Showing papers on "Phosphate solubilizing bacteria published in 2018"

Effect of coin coculation with phosphate and potassium solubilizing bacteria on mineral uptake and growth of pepper and cucumber

Abstract: Biofertilizers have been used as sources to improve plant nutrients in sustainable agriculture. Experiments were conducted to evaluate the potential of phosphate solubilizing bacteria (PSB) Bacillus megaterium var. phosphaticum and potassium solubilizing bacteria (KSB) Bacillus mucilaginosus inoculated in nutrient limited soil planted with pepper and cucumber. Results showed that rock P and K applied either singly or in combination did not significantly enhance soil availability of P and K, indicating their unsuitability for direct application. PSB was a more potent P-solubilizer than KSB, and co-inoculation of PSB and KSB resulted in consistently higher P and K availability than in the control without bacterial inoculum and without rock material fertilizer. Integrated rock P with inoculation of PSB increased the availability of P and K in soil, the uptake of N, P and K by shoot and root, and the growth of pepper and cucumber. Similar but less pronounced results were obtained when rock K and KSB were added concomitantly. Combined together, rock materials and both bacterial strains consistently increased further mineral availability, uptake and plant growth of pepper and cucumber, suggesting its potential use as fertilizer.

Phosphate solubilizing bacteria with glucose dehydrogenase gene for phosphorus uptake and beneficial effects on wheat.

Abstract: The aim of this study was to isolate, characterize and use phosphate solubilizing bacteria to enhance the bioavailability of insoluble Ca-phosphate for wheat plants For this purpose, 15 phosphorus solubilizing bacteria (PSB) were isolated from wheat rhizospheric soils of Peshawar and southern Punjab region, Pakistan These isolates were identified using light microscopy and 16S rRNA gene Among the isolated bacteria, two strains (Pseudomonas sp MS16 and Enterobacter sp MS32) were the efficient P solubilizers based on their P solubilization activity determined qualitatively (solubilization index 32-58) as well as quantitatively (136-280 μg mL-1) These two strains produced indole-3-acetic acid (256-281 μg mL-1), gibberellic acid (25-118), solubilized zinc compounds (SI 28-33) and showed nitrogenase and 1-Aminocyclopropane-1-carboxylic acid deaminase activity in vitro Phosphate solubilization activity of Pseudomonas sp MS16 was further validated by amplification, sequencing and phylogenetic analysis of glucose dehydrogenase (gcd) gene (LT908484) responsible for P solubilization Response Surface Methodology for large-scale production was used to find optimal conditions (Temperature 225°C, pH 7) for P solubilization Glucose was found to support higher P solubilization in vitro In an in vitro experiment, PSB treated wheat seedlings improved germination and seedling vigor (11% increases) as compared to un-inoculated control Rhizoscanning of these seedlings showed an increase in various root growth parameters Wheat inoculation with selected strain MS16 showed pronounced effect on grain yield in pot (385% increase) and field (17-18% increase) experiments compared to non-inoculated control Root colonization by PSB through Florescent in situ Hybridization and Confocal Laser Scanning Microscopy confirmed their rhizosphere competence in soil BOX-PCR confirmed the re-isolated colonies of Pseudomonas sp MS16 The results indicated that gluconic acid producing Pseudomonas sp MS16 from un-explored soils may be cost effective and environment friendly candidate to improve plant growth and phosphorous uptake by wheat plants

Isolation and Identification of Endophytic Bacteria with Plant Growth Promoting Activity and Biocontrol Potential from Wild Pistachio Trees

