Abstract:
The present study explores phytohormones production of Fusarium soil isolate and also their
production under the condition of heavy metal stress. Fusarium sp. was recovered from an
agricultural field of Murshidabad district in West Bengal, India. by soil dilution plate technique
on selective pentachloronitrobenzene (PCNB) medium and was later identified by routine
morphological studies and molecular analysis. The Fusarium species was proven non-pathogenic
based on germination percentage and vigour index values of the tested seed plants. The isolate
produced IAA in tryptophan supplemented medium (370 µg/ml) and also produced GA in huge
amount (4800 µg/ml). The Fusarium species was found to be quite resistant to the tested heavy
metals and its MIC value ranges from as low as 175 ppm (Cd) to as high as 350 ppm (Fe). The
isolate was capable of producing both IAA and GA in metal contaminated broth. But, Cd (50
ppm) completely checked both IAA and GA production. Zn (50 ppm) was also toxic to the
species in terms of its ability to produce IAA. But GA production continued unabated (3500-
4250 µg/ml) in presence of the other heavy metals at 50 ppm concentration. Thus, the soil isolate
could be used in metal contaminated agricultural soil to improve yield. |
