胡麻黑斑病病原菌生物学特性研究OA

To elucidate the biological characteristics and pathogenic mechanisms of Alternaria alter-nata,the causative agent of linseed black spot disease,a investigation was conducted to evaluate the effects of temperature,pH,carbon sources,and nitrogen sources on mycelial growth and conidial germi-nation using growth rate assays and concave slide germination tests.Enzymatic activity assays were carried to determine the types and concentrations of cell wall-degrading enzymes.The results demonstrated that the optimal condition for both mycelial growth and conidial germination was 25℃,with pH 7.The lethal temperature for mycelia was 56℃.Significant variations in mycelial growth and spore germination were observed under different carbon and nitrogen sources:maltose and soluble starch served as theoptimal carbon sources for mycelial growth,while potassium nitrate and sodium nitrate were the preferred nitrogen sources.For conidial germination,glucose and fructose were identified as the optimal carbon sources,with ammonium sulfate and ammonium nitrate as the optimal nitrogen sources.The pathogen exhibited production of pectinase,protease,and cellulase,with the highest activity observed for pectin methylga-lacturonase(773.23 ng/L).This study lays a theoretical foundation for disease-resistant breeding and field management strategies against linseed black spot disease.