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20132
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Subject: Microbiology × Author: SHARMA, KRITIKA × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    CHARACTERIZATION OF PLANT GROWTH PROMOTING RHIZOBACTERIA ISOLATED FROM THE RHIZOSPHERE OF APRICOT (Prunus armeniaca)
    (2013) SHARMA, KRITIKA; SHIRKOT, C.K.
    ABSTRACT Phosphorus (P) is considered the second most essential macronutrient following nitrogen. Plants acquire phosphorus from soil solution as phosphate anion. Phosphorus solubilizing bacteria play role in phosphorous nutrition by enhancing its availability to plants through release from inorganic and organic soil P pools by solubilizing and mineralization. Therefore, the aim of this study was to determine the phosphate solubilizing potential of plant growth promoting rhizobacteria (PGPR) isolated from apricot trees. One hundered and eighty eight bacterial isolates were selected (by replica plating technique) as the representative of the total plated population from the rhizosphere soil and rhizome/roots of the apricot trees from mid hill and high hills region of Himachal Pradesh. All the bacterial isolates were able to grow simultaneously on nutrient agar, Pikovskaya’s, nitrogen free media and CAS media and selected for further screening for various plant growth promoting activities. Seventy two P-solubilizing bacterial isolates (rhizospheric and endorhizospheric) were further studied for different activities such as IAA production, Siderophore production, HCN production and Antifungal activity. Variation was also observed in type of siderophore (Hydroxymate and carboxylate), IAA, HCN and antifungal. Forty seven isolates exhibited antifungal activity against Dematophora necatrix. Out of seventy two isolates, fourteen were further screened for P-solubilization as well as other multiple PGP traits, further studies were carried out with isolate AG1(3) which produced 130.60 ug/ml of P-solubilization under un-optimized cultural conditions. Optimizing the cultural conditions after 72 h of incubation at 30ºC , at pH 7, 1.00% TCP concentration and 2.00% inoculums size resulted in significance increase in P solubilization by the isolate AG1(3), identified as Bacillus subtilis on 16S rDNA analysis. The present study, therefore suggest that the use of P-solubilizing bacteria as as bio-inoculant that might be beneficial for raising quality apricot plant in long term and to develop cost effective ecofriendly sustainable system for horticultural crops.
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    ThesisItemOpen Access
    rhizobacteria (PGPR) isolated from apricot trees.
    (2013) SHARMA, KRITIKA; SHIRKOT, C.K.
    ABSTRACT Phosphorus (P) is considered the second most essential macronutrient following nitrogen. Plants acquire phosphorus from soil solution as phosphate anion. Phosphorus solubilizing bacteria play role in phosphorous nutrition by enhancing its availability to plants through release from inorganic and organic soil P pools by solubilizing and mineralization. Therefore, the aim of this study was to determine the phosphate solubilizing potential of plant growth promoting rhizobacteria (PGPR) isolated from apricot trees. One hundered and eighty eight bacterial isolates were selected (by replica plating technique) as the representative of the total plated population from the rhizosphere soil and rhizome/roots of the apricot trees from mid hill and high hills region of Himachal Pradesh. All the bacterial isolates were able to grow simultaneously on nutrient agar, Pikovskaya’s, nitrogen free media and CAS media and selected for further screening for various plant growth promoting activities. Seventy two P-solubilizing bacterial isolates (rhizospheric and endorhizospheric) were further studied for different activities such as IAA production, Siderophore production, HCN production and Antifungal activity. Variation was also observed in type of siderophore (Hydroxymate and carboxylate), IAA, HCN and antifungal. Forty seven isolates exhibited antifungal activity against Dematophora necatrix. Out of seventy two isolates, fourteen were further screened for P-solubilization as well as other multiple PGP traits, further studies were carried out with isolate AG1(3) which produced 130.60 ug/ml of P-solubilization under un-optimized cultural conditions. Optimizing the cultural conditions after 72 h of incubation at 30ºC , at pH 7, 1.00% TCP concentration and 2.00% inoculums size resulted in significance increase in P solubilization by the isolate AG1(3), identified as Bacillus subtilis on 16S rDNA analysis. The present study, therefore suggest that the use of P-solubilizing bacteria as as bio-inoculant that might be beneficial for raising quality apricot plant in long term and to develop cost effective ecofriendly sustainable system for horticultural crops.