• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.4
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• pp.371-378
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• 1997

The purpose of this research was to investigate the effect of P fertilization and cutting fkquency without N fertilizer on nutritive value and nitrogen fixation activity of alfalfa. A field experiment was conducted on the experimental farm of Kongju National University at Yesan from 1994 to 1996. The experimental design was a split plot design with two P levels as main plot and two cutting frequencies as the sub-plot. The results obtained are summarized as follows. Available phosphate, exchangeable Ca and Na in the soil were slightly increased with P fertilizer and basal treatment of lime. Average DM yield was 1.5 ton and 1.4 ton in second and third year. There was no significant difference within P level and cutting kquency. The first cut showed higest CP value as cutting times increased the value tend to be lowered. Crude protein content in 3 and 4 cutting regimes were from 16.3 to 16.6% 17.4 to 17.9% respectively, but no significant effect were found among the main and sub-plot. ADF and NDF in 1995 were ranged from 38.2 to 39.9, 45.1 to 58.1% respectively. ADF was 2% more higher in 1996 compared to previous year and NDF was slightly higher in 1996. There was significant difference of ADF between main plot in 1995. .P, Ca, K and Mg of 200kg P level with 3 times cutting treatment in 1995 and 1996 were 0.32 and 0.23, 0.95 and 0.84, 3.24 and 2.87, and 0.36 and 0.26. Significant difference of K and Mg between cutting frequency was observed in 1995. Nitrogen fixing activity of 400kg P fertilizer plots were higher than 200kg P level and 3 times cutting plot also showed higher acetylene reduction activity than that of 4 cutting per year. Phosphate level and cutting frequency treatment of did not significantly affect nitrogen fixation activity.

• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1614-1623
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• 2010

Bacteria were isolated from roots of sugarcane varieties grown in the fields of Punjab. They were identified by using API20E/NE bacterial identification kits and from sequences of 16S rRNA and amplicons of the cpn60 gene. The majority of bacteria were found to belong to the genera of Enterobacter, Pseudomonas, and Klebsiella, but members of genera Azospirillum, Rhizobium, Rahnella, Delftia, Caulobacter, Pannonibacter, Xanthomonas, and Stenotrophomonas were also found. The community, however, was dominated by members of the Pseudomonadaceae and Enterobacteriaceae, as representatives of these genera were found in samples from every variety and location examined. All isolates were tested for the presence of five enzymes and seven factors known to be associated with plant growth promotion. Ten isolates showed lipase activity and eight were positive for protease activity. Cellulase, chitinase, and pectinase were not detected in any strain. Nine strains showed nitrogen fixing ability (acetylene reduction assay) and 26 were capable of solubilizing phosphate. In the presence of 100 mg/l tryptophan, all strains except one produced indole acetic acid in the growth medium. All isolates were positive for ACC deaminase activity. Six strains produced homoserine lactones and three produced HCN and hexamate type siderophores. One isolate was capable of inhibiting the growth of 24 pathogenic fungal strains of Colletotrichum, Fusarium, Pythium, and Rhizoctonia spp. In tests of their abilities to grow under a range of temperature, pH, and NaCl concentrations, all isolates grew well on plates with 3% NaCl and most of them grew well at 4 to $41^{\circ}C$ and at pH 11.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.1
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• pp.67-72
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• 1990

A number of nitrogen-fixing microorganisms were isolated from roots of non-legumious crops and evaluated for their nitrogen-fixing ability on their host crops. The results are summarized as follows: 1. Among nitrogen-fixing isolates obtained from 9 different crops, several isolates showed relatively higher level of acetylene reduction activity on Spinach, Chinese cabbage, Cucumber, mustard and Egg plant. 2. When the isolates were inoculated into 4 host crops, a number of isolates were found to grow well on Spinach, Chinese cabbage and Cucumber, but particularly well on the former. 3. Results of this study suggest that nitrogen-fixing a symbiotic microorganisms are also present and able to grow well on roots of non-legumious crops, and stimulate plant growth by promoting growth and differentiation of roots.

