Isolation of endophytic fungi from leaves of neem (Azadirachta indica A. Juss.)

Occurrence of asymptomatic fungal endophytes in green and senescent leaves of neem is reported. Only five endophytes were isolated from the leaves. Of these, four were sterile forms and one was Fusarium avenaceum.. The frequency of occurrence of endophytes was significantly higher in the basal leaflets than in the apical or middle leaflets and in the main vein of the leaflet than in the lamina tissue. The frequency of colonization of green leaves by endophytes increased during the rainy season although no new endophyte species could be recovered. The restricted number of endophytic fungal genera and the absence of common endophytic fungi in the neem leaves could be due to the antifungal metabolites present in the leaves. The results suggest that occurrence of foliar endophytes in tropical trees is influenced by environment, and type and chemistry of the host tissue.