Abstract: In this study, samples were collected from the leaves and stems of healthy wild Pistachio trees (Pistacia atlantica L.) from various locations of Baneh and Marivan regions, Iran. In total, 61 endophytic bacteria were isolated and grouped according to phenotypic properties. Ten selected isolates from each group were further identified by partial sequencing of the 16S rRNA gene. Based on the results, isolates were identified as bacteria belonging to Pseudomonas, Stenotrophomonas, Bacillus, Pantoea and Serratia genus. The ability of these isolates was evaluated to phytohormone production such as auxin and gibberellin, siderophore production, phosphate solubilization, atmospheric nitrogen fixation, protease and hydrogen cyanide production. All strains were able to produce the plant growth hormone auxin and gibberellin in different amounts. The majority of strains were able to solubilize phosphate. The results of atmospheric nitrogen fixation ability, protease and siderophore production were varied among strains. Only Ba66 could produce a low amount of hydrogen cyanide. The results of biocontrol assay showed that Pb78 and Sp15 strains had the highest and lowest inhibition effects on bacterial plant pathogens, Pseudomonas syringae pv. syringae Pss20 and Pseudomonas tolaasii Pt18 under in vitro condition. Pb3, Pb24 and Pb71 strains significantly promote root formation on carrot slices. To our knowledge this is the first report of the isolation of endophytic bacterial strains belonging to Pantoea, Bacillus, Pseudomonas, Serratia and Stenotrophomonas genus from wild pistachio trees with plant growth promoting potential and biocontrol activity.

How do arbuscular mycorrhizal fungi handle phosphate? New insight into fine-tuning of phosphate metabolism.

Abstract: Contents Summary 1116 I. Introduction 1116 II. Foraging for phosphate 1117 III. Fine-tuning of phosphate homeostasis 1117 IV. The frontiers: phosphate translocation and export 1119 V. Conclusions and outlook 1120 Acknowledgements 1120 References 1120 SUMMARY: Arbuscular mycorrhizal fungi form symbiotic associations with most land plants and deliver mineral nutrients, in particular phosphate, to the host. Therefore, understanding the mechanisms of phosphate acquisition and delivery in the fungi is critical for full appreciation of the mutualism in this association. Here, we provide updates on physical, chemical, and biological strategies of the fungi for phosphate acquisition, including interactions with phosphate-solubilizing bacteria, and those on the regulatory mechanisms of phosphate homeostasis based on resurveys of published genome sequences and a transcriptome with reference to the latest findings in a model fungus. For the mechanisms underlying phosphate translocation and export to the host, which are major research frontiers in this field, not only recent advances but also testable hypotheses are proposed. Lastly, we briefly discuss applicability of the latest tools to gene silencing in the fungi, which will be breakthrough techniques for comprehensive understanding of the molecular basis of fungal phosphate metabolism.

Glyphosate induced toxicity to chickpea plants and stress alleviation by herbicide tolerant phosphate solubilizing Burkholderia cepacia PSBB1 carrying multifarious plant growth promoting activities

Abstract: In this study, strain PSBB1 isolated from Vicia faba rhizosphere was identified as Burkholderia cepacia, by 16S rDNA sequence analysis and characterized. Strain PSBB1 tolerated glyphosate up to 3200 μg ml−1 and produced IAA (81.6 μg ml−1), ACC deaminase (69.3 mg−1 protein h−1), SA (39.3 μg ml−1) and 2,3-DHBA (26.6 μg ml−1), solubilized insoluble P (50.8 μg ml−1) and secreted 29.4 μg ml−1 exopolysaccharides, which decreased with increasing concentrations of glyphosate. Cell damage following glyphosate application was visible under SEM and CLSM. The phytotoxicity of glyphosate on chickpea was variable but significant. B. cepacia mitigated toxicity and enhanced the size, dry matter, symbiosis, seed attributes and nutritional contents of chickpea. Further, B. cepacia strain PSBB1 declined the levels of CAT, POD, APX and GPX and MDA contents at 4332 μg kg−1 soil glyphosate. Proline also increased under glyphosate stress but declined in B. cepacia inoculated plants. The ability to tolerate higher concentration of glyphosate, the capacity to secrete plant growth regulators even under herbicide stress and potential to reduce the level of proline and antioxidant enzymes makes B. cepacia as an interesting choice for enhancing chickpea production in soils contaminated even with herbicides.

