K.S. JagadeeshSheela R. Pattanashetti2016-11-142016-11-142012http://krishikosh.egranth.ac.in/handle/1/85484Investigations were carried to isolate Pink Pigmented Facultative Methylotrophs (PPFM), characterize them and study their beneficial effects on Coleus forskohlii. Samples of C. forskohlii were collected grown in different villages such as Nandihalli, Naganahatti, Rajahamsagada, Tarihalli, Hidakal, of Belgaum district, UAS, Dharwad and UAS, Bangalore (GKVK). As many as fifty isolates were isolated from these samples on selective AMS medium. The isolates were characterized based on their morphological and biochemical characteristics. The results revealed that all the isolates were Gram negative and rod shaped with the dimension ranging from 0.6- 1.0 x 1.0-1.5 μm. The colonies were pink in colour due to pigmentation. The biochemical characteristics revealed that all the isolates showed positive for oxidase, urease, citrate and catalase tests. All the isolates utilized glucose, glycerol, tartarate and acetate. Further, the isolates were screened for beneficial characters. The results revealed that the highest indole acetic acid production was recorded in the isolates PPFM 36 and PPFM 50 (29.97 μg ml-1 of each culture filtrate) and the maximum GA production (59.13 μg ml-1 of culture filtrate) was by the isolate. The isolates were also tested for P-solubilization activity, antagonistic activity, siderophore and HCN production. The maximum Pi release was observed in PPFM 138 (10.07%). None of the isolates produced HCN and siderophores. And, as many as nineteen isolates showed antifungal activity against three important fungal pathogens of Coleus namely Sclerotium rolfsii, Fusarium oxysporum and Rhizoctonia bataticola. Based on these beneficial characters, three efficient PPFM isolates were selected for the pot culture experiment. The results have revealed that all the PPFM isolates performed better than the reference strain (Methylobacterium extorquens) and uninoculated control. The isolate PPFM 50 isolated from Nandihalli village was most promising which recorded significantly higher growth and tuber yield parameters of C. forskohlii followed by PPFM 32.Agribusiness ManagementThesis