玉露香梨采后病原菌分离鉴定及其生物学特性研究

Isolation, Identification and Biological Characteristics of Postharvest Pathogens of Yuluxiang Pear

真菌侵染造成的腐烂是影响玉露香梨采后贮藏的主要因素。为明确导致玉露香梨采后腐烂的病原菌种类及其生物学特性,对其采后病原菌进行分离纯化,结合形态学和分子生物学特征确定其种类,并明确在不同温度、pH、碳源和氮源条件下病原菌的生长情况。结果表明:Alternaria alternata、Aspergillus、Penicillium polonicum和Fusarium是导致玉露香梨采后腐烂的主要病原菌。Alternaria alternata和Fusarium的最适生长温度为25~30℃,而Aspergillus和Penicillium polonicum最适生长温度分别为25~35℃和20~25℃;Alternaria alternata和Aspergillus的最适生长pH分别为6~10和7,而Penicillium polonicum和Fusarium最适生长pH则均为5~7;Alternaria alternata和Penicillium polonicum的最适生长碳源分别为葡萄糖和甘露醇,Aspergillus和Fusarium最适生长碳源为麦芽糖;Alternaria alternata、Aspergillus和Fusarium最适生长氮源为牛肉膏,而Penicillium polonicum最适生长氮源为蛋白胨。

The rot caused by fungal infection is the main factor affecting the postharvest storage of Yuluxiang pear. In order to clarify the species and biological characteristics of pathogenic bacteria that cause postharvest rot of Yuluxiang pear, the postharvest pathogenic bacteria were isolated and purified, combining morphological and molecular biological characteristics to determine its species, and to clarify the growth of pathogenic bacteria under different temperature, pH,carbon and nitrogen source conditions. The results showed that: Alternaria alternata, Aspergillus, Penicillium polonicum and Fusarium were the main pathogens causing postharvest rot of Yuluxiang pear. The optimum growth temperature of Alternaria alternata and Fusarium was 25~30 ℃, while the optimum growth temperature of Aspergillus and Penicillium polonicum were 25~35 ℃ and 20~25 ℃, respectively. The optimum growth pH of Alternaria alternata and Aspergillus were 6~10 and 7, respectively, while the optimum growth pH of Penicillium polonicum and Fusarium were both 5~7. The optimum growth carbon sources of Alternaria alternata and Penicillium polonicum are glucose and mannitol, respectively,the optimum growth carbon source of Aspergillus and Fusarium was maltose. The optimum growth nitrogen source of Alternaria alternata, Aspergillus and Fusarium was beef extract, and the optimum growth nitrogen source of Penicillium polonicum was peptone.