Author Correction: Phosphate-Solubilizing Bacteria Nullify the Antagonistic Effect of Soil Calcification on Bioavailability of Phosphorus in Alkaline Soils.

Abstract: A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Preliminary study on phosphate solubilizing Bacillus subtilis strain Q3 and Paenibacillus sp. strain Q6 for improving cotton growth under alkaline conditions.

Abstract: Background Low phosphorus availability limits crop production in alkaline calcareous soils in semi-arid regions including Pakistan. Phosphate solubilizing bacteria may improve crop growth on alkaline calcareous soils due to their ability to enhance P availability. Methods Twenty rhizobacterial isolates (Q1-Q20) were isolated from rhizosphere of cotton and characterized for their growth promoting attributes in vitro. The selected phosphate solubilizing isolates were further screened for their ability to improve cotton growth under axenic conditions (jar trial). The phosphorus solubilization capacities of selected strains were quantified and these strains were identified through 16S rDNA sequencing. Results Isolates Q2, Q3, Q6, Q7, Q8, Q13 and Q14 were able to solubilize phosphate from insoluble sources. Most of these isolates also possessed other traits including catalase activity and ammonia production. The growth promotion assay showed that Q3 was significantly better than most of the other isolates followed by Q6. Maximum root colonization (4.34 × 106 cfu g-1) was observed in case of isolate Q6 followed by Q3. The phosphorus solubilization capacities of these strains were quantified, showing a maximum phosphorus solubilization by Q3 (optical density 2.605 ± 0.06) followed by the Q6 strain. The strain Q3 was identified as Bacillus subtilis (accession # KX788864) and Q6 as Paenibacillus sp. (accession # KX788865) through 16S rDNA sequencing. Discussion The bacterial isolates varied in their abilities for different growth promoting traits. The selected PGPR Bacillus subtilis strain Q3 and Paenibacillus sp. strain Q6 have multifarious growth promoting traits including ability to grow at higher EC and pH levels, and phosphorus solubilizing ability. These strains can efficiently colonize cotton roots under salt affected soils and help plants in phosphorus nutrition. It is concluded that both strains are potential candidates for promoting cotton growth under alkaline conditions, however further investigation is required to determine their potential for field application.

Effect of Phosphate-Solubilizing Bacteria on the Mobility of Insoluble Cadmium and Metabolic Analysis.

Abstract: Phosphate-solubilizing bacteria (PSB) can promote plant growth by dissolving insoluble phosphate. Therefore, PSB may have the potential to improve the mobility of heavy metals in soils and enhance phytoextraction. This study isolated a few PSB strains that could dissolve CdCO₃ and solid Cd in soil. Two typical PSB, namely, high- and low-Cd-mobilizing PSB (Pseudomonas fluorescens gim-3 and Bacillus cereus qh-35, respectively), were selected to analyze the metabolic profiles, metabolic pathways, and mechanisms of mobilization of insoluble Cd. A total of 34 metabolites secreted by the two PSB strains were identified. Gluconic acid was the main contributor to Cd dissolution (42.4%) in high-Cd-mobilizing PSB. By contrast, gluconic acid was not secreted in low-Cd-mobilizing PSB. Metabolic pathway analysis showed that gluconic acid was produced by the peripheral direct oxidation pathway. Hence, PSB with peripheral direct oxidation pathway were likely to have high-Cd-mobilizing capacity.

