Inhibitory activity against all five fungal phytopathogens; Colletotrichum capsici DOAC 1511, C. gloeosporioides DOAC 0782, Fusarium oxysporum DOAC 1808, F. subglutinans DOAC 0761 and Pestalotiopsis sp. DOAC 1098, was found in a marine fungus Astrosphaeriella cf. striatispora BUCS 055-1. Extracts from Astrosphaeriella cf. striatispora strongly inhibited growth of all tested phytopathogens and inhibited spore germination of two tested Fusarium species. Under light and scanning electron microscope, its extract affected hyphae of C. gloeosporioides DOAC 0782 with various types of abnormality, mostly with swelling at hyphal tip, loss of protoplasm and lysis of hyphal tip. The results indicate that Astrosphaeriella cf. striatispora is a potential source for bioactive metabolites against fungal phytopathogens
