Search

Analysis of phenazine for fifteen pigment-producing Fusarium oxysporum f. sp. ciceris (Foc) antagonistic rhizobactria, ranged between 20.5 and 706.4 μg/mL, with the maximum production recorded by the isolate Ps45. Similarly, isolate Ps45 exhibited the highest values of phenazine-1-carboxylic acid (PCA) and 2-hydroxy-phenazine carboxylic acid (2-OH-PCA) concentration (268.1 and 44.4 μg/mL, respectively), whereas isolate Ps44 exhibited the highest hydroxy phenazine-dioxide (OH-P-dioxide) or iodinin concentration (621.2 μg/mL). In 10 pseudomonads, phz CD genes were marked for their capability to synthesize PCA. Thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) of five potential phenazines producers showed coloured spots with the same mobility and Rf value with the standard phenazine and a typical peak maxima at 247 nm. The highest phenazine concentration (612.1 μg/mL) was recorded by isolate Ps44. Scanning electron microscopic(SEM) evaluation of the crude phenazine extract of potential isolates disclosed disrupting and dwindling effects on the hyphal growth of selected virulent strain of Foc hyphal growth.

The latest soil management scenario is occupied by destructive chemical fertilizers, which is a serious risk to both human health as well as to the environment. Advantageous microbes present in soil are used as a biofertilizers for a promising role in sustainable agriculture. Pigeon pea (Cajanus cajan L.) is a primitive protein rich leguminous pulse in India. Thirty-five isolates from rhizospheric soil samples were collected from twelve different locations of Punjab (India). Morphological and biochemical characterization for selection of potential plant growth promoting traits with antifungal properties was undertaken. Most of the inoculated seeds with rhizoisolates evolved a significant increase in growth parameters of pigeon pea as compared to uninoculated seeds, both in vitro and in vivo conditions. Plant growth promoting rhizobacterias (PGPRs) are environmentally safe as they lead to increased production and resistance against diseases of crops.

Background: Phytophthora blight (PB), caused by Phytophthora drechsleri f. sp. cajani, is soil borne disease of pigeonpea (Cajanus cajan L). The use of PGPR in agriculture leads to alternative disease management of crop in a sustainable ecofriendly way. Methods: In vitro and In vivo experimentation was conducted at fields of Punjab Agricultural University, Ludhiana during kharif season of 2017-18 to study the percentage of blight inhibition by rhizobacteria and production potential in pigeonpea. The present study consisted of 6 treatments of dual inoculation of antagonistic bacteria with recommended rhizobium of PAU (LAR-06).Results: The selected rhizoisolates were studied against Phytophthora drechsleri caused stem blight of pigeonpea. The allelochemicals and Plant Growth Promoting Rhizobacteria traits involved in antagonistic behavior significantly inhibited the growth of the test fungus. Scanning electron microscopy between potential rhizoisolates and test fungus revealed intumescent hyphae with irregular cell surface morphology. The synergistic effects of LAR-06 + S-2 and LAR-06+ S-18 were found to be the most potent ones in inhibiting the radial growth of the test pathogen with increased yield production in the field as well as greenhouse conditions.

Soil management today is dominated by toxic chemical fertilizers that pose a serious health and environmental risk. Beneficial soil microbes play a promising role in sustainable agriculture when used as biofertilizers. Pigeonpea (Cajanus cajan) is an ancient protein-rich leguminous pulse in India. Twelve different locations in Punjab (India) provided rhizospheric soil samples and the growth rates of 35 isolates were assessed at various temperatures. To identify potential plant growthpromoting traits with antifungal properties, morphological and biochemical characterization were carried out. Compared to uninoculated pigeonpea seeds, inoculated seeds with rhizoisolates showed a significant increase in growth parameters in greenhouse pot conditions. Plant growth-promoting rhizobacteria (PGPRs) are a good way to increase crop yields while also controlling disease outbreaks.

Aims To explore the impact of incorporating a faster cardiac magnetic resonance (CMR) imaging protocol in a low–middle-income country (LMIC) and using the result to guide chelation in transfusion-dependent patients. Methods and results A prospective UK–India collaborative cohort study was conducted in two cities in India. Two visits 13 months apart included clinical assessment and chelation therapy recommendations based on rapid CMR results. Participants were recruited by the local patient advocate charity, who organized the patient medical camps. The average scanning time was 11.3 ± 2.5 min at the baseline and 9.8 ± 2.4 min (P Conclusion For thalassaemia patients in an LMIC, a simplified CMR protocol linked to therapeutic recommendation via the patient camp model led to enhanced chelation therapy and a reduction in cardiac iron in 1 year.

