Abstract

In Côte d'Ivoire, kola tree cultivation is a real source of income for thousands of people. However, it is threatened by witches' broom disease, which causes significant yield losses. The aim of this study was to characterize the fungal microflora associated with witches' broom disease of the kola tree. To this end, symptomatic branches from six major agro-ecological zones were sampled. Associated fungi were isolated on agar medium and analyzed on molecular basis. Fungi belonging to four genera namely Lasiodiplodia, Pestalotiopsis, Fusarium and Trichoderma were isolated. The Lasiodiplodia genus was the most frequently associated with the diseased plants, with 93% occurrence. Four species of Lasiodiplodia identified in this study included L. theobromae with 179 isolates, L. brasiliensis, L. iranensis and L. jatrophicola. For the genus Pestalotiopsis, 5 fungal species namely P. microspora, P. saprophytica, P. theae, P. clavispora and P. formicarum were identified. Two species of Fusarium (F. fujikuroi and F. oxysporum) and one species of Trichoderma namely T. harzianum were also identified. Sequences of the fungal species were deposited in GenBank with accession numbers ranging from PP824668 to PP824719. DNAs from species of all the 5 fungal genera had 98–100% identity compared with those existing in GenBank. These results open up new avenues of research into the involvement of these fungal genera in symptom expression.