• Current Research on Agriculture and Life Sciences
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• v.15
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• pp.7-16
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• 1997

The effects of liming and inoculation of nodule bacteria on the growth and yield of soybeans in the 1st and 3rd year paddy-upland rotated paddy fields was investigated. Compared with the 1st rotated field, the degree of nodulation was much higher in the 3rd rotated one with greater difference at flowering stage than at the early stage of soybean growth. At the same time, greater difference in the degree of nodulation was also recognized between soybean varieties. In the 3rd year rotated field, a great deal of nodulation effect was recognized in the no-limed field but not in the limed one. The growth of soybean was not much affected by liming and nodulation at early stage but it was much increased by liming at flowering stage, especially in Williams 79, indeterminate type variety. Most of yield components and yield of soybean at maturity was much increased by liming with greater in Williams 79 than in Namhaekong. Nodulation effect on the yield components and yield was great in the no-limed filed but not in the limed one for both varieties. The yield and yield components of soybean, without no relation with liming and nodulation, was much great in the 3rd year rotated paddy fields than in the 1st year one, which was inferred that the more rotated fields the more yield and better growth of soybeans could be possible in the paddy-upland rotatonal soybean croppings.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.77-88
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• 1992

Effective strains of cowpea bradyrhizobia JB7 $nal^rspe^r$ and CB756 $str^rrif^r$, antibiotic-resistant variants of JB7 and CB756, respectively, were used to examine changes of rhizosphere populations and nodule occupancy. Populations of each strain increased gradually in the rhizosphere, reaching a maximum of about $10^8$ cells per root system. Nodule number increased as the density of inoculum increased from $10^2$ cells to $10^8$ cells per seed. Inoculation with liquid suspension resulted in the formation of more nodules than the peat slurry or granule inoculation. When JB7 $nal^rspe^r$ and CB756 $str^rrif^r$ were introduced in equal numbers in inoculum mixtures the former consistantly occupied the majority of nodules with all three groundnut cultivars used. There was no difference in yield between nitrogen treatments and inocultation treatments.

• Applied Biological Chemistry
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• v.13 no.1
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• pp.51-57
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• 1970

On the basis of the specific interrelationship between the species or variety of leguminous crops and the species or strain of nodule bacteria, Rhizobia, the rhizobial species and strain must be effectively chosen for the successful inoculation. The present paper describes on some results of the isolation and taxonomic study on the native rhizobial strains isolated from the nodules of five species of leguminous crops such as numerous varieties of soy bean, lespedeza, birdfoot trefoil, ladino and red clovers. The isolated strains of soy bean nodule bacterium, Rhizobium japonicum were grouped through the inoculation test on variety Changdanbaikmock into the effective, noneffective and toxic strain for the nodule formation. In the study of the effect of some inorganic and organic nitrogenous compounds on the growth of Rhizobium japonicum strain Ac 20, a promotive response was showed by asparagine, and glutamine, but hydroxylamine, nitrite, hydrazine and azide was inhibitory at the concentration of $10^{-2}M/l$ in mannitol-yeast extract basal medium. In the physiological characteristics each strain showed somewhat different activities of the indole-3-actic acid formation and hydrogenase and discussed with these characters in relation to nodule forming ability.

• Journal of Plant Biology
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• v.37 no.3
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• pp.387-394
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• 1994

Effects of environmental factors of light, temperature, nitrogen sources and water stress were analyzed quantitatively on the nodule formation and nitrogen fixation activity of autumn olive plant (Elaeagnu$ umbellala Thunb.) during the seedling growth. Seedlings showed the maximum nitrogenase activity of $72.5\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$ in the early nodulation stage. The relative growth rate and T/R ratio changed from $1.60%{\cdot}d^{-1}$ and 1.12 in the earlier stage to $3.75%{\cdot}d^{-1}$ and 2.31 in the later stage, respectively. light conditions of 20-25, 1015 and 4-6% resulted in decreases of 41, 54 and 71% of the nitrogenase activity, respectively. Nodules incubated in 15, 20, 25 and $30^{\circ}C$ showed the activities of 5.4, 24.7, 51.6 and $58.5\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$ respectively. Pretreatment with low temperature ($15^{\circ}C$) followed incubation at $30^{\circ}C$ attained higher nitrogenase activity ($66.5\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$) than that with higher temperature ($35^{\circ}C$). The oxygen pressure above 16 kPa is necessary for saturation of the nodule activity, but the activity was inhibited severely by physical impact such as the exision or isolation of nodules from the root. The relative activities of early nodules grown in pH 5.5, 6.5 and 8.0 were 89, 100 and 40% and those grown in 1 and 3 mM of $NO_3\;and\;NH_4$ were 6, 1 and 68, 50%, respectively. Watering levels of 20, 50 and 100 mL during the seedling growth resulted in 35, 120 and 8 mg of nodule formation and 33.6, 58.4 and $8.4\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$ of the nitrogenase activity, respectively. Water stress with 86% decrease of soil water content caused temporary wilting point of leaf and a complete disappearance of nitrogenase activity of nodules, though the water content and transpiration rate in plant were reduced to 90 and 53%, respectively.tively.