In the present study five potent rhizobacterial antagonists of Fusarium oxysporum f. sp. ciceris alone and in combination with Mesorhizobium (M) were evaluated for their potential to elicit the defence response reactions to reduce the total loss of plants and enhance the growth of two chickpea cultivars i.e. resistant GPF-2 and susceptible JG-41. Observations revealed that maximum phenolic, peroxidase (PO) and polyphenol oxidase (PPO) activity was induced after 30th day of germination. Maximum phenol concentration of 745.8 and 724.1 μg/gfw root tissues was recorded by Ps45 when co-inoculated with Mesorhizobium in both the varieties i.e. GPF-2 and JG-41 respectively. Isolates Ps45, Ps47 and Ps44 were found most promising to induce PO and PPO activity, in combination with Mesorhizobium and recorded superior over the fungicide with respect to negative control. Similar results were recorded for the phenylalanine ammonia lyase (PAL), maximally induced on 20th day after germination, where dual inoculation of Ps44+M and Ps45+M induced 57.0 and 54.2 nmol of cinnamic acid min−1 gfw−1 in GPF-2. However in case of JG-41, Ps45 and Ba1a exhibited highest PAL activity of 54.2 and 41.4 nmol of cinnamic acid min−1 gfw−1. Malonic aldehyde concentration in stem tissues at 30th day revealed that lipid peroxidation was effectively reduced in rhizobacterial treated plants compared to fungicide and negative control, signifying the role of antagonistic plant growth promoting rhizobacteria in reducing the stress and enhancing the plant’s defence response to reduce the disease incidence and thus improving the plant growth and yield. Moreover the dual inoculations were observed superior over the fungicide treatment as well as single inoculations in terms of growth (root/shoot length and weight), signifying the synergistic effect of screened antagonists and native Mesorhizobium in suppressing the pathogen and thereby enhancing the plant growth.

The study envisaged at eliciting defense in chickpea plants challenged with and without Fusarium oxysporum f. sp. ciceris on prior inoculating seeds with two bioagents, Bacillus sp. and Brevibacillus brevis alone and in conglomeration with rhizobia. Spectrophotometric analysis for defense-related enzymes demonstrated higher accrual of peroxidase (PO), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), phenols and total proteins in bacterized plants compared to uninoculated control and only pathogen inoculated chickpea roots. Nevertheless, activities of PAL, PO and PPO were found to be higher in the bacterized root tissue of the plants challenged with F. oxysporum compared to only bacterized plants. Combined administration of bacterial isolates with rhizobia resulted in stimulated expression of defense enzymes than with either agent alone. The steady increase in synthesis of defense enzymes was recorded up to 15 days which reached maximum by 20th day and then declined drastically. Native-polyacrylamide gel electrophoresis analysis for PO and PPO anionic forms following activity staining revealed higher expression of PO3, PO5, PO4, PO7, PPO1 and PPO3 isoforms in bacterized chickpea root tissues challenge inoculated with the pathogen. Higher expression of enzymes could be associated with defense against ingressing pathogen.

Field experiments evaluated the effects of integrated nutrient management on symbiotic parameters, growth, nutrient accumulation, productivity and profitability of lentil (Lens culinaris Medikus). Application of recommended dose of nutrients (RDN, 12.5 kg N ha−1 + 40 kg P2O5 ha−1) + 25 kg ZnSO4 ha−1 + seed inoculation with biofertilizers [Rhizobium + phosphate solubilizing bacteria (PSB) + plant growth promoting rhizobacteria (PGPR)] + 1.0 g ammonium molybdate kg−1 seed recorded the highest number & dry weight of nodules, leghaemoglobin content, root & shoot dry weight, plant height, number of pods plant−1 and 100-seed weight. The next best treatment was RDN + seed inoculation with biofertilizers + 1.0 g ammonium molybdate kg−1 seed. On the basis of mean of three-year data, the treatment of RDN + 25 kg ZnSO4 ha−1 + seed inoculation with biofertilizers + 1.0 g ammonium molybdate kg−1 seed proved the best in realizing the highest grain yield (34.0%), gross returns (34.0%) and net returns (54.8% high...

