Identification of a new species of Cercospora causing leaf spot disease in Capsicum assamicum in northeastern India

Abstract

Northeastern India is one of the most important biodiversity hotspots in the world. However, hot and humid climatic conditions of the region favor growth and development of foliar fungal phytopathogens such as cercosporoid fungi. The genus Cercospora is one of the largest genera of hyphomycetes. Species of Cercospora are known to cause leaf spot disease in several cultivated and non-cultivated plants leading to considerable losses. In this study, we describe a new species of Cercospora which was isolated from the leaves of Naga chilli (Capsicum assamicum Purkayastha & Singh) grown in northeastern India. Comparison of the detailed morphological characteristics along with the DNA sequences for four gene regions, namely actin, calmodulin, histone H3 and translation elongation factor-1α of this isolate, was made with those of some previously reported Cercospora species infecting Capsicum and other similar species of Cercospora from other hosts. The results suggested that our isolate represents an undescribed taxon and warrants the establishment of a new species, Cercospora tezpurensis sp. nov.