Effect of light and aeration on the growth of Sclerotium rolfsii in vitro

Sclerotium rolfsii is one of the devastating soil-borne plant pathogens which cause severe loss at the time of seedling development. It also causes leaf spots in several crops and wild plants. In this experiment, exposure of pathogen to different light period and aeration in order to assess the mycelial growth, biomass production, weight and number of sclerotia of S. rolfsii was done. Three-fourth area of three plates, 50% area of three plates and 100% area of three plates were sealed with cellophane tape. The other three plates were not sealed. Two sets of such plates were prepared. All the plates were incubated at 28±2°C. One set was incubated in light whereas the other set was incubated in the dark. The results reveal that there was no significant difference in mycelial growth and number of sclerotia among them but significant difference was observed when compared with the control, that is, the plates which were not sealed. Sclerotial formations were directly influenced by air as completely sealed plates failed to produce sclerotia. Generally, the light condition induces the production of more number of sclerotia than dark condition. In another study, the exposure of pathogen to different light periods revealed that alternative cycles of 12 h light and 12 h darkness for ten days resulted in the maximum mycelial growth and dry weight, more number of sclerotia and weight of sclerotia was also seen when compared with other treatments.Key words: Sclerotium rolfsii, aeration, light, peppermint