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Not AvailableTwo Azospirillum brasilense strains, CDJA and A40, capable of growing and producing plant growth-promoting (PGP) substances at the sub-optimal temperature (SOT) of 22C, were tested for their ability to survive, colonize and enhance wheat growth and yield under field conditions upon inoculation. The response was compared with that of A. brasilense strain, A9, impaired in growth and PGP activities at SOT (22C) but otherwise comparable to CDJA and A40 at 37C. A field experiment was carried out in a split-plot design with four levels of N as main plots and three strains and an uninoculated control as subplots. A differential response in the establishment of the strains and in plant growth and yield was obtained, due to the categories of strains, particularly at lower levels of N (0 kg and 40 kg N ha-1). The results clearly demonstrated that strains capable of growing and producing PGP substances at SOT are better inocula for wheat.Not Availabl

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Not AvailableSeventeen strains of Rhizobium leguminosarum biovar viceae specific to the lentil (Lens culinaris L.) were screened, using the high-yielding lentil cultivar L 4076, for their tolerance to three levels of NO sup- inf3 : 0, 4, and 8 mM NO sup- inf3 . Preliminary screening of this symbiosis for nodulation and N fixation in the presence of NO sup- inf3 showed significant variations among the strains. The number of nodules decreased and nitrogenase activity was depressed in all strains in the presence of NO sup- inf3 . Strains L-1-87, L-27-89, L-33-89, and L-40-89 tolerated 8 mM NO sup- inf3 . Four strains, three tolerant of NO sup- inf3 (L-1-87, L-27-89, and L-33-89), and one sensitive (L-11-89) to NO sup- inf3 , were selected from preliminary screening and used in a pot experiment to assess the symbiosis in the presence of 6 mM NO sup- inf3 at three stages of plant growth, viz., 40 days, 60 days, and at the final harvest. In general, the weight of nodules and C2H2 reduction activity was significantly higher after 60 days than after 40 days. Inoculation with strain L-1-87 produced the maximum number of nodules, and root and shoot biomass both in the presence and the absence of NO sup- inf3 . Nitrate reductase activity in the tops and nodules was assayed only after 60 days and did not show significant variations among strains and NO sup- inf3 treatments. The grain yields for all strains except L-11-89 were significantly higher in the presence of NO sup- inf3 than in the absence of NO sup- inf3 , indicating that tolerant strains contributed symbiotically fixed N to the plant's N pool, resulting in an additive effect on yield. Inoculation with strain L-1-87 produced the maximum grain yield and this strain appears to have potential use as an inoculant in the presence of high levels of soil N.Not Availabl

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Not AvailableFourteenAzospirillum brasilense strains growing at a sub-optimum temperature were selected based on their ability to grow and carry out plant growth promoting activities at 22°C. The strains were tested for their response to inoculation in wheat (two popular cultivars, HD2285 and WH547, under sterile conditions) crop using sterile and nonsterile rooting medium. Significant increase in plant growth parameters was observed: the overall response to inoculation was better in cultivar HD 2285. Based on their performance under sterile conditions, 4 strains were selected and compared under nonsterile conditions with strain sensitive to a sub-optimum temperature in pots using wheat variety HD2285. The strains capable of growing at the sub-optimum temperature can colonize the wheat endorhizosphere efficiently and improve the plant growth and yield as compared to sensitive strain; a 25–27% increase in grain yield was found on inoculating two selected strains compared to NO - 3 control.Not Availabl

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Not AvailableCarrier-based (soil/FYM, 1:1) plant growth-promoting rhizobacteria (PGPR) isolates (Bacillus subtilis, Klebsiella planticola and Proteus vulgaris) were tested individually and in combination with Bradyrhizobium japonicum and Rhizobium leguminosarum biovar viciae under field conditions on soybean and lentil crops, respectively, under field conditions. Inoculation of soybean (Glycine max) cv. Pusa 22 with B. subtilis produced maximum nodule number, mass and nitrogenase activity (acetylene reduction activity, ARA) followed by B. japonicum (SB 271). Maximum soybean yield was registered with the coinoculation of B. japonicum and B. subtilis over an uninoculated control. Maximum nodulation in the lentil (Lens culinaris) cv. L 4147 was obtained with a combination of R. leguminosarum (L-12-87) and P. vulgaris inoculation followed by a single inoculation with Rhizobium and B. subtilis. None of the PGPR isolates either singly or in coinoculation with R. leguminosarum could significantly influence the yield of the lentil crop.Not Availabl

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Not AvailableAzospirillum brasilense strains, CDJA and A40, capable of growing at sub-optimal temperature were tagged with stable chromogenic marker Tn5-lacZ. Mutants were screened for plant growth promoting activities at 20, 22, 25, 30 and 37 °C. Mutants MC48 and MA3 were found to fix nitrogen upto 85% and produced indole acetic acid (IAA) and siderophore in isogenic manner to their respective wild type strains, CDJA and A40, at sub-optimal temperatures. Co-inoculation of mutants with their respective parent (1:1 ratio) to the wheat revealed that colonization potential of the mutants was affected greatly. Tn5-lacZ tagged mutants MC48 and MA3 were found isogenic to their respective wild type Azospirillum strain, with regards to plant growth promoting activities and root colonization ability.Not Availabl

