Isolation and characterization of non-pathogenic strains of Fusarium spp. from the rhizosphere of chrysanthemum

Abstract

The wilt of Chrysanthemum is caused by Fusarium oxysporium f. sp. chrysanthemi. As a biocontrol aspect the non-pathogenic Fusarium spp. were isolated and studied to test against the pathogenic Fusarium spp. Totally 67 isolates of Fusarium were isolated from the southern districts of Karnataka. Out of which, five isolates were found to be non-pathogenic Fusarium spp. by four different non-pathogenicity tests. The isolates are UASB NPF-I, UASB NPF-II, UASB NPF-III, UASB NPF-IV and UASB NPF-V. The isolates were observed for microconidia, macroconidia and chlamydospores. The microconidial size varied from 7×2.2 µm to 9.1×2.4 µm, macroconidial structure varied from 26×7.2 µm to 32×7.2 µm and the chlamydospores from 4.2 to 5.2 µm in diameter. Also, the Fusarium cultures were studied for their morphological and cultural characters on different culture media and they were recorded with different growth parameters like colony colour, colony diameter, pigmentation.