Incidence of Leptosphaerulina crassiasca in symptomless leaves of peanut in southern India.

A Loculoascomycete fungus belonging to the genus Leptosphaerulina was found to survive as symptomless endophyte in the leaflets and rachis of peanut plant (TMV 7). Based on morphological and colony characteristics, it is identified as Leptosphaerulina crassiasca, a fungus that causes the pepper spot and leaf scorch diseases in peanut. Although several common endophytic fungi were recovered from the leaves of peanut, L . crassiasca showed a high relative density of infection. Owing to its endophytic nature, its pathogenicity could not be proved by infection studies. However, its identification as L. crassiasca suggests that this pathogen survives as symptomless endophyte in its host. There are limited studies on fungal endophytes of cultivated crops and hence, the present observation underlines the need to know more about the biology of endophytic fungi of crop plants.