Krishna Naik, L.SWATHI, M.2020-10-072020-10-072019-12-28Th-12557https://krishikosh.egranth.ac.in/handle/1/5810152659A study was carried out to evaluate the non pathogenic strains of Fusarium spp. for the management of Fusarium wilt of Chrysanthemum. Out of 67 Fusarium cultures isolated from rhizosphere soil of Chrysanthemum fields, five Fusarium isolates proved to be non pathogenic to Chrysanthemum and other non host crops. Morphological, cultural and molecular characterization of non pathogenic Fusarium cultures was performed and among five isolates, two were identified as Fusarium chlamydosporum, two as Fusarium oxysporum and one was Fusarium solani. Antagonistic inhibition in growth of the wilt pathogen was showed by non pathogenic Fusarium cultures UASB NPF-I, UASB NPF-II and UASB NPF-III under in vitro dual culture study. The culture filtrate extracts and volatile compounds of non pathogenic cultures showed substantial results on inhibition of pathogen in vitro. Increased levels of total protein, phenols and defense enzymes such as peroxidase, polyphenol oxidase, phenylalanine ammonia lyase, β-1,3-glucanase and chitinase were observed in the plants treated with non pathogenic Fusarium cultures. Higher levels of defense enzymes got induced in the plants inoculated with non pathogenic Fusarium isolates followed by challenged inoculation of pathogen. All the non pathogenic Fusarium cultures were positive for phosphate solubilization and production of IAA and GA. Under greenhouse conditions significant increase in plant growth parameters, reduced wilt disease incidence and better root colonization by non pathogenic Fusarium cultures was observed. The treatments which received non pathogenic Fusarium + pathogenic Fusarium showed a slight increase in the plant growth parameters compared to inoculation of non pathogenic Fusarium isolates alone. The isolate UASB NPF-III performed better than other isolates throughout the studies.EnglishThesis