Identification of fungal pathogens occurring in eucalypt and pine plantations in Zambia by comparing DNA sequences

Abstract

Commercial forestry plantations in Zambia were initiated during the 1960s. Since then, very little attention has been given to diseases that impact negatively on the production of these plantations. Recent field surveys have highlighted the occurrence and impact of several diseases. This study was undertaken to determine, to species level, the identity of fungal pathogens associated with diseases of eucalypt and pine plantations in the country. Fungal morphology and DNA sequence data of the internal transcribed spacer (ITS) and β-tubulin gene regions were used to characterize isolates. Eleven fungal species were identified of which Teratospheria zuluensis, causing Coniothyrium canker, and Lasiodiplodia theobromae, causing stem canker and die-back on Eucalyptus spp., were the most serious and prevalent. A serious post-emergence damping-off disease of Pinus oocarpa and Pinus kesiya seedlings in nurseries yielded Calonectria pauciramosum. This study, which provides the first detailed species level identification of plantation tree pathogens in Zambia, provides a foundation for future work to develop management strategies aimed at reducing the impact of plantation diseases in the country.