Effect of Pb-resistant plant growth-promoting rhizobacteria inoculation on growth and lead uptake by Lathyrus sativus

Abstract: In search of efficient and resistant plant growth-promoting rhizobacteria (PGPR) strains with multiple activities, a total of twelve bacterial belonging to R. leguminosarum, S. meliloti, Pseudomonas sp., P. fluorescens, Luteibacter sp., Variovorax sp., B. simplex, and B. megaterium were isolated from root nodules of grass pea (Lathyrus sativus L.) grown in contaminated soils. Upon screening, all test strains were able to synthesize indoleacetic acid; more than 90% were siderophore producers and 75% showed varying levels of phosphate solubilizing ability. The gaseous metabolite biosynthesis showed that 42% of strains were cyanogenic. The lead (Pb) bioaccumulation differs with incubation times between cell wall and cytoplasm. Indeed, the most part of Pb was adsorbed to cell surface. A pot experiment was conducted for investigating the capability of combined bacteria to promote plant growth of Lathyrus sativus under controlled conditions. Subsequently, the performance of symbiosis Lathyrus sativus-PGPR (I4: R. leguminosarum (M5) + B. simplex + Luteibacter sp. + Variovorax sp.) was investigated under lead stress using hydroponic culture to elucidate the effect of bacterial inoculation on Pb uptake as well as plant growth. Results showed that under 0.5 mM Pb, inoculation with I4 significantly increased shoots and roots biomass by 59% and 56%, respectively, and improved Pb uptake in both shoots and roots by 39% and 47%, respectively, as compared to uninoculated plants. The inoculation of Lathyrus sativus with efficient and Pb resistant PGPR is a promising symbiosis that having significant potential to improve phytoremediation of Pb-polluted soils.

Characterization of mineral phosphate solubilizing and plant growth promoting bacteria from termite soil of arid region.

Abstract: Five highly efficient phosphate solubilizing bacteria, viz., Pantoea sp. A3, Pantoea sp. A34, Kosakonia sp. A37, Kosakonia sp. B7 and Bacillus sp. AH9 were isolated from termitorial soils of Sanjivani island of southern Maharashtra, India. These isolates were characterized and explored for phosphate solubilization and plant growth promotion. Among these, Bacillus sp. AH9 showed highest phosphate solubilization index (3.5) and solubilization efficiency (250%) on Pikovskaya agar. Interestingly, Pantoea sp. A34 displayed maximum mineral phosphate solubilization (1072.35 mg/L) in liquid medium and during this period the pH dropped to 3.13. All five isolates had highest P solubilization at 48 h after inoculation. During mineral phosphate solubilization, both gluconic acid and 2-keto gluconic acid were produced by Kosakonia and Bacillus isolates, while only 2-keto gluconic acid was detected in Pantoea isolates. Highest organic acid (39.07 ± 0.04 g/L) production was envisaged in Bacillus sp. AH9, while Pantoea sp. A34 produced the least amount (13.00 ± 0.01 g/L) of organic acid. Seed bacterization with Pantoea sp. A3 and Kosakonia sp. A37 resulted in ~ 37% and ~ 53% increase in root length of tomato seedlings, respectively, while Pantoea sp. A34 and Kosakonia sp. B7 had deleterious effects on root length as well as overall growth of the seedlings. To our knowledge, this is the first report of plant growth promoting potential of microorganisms isolated from termitorial soil of Sanjivani island, which is a drought-prone area. Therefore, such efficient growth promoting P solubilizers can offer an effective solution for sustainable agriculture in arid, dryland farming and drought-prone regions.

Phosphate Solubilization by Bacillus subtilis and Serratia marcescens Isolated from Tomato Plant Rhizosphere

Abstract: Plants need phosphorus for many physiological activities in a form of phosphate anions. Three different bacterial strains (Bacillus subtilis PH, Serratia marcescens PH1, and Serratia marcescens PH2), recently isolated from tomato plant rhizosphere, have high phosphate solubilization index (SI from 2.8 to 3.2) on Pikovskaya agar medium (which contains calcium phosphate). Moreover, phosphate release from calcium in Pikovskaya broth over 5 days is increasing with cell growth for the different isolates. The most efficient phosphate solubilization case is the mixed culture of the 3 strains (OD475 is almost 1). On the other hand, pH values decreased dramatically with time due to organic acids secretion and the maximum acidification level is recoded for Serratia marcescens PH2 (pH = 1.94). Interestingly, the isolates are resistance to important pesticides (oxamyl, thiophanate methyl, and captan) that are commonly used in the sampling area. This resistance is very favorable and increases the persistence of the phosphate solubilizing bacteria in contaminated soils. The isolates are therefore plant symbionts and growth promoting agents.

