scholarly journals EFFECT OF TRIFLURALIN AND METRIBUZIN ON FABA BEAN GROWTH, DEVELOPMENT, AND SYMBIOTIC NITROGEN FIXATION

1985 ◽  
Vol 65 (1) ◽  
pp. 9-21 ◽  
Author(s):  
J. BERTHOLET ◽  
K. W. CLARK
Keyword(s):  
Nitrogen Fixation ◽  
Faba Bean ◽  
Root Length ◽  
Symbiotic Nitrogen Fixation ◽  
Nitrogenase Activity ◽  
Dry Weight ◽  
Field Studies ◽  
Total Root Length ◽  
Self Sufficiency ◽  
Root Inhibition

Field studies were conducted to determine if trifluralin [α,α,α-trifluro-2,6,-dinitro-N,N-dipropyl-p-toluidine] and metribuzin [4-amino-6-tert-butyl-3-(methylthio)-a5-triazin-5(4H)one] affect the growth and nitrogen self sufficiency of faba bean (Vicia faba L.). Metribuzin applied at 0.42 kg/ha as a pre-plant incorporated treatment resulted in substantial crop injury in 1981. Compared to the inoculated control, overall reductions averaged over the entire growing season, in plant dry weight, nodule dry weight, nitrogenase activity, and yield due to metribuzin were 59, 85, 92, and 65%, respectively. In 1982 metribuzin at 0.4 kg/ha was not as phytotoxic. Averaged over the season, the reductions recorded in plant dry weight, nodule dry weight, nitrogenase activity, and yield were 25, 33, 49, and 9%, respectively. The differences in phytotoxicity in the 2 yr at the two sites were attributed to differences in soil organic matter, and both the degree and timing of rainfall. During both years trifluralin did not cause any significant reductions in the parameters investigated. Reductions in nodulation and nitrogen fixation as a result of metribuzin application were evident only when the crop was injured and the plants were under stress from herbicide application. Trifluralin at 1.1 kg/ha reduced the phytotoxicity caused by metribuzin when the two chemicals were tank mixed. In 1981 there was a 23% yield improvement with the tank mix compared to metribuzin applied alone. In 1982, non-significant decreases in phytotoxicity with the tank mix were evident for the parameters studied. This reduced phytotoxicity may be explained on the basis of lateral root inhibition attributable to the trifluralin in the tank mix as was evident in the growth room study. The tank mix of trifluralin and metribuzin at 1.1 and 0.4 kg/ha, respectively, caused a 56% reduction in total root length compared to the inoculated control one week after emergence. Conversely, the total root length of the plants receiving only the 0.4 kg/ha rate of metribuzin did not differ significantly from the control. This may allow for greater herbicide uptake in the plants treated with only metribuzin leading to a greater level of injury.Key words: Faba bean, growth, symbiotic nitrogen fixation, trifluralin, metribuzin

Inheritance of Symbiotic Nitrogen Fixation in Two Peanut Crosses1

1989 ◽  
Vol 16 (2) ◽  
pp. 66-70 ◽  
Author(s):  
T. D. Phillips ◽  
J. C. Wynne ◽  
G. H. Elkan ◽  
T. J. Schneeweis
Keyword(s):  
Nitrogen Fixation ◽  
Symbiotic Nitrogen Fixation ◽  
Specific Activity ◽  
Nitrogenase Activity ◽  
Dry Weight ◽  
Dominance Model ◽  
Nodule Number ◽  
Shoot Dry Weight ◽  
Arachis Hypogaea L ◽  
Reciprocal Differences

Abstract Symbiotic nitrogen fixation in peanut (Arachis hypogaea L.) may be improved by genetically manipulating the host plant. This requires an understanding of the inheritance of the traits involved in nitrogen fixation. The objectives of this study were to determine the inheritance of several N2 fixation-related traits for two peanut crosses based on Mather and Jink's fixation-related traits for two peanut crosses based on Mather and Jink's additive-dominance model, and to determine if epistasis was important in the inheritance of these traits. A generation means analysis usingparents, reciprocal F1s and F2s, and two back-cross generations was conducted for both crosses. Plants of different generations were grown in modified Leonard jars in the greenhouse for about 60 days at which time nodule number and dry weight, shoot dry weight, nitrogenase activity, and specific activity were measured. Means of the traits for the generations from both crosses (Robut 33-1 x NC 4 and Robut 33-1 x Argentine) showed significant differences. Reciprocal differences were found for most traits measured in the cross of Robut 33-1 x Argentine, a cross of Virginia x Spanish botanical types. Lack of fit of the additive-dominance model indicated significant epistasis for inheritance of nodule number, nodule weight, top dry weight, and nitrogenase activity in both crosses. Three types of digenic interactions (additive x additive, additive x dominance and dominance x dominance) were found. The presence of nonadditive genetic effects suggests that early generation selection would be ineffective.

