Variability in the Fusarium isolates from the basmati rice infected with foot rot disease

The isolations were made from the roots and the stem portions of the foot rot infected basmati plants showing different types of symptoms. Three types of Fusarium colonies were obtained which were further purified by single spore method. They were identified morphologically on the basis of morphology of macro, micro conidia, phialides etc by growing them on specific media. Out of three isolates two were of Fusarium moniliformae (on the basis of absence of chlamydospores and presence of micro conidia in chains). The isolate, which was obtained from the dying plants, was named as FRD and the isolate, which was obtained from the elongated seedlings, was named as FRE. The third isolate was of Fusarium, which produced abundant macro conidia but was not recognized up to species level. The pathogenicity test was conducted for all the three isolates on the foot rot susceptible variety Pusa 1121 in the earthen pots. After 20 days of sowing in FRD treated pots death of seedlings was observed and ultimately all the plants died. But in FRE treated pots the 70–80 per cent plants showed elongation of seedlings and other 20–30 per cent got killed. Third isolate was failed to prove its pathogenicity. The plants were as healthy as in control pot. These two isolates also showed different behaviour under laboratory conditions in terms of sporulation and growth.