Studies on plant growth promoting rhizomicroorganisms of tea (camellia sinensis l. (o.) kuntze) plants
KrishiKosh
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Title |
Studies on plant growth promoting rhizomicroorganisms of tea (camellia sinensis l. (o.) kuntze) plants
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Creator |
Priyanthi K.Tennakoon
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Contributor |
A.R.Alagawadi
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Subject |
Agricultural Microbiology
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Description |
In the investigations carried out on plant growth promoting rhizomicroorganisms of tea plants, 20 Azospirillum, 18 Beijerinckia, 23 PSB and 28 fluorescent pseudomonads and 10 Bacillus were isolated from rhizosphere of tea plants grown in Kodagu district of Karnataka. All the isolates were tentatively identified based on morphological, biochemical and physiological characters. The isolates were also examined for various beneficial characters and for growth promotional activity in tea plants. The amount of nitrogen fixed by Azospirillum isolates ranged from 7.23 to 22.16 mg g-1 malate. Sixteen Azospirillum isolates produced both IAA and GA in the range of 334 to 874 μg and 33 to 230 μg L-1 broth, respectively. Nitrogen fixation by Beijerinckia isolates ranged from 2.86 to 5.54 mg g-1 of glucose. Five Beijerinckia isolates produced both IAA and GA which ranged from 53 to 169 μg and 44 to 90 μg L-1 broth, respectively. The amount of Pi released by PSB isolates ranged from 9.54 to 26.11 per cent. Ten PSB isolates produced IAA and GA which ranged from 54 to 357 μg and 37 to 166 μg L-1 broth, respectively. All 28 fluorescent pseudomonads solubilized tricalcium phosphate in the range of 9.39 to 22.97 per cent. Sixteen of them produced IAA and GA in the range of 126 to 664 μg and 32 to 284 μg L-1 broth. Eleven fluorescent pseudomonads also showed in vitro inhibitory activity against plant pathogenic fungi, viz., Pestolotia thea, Fusarium oxysporum, Rhizoctonia bataticola and Sclerotium rolfsii. The biocontrol mechanisms in the antagonistic isolates included production of siderophores, volatile compounds and antimicrobial metabolites. In nursery evaluation, 9 Azospirillum isolates and seven each of phosphate solubilizing bacteria and fluorescent pseudomonads improved growth, dry matter content and nutrient uptake of tea plants significantly over control. |
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Date |
2016-10-17T11:35:00Z
2016-10-17T11:35:00Z 2007 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/80687
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Format |
application/pdf
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Publisher |
UAS, Dharwad
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