Abstract:
Rhizosphere is the soil adjacent to plant root system and is a region with intense microbial activity. The
role and importance of rhizosphere microorganisms in sustainable crop production have been reviewed
by several researchers. Considering the negative impacts of agrochemicals, it is urgently needed to reduce
the use of agrochemicals and use eco-friendly technologies to increase rice production. The objective of
this study was to isolate fungi with antifungal activity and phosphate solubilizing ability from rice
rhizosphere. In this study, fungi were isolated from rhizospheres of Bw 367, Bw 372 and Bw 272-6B rice
varieties grown under drained and water logging conditions of paddy fields in the low country wet zone of
Sri Lanka. The spread plate technique was used to isolate and purify all the isolates on Potato Dextrose
Agar medium. A total of 41 and 32 fungal isolates were recorded in the rice rhizosphere under drained
and water logging conditions, respectively. Antifungal activity of all the isolates was determined against
Rhizoctonia solani, Bipolaris oryzae and Curvularia sp. using dual culture method. Two fungal isolates from
rhizospheric soils of drained paddy field and three isolates from water logging paddy field showed more
than 70% inhibition of the three pathogens by competition. All the isolates were screened for phosphate
solubilisation on Pikovskaya’s agar medium and nine were identified as phosphate solubilisingO isolates.
This study reveals that the rice rhizosphere is a rich source of fungi with antifungal activity and phosphate
solubilizing ability.