Comparative phosphate solubilizing efficiency of psychrotolerant Pseudomonas jesenii MP1 and Acinetobacter sp. ST02 against chickpea for sustainable hill agriculture

Abstract: Phosphorus (P) is an important plant nutrient for agricultural production Adding phosphorus fertilizer to the soil not only increases the cost but also create environmental destruction Therefore, the use of phosphate solubilizing bacteria (PSB) could be an eco-friendly approach for sustainable agricultural development Large scale field trial study was conducted to explore inherent phosphate solubilizing potential of Himalayan psychrotrophic bacterial strains Pseudomonas jesenii MP1 and Acinetobacter sp ST02 against native chickpea to achieve agricultural sustainability in traditional mountain agro-ecosystems Both the strainsMP1 and STO2 were able to solubilise a maximum of 39814 μg mL−1 and 3299 μg mL−1 of P, respectively Besides enhancing Chickpea seed germination of 92% (MP1) and 85% (STO2); both have shown a significant increment in plant agronomical as well as biochemical parameters with respect to their respective controls The maximum grain yield of 2623 kg and harvesting index 5569 was observed for MP1 along with 40 Kg P2O5 ha−1 thereby, indicating the use of bio-inoculants with recommended dose of phosphate fertilizers to promote crop production Further, contrary to chemical phosphatic fertilizers, they need to apply only once in the field and persist till the end of crop maturity In the present scenario, they can be explored as natural “P” resource for high altitude agriculture; therefore, additional impetus in their bio-formulation will be a step forward towards sustainable hill agriculture systems and holistic growth

Phosphorus Availability in Wheat, in Volcanic Soils Inoculated with Phosphate-Solubilizing Bacillus thuringiensis

Abstract: The use of phosphate solubilizing bacteria (PSB) is an ecological strategy that allows for increasing the availability of phosphorus (P) in soil. The objective of this study was to evaluate P availability in wheat, in soils derived from volcanic ash (Andisol and Ultisol,) and inoculated with phosphate-solubilizing Bacillus thuringiensis, the experiment was conducted in pots under greenhouse conditions using a completely randomized design. Wheat plants were inoculated and re-inoculated at 20 and 46 days after sowing (DAS), respectively, with B. thuringiensis; and, soil and plant sampling was performed after 46, 66, and 87 days based on the Zadoks growth scale (Z). The inoculation resulted in an 11% increase in P of the rhizosphere at Z46 (Ultisol), P also increased 34% and 67% in aerial tissues at Z46 (Andisol and Ultisol), respectively, while an increase of 75% was observed in root tissues at Z87 (Ultisol). Similarly, the inoculation resulted in increases in acid phosphatase activity (Andisol), soil microbial biomass (Andisol and Ultisol), and root biomass in plants (Ultisol), without achieving increase of the aerial biomass of the plants. The phosphate solubilizing B. thuringiensis strain showed some positive, but also negative effects in soils and plants, depending on the soil.

Isolation and characterization of halotolerant phosphate-solubilizing microorganisms from saline soils.

