Simple sequence repeat markers reflect the biological phenotype differentiation and genetic diversity of Colletotrichum gloeosporioides strains from Capsicum annuum L. in China

Pepper anthracnose, caused by fungi of the Colletotrichum complex, is one of the most important diseases in pepper production. Recent studies have revealed the rich genetic diversity of different Colletotrichum species originating from Capsicum annuum L. However, for Colletotrichum gloeosporioides, the dominant species from Capsicum annuum L., the relationships between the genetic diversity and biological phenotype differentiation remain unclear. Here, we developed a highly specific simple sequence repeat (SSR)-PCR system, which showed rich intraspecific genetic diversity in the tested Colletotrichum gloeosporioides strains. Moreover, we characterized the biological phenotypes of significantly differentiated strains, including their morphological and sporulation traits, and their pathogenicity. These results help us to elucidate the relationship between genetic diversity and biological phenotype differentiation in Colletotrichum gloeosporioides strains from Capsicum annuum L. Our findings will be useful for the prevention and control of pepper anthracnose and for pepper resistance breeding.