Jahir Basha, C. R.RAJANNA, H. HADIMANI2020-10-062020-10-062019-09-06Th-12468https://krishikosh.egranth.ac.in/handle/1/5810152564Endophytes are living microorganisms present inside the plant tissues imparting tolerance against abiotic and biotic stress, in turn getting food and livelihood from plants. Exploration for fungal and bacterial endophytes as potential biocontrol agents against Sclerotium rolfsii. infecting groundnut was made by conducting in-vitro studies. Fungal and bacterial endophytes isolated from three selected varieties of groundnut viz., ICGV- 91114, ICG-13902 and JL-24 at three different time intervals (30, 60 and 90 days after sowing). Total of 237 fungal and 310 bacterial endophytes were obtained from 324 processed tissue segments, and were morphologically categorized into 96 fungal and 86 bacterial Operational Taxonomic Units (OTU’s) by considering the colony colour, pattern and texture of the endophytes and evaluated against Sclerotium rolfsii. infecting groundnut by dual culture technique. Out of 96 fungal OTU’s, one OTU and out of 86 bacterial OTU’s twelve OTU’s showed more than 50 per cent inhibition. Bacterial endophytic OTU 8ns1 isolated from ICG-13902 showed highest per cent inhibition (83.28) of Sclerotium rolfsii. Molecular characterization of potential endophytes by amplifying ITS region (ITS1 and ITS4 primers) for fungus and 16s rRNA region for bacterial endophytes revealed that, fungal endophyte as Fusarium solani (4pr2) and the bacterial endophytes as Lysinibacillus sp (4nr1), Alcaligenes feacalis (4nr1), Alcaligenes sp (8ns1), Orchobacterium intermedium (8ns2), from 30-days old sample. Similarly, Burkholdera cepacia (8nl3), Orchrobacterium intermedium (4nl2), Orchrobacterium intermedium (17nr4), Paenibacillus sp (4nl3), from 60-days old sample and Orchrobacterium sp (4nl4), Bacillus subtilis (8nl1), Alcaligenes sp (8ns1), Bacillus subtilis (17nl2) from 90-days old sample.EnglishThesis