• Journal of Microbiology and Biotechnology
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• v.21 no.6
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• pp.545-555
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• 2011

The diversity elucidation by amplified ribosomal DNA restriction analysis and 16S rDNA sequencing of 96 associative diazotrophs, isolated from the feeder roots of tea on enriched nitrogen-free semisolid media, revealed the predominance of Gram-positive over Gram-negative bacteria within the Kangra valley in Himachal Pradesh, India. The Gram-positive bacteria observed belong to two taxonomic groupings; Firmicutes, including the genera Bacillus and Paenibacillus; and Actinobacteria, represented by the genus Microbacterium. The Gram-negative bacteria included ${\alpha}$-Proteobacteria genera Brevundimonas, Rhizobium, and Mesorhizobium; ${\gamma}$-Proteobacteria genera Pseudomonas and Stenotrophomonas; and ${\beta}$-Proteobacteria genera Azospira, Burkholderia, Delftia, Herbaspirillum and Ralstonia. The low level of similarity of two isolates, with the type strains Paenibacillus xinjiangensis and Mesorhizobium albiziae, suggests the possibility of raising species novum. The bacterial strains of different phylogenetic groups exhibited distinct carbon-source utilization patterns and fatty acid methyl ester profiles. The strains differed in their nitrogenase activities with relatively high activity seen in the Gramnegative strains exhibiting the highest similarity to Azospira oryzae, Delftia lacustris and Herbaspirillum huttiense.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.4
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• pp.274-277
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• 1993

We investigated the effects of applications of various levels of lime(0, 250, 500 and 1,000 kg/10a) and phosphate (0, 17 and 34 kg/10a) on growth and nitrogen fixation of alfalfa (Medicago sativa L.). Effects of lime and phosphate applications were significantly different on dry matter (DM) weight of each part and on acetylene reduction activity (ARA) of alfalfa at 9 weeks alter sowing (p<.05). The effect of lime on DM of shoot and root was not significantly different at 14 weeks after sowing (early bloom stage), but that of phosphate on DM was significantly improved as increasing of phosphate levels (p<.01). The effects of lime and phosphate on ARA were significantly increased (p<.05). Application of lime and phosphate decreased total nitrogen (TN) content of each part of alfalfa at 9 weeks after sowing (p<.05). The effects of lime application on TN was higher but that of phosphate application on TN was lower than no application of lime or phosphate at 14 weeks after sowing (p<.05).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.2
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• pp.125-130
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• 2005

In the absence of exogeneous nitrogen supply, evaluation of a symbiosis effectiveness of Bradyrhizobium japonicum USDA 110 in a supernodulating soybean mutant, SS2-2, its wild type, Sinpaldalkong 2, and control genotype, Jangyeobkong, was conducted in this study. Nodules in SS2-2 were initially white and similar to its wild type, Sinpaldalkong 2. At the late stage, the wild type nodules became dark pinkish by maturation, by contrast, mature nodules in SS2-2 remained light green to pinkish, indicating a lack of leghemoglobin. Tap root length was short in nodulated symbiotic SS2-2 than that of its wild type and the control genotype. Nodulated root length and nodule density on root length were significantly increased by B. japonicum inoculation, but no significant increase was observed on root length and percentage of nodulation to total root length. Regardless of Bradyrhizobium inoculation, SS2-2 showed higher nodule dry weight and higher acetylene reduction activity (ARA) when compared with its wild type and the control genotype. Inoculation of B. japonicum leaded the increase of ARA in 47 days after planting (DAP), in part because of nodule development. Supernodulating mutant, SS2-2, less responded to B. japonicum induction in terms of nitrogen fixation and nodulation characteristics than its wild type. Thus, interaction of supernodulating soybean mutant with Bradyrhizobium had less symbiotically associated response than normal nodulating soybean.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.2
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• pp.113-120
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• 1996

The experiment was carried out to investigate the effects of phosphate fertilizer level on growth, crude protein content and nitrogen fixation ability of alfalfa(Medicugo sariva L.) at sowing year. The experimental field was conducted using a randomized block design with three replications according to the phosphate application level (200 and 400kfia) in farm of Kongju National University. Research samples were collected at intervals of 7 days from October 7 to December 9 and nitrogen fixation activity of nodule was measured by using the acetylene reduction method (Hardy et al. 1968). The results obtained are summarized as follows : 1. Number of branches, root length and dry matter weight at phosphate fertilizer level of 400kg in sowing year were more increase than those of 200kfia. The number of nodules was not significantly difference between phosphate fertilizer level, because of low temperature to be enough to nodulation of alfalfa. 2. The crude protein content of leaf, stem and root were not significantly affected by the phosphate fertilizer level. but that of leaf was increased at 400kgha on 72 days after sowing. The crude protein content of each part according to growing stages was increased at 44 days and 72 days after sowing. 3. The dry weight of root was not significantly difference between phosphate fertilizer level from 30 days to 51 days after sowing, but that was increased at phosphate fertilizer level of 400kgha from 51 days afier sowing. 4. The amount of ethylene in the samples taken 2 hours and calculated amount of nitrogen fixation were increased at phosphate fertilizer level of 400kfia from 30 days to 65 days after sowing. but there was vice versa from 58 days after sowing.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.2
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• pp.88-92
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• 1994

