Identification and biological characteristics of the anthracnose pathogen of postharvest banana fruit | 香蕉采后果实炭疽病菌的鉴定及其生物学特性

Chinese. 摘　　要：采用组织分离法从表现炭疽病症状的采后香蕉果实中分离到4个炭疽病菌菌株。通过观察这4个菌株的菌丝生长速率、孢子萌发、附着胞形成和致病性,发现4个菌株的菌丝生长速率无显著差异,但菌株X4的孢子萌发率、附着胞形成率和致病力明显高于其他3个菌株。采用传统的形态学鉴定方法,并结合ITS序列分析技术,鉴定菌株X4为芭蕉炭疽菌（Colletotrichum musae）。生物学特性的观察结果表明：菌株X4菌丝生长温度范围是10-35℃,最适生长温度是28℃,其分生孢子萌发和附着胞形成的适宜温度范围是25-30℃,分生孢子在28℃萌发率最高;光照对菌丝生长速率、分生孢子和附着胞形成无显著影响;适宜菌丝生长和孢子萌发的pH值为5.0-8.0,最适pH值为6.0;菌株的菌丝和分生孢子的致死温度均为50℃/10 min。

English. Four isolates of the anthracnose pathogen were isolated from postharvest banana fruits displaying anthracnose symptoms by using tissue isolation technique.The differences in mycelial growth rate,conidial germination,appressorium formation and pathogenicity of the four isolates were compared under the same conditions.The results showed that there was no significant difference in the mycelial growth rate,but the percentages of conidial germination and appressorium formation,and the pathogenicity of isolate X4 were significantly higher than those of the other 3 isolates.The isolate X4 was identified as Colletotrichum musae based on the classical morphological taxonomy combined with the technique of ITS sequence analysis.Meanwhile,the effects of temperature,illumination and pH value on the mycelial growth,conidial germination and appressorium formation of isolate X4 were investigated.The results indicated that the temperatures for the mycelial growth were ranged from 10-35 ℃,with an optimum of 28 ℃ and the suitable temperatures for conidial germination and appressorium formation were from 25-30 ℃,with an optimum of 28 ℃.Illumination had no significant effect on the linear growth of mycelium,conidial germination and appressorium formation.The pH values for the mycelial growth and conidial germination were 5.0-8.0,with an optimum of pH 6.0.The lethal temperature of conidia and mycelia explored further were 50 ℃/10 min.