Species identification and pathogenicity study of Colletotrichum isolates isolated from red-pepper and Chinese matrimony vine

This study reports the identification of species of Colletotrichum strains originating from red-pepper and Chinese matrimony vine in Cheongyang. Ninteen isolates of red-pepper and 26 Coiletotrichum isolates of Chinese matrimony vine were compared with 5 isolates of strawberry representing C. gloeosporioides, by use of morphological and cultural criteria. Twenty three isolates among 26 isolates from Chinese matrimony vine were identified as C. acutatum, characterized by the low growth rates and the low sensitivity to carbendazim and diethofencarb. Also, all the isolates of red-pepper were identified as C. acutatum, showing the same characteristics as those of Chinese matrimony vine. Three and five isolates from Chinese matrimony vine and strawberry, respectively, were identified as C. gloeosporioides, characterized by the high growth rates and the high seneitivity to carbendazim and diethofencarb. There were differences in colony color and pathogenicity between Chinese matrimony vine isolates and red-pepper isolates of C. autatum. The isolates of C. acutatum from Chinese matrimony vine producing orange colored colonies with abundant spores showed the strong pathogenicity to Chinese matrimony vine, although they could not infect fruits of red-pepper by the wound inoculation. However, red-pepper isolates of C. acutatum producing gray colonies showed the strong pathogenicity to Chinese matrimony vine as well as red-pepper. Furthermore, comparative study on PCR amplification of ITS regions of rDNA was carried out using a number of Colletotrichum isolates. A species-specific primer could be used for the identification of C. acutatum from red-pepper and Chinese matrimony vine.