PGPR strains exhibiting optimum functional traits at high temperature and are compatible with Rhizobium can be used in pigeonpea as biofertilizer. A total of 45 rhizobacterial isolates were isolated from 13 different locations of pigeonpearhizospheric soil of Punjab. Out of the 45 isolates, 5 isolates selected on the basis of maximum growth at 30°C and 40°C were morphologically and biochemically characterized, belonging to genera Pseudomonas (P-6, P-9) and Bacillus (P-30, P-31, P-32). Selected isolates were further evaluated for the production of IAA, GA, SA and flavonoids. IAA production was estimated in the range from 0.45-25.13 μg/ml and 4.62-34.34 μg/ml in the presence of tryptophan at 30 and 40°C respectively. Maximum gibberellic acid production was recorded with P-30 (108.99 μg/ml and 112.12 μg/ml) at 30 and 40°C respectively. Similarly maximum salicylic acid was also estimated with P-30 (157.2 μg/ml) followed by P-31 (141.0 μg/ml) at 40°C. All the isolates were also found to produce flavonoids ranged from 2.98 - 4.40 μg/ml at 40 °C. Isolates P-30, P-31 showed superior production of growth hormones and flavonoid-like compounds can further be tested under the field conditions to enhance growth and yield of pigeonpea.

The study evaluated the effects of phosphorus (0, 20, 30, and 40 kg P₂O₅ ha⁻¹) and biofertilizers [Rhizobium (Rhizobium leguminosarum bv viciae), plant growth promoting rhizobacteria (PGPR) (Pseudomonas fluorescens), Rhizobium + PGPR, and uninoculated control] in lentil. Application of 40 kg P₂O₅ ha⁻¹ resulted in the highest number of nodules, nodule dry weight, leghemoglobin content in nodules, chlorophyll content, yield attributes, and grain yield. Coinoculated treatment performed better than uninoculated control, and individual inoculations of Rhizobium and PGPR in terms of all above mentioned parameters. Application of 20 kg P₂O₅ ha⁻¹ + Rhizobium inoculation gave statistically similar and 20 kg P₂O₅ ha⁻¹ + Rhizobium + PGPR inoculation gave significantly higher grain yield than that by 40 kg P₂O₅ ha⁻¹ alone. The use of Rhizobium alone and Rhizobium + PGPR consortium can save not only 20 kg P₂O₅ ha⁻¹ but also increase the grain yield of lentil.

The experiment was conducted to study the integrated nutrient management for high productivity and net returns in lentil. Results revealed that nodulation was significantly (P≥0.01) enhanced in treatments comprising of Rhizobium and phosphate solubilizing bacteria (PSB) along with recommended dose of fertilizer (RDF), farmyard manure (FYM) and vermicompost. Treatments comprising of Rhizobium + PSB along with RDF, 50% RDF, FYM and vermicompost showed higher nodule dry weight as compared to the treatments without biofertilizers. Pods plant-1 was highest in RDF + Rhizobium + PSB. Combination of different organic sources with RDF resulted in significantly (P≥0.001) higher grain yield than RDF only. RDF + 5 t ha-1 FYM resulted in 26.3 and 6.7 per cent higher grain yield over control and RDF alone, respectively. RDF + Rhizobium + PSB recorded the highest net returns (Rs 40321 ha-1) and B:C ratio (3.78). It can be concluded that supplementing the recommended dose of nutrients (12.5 kg N + 40 kg P2O5 ha-1) with 5 t ha-1 FYM or 2 t ha-1 vermicompost or Rhizobium + PSB inoculation help in obtaining high grain yields and net returns in lentil.

Sixty-nine rhizobacteria isolated from chickpea rhizosphere were screened for their antagonistic potential against Fusarium oxysporum f. sp. ciceris under in vitro condition. Of these, 30 isolates inhibited growth of the pathogen and 13 potent antagonists were assessed for their functionality traits. Among the antagonistic traits exhibited by antagonists, production of diffusible antimetabolites insured its inhibitory effect on growth of test fungus as well as spore germination on solid media. Inhibition of fungus biomass in broth-based dual culture was revealed by 11 antagonists, while metabolic extracts of 5 isolates reduced the radial proliferation on solid media. Implication of biocidal volatiles in antagonism was demonstrated by 11 isolates; 3 produced cyanogenic volatiles, while all were ammonia producers. Investigation for hydrolytic activity demonstrated production of chitinase by 4 isolates and β-1,4-glucanase by 11, while all were protease and amylase producers. Revealing the dual potential of bioantagonists, all the isolates tested positive for IAA and salicylic acid production, 7 for siderophore production while 10 were P-solubilizers and 8 Zn-solubilizers. Under glass house condition, bacterization of chickpea seeds with potential isolate Ps14c alone and in consortium with Mesorhizobium ciceris reduced wilt incidence in pots (soil amended with F. oxysporum) to 48 and 28%, respectively, as compared to uninoculated control (74%) and also recorded appreciable increase in growth parameters. Present investigation clearly reveals the potential of rhizobacteria for use as bioinoculants.