This study was carried out to investigate the effects of lime(0, 250, 500 and 1,000 kg/lOa) and phosphate (0, 17 and 34 kg/lOa) applications on growth and nitrogen fixation of alfalfa (Medicago sativa L.). The phosphate applications improved(p<0.05) shoot, root and root nodule dry weight of Alfalfa and acetylene reduction activity of alfalfa with increasing levels of phosphate in the soil pH 6.2 at 7 and 12 weeks(ear1y bloom) after sowing, but these were not influnced with lime applications. Total nitrogen content of each part of alfalfa was increased with lime application, but was not significantly different by levels of lime application at 7 weeks after sowing. Application of phosphate did not affect total nitrogen content of each part of alfalfa. Total nitrogen contents of each part of alfalfa were not significantly different between lime and non-lime application at 12 weeks(ear1y bloom) after sowing but were decreased(p<0.05) with phosphate application(p< 0.05). These results suggest that lime(250 kg/lOa) and phosphate(34 kg/lOa) applications are effective for the growth and the nitrogen fixation of alfalfa at the soil pH 6.20.

• Current Research on Agriculture and Life Sciences
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• v.12
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• pp.57-68
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• 1994

This experiment was conducted to isolate the mutants from S118 and to investigate the physiological characteristics of R. japonicum mutants. The results obtained were as follows; Based on nodulation and acetylene reduction, nodulation of rhizobia was divided into 4 groups, i.e. slow-nodulation, earlier-nodulation, infrequent-nodulation and non-nodulation. At 5% significant level, the growth of inoculated plant with SM255 was bad, but that of HP277 was good. Root-hairs curling was induced by strains S118 and HP277 on soybean, but not by strain SM255. S118 and SM255 were found to be slow-gorwers and produced alkali, whereas strain HP277 was fast-grower and produced acid in YEM broth. In litmus milk reaction, all strains indicated alkaline reaction, and serume-zone was induced weakly by HP277. All of the strains tested in this experiment utilized sucrose. HP277 and LP268 utilized xylose, whereas S118 and SM255 did not. SM255 showed bad growth in nitrogen carriers however utilization of $Ca(NO_3)_2{\cdot}4H_2O$ by HP277 was possible at 25mM and 10mM level. To compare with S118, the protein band of SM255's cell protein electrophoresis was not developed at 0.62 Rm position.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.134-138
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• 1997

The objective of this study was to examine the effect of phosphorus deficiency on nitrogen fixation and photosynthesis of nitrogen fixing soybean plant under $CO_2$ enrichment condition. The soybean plants(Glycine max [L.] Merr.) inoculated with Bradyrhizobium japonicum MN 110 were grown with P-stressed(0.05 mM-P) and control(1 mM-P) treatment under control$(400\;{\mu}l/L\;CO_2)$ and enrichment$(800\;{\mu}l/L\;CO_2)$ enviromental condition in the phytotron equipped with high density lamp$(1000\;{\mu}Em^{-2}S^{-1})$ and $28/22^{\circ}C$ temperature cycle for 35 days after transplanting(DAT). At 35 DAT, phosphorus deficiency decreased total dry mass by 64% in $CO_2$ enrichment condition, and 51% in control $CO_2$ condition. Total leaf area was reduced significantly by phosphorus deficiency in control and enriched $CO_2$ condition but specific leaf weight was increased by P deficiency. Phosphorus deficiency significantly reduced photosynthetic rate(carbon exchange rate) and internal $CO_2$ concentration in leaf in both $CO_2$ treatments, but the degree of stress was more severe under $CO_2$ enrichment condition than under control $CO_2$ environmental condition. In phosphorus sufficient plants, $CO_2$ enrichment increased nodule fresh weight and total nitrogenase activity(acetylene reduction) of nodule by 30% and 41% respectively, but specific nitrogenase activity of nodule and nodule fresh weight was not affected by $CO_2$ enrichment in phosphorus deficient plant at 35 DAT. Total nitrogen concentrations in stem, root and nodule tissue were significantly higher in phosphorus sufficient plant grown under $CO_2$ enrichment, but nitrogen concentration in leaf was reduced by 30% under $CO_2$ enrichment. These results indicate that increasing $CO_2$ concentration does not affect plant growth under phosphorus deficient condition and phosphorus stress might inhibit carbohydrate utilization in whole plant and that $CO_2$ enrichment could not increase nodule formation and functioning under phosphorus deficient conditions and phosphorus has more important roles in nodule growth and functioning under $CO_2$ enrichment environments than under ambient condition.