The Effect of Plant Growth Promoting Rhizobacteria on Barley Seedling Growth, Nutrient Uptake, Some Soil Properties, and Bacterial Counts

This study was conducted with barley in greenhouse conditions in order to investigate seed inoculation with 5 different N2-fixing (Bacillus licheniformis RC02, Rhodobacter capsulatus RC04, Paenibacillus polymyxa RC05, Pseudomonas putida RC06, and Bacillus OSU-142) and 2 different phosphate-solubilising (Bacillus megaterium RC01 and Bacillus M-13) bacteria in comparison to control and mineral fertiliser (N and P) application. Among the strains used in the present study, 6 plant growth promoting rhizobacteria (PGPR) stimulated indole acetic acid (IAA) production and 3 of them stimulated phosphate solubilisation; all bacterial strains fixed N2 and significantly increased the growth of barley. Available phosphate in soil was significantly increased by seed inoculation with Bacillus M-13 and B. megaterium RC01. Maximum NO3-N was found in soil after inoculation with N2-fixing Bacillus OSU-142, followed by P. polymyxa RC05 and R. capsulatus RC04. Total culturable bacteria count increased in all treatments with time, whereas N2-fixing bacteria decreased with time, except with B. megaterium RC01 inoculation. The data suggest that seed inoculation of barley with plant PGPR increased root weight by 17.9%-32.1% as compared to the control, and increased shoot weight by 28.8%-54.2%, depending on the species. N2-fixing bacterial inoculation significantly increased uptake of N, Fe, Mn, and Zn by barley. The production of hormones is suggested to be one of the mechanisms by which PGPR stimulate barley growth. Effective Bacillus species, such as OSU-142, RC07, M-13, P. polymyxa RC05, P. putida RC06, and R. capsulatus RC04, may be used in agriculture

ORGANIC FARMING AND SUSTAINABLE RURAL DEVELOPMENT: ÇORUH VALLEY

Organic farming has potential for reducing some of the negative impacts of conventional agriculture on the environment. Organic farming contributes to rural development and economy. These farming systems can also be the most important contributor to the rural economy of region and Çoruh Valley. Çoruh Valley contains rich biological diversity of plants, wildlife, and ecosystems. These natural and environmental resources will play an important role for rural development in this area. Some evidences suggested that an important benefit of organic farming is the creation of jobs in the rural economy and prevention of human erosion. Effective use of the source will come true with production, processing and marketing of organic products such as spices, pekmez, honey, fruit and vegetable juices, thyme juices, vegetable oils, herbal tea, chemical compounds of plant and food additives in Çoruh Valley

Enzyme activities and growth promotion of spinach by indole-3-acetic acid-producing rhizobacteria

The objective of this study was to evaluate the effects of twelve plant growth-promoting rhizobacteria (PGPR; Bacillus mycoides FD07, B. sphaericus RC12, B. pumilus RC19, B. cereus RC18, Variovorax paradoxus RC21, Paenibacillus polymyxa RC35, Pseudomonas putida RC06, B. megaterium RC07, B. megaterium M-3, B. licheniformis RC08, B. subtilis RC11, and B. subtilis OSU-142) used as biofertilisers, on various enzyme activities [glucose-6-phosphate dehydrogenase (G6PD); 6-phosphogluconate dehydrogenase (6PGD); glutathione reductase (GR); and glutathione S-transferase (GST)] and on seedling growth in spinach (Spinacia oleracea L.). Enhanced plant growth could result from rhizobacterial production of indole-3-acetic acid (IAA). The highest IAA-producing rhizobacteria (RC35 and RC06) produced the highest root and shoot weights. PGPR improved N and P nutrition in spinach, and therefore stimulated plant growth and key enzyme activities. The responses to inoculation, compared to uninoculated control plants, were: –1.9% to +36.4% for shoot fresh weights (FWs), –5.5% to +30.1% for root FWs, –3.5% to +29.8% for shoot dry weights (DWs), –3.8% to +38.5% for root DWs, and –5.9% to +30.1% for leaf areas. Plant growth responses were variable and dependent on the inoculant strain used, as well as on the enzyme activity and growth parameter being evaluated. Close correlations between plant shoot growth, PGPR inoculation, and G6PD (r = 0.28*), 6PGD (r = 0.55**), GR (r = 0.73**), and GST (r = 0. 64**) enzyme activities in spinach have been demonstrated

Role of inoculation with multi-trait rhizobacteria on strawberries under water deficit stress

