EFFECT OF ENDOMYCORRHIZAE ON WILT DISEASE OF STRAWBERRY CAUSED BY Verticillium dahliae IN MOROCCO

Strawberry is considered as a specific crop of the Loukkos area in Morocco. Its production is mainly intended for export. It is a Rosacea affected by a wide range of fungal diseases. The present work consists of the study of the effect of an endomycorrhizal inoculum on the development of strawberry wilt induced by Verticillium dahliae. Strawberry plants which are mycorrhized and inoculated with V. dahliae showed fewer symptoms of wilt than those inoculated only with the pathogen. The severity index of the disease reached 83% in plants inoculated only by V. dahliae and 27% in those inoculated by the pathogen and transplanted on a substrate supplied by an endomycorrhizal inoculum. The mean of mycorrhization intensity, vesicle and arbuscular contents in inoculated and mycorrhized plants were respectively 74%, 81% and 72% compared to 89%, 92% and 77% respectively for control plants. Mycorrhization status was dependent on treatment with V. dahlia; however, pathogen inoculation did not suppress the effect of mycorrhizas. Spore extraction has identified different types of morphotypes and the Glomus genus dominates. This study suggests a protective effect of mycorrhizal fungi on strawberry plants against V. dahliae.