Abstract: Halotolerant phosphate-solubilizing microorganisms (PSMs) capable of producing plant-growth-promoting traits were grown on salt medium containing Ca3(PO4)2 or egg yolk. The number of colonies on plates with Ca3(PO4)2 was higher than that on plates with egg yolk. Further, a total of 42 PSM isolates were purified. The majority were Bacillus spp., while one Providencia rettgeri strain was confirmed, for the first time, as a PSM. All PSMs had a phosphate-solubilizing index (PSI) between 1.1 and 2.58 and a strong capacity for dissolving calcium phosphate between 2.25 and 442 mg·L−1. In contrast, these PSMs were less effective when dissolving aluminum phosphate, ferric phosphate and lecithin. Isolates were also tested for growth-promoting substances. The results showed that all isolates were able to secrete indole-3-acetic acid in amounts ranging from 2.7 to 31.8 mg·L−1 and exopolysaccharide within the range 74.3 and 225.7 mg·L−1. Only 12 siderophore-producing strains with siderophore units of 1.9–42.1% were detected. Among them, ten isolates with solubilization rates greater than 200 mg·L−1 and relatively high NaCl tolerance (1.5 M) were classified as candidate PSMs. Eight different organic acids with different contents were detected in the culture filtrates, and propionic and oxalic acids have been proposed as the main mechanisms for solubilization. The ten isolates have the potential for use as bioinoculants to protect plants in saline environments.

Root Colonization and Growth Promotion of Soybean, Wheat and Chinese Cabbage by Bacillus cereus YL6

Abstract: Phosphate-solubilizing bacteria (PSB) have been isolated and used in agricultural production. However, comprehensive research on PSB colonizing the rhizosphere of different plants and promoting plant growth is lacking. This study was conducted to study the growth-promoting effects and colonizing capacity of the PSB strain YL6. The YL6 strain not only increased the biomass of pot-planted soybean and wheat but also increased the yield and growth of Chinese cabbage under field conditions. The promotion of growth in these crops by strain YL6 was related to its capacities to dissolve inorganic and organic phosphorus and to produce a certain amount of indole-3-acetic (IAA) and gibberellin (GA). After YL6 was applied to soybean, wheat and Chinese cabbage, the rhizosphere soil available phosphorus (available P) content increased by 120.16%, 62.47% and 7.21%, respectively, and the plant total phosphorus increased by 198.60%, 6.20% and 78.89%, respectively, compared with those of plants without the addition of YL6. To determine whether the phosphate solubilizing bacteria colonized these plants, YL6 labeled with green fluorescent protein (YL6-GFP) was inoculated into plant rhizospheres. YL6-GFP first colonized the root surface and hairs and then penetrated into intercellular spaces and vessels. Collectively, these results demonstrate that YL6 promoted the growth of three different crops and colonized them in a similar way and therefore provide a solid foundation for probing into mechanisms by which phosphate-solubilizing bacteria affect plant growth.

Effects of organochlorine pesticides on plant growth-promoting traits of phosphate-solubilizing rhizobacterium, Paenibacillus sp. IITISM08.

Abstract: The study aimed to identify an effective phosphate-solubilizing and organochlorine pesticide-tolerant bacterial strain(s). A total of 50 phosphate-solubilizing bacterial (PSB) strains were isolated from pesticide-stressed soil. Ten isolates showing higher solubilization were selected for organochlorine pesticides (endosulfan, aldrin, and lindane) tolerance. The strain IITISM08 showed the maximum potential of phosphorous solubilization in Pikovaskya agar medium (solubilization index = 3.2) and in broth medium (348 ± 2 μg mL−1) and tolerated up to 250 μg mL−1 of organochlorine pesticides. During phosphorous solubilization, the presence of functional group and organic acid production were also observed using FT-IR and HPLC. The plant growth-promoting (PGP) traits of the strain IITISM08 was highly inhibited in presence of endosulfan among the three organochlroine pesticides. The strain IITISM08 degraded aldrin (79%), lindane (68%), and endosulfan (51%) at a concentration of 50 μg mL−1. The strain IITISM08 was identified using 16S rDNA gene sequencing as Paenibacillus sp. (IITISM08). The study revealed that the strain IITISM08 can be used as PGP candidate even under organochlorine pesticide-stressed condition.

Phosphate-solubilizing bacteria improve the phytoremediation efficiency of Wedelia trilobata for Cu-contaminated soil.

