Isolation and identification of strawberry crown rot pathogen

Strawberry is a high-value crop for economy and nutrition. This study was conducted to identify of strawberry crown rot pathogen disease. Five fungal genera were isolated, purified and identified according to the phenotypic criteria studied: Pestalotiopsis spp., F. solani, F. oxysporum, Rhizoctonia solani, and Macrophomina phaseolina. Pestalotiopsis spp. fungus were the most common accounting for 42.3% of the total isolates. Moreover, F. oxysporum was isolated with a frequency of 23.7%, and F. solani with 14.8%. The pathogen isolated from crown root diseased strawberry plants was morphologically similar to the genus Neopestalotiopsis. Phylogenetic tree based on ITS sequences of rDNA of the fungal sample isolated in the present study (Pestalotiopsis microspora strain AUMC16335, arrowed) aligned with closely related strains accessed from the GenBank. This strain showed 99.81% identity and 100% coverage with several strains of the same species. A close relationship was also observed between the current strain sequences and some Pestalotiopsis haikouensis strains. Pestalotiopsis microspora strain (AUMC16336, arrowed) aligned with closely related strains accessed from the GenBank. This strain showed 99.81% identity and 100% coverage with several strains of the same species. Five strawberry varieties were evaluated for resistance to Pestalotiopsis. Both Sensation and Fortuna cultivars showed a significant increase in the disease incidence rate (DI), which they recorded at 93.33%. The Florida Beauty variety recorded an infection rate of 87.67%. The Winter Star and Festival varieties also recorded the lowest infection rate, with 80.00% and 73.33%.