烟草米根霉致病力及不同渗透压和pH环境下的代谢表型特征分析

为明确温度、叶位和创伤对烟叶霉烂病病原菌米根霉致病力的影响,及不同渗透压和pH环境下病原菌的代谢表型特征,采用穿刺法接种烟草离体叶片,测定了米根霉在不同温度及不同叶位烟叶中的致病力,并在Biolog PM 9和PM 10代谢板中96种渗透压和96种pH环境下培养米根霉,分析了其代谢表型特征.结果表明,米根霉可致病的温度...

Pathogenicity to tobacco and metabolic phenotypic characteristics of Rhizopus oryzae under different osmotic pressures and pHs

In order to investigate the effects of temperature, stalk position and wound on the pathogenicity of Rhizopus oryzae which is the pathogenic bacteria of tobacco pole rot and its phenotypic characteristics under different osmotic pressures and pH conditions, the pathogenicity to tobacco leaves at different stalk positions under different temperatures were studied through puncturing inoculation. The metabolic phenotypic characteristics of R. oryzae were analyzed on Biolog PM 9 and PM 10 microplates under 96 osmotic pressures and 96 pH conditions. The results showed that R. oryzae was pathogenic at temperatures ranged from 20 to 38 ℃, while it was nonpathogenic at temperatures higher than 45 ℃. R. oryzae could infect both the petioles and laminae, and wound was beneficial to the infection. The pathogenicity of R. oryzae to leaves at different stalk positions was different, it was stronger for the lower mature leaves and weaker for the upper tender leaves. R. oryzae had various adaptabilities to different osmotic pressures and pHs. It could metabolize in osmotic environments of 1%-10% (mass fraction) sodium chloride, 3%-6% (mass fraction) potassium chloride, 2%-5% (mass fraction) sodium sulfate, 5%-20% (mass fraction) ethylene glycol, 1%-2% (mass fraction) sodium formate, 2%-3% (mass fraction) urea, 1%-12% (mass fraction) sodium lactate, 20-200 mmol·L-1 (volume fraction) sodium phosphate (pH 7.0), 10-100 mmol·L-1 (volume fraction) ammonium sulfate (pH 8.0) and 10-100 mmol·L-1 (volume fraction) sodium nitrate, but could not metabolize in osmotic environments of 3%-6% (mass fraction) sodium formate, 4%-7% (mass fraction) urea and 20-200 mmol·L-1(volume fraction) sodium benzoate (pH 5.2). R. oryzae was adaptive to pH between 3.5 to 10.0 with the optimal pH around 7.0. It had a strong decarboxylase activity and a weak deaminase activity.