• The Korean Journal of Ecology
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• 제18권3호
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• pp.323-332
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• 1995

Effects of wintering and temperature on nitrogen fixation activity of nodules of Melilotus suaveolens Ledeb. grown in the field and growth chamber conditions were investigated. The biennial plants transfered to the growth chamber from winter field recovered the activity in 3 weeks of incubation and attained the maximum rate of $153{\mu}mol\;C_2H_4{\cdot}g$ fr wt $nodule^{-1}{\cdot}h^{-1}$ in 5 weeks. When root nodules which adapted to different temperatures, were pretreated with 10, 20 and $30^{\circ}C$ for 1 hour, and then transfered to $30^{\circ}C$, nitrogen fixation activity was promoted in the nodules exposed to lower field temperature ($12^{\circ}C$) with 1$0^{\circ}C$ pretreatment. M. suaveolens maintained nitrogen fixation activity in the wide range of temperatures, and was more tolerant to lower temperature than those of other woody leguminous plants, Diurnal changes of nodule activity showed increase with sunrise and decrease with sunset during spring and autumn, but the activity was inhibited during July and August because of high temperature with stron irradiation. Nitrogen fixation activity of annual plant appeared in mid-April, and showed two peaks (104 and 43 mol $C_2H_4{\cdot}g$ fr wt $nodule^{-1}{\cdot}h^{-1}$) in July and September, and then disappeared after October. Nitrogen fixation activity of biennial plant reappeared in mid-March after wintering and attained two peaks (102 and 82 ${\mu}mol\;C_2H_4{\cdot}g$ fr wt $nodule^{-1}{\cdot}h^{-1}$) in April and June of flowering period, and then disappeared after July due to plant withering by severe drought.

• The Korean Journal of Ecology
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• 제13권2호
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• pp.93-100
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• 1990

The activity of symbiotic -fixation and environmental factors of Robinia pseudo-acacia L., bearing root nodules, were quantitatively analyzed during the growing period. Among changes of total nitrogen and phosphorus contents of each organ, leaves showed prominent decreases from the highest quantity of the early growing period to the lowest of the late period. The rhizosphere showed acidic pH and low level of nitrogen, phosphorus and organic matter contents during the growing period. -fixation activity of nodules initiated from April and showed the maximum value of 190 $\mu$/g DW/hr in late June and than decreased to 50$\mu$M/g DW/hr during the rainy and dry season. Another peak of the activity attained 246$\mu$M/g DW/hr in the late growing stage of September. The maximum value of nitrogen fixation activity was observed at the conditions of pH7, $25\{\circ}C$ of temperature and 20 Kpa of oxygen partial pressure.

• 생명과학회지
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• 제12권5호
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• pp.544-548
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• 2002

대두의 질소고정 근류균들 중 우리나라 토착균, USDA110, USDA122, RJl-29, R2l4 등으로 종자분의접종한 삼남콩을 폿트에 재배하여 개화기에 한발처리한 것과 관행으로 폿트에 재배한 것과의 근류균별 질소고정력 조사와 콩의 제요인에 미치는 근류균의 영향, 한발조건시 근류균 질소고정력과 협중과의 상관관계, 식물체 호흡량과 엽면적과의 상관관계 등을 시험한 결과를 요약하면 다음과 같다. 관행재배에서는 근류균의 질소고정력이 R2l4와 토착균이 높게 나타났으나, 개화기에 한발처리를 한 구에서는 토착근류균 보다 R2l4와 Rll-29의 균들이 질소고정력을 높게 나타내었다. 토착근류균에 비하여 USDA122와 RJl-29의 근류균을 접종한 구가 한발조건에서 식물체 호흡량을 적게 유지하여 엽면적 및 협중의 상대지수를 높게 나타내었다. 한발조건에서 근류균 질소고정력과 협중 상대지수와의 상관관계는 r=0.85'로서 유의적인 정의 상관관계를 나타내었다. 한발조건에서 식물체 호흡량과 엽면적 상대지수와의 상관관계는 r=-0.89'로서 유의적인 부의 상관관계를 나타내었다.