A pot experiment was conducted in glass house at PAU research farm, Ludhiana, Punjab, India to evaluate effect of co-inoculation of plant growth promoting rhizobacteria with Rhizobium on mungbean productivity. Coinoculation showed a significant increase at 5% in nodule number, nodule dry weight, shoot and root dry and fresh weight, plant length, no. of pods, chlorophyll and leghaemoglobin content, over Rhizobium alone. Application of PGPRs R-4, R-6, S-5, S-9 and S-11 along with Rhizobium further enhanced the grain yield over Rhizobium inoculation alone. Rizobacterial isolates R-6 and S-11 co-inoculated with Rhizobium showed better result than other isolates.These plant beneficial rhizobacteria may decrease the global dependence on various hazardous agricultural chemicals used in mungbean.

A field experiment was conducted during kharif (rainy season) 2008 and 2009 at research farm of the Punjab Agricultural University, Ludhiana, to study the effect of four/three sowing dates (1 May, 15 May, 1 June and 15 June in 2008 and 15 May, 1 June and 15 June in 2009) on the symbiotic characters, thermal requirement, growth, productivity and economics of four pigeonpea genotypes (AL 201, AL 1507, AL 1578 and AL 1593). Days taken to 50% flowering, physiological maturity, and various agroclimatic indices i.e. AGDD, AHTU, APTU and HUE decreased with delay in sowing. The crop sown on 15 May recorded the highest nodule dry weight plant -1. The grain yield was significantly higher for the 15 May sowing compared to the 15 June sowing. During the two years, the crop sown on 15 May registered on average 6.7 and 48.0 percent higher grain yield than the1 June and 15 June sowings, respectively. The crop sown on 15 May gave the maximum gross returns, net returns and benefit-cost (B:C) ratio. Among the genotypes, AL 1507 recorded the highest nodule number plant-1 and AL 1578 recorded the maximum nodule dry weight plant-1.Genotypes AL 1507, AL 1578 and AL 1593 registered on average 19.4, 19.2 and 20.0 percent higher grain yield relative to AL 201, respectively. The genotype AL 1507 in 2008 and AL 1593 in 2009 performed better in terms of heat use efficiency for grain yield.

Cold-tolerant plant growth-promoting rhizobacteria (PGPR) are of immense agronomic importance due to the fact that the winter season crop growing cycle is subject to varying spells of low temperatures and such PGPRs are metabolically functional at cold conditions. Thirty-five (35) rhizobacterial isolates were isolated from lentil rhizospheric soil, six isolates showing maximum exponential growth at both 10 and 15°C after 24 h were selected and characterized belonging to genera Bacillus and Pseudomonas. Production of indole acetic acid (IAA) ranged from 12.7-17.5 µgml-1 at 10°C to 18.4-20.4 μg/ml at 15°C. At 15°C, an isolate J-17 was found to be strong HCN producer whereas at 10°C, only two isolates: J-26 and J-30 were moderate producers. P-solubilizion at 15°C, ranged from 62.5 - 77.2 µgml-1. However, at 10°C none of the isolates solubilized P. At 15°C, catechol type siderophore production ranged from 523.4 - 606.1 µgml-1. On the basis of the PGP traits, four isolates J-3, J-17, J-18 and J-30 were selected for evaluation under field conditions of lentil at research farm of PAU, Ludhiana, Punjab, India. Coinoculation exhibited a significant increase in nodule number, nodule dry weight, plant and root dry weight, chlorophyll and leghaemoglobin content over Rhizobium alone. Application of J-3, J-17, J-18 and J-30 along with Rhizobium further enhanced the grain yield (1.8, 4.4, 3 and 1.4%). Key words: HCN production, indole acetic acid, siderophore, P-solubilization.

