauterin

为寻找与致病性有关的生化因子,在含有酶基质的培养基上测定12株木薯细菌性枯萎病菌(Xanthomonas axonopodis pv.manihotis Vauterin,Kerters&Swings,简称X am)5种胞外酶的活性,并结合菌株接种后的病斑平均面积进行相关性分析。结果显示,供试菌株的胞外淀粉酶与病斑面积呈正相关,其酶活性与病斑面积的回归方程为:y=0.0426x+4.9522,r值为0.9789,菌株的胞外酯酶和纤维素酶活性与病斑面积相关性不明显,没有检测到菌株胞外蛋白酶和胞外果胶酶的活性。菌株胞外淀粉酶在致病过程中起着比较重要的作用。

To find biochemical factors related to pathogenicity,the activity of 5 extracellular enzymes about 12 Xanthomonas axonopodis pv.manihotis Vauterin was first determined in medium containing enzyme matrix,and correlation analysis with average lesion area after strains inoculated was conducted.The result showed that,the extracellular amylase of strains tested was positively correlated with the lesion area,and the regression equation between amylase activity and lesion area was： y=0.0426x＋4.9522,r=0.9789.The correlation between the activity of extracellular pectinase or cellulase and lesion area was not obvious,and the activity of extracellular protease and extracellular esterase was not detected.The extracellular amylase of strains played an important role in pathogenic process.