Biological characteristics of a new pathogen in Eucommiaulmoides black spot

ABSTRACT: In this study,the causative pathogen was isolated from Eucommia ulmoides,verified using Koch’s postulates, identified by morphology and molecular biology, and assessed the biological characteristics. The effects of agar media, pH, temperature, light, carbon sources, and nitrogen sources on hyphal growth of Pestalotiopsistrachicarpicola were under investigation, and the influences of time, liquid matrix, light, temperature on conidial germination were studied. The results showed that P. trachicarpicola was a new pathogen causing black spot disease of E. ulmoides, and the mycelial growth of P.trachicarpicola was the best in the potato dextrose agar (PDA) medium, pH 7.0, the temperature was 20~25 °C, light, and glucose and beef extract were the best for carbon and nitrogen, respectively. The germination rate of the conidia increased from the time, darkness, and a proper supply of sugar. The lethal temperatures of the hyphae and conidia were 52 °C and 72 °C, respectively.We can conclude that appropriate environmental conditions are more conducive to the growth of the pathogen and the germination of spores, which leads to the occurrence of disease. This study constituted the first report on the new causative pathogen in E. ulmoides black spot and the biological characteristics. Theis study provided a theoretical basis to prevent the occurrence of this disease.