The antagonistic activity against Fusarium oxysporum f. sp. ciceris was determined for 40 chickpea rhizobacteria. Twenty eight isolates showed antagonistic activity against test fungus ranging from 18.2 to 41.8%. Characterization of the antagonistic attributes showed that all the antagonistic isolates produced diffusible and volatile antifungal metabolites in terms of growth inhibition, maximum being with the isolates 39P (77.8%) and 15B (64.2%), respectively. Nineteen of the isolates showed catechol and hydroxamate type siderophore production. All the isolates produced ammonia and twelve showed HCN production. On the basis of their antagonistic and PGP functionality traits, five isolates (2B, 7B, 28P, 34P and 38P) were selected for glass house studies on two chickpea varieties (JG-62 and GPF-2). Isolates 28P, 34P and 38P were found to be most promising for wilt control and plant growth promotion. Isolate 38P reduced the wilt incidence to 44.6% which was at par with fungicide treatment (55.5%) and had a significant edge over negative control (85%) in the chickpea variety JG-62. Similar trend of wilt incidence was observed in GPF-2 variety. Green house experiments on two varieties of chickpea JG-62 and GPF-2 showed that seed treatment with plant growth promoting rhizobacteria (PGPR) + Mesorhizobia had a synergistic effect in terms of disease control and growth promotion as compared to use of single bioinoculants, thus positively influencing plant microbe interaction. Key words: Antagonism, chickpea, Fusarium, plant growth promoting rhizobacteria (PGPR), Rhizobium.

A field experiment was conducted during Kharif season to study the efficacy of different pre-and post-emergence herbicides for weed management in greengram. Pre-emergence (PE) application of pendimethalin + imazethapyr at 0.75 kg/ha (pre-mix) effectively reduced both the density and dry matter of weeds whereas post-emergence (PoE) application of imazethapyr 10 SL at 55 g/ha significantly reduced Cyperus rotundus. All the PE and PoE herbicides significantly reduced the dry weight of weeds at 30 and 60 days after sowing (DAS) as compared to weedy check. The highest weed control efficiency was recorded in two hand weeding (90.2%), and was followed by pendimethalin + imazethapyr (pre-mix) 0.75 kg/ha applied as PE (86.8%). PoE herbicides (imazethapyr, imazamox+ imazethapyr and clodinafop-propargyl + aciflourfensodium) not only suppressed the crop growth, but also exhibited antagonistic effect on root nodulation. Significantly higher seed yields were recorded under two hand weeding and pendimethalin + imazethapyr at 0.75 kg/ha (PE). Two hand weeding also recorded the highest gross and net returns, and was followed by pendimethalin + imazethapyr (pre-mix) at 0.75 kg/ha (PE). Application of pendimethalin + imazethapyr at 0.75 kg/ha (PE) also gave the highest B: C ratio, and it was followed by two hand weeding. All the PoE herbicides fetched comparatively lower returns and B: C ratio.

To mitigate environmental stresses, use of aminocyclopropane-1-carboxylic acid (ACC)-deaminase containing plant growth promoting rhizobacteria (PGPR) as agricultural inputs for improved crop production is required. A total of 47 bacterial isolates from different rhizospheric soils of chickpea from Punjab were biochemically characterized and found to be representatives of genus Bacillus (25) and Pseudomonas (22). Ten (10) of the isolates were able to utilize ACC as a sole source of nitrogen, maximum growth (in terms of optical density λ600) being recorded with Bacillus isolate 23-B (0.463) followed by Pseudomonas 6-P (0.317). Three isolates were P-solubilizers and their relative P-solubilization efficiency ranged from 14.6 to 21.6 mg/100 ml culture broth. All the isolates produced Indole-3-acetic acid (IAA) (4.4-22.8 µg/ml). Two PGPR’s 23-B and 6-P alone and in combination with recommended (for Punjab state) Mesorhizobium ciceris, were evaluated for water stress mitigation and plant growth promotion under axenic conditions on Cicer arietinum varieties (Kabuli L-552 and Desi GPF-2). Both the rhizobacteria significantly improved germination, root and shoot length and fresh weight of chickpea seedlings under osmotic potential of up to 0.4 MPa over uninoculated control. Proline content was considerably higher in PGPR treated varieties of chickpea under water stress. Co-inoculation of 23-B with Mesorhizobium enhanced all growth parameters under water stress. Key words: Aminocyclopropane-1-carboxylic acid (ACC)-deaminase, axenic, chickpea, polyethylene glycol (PEG), proline.