• Korean Journal of Microbiology
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• v.14 no.1
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• pp.36-38
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• 1976

The insecticides, Dithane-M45 and copper sulfate, were introduced in this experiments to elucidate their effects on the nodulation of soybean plant(Glycine max Meer) by Rhizobium japonicum. The nodulation activity was inhibited in accordance with increase of their concentration.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.2
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• pp.190-198
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• 1996

The Neomycin resistant gene in transposon 5 (Tn5) was introduced into a mutant of Bradyrhizobium japonicum RJB 6 $str^rnal^r$ by conjugation. This marked strain was used in coinoculation of soybean with Pseudomonas fluorescens(Ps-3) and Bacillus subtilis(BCAC-4) and in antibiotic treatment of soybean for studying rate of nodule formation and growth promoting effect on soybean plant. When the marked strain RJB 6 $str^rnal^rneo^r$ with Ps-3, BCAC-4, and Ps-3 plus BCAC-4 was coinoculated into two soils, the recovery rate of the marked strain was 8.5, 4.3 and 2.9 percent in soybean cultivated soil, and 10.3. 6.0 and 5.0 percent in soybean uncultivated soil. The best growth promoting effect of coinoculation on soybean plant was found with the marked strain plus Ps-3. When the marked strain was inoculated into soybean with antibiotic treatment, the rate of nodule formation in soybean cultivated soil was between 12.5 and 25.4 percent, while that in soybean uncultivated soil was between 23.7 and 43.2 percent. The highest rate of nodule formation with the marked strain was found in streptomycin 1000 ppm treatment plot.

• Applied Biological Chemistry
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• v.41 no.3
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• pp.247-252
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• 1998

To obtain the basic information for suitable use of soybean-Bradyrhizobium japonicum symbiosis, on soybean cv. Danweonkong and Namhaekong the symbiotic potential of B. japonicum indigenous to plain upland (PU), plain paddy(PP), and mountainous upland(MU) soils in southern part of Korea were surveyed and discussed. Populations of B. japonicum in soils were the highest in MU soils with $5.7{\times}10^4\;cells/g.soil$ followed by PU with $5.0{\times}10^4$ and PP soils with $4.0{\times}10^3\;cells/g.soil$. Shoot dry weight at flowering stage and grain yields at harvesting stage, which mutually showed an high correlation $(P{\leqq}0.001)$, were high in the order of PU > MU > PP soil inocula. Amongst PU soils, Namhae acid Seonsan soils were prominent inocula for shoot dry weight and Kimhae for grain yields at P 0.05, respectively. In cases of nodule number and nodule mass surveyed at the flowering stage, shoot dry weight gave an higher correlation with the latter $(r=0.439^*)$ than the former $(r=0.383^*);$ grain yields with the former $(r=0.505^{**})$ that flue latter $(r=0.449^{**})$. In comparison with Namhaekong showed 1.7 and 1.4 fold higher values in shoot dry weight and grain yields per nodule mass, respectively.

• Applied Biological Chemistry
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• v.30 no.2
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• pp.153-162
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• 1987

Soybean rhizobia were isolated from 101 soybean (Glycine max.) cultivar which had been grown for the breeding experiment in Korea. Seven strains of the fast-growing soybean rhizobia and nine strains of the slow-growing soybean rhizobia were selected on the basis of their growth rate in AMA medium and their high ability of nodulation. The slow-growing soybean rhizobia were identified as Bradyrhizobium japonicum in the acetylene-reducing activity, microbial characteristics, and biochemical characteristics whereas the fast-growing soybean rhizobia were very similar to Rhizobium fredii.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.3
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• pp.245-252
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• 1989

This experiment was carried out to study the effects of nitrogen concentration of cultural solution, rhizobium inoculation, and planting density on nodulation, contents of total-N and allantoin-N of the plants, and contents of crude fat and protein of the seeds with 4 cultivars and 1 non-nodulation isogenic line (Hwangeumkong, Jangbaegkong, Paldalkong, Clark, non-nodulating Clark) in nutri-culture. Modulation was increased significantly by the rhizobium inoculation and decreased by the increase of nitrogen concentration of the cultural solution and planting density, and more nodule per plant was observed in Hwangeumkong than other cultivars. Total nitrogen contents of the soybean plant were higher in Hwangeumkong and Janbaegkong compared with other two cultivars, and were increased by rhizobium inoculation and the increase of nitrogen concentration of the cultural solution except in case of $R_3$ stage of non-inoculation of rhizobium, and was decreased by the increase of planting density. Allantoin nitrogen contents of stem were lower in Paldalkong compared with other cultivars and was increased significantly by the rhizobium inoculation, and thus was correlated significantly with nodulation. Allantoin-N contents were also decreased by the increase of planting density and nitrogen concentration of the solution, and was very low in case of non-nodulating isogenic line at any level of nitrogen concentration. The contents of crude fat of the seed were lower in cases of higher nitrogen concentration of the solution and more plants per pot, but no effects of rhizobium inoculation was observed. The contents of crude protein were tend to increase by the increase of nitrogen concentration, but were little effected by rhizobium inoculation and planting density.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.4
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• pp.277-283
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• 1982

A series of experiments were conducted on procedures of $N_2$ fixation measurements with soybean (Glycine max. L.) root nodules by acetylene reducing assay and estimation of amounts of $N_2$ fixed by soybean root nodules grown in the pot. The results are summarized as follows; 1. In case of nitrogen fixing activities were determined by means of acetylene reducing method, more appropriates results were obtained with direct determination of root nodules which was adhering from root under 2 hours after incubation, while more fluctuated data was obtained with root nodules determined under separated conditions. 2. The weight of soybean nodules was linearly increased from 17 days to 55 days after planting, whereas, the amounts of $N_2$ fixation from soybean nodules were Peaked at 38 days after planting, and declined thereafter. 3. When calculated upon the basis of the amounts of $N_2$ fixed as measured by acetylene reducing activities in single soybean plant, it was found that the average amount of symbiotic $N_2$ fixation falls in the range of 80 kg N per ha.