• The Korean Journal of Ecology
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• 제20권1호
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• pp.35-41
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• 1997

Effects of cadmium on growth and nitrogen fixation activity of Melilotus suaveolens, a biennial legume plant dominating in the area of poor soil were quantitatively analyzed during the growing period. Cadmium treatments of 10, 30 and 100 ppm resulted in 12, 22 and 35% inhibition of plant height and 14, 25 nd 26% reduction of chlorophyll contents of leaves, respectively. The plant biomass reduced 51, 70 and 89% for leaves, 33, 50 and 59% for stems, and 42, 52 and 70% for roots, respectively by 10, 30 and 100 ppm Cd treatments. Cadmium contents of roots treated with 10, 30 and 100 ppm Cd were 62, 112 and 183 folds higher than that of the control, respectively. Cadmium contents of stems were about 1/2.2 of those of roots, but leaves contained only 1/27.8 of those of roots. Cadmium treatments resulted in increase of T/R ratios and decrease of F/C ratios significantly in the later growth period. Nodule formation was reduced to 8% in 42 days by the treatment of 100 ppm Cd. Specific nitrogen fixation activity of nodules attained 61.0, 24.0, 1.6 and 0.7 mol $C_2H_4{\cdot}g$ fr wt $nodule^{-1}{\cdot}h^{-1}$ on 42nd day, respectively for 0, 10. 30 and 100 ppm of Cd treatments. Total amount of nitrogen fixation per plant reduced by 73, 98 and 99% with the treatments of 10, 30 and 100 ppm Cd.

• Environmental Engineering Research
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• 제12권4호
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• pp.136-147
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• 2007

In an effort to identify possible microbes for seeking bioagents for remediation of herbicide-contaminated soils, seven species of phototrophic nonsulfur bacteria (Rhodobacter capsulatus and sphaeroides, Rhodospirillum rubrum, Rhodopseudomonas acidophila, blastica and viridis, Rhodomicrobium vannielii) were grown in the presence of the herbicide, butachlor, and bacterial growth rates and nitrogen fixation were measured with different carbon sources. Under general conditions, all species showed 17-53% reductions in growth rate following butachlor treatment. Under nitrogen-fixing conditions, Rb. capsulatus and Rs. rubrum showed 1-4% increases in the growth rates and 2-10% increases in nitrogen-fixing abilities, while the other 5 species showed decreases of 17-47% and 17-85%, respectively. The finding that Rp. acidophila, Rp. blastica, Rp. viridis and Rm. vannielii showed stronger inhibitions of nitrogenase activity seems to indicate that species in genera Rhodobacter and Rhodospirillum are less influenced by butachlor than those in Rhodopseudomonas and Rhodomicrobium in terms of nitrogen-fixing ability. Overall, nitrogenase activity was closely correlated with both growth rate and glutamine synthetase activity (representing nitrogen metabolism). When the carbon sources were compared, pyruvate (three carbons) was best for all species in terms of growth rate and nitrogen fixation, with malate (four carbons) showing intermediate values and ribose(five carbons) showing the lowest; these trends did not change in response to butachlor treatment. We verified that each of the 7 species had a plasmid ($12.2{\sim}23.5\;Kb$). We found that all 7 species could use butachlor as a sole carbon source and 3 species were controlled by plasmid-born genes, but it is doubtful whether plasmid-born genes were responsible to nitrogen fixation.

• The Korean Journal of Ecology
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• 제15권4호
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• pp.377-386
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• 1992

Seasonal changes of symbiotic nitrogen-fixation activity and growth characteristics of four different natural populations of kummerowia striata were quantitatively analyzed during the growing period. the nitrogen-fixation activity of root nodules attained the maximum rates of 148, 132, 102 and 100$\muM\;C_2H_4\;\cdot\;g\;fw\;nodule^{-1}\;\cdot\;hr^{-1}$, respectively for sunny, multibranched, shade and unibranched populations at the optimum growth conditions. and the seasonal changes showed fluctuations by environmental conditions such as light, temperature, nutrient contents, water stress and plant ages, etc. The multibranched plant showed the greater amount of leaf and root nodule biomass, and the higher nitrogenase activity than the unibranched plant. the optimum conditions of leaf chloropht11 and water content of each organ indicated the active growth and the maximum fresh biomass of 4 different populations were 1.92, 1.85, 0.97 and 0.56 g $fw\cdotplant^{-1}$ for shade multibranched, sunny and unibranched populations, respectively.