The experiment was conducted to study the effect of four levels of phosphorus (0, 20, 30 and 40 kg P2O5 ha-1) and four biofertilizer treatments [uninoculated control, Rhizobium, plant growth promoting rhizobacteria (PGPR) and Rhizobium + PGPR] on growth and grain yield of lentil. The experiment was conducted in factorial randomized complete block design (RCBD) with three replications. The periodic data recorded at 30, 60, 90, 120 days after sowing (DAS) and at harvest showed that the highest growth in various parameters i.e. plant height, branches plant-1 and shoot dry matter accumulation was recorded with application of 40 kg P2O5 ha-1, however, it was at par with 30 P2O5 ha-1. Among the biofertilizers, Rhizobium + PGPR treatment gave maximum values of growth parameters like plant height, branches plant-1 and shoot dry matter accumulation at all the stages. At 30-60 DAS, the maximum crop growth rate (CGR) was recorded with the application of 40 kg P2O5 ha-1 (71.3 kg ha-1 day-1) and co-inoculation of Rhizobium and PGPR (72.0 kg ha-1 day-1). Application of 40 P2O5 ha-1 and use of coinoculation (Rhizobium + PGPR) provided the highest grain yields. The study highlights the importance of phosphorus application and biofertilizers inoculation for improving the growth and grain yield of lentil.

Abiotic and biotic stresses highly impacts production of principal crops all around the world. Due to climate change, extreme abiotic factors like high and low temperatures, droughts, salinity, osmotic stress, heavy rains, floods and frost damages are posing grave threats to crop production. There is a dire need to mitigate these stresses, so in order to cope with such impacts, microorganisms can be employed as best alternatives to chemical inputs by exploiting their unique properties of tolerance to extreme environments, their ubiquity, their genetic diversity and their interaction with crop plants and by developing methods for their successful employment in agriculture production. Plant-growth-promoting rhizobacteria (PGPRs) mitigate abiotic stresses on plants most effectively through degradation of ACC, the ethylene precursor by bacterial ACC-deaminase and through biofilm and exopolysaccharide production. Alleviation of environmental stresses in crop plants using these microorganisms opens new and emerging applications in sustainable agriculture.

Nitrogen fixing bacteria, rhizobia and phosphate solubilizing bacteria (PSB) are the commonly applied microbial inoculants in grain legumes (Pulses). It is important to apply herbicides to control weeds in order to augment yield of the crop. The herbicides may however, be incompatible with the microbial inoculants. This study compared the effect of the recommended pre-plant incorporated herbicide, fluchloralin (20.25 × 10(4) ppm) and pre-emergence herbicide, pendimethalin in two doses (9 × 10(4) and 15 × 10(4) ppm) on the growth and survival of mungbean Rhizobium and PSB, under laboratory conditions. These herbicides were also used under field conditions in conjunction with biofertilizers (R, PSB) to improve grain yield of mungbean. It was found that fluchloralin (20.25 × 10(4) ppm) and the lower dose of pendimethalin (9 × 10(4) ppm) had no adverse effect on growth of Rhizobium and PSB. The higher dose of pendimethalin (15 × 10(4) ppm) was safe on PSB but it imposed a retarding effect on the growth of Rhizobium.

The present investigation was conducted to evaluate the effect of plant growth promoting rhizobacteria (PGPR) cultures on the activities of antioxidant enzymes in brinjal seedlings. The treatment with these PGPR cultures enhanced the activities of these enzymes. The brinjal seedlings inoculated with PGPR7 (Bacillus spp.) showed maximum activity of superoxide dismutase, catalase and amylase. Minimum peroxidase activity was observed in the seedlings treated with PGPR2 (Pseudomonas spp.). Based on the results of the experiment, the use of plant growth promoting rhizobacteria treatment may provide a means of preventing the oxidative stress in plants by enhancing the activities of antioxidant enzymes.

Nodal anatomy of 14 species belonging to 10 genera of Bignoniaceae is described. Unilacunar is the basic nodal pattern for the family with triple and multi-traced condition. The former type is observed inCampsis grandiflora, Pyrostegia venusta, Doxyantha unguis-cati, Stenolobium stans, Tabebuia pentaphylla andTecoma spp., while the latter is found inAdenocalymma alliaceum, Haplophragma adenophyllum, Jacaranda mimosifolia, Millingtonia hortensis, Spathodea campanulata, Tecoma capensis andT. jasminoides. Parmentiera cereifera has an arc of vascular elements passing through the single gap. Phylogenetic aspect of nodal anatomy is discussed.

The petiolar anatomy of sixteen species belonging to fourteen genera of Bignoniaceae has been studied. Two aspects, namely, the vascular pattern in the slender part of the petiole and the mode of vascular supply from the primary rachis to leaflets or secondary rachii, are taken into consideration. On the basis of the vasculature as seen in transection of the slender part, four main types of petioles have been recognised, while there are three patterns of vascular supply. A key also has been devised to identify these sixteen species.