Avicennia marina endophytic fungi shows antagonism against tomato pathogenic fungi

Mangrove endophytes have been widely studied for several years and Avicennia marina endophytic fungi is known for its remarkable activity against many plant pathogens. Tomato is an important food crop in Saudi Arabia but it is susceptible to fungal diseases.The control of these phytopathogens through fungicides and pesticides is temporary. Thus, this study is aimed to isolate mangrove plant i.e. Avicennia marina endophytic fungal antagonists, characterize their phylogenetic positions and determine their antagonistic activities against tomato fungal pathogens. This study isintended to find a suitable alternative method to control or limit the spread of tomato diseases by using endogenous fungi of mangroves. Ninety fungal pathogens were isolated from three tomato farms in different regions of Riyadh city, Saudi Arabia. In addition, 40 endophytic mangrove i.e. Avicennia marina fungi were isolated from the eastern and western mangrove stands of the Kingdom of Saudi Arabia using potato dextrose agar, Czapek dox broth and malt extract broth media. These fungal strains were phylogenetically classified into at least sixteen genera based on 18S rRNA gene sequencing analysis. The antagonistic strains were screened via a Dual Culture Plate Assay and filter paper disc method. This study showed that endophytic fungal isolates have an antagonistic effect on most tomato pathogenic fungi. Cladosporium sphaerospermum had the highest inhibition while Trichoderma asperellum showed least antagonism against Avicennia marina endophytic fungi. This study proved that endophytic fungi present in Avicennia marina can control many tomato pathogens and their respective diseases. This work also cleared many aspects regarding the use of Avicennia marina endophytic fungal strains as potential biocontrol agents. Also, the diversity observed by these endophytic fungal strains from different areas of Saudi Arabia opened many doors for future research in the control of fungal pathogens.