Botryosphaeriaceae associated with Pterocarpus angolensis(kiaat) in South Africa

There have been several recent reports of Pterocarpus angolensis(kiaat) trees dying in South Africa, Zambia and Zimbabwe, where this tree is used in traditional medicine and is a valuable source of timber for woodcarving and furniture. A survey of material from diseased P. angolensistrees in South Africa yielded isolates of the Botryosphaeriaceae, an important fungal family known to cause a number of tree diseases. The aim of this study was to identify these Botryosphaeriaceae and to determine their pathogenicity to P. angolensiswith branch inoculations. Seven species of the Botryosphaeriaceae were identified based on a combination of morphological characteristics and sequences from the ITS and EF-1α gene regions. Four of these represent undescribed taxa for which the names Pseudofusicoccum violaceum, P. olivaceum, Diplodia alatafructaand Fusicoccum atrovirensare provided. The remaining three species collected include Lasiodiplodia theobromae, L. pseudotheobromaeand L. crassispora. Inoculation trials on tree branches showed that L. pseudotheobromaeand one isolate of D. alatafructadiffered significantly from control inoculations. The high levels of virulence and common occurrence of L. pseudotheobromaesuggest that this species could play a role in tree dieback and death.