This study was conducted during 2011 and 2012 to evaluate the effect of 1-aminocyclopropane-1-carboxylate (ACC) deaminase-containing, N2-fixing and P-solubilizing bacteria on the yield and morpho-physiological parameters of strawberry. A total of 8 applications at the trial set, with four water regimes were randomly distributed into the pots. The diminishing water supply caused a gradual decrease in the plant growth, chlorophyll content and berry yield, accompanied by increasing activities of drought stress markers such as total phenolics content (TPC), trolox equivalent antioxidant capacity (TEAC), malondialdehyde (MDA) content, hydrogen peroxide (H2O2), glutathione reductase (GR), glutathione S-transferase (GST), catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) and ascorbate peroxidase (APX) in the leaves of strawberry. The multi-trait bacteria also increased plant growth and yield as well as TPC, TEAC, antioxidant enzymes (GR, GST, CAT, POD, SOD and APX) activity, phytohormone (GA, SA and IAA) and the contents of N, P, K, Ca, Fe, Mn, Zn and Cu, but decreased MDA and H2O2 contents which may contribute in part to activation of physiological and biochemical processes involved in the alleviation of the effect of drought stress

Effects of plant growth promoting rhizobacteria (PGPR) on rooting and root growth of kiwifruit (Actinidia deliciosa) stem cuttings

The effects of plant growth promoting rhizobacteria (PGPR) on the rooting and root growth of semi-hardwood and hardwood kiwifruit stem cuttings were investigated. The PGPR used were Bacillus RC23, Paenibacillus polymyxa RC05, Bacillus subtilis OSU142, Bacillus RC03, Comamonas acidovorans RC41, Bacillus megaterium RC01 and Bacillus simplex RC19. All the bacteria showed indole-3-acetic acid (IAA) producing capacity. Among the PGPR used, the highest rooting ratios were obtained at 47.50% for semi-hardwood stem cuttings from Bacillus RC03 and Bacillus simplex RC19 treatments and 42.50% for hardwood stem cuttings from Bacillus RC03. As well, Comamonas acidovorans RC41 inoculations indicated higher value than control treatments. The results suggest that these PGPR can be used in organic nursery material production and point to the feasibility of synthetic auxin (IBA) replacement by organic management based on PGPR

EFFECTS OF PLANT GROWTH-PROMOTING RHIZOBACTERIA ON SOME MORPHOLOGIC CHARACTERISTICS, YIELD AND QUALITY CONTENTS OF HUNGARIAN VETCH

This research study was designed to determine the effects of plant growth-promoting rhizobacteria (PGPR) on some morphological characteristics, yield and quality contents of Hungarian vetch (Vicia pannonica Crantz.) in the Kelkit Aydin Dogan Vocational Training School Research Area during 2008-2009 and 2009-2010 plant growing season. The research consisted of a control (without plant growth-promoting rhizobacteria) and 12 different plant growth-promoting rhizobacteria (Pseudomonas putida PPB310, Bacillus cereus BCB51, Pantoea agglomerans PAB58, Pseudomonas fluorescens PFC82, Pseudomonas fluorescens PF84, Arthrobacter mysorens AM235, Paenibacillus polymyxa PP315, Pantoea agglomerans PAA362, Bacillus atrophaeus BA361, Bacillus megaterium BMA424, Bacillus megaterium BMA479 and Bacillus subtilis BS521) seed inoculations and three replicates. Some morphological characteristics (stem diameter, plant height and leaf number), dry matter yield, crude protein, crude protein yield, ADF, NDF, macro and micro-elements (B, Ca, Na, K, Mg, P, S, Cu, Fe, Mn and Zn) were tested in the research study. According to the results of the research study, some of the PGPR treatments had positive effect on morphological characteristics (especially PFC82, BA361 and PAB58), dry matter yield (very little PAA362), crude protein (very little PFC82), ADF and NDF (especially BA361) and macro and micro-elements (especially PAA362) of Hungarian vetch

BIOLOGICAL CONTROL OF ROOT ROT DISEASE CAUSED BY Rhizoctonia solani Kuhn ON POTATO AND BEAN USING ANTAGONIST BACTERIA

WOS: 000363405500003In this study the use of 73 bacteria, isolated from rhizosphere area of tea (Camellia sinensis) plants in Black Sea Region in Turkey, as potential biocontrol agent against root rot disease caused by Rhizoctonia solani that was known as an important disease on potato and bean plants in Turkey and in the world were investigated. In in vitro conditions, 73 bacteria used for antagonistic tests, and 15 out of 74 were found to be effective against R. solani and formed between 0.20-2.30 cm inhibition zone and inhibited mycelium development of the pathogen. In vivo pot experiment also showed that antagonist bacteria strains had various level inhibition effect (between 12% and 83%) on R. solani compared to control. The study revealed that biocontrol agents might play an essential role in management of root rot diseases in potato and bean