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Not AvailableCarrier-based (Soil: FYM:: l: l) plant growth promoting rhizobacteria (PGPR) isolates [Bacillus subtilis, Klebsiella planticola, Proteus vulgaris, Azospirillum brasilense(CDJA), Azotobacter chroococcum (CBD 15)] were tested on mustard (Brassicajuncea L. cv. Pusa Bold), sunflower (Helianthus annuus L. cv. Morden) and teff (Eragrostis teffcv. DZ-01-354), for their ability to influence the growth and yield in the presence and absence of applied fertilizer nitrogen. The results revealed in general, with the increase in nitrogen level there was significant increase in the population of inoculant bacteria. The biomass and seed yield were not influenced markedly by the application of nitrogen fertilizer when tested under green house conditions.. Among inoculants, Bacillus subtilis resulted in significantly more biomass and grain yield than uninoculated control at 0 level of N. Further, the interaction of N and inoculants also revealed better performance.Not Availabl

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Not AvailableThe molecular basis of antifungal toxin production by a fluorescent Pseudomonas strain EM 85 was studied. The bacterial strain showed in vitro inhibition of growth of Rhizoctonia solani. NTG mutagenesis of the wild type strain helped in the isolation of a antifungal-toxin-defective mutant AN 21. A genomic library of the wild type strain was constructed in the cosmid vector pLAFR 1 and maintained in an E. coli background. Complementation analysis with cosmid library resulted in the isolation of a cosmid clone which complemented the defective character in the mutant AN 21. The size of the complementing DNA fragment was found to be 23.5kb.Not Availabl

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Not AvailableFourteen plant growth promoting rhizobacteria (PGPR) isolated from rhizotic zones of field - grown green gram Vigna radiata (L.) Wilczekl plants were examined for their growth - promoting attributes and ability to affect the growth in vitro of 10 strains of Bradyrhizobium sp. (Vigna). None of the rhizosphere bacteria was found to repress or stimulate the growth of any of the Bradyrhizobium strains tested. However, they produced antibiotics and siderophores and plant growth promoting substances. Ex planta and plant nitrogen fixation and phosphate solubilization was not detected by any of the isolates. Under in - vitro conditions, nine isolates inhibited growth of soil - borne fungal pathogens: one of them identified as Bacillus sp. antagonized all the fungi tested on two different media. All PGPR isolates were tested both in sterile and unsterile soil for their ability to promote nodulation, nitrogen fixation, growth, and yield of green gram in the presence of two Bradyrhizobium sp. (Vigna) strains S 24 and Cog 15. In sterile soil, all PGPR isolates had a positive effect on shoot biomass developement, acetylene reduction assay (ARA), and N content when co - inoculated with Bradyrhizobium strain Cog 15, but could influence only shoot biomass development in the presence of strain S 24. In unsterile soil, PGPR isolates had a nodule - stimulatory effect on strain Cog 15 and a plant growth promoting effect on strain S 24, after 50 and 90 days of plant growth. Five isolates EG - RS - 3, EG - RS - 4, and NG - ER - 7 (Bacillus spp), and KG - ER - 1 and EG - ER - 2 (Enterobacter spp) significantly increased yield of green gram in unsterile soil.Not Availabl

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Not AvailableFour plant growth promoting rhizobacterial (PGPR) isolates belonging to genera Bacillus and Enterobacter and two Bradyrhizobium spp. (Vigna) strains Cog 15 and S 24 were selected for competition studies. PGPR isolates did not antagonize Bradyrhizobium strains Cog 15 and S 24 on plates. In unsterile soil, co-inoculations of PGPR and Bradyrhizohium strains failed to show any conclusive influence on nodulation and ARA at 50 days of plant growth. PGPR isolates had a direct effect on shoot biomass development, N content and grain yield when tested with Bradyrhizohium strain S 24, after 50 and 80 days of plant growth. Single inoculations of PGPR isolates significantly increased grain yield over uninoculated control. The influence of PGPR isolates on the ability of Bradyrhizohium strains to compete with indigenous population of bradyrhizobia was studied in terms of nodule occupancy. Bradyrhizobium strains were genetically marked by studying their intrinsic Antibiotic Resistance pattern. The nodule occupancy of Bradyrhizobium strainS 24 increased from 60% (treatment with single inoculation of S 24) to 81% in presence of an Enterobacter isolate EG-ER-2. Another Enterobacter isolate KG-ER-1 increased nodule occupancy of bradyrhizobial strain Cog 15 from 77% (treatment with single inoculation of Cog 15) to 88%.Not Availabl

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Not AvailableA plant growth-promoting isolate of a fluorescent Pseudomonas spp. EM85 was found strongly antagonistic to Rhizoctonia solani, a causal agent of damping-off of cotton. The isolate produced HCN (HCN+), siderophore (Sid+), fluorescent pigments (Flu+) and antifungal antibiotics (Afa+). Tn5::lacZ mutagenesis of isolate EM85 resulted in the production of a series of mutants with altered production of HCN, siderophore, fluorescent pigments and antifungal antibiotics. Characterisation of these mutants revealed that the fluorescent pigment produced in PDA and the siderophore produced in CAS agar were not the same. Afa− and Flu− mutants had a smaller inhibition zone when grown with Rhizoctonia solani than the EM85 wild type. Sid− and HCN− mutants failed to inhibit the pathogen in vitro. In a pot experiment, mutants deficient in HCN and siderophore production could suppress the dampingoff disease by 52%. However, mutants deficient in fluorescent pigments and antifungal antibiotics failed to reduce the disease severity. Treatments with mutants that produced enhanced amounts of fluorescent pigments and antibiotics compared with EM85 wild type, exhibited an increase in biocontrol efficiency. Monitoring of the mutants in the rhizosphere using the lacZ marker showed identical proliferation of mutants and wild type. Purified antifungal compounds (fluorescent pigment and antibiotic) also inhibited the fungus appreciably in a TLC bioassay. Thus, the results indicate that fluorescent pigment and antifungal antibiotic of the fluorescent Pseudomonas spp. EM85 might be involved in the biological suppression of Rhizoctonia-induced damping-off of cotton.Not Availabl