• KSBB Journal
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• 제5권2호
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• pp.151-158
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• 1990

부질소 1-B5 배지에서 단독 배양한 담배 배양세표의 nitrate reductase 활성은 1-B5 배지에서 배양한 담배 배양세포에 비해 50% 이상 감소되었으나 $10^{-4}$ sper-mine 처리구에서는 그 활성이 가장 증가되었으며, N.muscorum파 혼합 배양시 그 활성이 현저히 증가한 반면 polyamine은 거의 영향을 미치지 않았다. Glutamate dehydrogenase 는 혼합 배양시 담배 배양세포플 단독 배양하였플 때보다 약 4배 감소 되었으며, glutamate synthas$\xi$의 활성은 $10^{-4}M$ spermlne 처리구에서 혼합 배양 하였을 때 그 활성이 가장 높았다.

• Journal of Plant Biology
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• 제30권3호
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• pp.205-213
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• 1987

Soybean, inoculated with effective Rhizobium japonicum 110, were grown by sand culture with nutrient solution containing either of 0, 1, 3, 10 or 30mM NO3-/l, and analyzed growth characteristics, NR activity, N2-fixation activity, and changes of ureide contents during the growing period. The amount of nodule formation decreased abruptly by nitrate treatment, the maximum nodule dry weight was 1.59, 1.05, 0.78, 0.09 and 0.008 g plant-1, respectively for each treatment on the 98th day. Specfic activity of N2-fixation showed the maximum rates of 140, 101, 37, 5 and 2.2 nM dw.mg-1.hr-1, respectively for each treatment in the earlier growth period. The maximum acetylene reduction activity on the 98th day after sowing was 81.5, 35.3, 14.3, 0.1 and 0.0045 $\mu$M C2H4 plant-1.hr-1, respectively for 0, 1, 3, 10 and 30 mM of NO3- gradients. Nitrate reduction activity increased along with nitrate gradients, and decreased abruptly with age. Relative abundance of ureides in plant organs was high in reproductive growth, and showed the maximum value in fully symbiotic dependent plant. Relative abundance of ureides in stem is a useful indication for the evaluation of nitrogen fixation in nodules of symbiotic plant.

• 한국미생물·생명공학회지
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• 제14권2호
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• pp.187-192
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• 1986

대두근류균 접종제 개발을 목적으로 수집 분리되어 우수균주로 선발된 근류균(Rhizobium japonicum)을 대상으로 가기 재배경력이 상이한 3종류의 토양에 장엽콩을 공시 품종으로 하여 접종효과 시험을 실시하였다. 그 결과 근류형성정도 및 질소고정활성을 보면 근류균무접종구에 비하여 근류균을 접종함으로써 3토양 모두 현저한 근류형성 및 질소고정활성의 증가를 보였고 그에 따라 대두의 생육정도도 양호하여 평균 10％의 건물중의 증가를 보였다. 토양별 총질소고정활성의 증가지수는 개간전토양 238％. 미숙전토양 266％, 숙전토땅 157％로 개간전 및 미숙전토양에서 접종효과가 뚜렷하였다. 공시 근류균주별 접종효과는 Rhizobium japonicum R-214, R-138 균주가 우수한 접종효과를 나타냈다.

• The Korean Journal of Ecology
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• 제21권3호
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• pp.187-193
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• 1998

Seasonal changes of nitrogen fixation and growth characteristics of Melilotus suaveolens population under different light conditions were quantitatively analyzed during growting period. Height growth of M. suaveolens population was promoted after April and the shade (site 2) showed 10-20% increase of height growth in compared with that of sunny (site 1). Seasonal changes of biomass were in creased after March, the biomass at site 1 attained 78.5% that of site 2 in May. Chlorophyll content was maintained high value from March to April but, Chlorophyll content of leaf at site 1 was decreased 11.7% compared to that of site 2 in May. The nitrogen content of each organ of M. suaveolens showed higher value in March and then decreased, the high nitrogen contents of reproductive organ were achieved at the flowering stage at site 1. The root nodule of M. suaveolens population appeared in March and showed maximum value in early June and decreased remarkably after July, the amount of nodule formation of M. suaveolens at site 2 showed higher than that of site 1. The nitrogen fixation activity of root nodule of M. suaveolens initiated with shoot growth and showed maximum value in mid April, and attained second peak in early June and then decreased after July. The total nitrogen fixation of the plant showed higher value at site 2 than that of site 1. From the overall results, M. suaveolens showed increased growth under half-shady, well ventilated barren soil than fertile sunny site.