• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.325-331
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• 2012

The dual inoculation response of soybean with rhizobium and mycorrhiza was examined in pot vermiculite and field soils. In order to select a symbiotically compatible mycorrhiza with Bradyrhizobium japonicum, a highly germinating spore among 60 strains from 32 upland soils in southern part of Korea was obtained in Acaulospora sp., Gigaspora sp. and Glomus sp., respectively. As a result of dual inoculation of Glycin max cv. Dajangkong and Eunhakong both with $1{\times}10^8$cells of B. japonicum YCK 213 and 10 spores of each mycorrhiza in vermiculite pot, only Glomus sp. treatment together with the rhizobium showed significant increase ($P{\leqq}0.05$) both in shoot dry wt and nodule mass of not Eunhakong but Dajangkong. In red-yellow soils with pH 5.2($1:5H_2O$) and 203 mg of Lancaster P per kg of soil, in which $10^3$ cells of B. japonicum and $10{\pm}0.2$ spores of mycorrhizae per gram of soil were naturalized, grain yield of G. max cv. Dajangkong was increased to 3.9% by dual inoculation both of $4.8{\times}10^6$cells of B. japonicum and 10 spores of mycorrhizae per two seeds under condition applied with 30 kg $P_2O_5$ and 34 kg $K_2O$ per hectare compared to conventionally fertilized plot (2.75 MT $ha^{-1}$) added with 30 kg N $ha^{-1}$. However, there was not significant.

• Bulletin of the Korean Chemical Society
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• v.28 no.2
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• pp.347-350
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• 2007

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.3
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• pp.288-294
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• 1997

In order to obtain a basic information related to the utility of Sinorhizobium fredii for field soybean, the effectiveness and competitiveness of nine fast-growing S. fredii strains including TAL 1871 etc. were examined on eleven Korean soybean(Glycin max L.) cultivars. Nine S. fredii strains all modulated soybean cv. Kwangkyo, but did not Danyeobkong. The averaged shoot dry weight by S. fredii strain TAL 1781, TAL 1840, TAL 1899 marked only about 53% as compared to that by Bradyrhizobium japonicum strain YCK 213 and USDA 110. The shoot dry weight by S. fredii strains, of which TAL 1781 was the most effective in that, was increased by coinoculation with B. japonicum YCK 213 rather than with B. japonicum USDA 110. Nodule occupancy by S. fredii ranged from 8.3 to 26.7% in coinoculation with B. japonicum YCK 213, but did from 10.0 to 30.0% with B. japonicum USDA 110. These results indicated that S. fredii strains were inferior effective and competitive to B. japonicum strains.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.1
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• pp.61-68
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• 1991

Thirty Bradyrhizobium japonicum isolates (10 strains per each soil) from 1 uncultivated [Sangnam(Soil 1), Milyang]- and 2 cultivated [Dong(Soil 2)and Chinbuk(Soil 3), Changweon] upland soils in Yeongnam area were evaluated on their symbiotic effectiveness to soybean [Glycin max (L.)] cv. Korean Jangbaekkong and American Clark and examined on their serological diversity. The results obtained were summarized as follows : 1. On symbiotic effectiveness of B. japonicum with plant genotypes, isolates showed a relatively high value of nodule mass in Jangbaekkong cv. and of shoot dry weight and total nitrogen in Clark cv. demonstrating the order of Soil 1> Soil 2> Soil 3 isolates. 2. Among 30 B. japonicum isolates, YCK 141 showed the best effectiveness on mean nitrogen fixation of two cultivars. 3. Thirty indigenous B. japonicum showed 6 types of serological diversities in the immunoblot analysis which were present in various proportions at Soil 2(5) and Soil 3(5) except Soil 1 where all isolates fell into the YCK 117 serogroup. And their distribution order was serotype YCK 117( 12 strains) > USDA 1l0(5strains), USDA 123(5 strains) > YCK 150(4 strains) > YCK 141(3 strains) > YCK 226(1 strain). 4. Especially, 10 isolates from Soil 1, an uncultivated orchard, showed a very homologous pattern in not only effectiveness but serological distribution. It seemed to indicate that the isolates were typically affected by numerous physical and environmental factors of the soil.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.4
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• pp.265-270
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• 1993

The symbiotic dynamics of Bradyrhiwbium japonicum YCK strains indigenous to Korean soils were investigated accordingly to their competitive conditions for nodulation. For this experiment the single strain inoculants of YCK strains and the mixed inoculants of one YCK strain and one USDA strain were applied to Korean Jangbaekkong and American Clark soybeans at mollisol soils(Torroxic Haplustoll, pH 6.8). The results were summarized as follows : 1. The symbiotic effectiveness of B. japonicum YCK strains was increased on the average of nitrogen accumulation by mixing with USDA strains, especially with strain USDA 110. 2. The effectiveness of each mixed inoculant was affected by soybean cultivar. 3. YCK strains occupied on the average of 83 and 86 % of the nodules against strain USDA 110 on Jangbaekkong and Clark soybeans, respectitvely. 4. The most effective strain among three YCK strains was strain YCK 213 as a single inoculant and was strain YCK 141 as a mixed inoculant with USDA strains. 5. The mixed inoculants of YCK strains and strain USDA 123 showed antagonism for nodulation.

