Characterisation of Mycosphaerella species associated with pink spot on guava in South Africa

Abstract

Pink spot symptoms on guava fruit in the Lowveld region were in the past attributed to Colletotrichum gloeosporioides, but recently Mycosphaerella species were suggested to be part of a disease complex, including pink spot symptoms. During routine surveys of guava diseases in the Lowveld area of the Mpumalanga Province in South Africa, Mycosphaerella species were consistently isolated from guava fruit. Colletotrichum gloeosporioides was also retrieved, especially from older, bigger lesions. The Mycosphaerella isolates were compared based on their growth characteristics in culture and on DNA sequences of the internal transcribed spacer region, large subunit of the ribosomal DNA as well as the β-tubulin and translation elongation factor 1α gene regions. The phylogenetic analyses indicate that the isolates from the present study represent at least three species not previously reported on guavas. This report is therefore the first report of Mycosphaerella species associated with Psidium guajava in South Africa.