Identification of Alternaria species using PCR with species-specific primers

Abstract

This study aimed to develop a rapid and efficient technique for the identification of Alternaria species isolated from field-infected broccoli plants exhibiting black spot symptoms. To achieve this, we focused on nucleotide sequences of the Alt a 1 region and designed species-specific primers capable of detecting four Alternaria species: A. japonica, A. brassicicola, A. brassicae, and A. alternata.

The specificity of the primer sets was evaluated using DNA extracted from standard strains of the four species. The results revealed that each species could be specifically detected. Furthermore, 102 Alternaria isolates obtained from broccoli and cabbage in Aichi Prefecture were identified using these primer sets. Genetic diagnostics enabled more accurate identification than morphological observations.