• Korean Journal of Microbiology
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• v.32 no.1
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• pp.1-6
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• 1994

DNA-DNA hybridization by kinetic method was carried out between species of purple nonsulfur photosynthetic bacteria and nonphotosynthetic bacteria. The degrees of homology percent were shown to be low (2-35 D%) with the exception of high homology % (72-88 D%) for strains within a species and between Rhodobacter capsulatus and Rhodopseudomonas blastica. The D% between the purple nonsulfur photosynthetic bacteria, Rhodopseudomonas palustris, and nonphotosynthetic bacteria, Pseudomonas aeruginosa ATCC 27853 or Bradyrhizobium japonicum were a little higher (26-33 D%) than the D% between any other photosynthetic bacteria. The homology % between Rhodopseudomonas blastica and Rhodobacter capsulatus was 72 D%, which showed genetic relationship.

• Korean Journal of Organic Agriculture
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• v.14 no.4
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• pp.411-420
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• 2006

Indole-3-acetic acid (IAA) biosynthesis by bacteria occurs widely in rhizospheres. Bacterial species able to synthesize IAAmay be exploited for beneficial interactions in crop management systems. The objective of this study was to determine the response of ivyleaf morningglory (Ipomoea hederacea) seedlings to IAA and to an IAA-producing rhizobacterum, Bradyrhizobium japonicum isolate GD3. IAA solution and isolate GD3 suppression of seedling growth measured as radicle length and biomass depended on IAA concentration. Seedling radicle length was significantly reduced by ca. 29% with more than $1.0{\mu}M$ of IAA solution, compared to the control, 48 h after application. The cell concentration at 50% growth reduction ($GR_{50}$) of the seedling radicle was IAA production by isolate GD3 at $10^{4.82}\;cfu$, the cell concentration for 50% growth reduction ($GR_{50}$) of seedling radicle was 0.24 iM, which was much lower than the IAA solution concentration ($117.48{\mu}M$) required for $GR_{50}$. Therefore, excess IAA production by isolate GD3 may be more detrimental to morningglory radicle growth than standard IAA solution. Results confirmed involvement of IAA in suppressive effects of isolate GD3 on morning-glory seedlings grown in a hydroponic system.

• Korean Journal of Microbiology
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• v.30 no.4
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• pp.246-251
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• 1992

Molccular cloning of nod genes from Bradvrhizobium sp. SNU001, a nitrogen-fixing symbiont isolated from thc root nodules of soybean (Clycine trim) . was carried out. nod genes were found to be located on thc genome of the symbiont by gcnomic hybridization with 4.5 kb EcoRI/HndIII fragment (nod DABC) of Rhizohium meliloti as probe. Genomic library of this symbiont was constructed using h phage EMBL3-BanlHI vector. from which five nod positive clones were sclectcd by primary and secondary screening methods. The partial restriction map of inserted genomic DNA of h CNS-l(c1one 2) was constructed. and 3.9 kh Bun7HI fragment. which showed strong hybridization signal to the probe, was subcloned into pBS KS(+) plasmid vector. Partial restriction inap ot' a selected subclone (pBjCNS-I) was constructed and nod DABC was found to be located on the 1.8 kb KpnI/Sacl fragment of this subclone.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.2
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• pp.181-188
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• 1992

This study was carried out to evaluate the fate of inoculant Bradyrhizobium japonicum and the inoculation effect on soybean in complex soil environment. To moniter Rhizobium strains from the root, streptomycine and streptomycine and nalidixic acid resistant marker strains were prepared by spontaneous mutagenesis. The characteristics and properties of antibiotic marked strains were not altered by the mutagenesis. The comparison of properties of wild type and antibiotic resistant Bradyrhizobium strains are summarized as follow : 1) The strains of USDA110K-$STR^r$, USDA110N-$STR^r$ and R318-$STR^r$ showed weak tolerance to pH 9.0. The utilization of carbon sources by fast growing group was different from that of slow growing group. The marked strains of R214-$STR^rNAL^r$, USDA110K-$STR^r$ and USDA110N-$STR^r$ was doubtful in utilization of sorbitol and R138-$STR^rNAL^r$ was doubtful in utilization of xylose as a carbon source. 2) By examining the agglutination reaction of serogroups, the strains used were identified as different ones. There were no differences between wild type and marked strains in agglutination titer values. 3) The plasmid size of fast group was slightly greater than that of slow group. However, there was no differences in plasmid size between the wild type and antibiotic resistant strains. This result indicates that the antibiotic resistance was not encoded in plasmid. 4) The recovery of the inoculated strains was up to 12.5 % in soybean cultivated soil and was up to 25 % in soybean uncultivated soil. 5) When the wild type or marked strains were inoculated. there was no significant effect on soybean plant, whereas the inoculation effect was pronounced in soybean uncultivated soil. The inoculation effect seemed to be more pronounced in wild type strains than antibiotic resistant strains. however, the difference was not significant.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.551-555
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• 1997

This experiment was carried out to elucidate the biological activity and absorption characteristics of flavonoids in Rhizobium and Bradyrhizobium and to obtain basic information on host specific nodulation by flavonoids in rhizobium-legume symbiosis. The purpose of the present study was to explore the biological activity and the flavonoid absorption indicates that host-specificity is induced by flavonoids in symbiotic nitrogen fixation. Biological activity increased by daidzein and genistein treatment on B. japonicum KCTC 1539 whereas decreased by luteolin treatment but increased by luteolin treatment on R. meliloti whereas decreased by daidzein and genistein treatment. Daidzein and genistein are absorbed by B. japonicum, KCTC 1539 at higher rate than other flavonoids. Especially, luteolin was absorbed at a least rate. Luteolin are absorbed by R. meliloti KCTC 2353 at higher rate than other flavonoids. Especially, daidzein and genistein was absorbed at a least rate.