Abstract: In a controlled experiment, we assessed the effect of phosphate-solubilizing bacterium (PSB) on the soil metal (Cu2+) phytoremediation by Wedelia trilobata and examined the effect of the interaction of Cu contamination and PSB on the growth of W. trilobata. We also explored the effect of the interaction of Cu contamination and PSB on the soil microflora. The results showed that the removal efficiency of Cu from soil by W. trilobata increased with an increase in the concentration of PSB, and the translocation factors of Cu (i.e., leaf:root and stem:root) were both significantly upregulated by PSB. The PSB significantly promoted the growth of W. trilobata; however, the effect of the Cu-PSB interaction on the leaf net photosynthetic rate (Pn) of W. trilobata was not significant, whereas copper contamination had a significant negative influence on the soil microflora, PSB had a significant positive influence on the soil microflora. Thus, PSB improved the phytoremediation efficiency of W. trilobata in Cu-contaminated soil because of the positive influence on the soil microflora, improving soil quality, which then increased the growth of W. trilobata in Cu-contaminated soil. The vigorous growth of W. trlobata led to higher of Cu absorption and translocation from soil as the ultimate result.

Community composition and functions of endophytic bacteria of Bt maize

Abstract: We investigated the potential effects of genetic modification of Bt maize on the community composition and functions of bacterial endophytes associated with transgenic maize (Bt MON 810) in comparison with its isogenic parental line at two developmental stages. Bacterial isolates were obtained from transgenic (Bt) and non-transgenic (non-Bt) maize at 50- and 90-day-old developmental stages. Isolated bacterial endophytes were screened for their capabilities in phosphate solubilisation, nitrogen fixation, production of antifungal metabolites and production of indole acetic acid. After molecular identification, 60 isolates were obtained and clustered into 19 and 18 operational taxonomic units from 50- and 90-day-old maize, respectively. The isolates belonged to the genera Bacillus, Pantoea, Serratia, Yersinia, Enterobacter, Pseudomonas, Acinetobacter and Stenotrophomonas. Functional attributes and diversity of the isolated endophytes at both developmental stages were not significantly different for both maize varieties. However, functional attributes were significantly affected by plant growth stage. Isolates from younger plants were more efficient producers of indole acetic acid, but exhibited little or no capabilities for nitrogen fixation, phosphate solubilisation and antifungal activity in both maize genotypes. Based on these outcomes, Bt modification in maize does not seem to affect the community composition or functional attributes of bacterial endophytes. Significance: • Bt modification in maize does not affect the ecological guild or functional attributes of cultivable bacterial endophytes.

Molecular diversity of phosphate solubilizing bacteria isolated from the rhizosphere of chickpea, mustard and wheat

Abstract: Molecular diversity of native phosphate solubilizing bacteria from rhizosphere of important crops like chickpea (Cicer arietinum), mustard (Brassica campestris) and wheat (Triticium aestivum) grown in Haryana was studied A total of 193 isolates were selected from the rhizosphere of chickpea (76), mustard (68) and wheat (49) based on zone of P-solubilization. These were screened for P-solubilization on solid as well as liquid Pikovskaya's medium. All the isolates showed large variations in P-solubilization.On the basis of the 20 biochemical tests, a dendrogram was constructed using UPGMA with which all the PSB isolates were clustered in nine major groups. The isolates from chickpea, mustard and wheat rhizosphere were randomly distributed. Twenty three PSB isolates representing nine biochemical groups were selected and genetic diversity was determined by amplified ribosomal DNA restriction analysis (ARDRA) using Hinf1 and Msp1. The banding pattern was analyzed using NT-SYS programme and a dendrogram was constructed. The isolates were divided into 10 ARDRA groups at 85% similarity level. Majority of the isolates fell in one group while the remaining isolates constituted the separate groups. PSB from different crops rhizosphere were randomly distributed. Biochemical groups did not correlate to the ARDRA groups.