High-temperature-adaptedAzospirillum brasilensestrains: growth and interaction response on associative nitrogen fixation, mineral uptake and yield of cheena (Panicum miliaceumL.) genotypes in calcareous soil

1988 ◽  
Vol 110 (2) ◽  
pp. 321-329 ◽  
Author(s):  
R. Rai
Keyword(s):  
Nitrogen Fixation ◽  
High Temperature ◽  
Calcareous Soil ◽  
Nitrogenase Activity ◽  
Dry Weight ◽  
Cross Resistance ◽  
Mineral Uptake ◽  
Associative Nitrogen Fixation ◽  
Seed Inoculation ◽  
Resistance To Penicillin

SummaryHigh-temperature-adapted strains RAU 1, RAU 2 and RAU 3 ofAzospirillum brasilenseC 7 were isolated from stepwise transfer to higher temperature (30 to 42 °C). One of the strains (RAU 1) showed more growth, greater nitrogenase and hydrogenase activities at 30 and 42 °C than parental and other temperature-adapted strains. This strain also showed growth and more nitrogenase activity from pH 6·5 to 8·0. Strain RAU 1 showed cross-resistance to penicillin (300/µg/ml) but not to streptomycin, kanamycin, viomycin and polymixin B at 30 and 42 °C. It was demonstrated in field plots in calcareous soil that seed inoculation with RAU 1 enhanced mineral uptake of cheena. Inoculation with RAU 1 led to a significant increase in associative nitrogen fixation, dry weight of roots, grain and straw yield of cheena compared with the uninoculated control with or without applied N, but the effect of seed inoculation with high-temperature-adapted strains was variable with different genotypes of cheena.

scholarly journals Potential of Phototrophic Purple Nonsulfur Bacteria to Fix Nitrogen in Rice Fields

2021 ◽  
Vol 10 (1) ◽  
pp. 28
Author(s):  
Isamu Maeda
Keyword(s):  
Nitrogen Fixation ◽  
Regulatory Networks ◽  
Nitrogenase Activity ◽  
Field Studies ◽  
Rice Fields ◽  
Purple Nonsulfur Bacteria ◽  
Available Nitrogen ◽  
Nitrogenase Activities ◽  
Plant Available Nitrogen ◽  
Biological Nitrogen

Biological nitrogen fixation catalyzed by Mo-nitrogenase of symbiotic diazotrophs has attracted interest because its potential to supply plant-available nitrogen offers an alternative way of using chemical fertilizers for sustainable agriculture. Phototrophic purple nonsulfur bacteria (PNSB) diazotrophically grow under light anaerobic conditions and can be isolated from photic and microaerobic zones of rice fields. Therefore, PNSB as asymbiotic diazotrophs contribute to nitrogen fixation in rice fields. An attempt to measure nitrogen in the oxidized surface layer of paddy soil estimates that approximately 6–8 kg N/ha/year might be accumulated by phototrophic microorganisms. Species of PNSB possess one of or both alternative nitrogenases, V-nitrogenase and Fe-nitrogenase, which are found in asymbiotic diazotrophs, in addition to Mo-nitrogenase. The regulatory networks control nitrogenase activity in response to ammonium, molecular oxygen, and light irradiation. Laboratory and field studies have revealed effectiveness of PNSB inoculation to rice cultures on increases of nitrogen gain, plant growth, and/or grain yield. In this review, properties of the nitrogenase isozymes and regulation of nitrogenase activities in PNSB are described, and research challenges and potential of PNSB inoculation to rice cultures are discussed from a viewpoint of their applications as nitrogen biofertilizer.

Phenotypic reversion of nitrogenase in pleiotropic mutants of Rhizobium meliloti

1979 ◽  
Vol 25 (3) ◽  
pp. 298-301 ◽  
Author(s):  
Ilona Barabás ◽  
Tibor Sik
Keyword(s):  
Amino Acids ◽  
Nitrogen Fixation ◽  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Symbiotic Nitrogen Fixation ◽  
Rhizobium Meliloti ◽  
Nitrogenase Activity ◽  
Reductase Activity ◽  
Amino Acid Utilization ◽  
Phenotypic Reversion

In two out of three pleiotropic mutants of Rhizobium meliloti, defective in nitrate reductase induced by amino acid utilization in vegetative bacteria and in symbiotic nitrogen fixation, nitrogenase activity could be restored completely by purines and partially by the amino acids L-glutamate, L-aspartate, L-glutamine, and L-asparagine. The compounds restoring effectiveness in nitrogen fixation did not restore nitrate reductase activity in vegetative bacteria. The restoration of effectiveness supports our earlier conclusion that the mutation is not in the structural gene for a suggested common subunit of nitrogenase and nitrate reductase.

scholarly journals EFFETS DES SOUCHES DE RHIZOBIUM MELILOTI ET DES COUPES SUCCESSIVES DE LA LUZERNE (MEDICAGO SATIVA) SUR LA FIXATION SYMBIOTIQUE D’AZOTE

