Studies on the biological characteristics of Sclerotium rolfsii strain SC64 causing southern blight on Solidago canadensis L. | 加拿大一枝黄花白绢病（Sclerotium rolfsii）菌株SC64的生物学特性研究

中国人. 摘　　要：在实验室条件下初步研究了加拿大一枝黄花白绢病菌株SC64的形态特征、致病性和生物学特性。结果表明：引起加拿大一枝黄花白绢病的病原物是罗氏白绢小菌核菌（Sclerotium rolfsii Sacc.）;病菌最适生长培养基为Richard固体培养基和PDA,菌丝生长温度为15～40℃,最适30℃;在偏酸性条件下生长较好,生长适宜pH值为4.0～6.0,最适为5.0;在所测试的碳源中,对蔗糖的利用最好,对乳糖和半乳糖利用最差;氮源测试结果显示对蛋白胨和硝酸钾利用最好,对尿素的利用最差。菌核萌发温度为15～40℃,最适为30℃;菌核在含水量≥50%的麸皮基质上萌发较好;适宜萌发的pH值范围为3.0～9.0。菌丝的致死温度为45℃10 min,菌核的抑制萌发温度为50℃10 min。

英语. A southern blight of Canadian goldernrod（Solidago canadensis）was found to be an important disease.The pathogen was identified as Sclerotium rolfsii Sacc.based on morphological characteristics.Factors influencing mycelial growth and sclerotia germination of strain SC64 of Sclerotium rolfsii were studied.The results indicated that the most optimum media for the mycelial growth were modified Richard and potato dextrose agar（PDA）,the range of temperature for the mycelium growth was 15-40 ℃,with the optimum at 30 ℃,and the range of pH was 4.0-6.0,with the optimal pH of 5.0.Through carbon sources testing on amended Czapek,sucrose was found to support growth significantly faster than other sources,while lactose was found to provide the slowest growth.Among the 13 nitrogen sources tested,peptone and potassium nitrate gave the best growth whereas urea gave the least growth.The range of temperature for sclerotia germination was 15-40 ℃,with the optimum at 30 ℃.Sclerotia germination reached 100% when incubated on bran substrate with ≥50% moisture.The range of pH for sclerotia germination was 2-10,with 100% germination at 3-9.Hyphal and sclerotia viability was completely lost when hyphal agar plugs and sclerotia were incubated at 45 ℃ 10 minutes and 50 ℃ 10 minutes,respectively.