1977 ◽  
Vol 57 (2) ◽  
pp. 433-439 ◽  
Author(s):  
L. M. BORDELEAU ◽  
H. ANTOUN ◽  
R. A. LACHANCE
Keyword(s):  
Nitrogen Fixation ◽  
Medicago Sativa ◽  
Statistical Study ◽  
Symbiotic Nitrogen Fixation ◽  
Rhizobium Meliloti ◽  
Dry Weight ◽  
Indirect Measurement ◽  
Controlled Environment ◽  
Symbiotic Efficiency ◽  
Plant Yield

Symbiotic nitrogen fixation with 49 isolates of Rhizobium meliloti was studied under controlled environment with alfalfa cv. Saranac. It was shown that plant yield in dry weight can be used as an indirect measurement of nitrogen fixation, and as a criterion for selecting efficient strains of R. meliloti. Statistical study on yields of three cuttings has established that the second cutting gives the most necessary information to correctly evaluate the symbiotic efficiency of the isolates. Six very efficient strains were selected.

Studies on associative nitrogen fixation by antibiotic-resistant mutants ofAzospirillum brasilensewith genotypes of lentil (Lens culinaris)Rhizobiumstrains in calcareous soil

1985 ◽  
Vol 104 (1) ◽  
pp. 207-215 ◽  
Author(s):  
R. Rai
Keyword(s):  
Nitrogen Fixation ◽  
Azospirillum Brasilense ◽  
Calcareous Soil ◽  
Lens Culinaris ◽  
Nitrogenase Activity ◽  
Dry Weight ◽  
Antibiotic Resistant ◽  
Uninoculated Control ◽  
Resistant Mutants ◽  
Antibiotic Resistant Mutants

SummaryNitrosoguanidine-induced mutation frequencies for resistance to streptomycin, spectinomycin, erythromycin and novomycin were studied inAzospirillum brasilense.Lentil inoculated withA. brasilenseand its mutants andRhizobiumstrains produced increased nodule dry weight, nitrogenase activity of nodules and roots and grain yield compared with an uninoculated control.

scholarly journals About the work of Vinnytsia regional branch of the Ukrainian Society of Plant Physiologists

2020 ◽  
Vol 52 (5) ◽  
pp. 422-433
Author(s):  
V.G. Kuryata ◽  
Keyword(s):  
Nitrogen Fixation ◽  
Abscisic Acid ◽  
Plant Development ◽  
Acid Content ◽  
Symbiotic Nitrogen Fixation ◽  
Nitrogenase Activity ◽  
Free Form ◽  
Linear Growth Rate ◽  
Wide Range ◽  
Source Sink

The work and the main scientific results of the Vinnytsia branch of the USPP from the moment of its formation to the present time are analyzed. The main direction of research is exogenous regulation of plants source-sink relations in the systems «photosynthesis—growth», «depot of assimilates—growth» in the heterotrophic phase of plant development, and «macrosymbiont—microsymbiont» in symbiotic nitrogen fixation systems. Gibberellin and antigibberellin preparations (retardants) were used to create different tension of source-sink relations. It was found that under the influence of retardants, the decrease in the linear growth rate was accompanied by an increase in the cytokinins content with a decrease in the indoleacetic acid content in stems and leaves tissues of a wide range of plants. The free gibberellins activity was lower compared to control. At the same time, the content of these phytohormones antagonist, abscisic acid, increased. The retardants increased the stem branching, leaves number, weight and leaf surface area, optimized the leaves mesostructural organization, resulting in an increase in the photosynthetic net productivity. These changes lead to increased crop productivity. Under the conditions of artificial combination of external (light/dark) and hormonal factors (gibberellic acid and retardants) during seed germination, changes in the functioning of the source-sink system in the heterotrophic stage of plant development from seeds with different reserve substances types were studied. Gibberellin stimulated the starch breakdown in both light and dark, but under conditions of germination in the dark, the rate of reserve seed starch use was higher. Gibberellin also stimulated the seed reserve proteins hydrolysis, but the process began after intensive starch hydrolysis. Peculiarities of regulation of source-sink relations in the system «macro—microsymbiont» during the processes of symbiotic nitrogen fixation under the action of antigibberellin preparations — retardants are revealed. It was found that the typical reaction of soybean plants to the paclobutrazol application was a decrease in the free form gibberellins activity and an increase in the abscisic acid content, which led to changes in morphogenesis. Under the retardants action, the processes of formation of the symbiotic complex «soybean—Bradyrhizobium japonicum» intensify, nitrogenase activity increased, crop yield rised.

scholarly journals SYMBIOTIC NITROGEN FIXATION OF FABA BEAN PLANTS INOCULATED WITH SALT-TOLERANT Rhizobium ISOLATES

2012 ◽  
Vol 3 (10) ◽  
pp. 411-423 ◽  
Author(s):  
Nagwa M. M. El-Khateeb ◽  
M. E. Shalaby ◽  
E. B. A. Belal ◽  
SH. M. A. El-Gremi
Keyword(s):  
Nitrogen Fixation ◽  
Faba Bean ◽  
Symbiotic Nitrogen Fixation ◽  
Salt Tolerant ◽  
Bean Plants
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