Factors Affecting Symbiotic Nitrogen Fixation in Soybeans [Glycine Max (L.) Merr.]. PDF Download
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![Factors Affecting Symbiotic Nitrogen Fixation in Soybeans [Glycine Max (L.) Merr.]. PDF](https://books.google.com/books/content/images/frontcover/IpXuaddlqL4C?fife=w150-h200)
Author: R. J. Lawn
Publisher:
ISBN:
Category :
Languages : en
Pages : 226
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Book Description
![Factors Affecting Symbiotic Nitrogen Fixation in Soybeans [Glycine Max (L.) Merr.]. PDF](https://books.google.com/books/content/images/frontcover/IpXuaddlqL4C?fife=w80-h100)
Author: R. J. Lawn
Publisher:
ISBN:
Category :
Languages : en
Pages : 226
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Author: Jayne T. MacLean
Publisher:
ISBN:
Category : Nitrogen
Languages : en
Pages : 44
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Book Description
Author: Arief Indrasumunar
Publisher:
ISBN:
Category : Acid soils
Languages : en
Pages : 220
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Author: Luiz Moro Rosso
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
Soybean [Glycine max (L.) Merr.] production currently faces several challenges linked to global food security (both quantity and quality) raised by an overgrowing human population, limited cropland, and diversified dietary in developed regions. To sustain seed yield and high protein levels, soybeans depend on large nitrogen (N) uptake, which is mostly attained by the symbiotic N fixation (SNF) process. Although SNF has been extensively investigated with single assessments during the season, just a few recent reports looked at the temporality of N sources (soil and SNF) while taking into consideration seasonal dry matter accumulation and soil nitrate (NO3) and ammonium (NH4) availability. Furthermore, it is still unclear how the overall changes in N uptake dynamics supports yield formation and seed components among canopy portions, especially considering the branches as potential contributors for high yield in modern genotypes. Following this rationale, this project presents two overall objectives: 1) to identify the impact of soil NO3 and NH4 temporal availability on seasonal SNF [N derived from the atmosphere (Ndfa)], N uptake, and dry matter accumulation (herein called study 1); and 2) to characterize seed yield, protein, oil, amino acids (AA), and fatty acids (FA) from the main stem and branches (herein called study 2) for different commercial soybean varieties. To address the first objective, four genotypes were field grown at Manhattan (Kansas, US) during 2019 and 2020 growing seasons. Dry matter, N concentration, N uptake, Ndfa, fixed N, soil NO3, and NH4 (60-cm depth) were measured at six phenological stages, along with seed yield, protein, and oil concentration at harvest time. Seasonal exposure to NH4 (area under the curve) showed a stronger suppression of Ndfa at the end of the season than NO3. However, a mid-season NO3 peak delayed uptake from soil and SNF, but only decreased maximum uptake rates from SNF. Additionally, dry matter was used as a seasonal linear predictor of fixed N to simplify the process model. However, this relationship was deeply affected by soil N availability across environments (boundary functions) and also by a potential dry matter threshold around 5 Mg ha−1 across genotypes and site-years. For the second objective, another four genotypes were field-grown during the 2018 and 2019 growing seasons at Ashland Bottoms and Rossville (Kansas, US), respectively. At harvest time, seeds from the upper, middle, lower main stem, and branch nodes were manually separated and assessed for yield, seed size, protein, and oil (seed content and concentration), abundance of limiting AA within protein, and FA ratio (oleic / linoleic + linolenic). The accumulation of protein was more responsive to node position than oil, determining high protein concentration in the upper main stem and high oil concentration in the lower main stem nodes. However, the protein quality (limiting AA) was higher in the lower main stem, while the FA ratio (oil quality) was greater in the upper section of the plant. Branches presented the less-rich seed composition relative to the main stem, but their contribution to yield was positively associated with oil and limiting AA abundance across genotypes. In summary, the main outcomes of the present thesis are related to 1) the importance of soil NO3 and NH4 to regulate Ndfa during the season, 2) the timing of Ndfa assessment or prediction for an accurate fixed N calculation throughout the season, and 3) the underlaying effect of branch yield allocation on the seed composition of the whole soybean plant, plausibly moderating changes across genotypes, environments, and management practices. A better understanding of soybean N acquisition and allocation for yield and quality formation within the plant is important to sustain the yield increase, offset protein decay, and assure cropping systems sustainability and food security in a long-term standpoint.
![Factors Influencing the Interactions Among Photosynthesis, Translocation, and Nitrogen Fixation in Soybeans (G̲l̲y̲c̲i̲n̲e̲ M̲a̲x̲ [L.] Merr.) PDF](https://books.google.com/books/content/images/frontcover/JoZCPwAACAAJ?fife=w80-h100)
Author: Gary Alan Finn
Publisher:
ISBN:
Category : Nitrogen
Languages : en
Pages : 126
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Book Description
Author: William Shurtleff; Akiko Aoyagi
Publisher: Soyinfo Center
ISBN: 1948436000
Category : Nitrogen
Languages : en
Pages : 1129
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Book Description
This is the world's most comprehensive, well documented, and well illustrated book on this subject. With extensive subject and geographical index. 91 photographs and illustrations - mostly color, Free of charge.
Author: Lisbet Ann Phillips
Publisher:
ISBN:
Category :
Languages : en
Pages : 152
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Book Description
Author: Fernando Salvagiotti
Publisher: ProQuest
ISBN: 9780549637431
Category : Nitrogen fertilizers
Languages : en
Pages :
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Author: Takuji Ohyama
Publisher: Nova Science Publishers
ISBN: 9781606928561
Category : Nitrogen
Languages : en
Pages : 131
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Book Description
In the first part, the authors introduce the progress of researches on nitrogen metabolism of soybean nodules and roots. They investigate the fate of nitrogen fixed in soybean nodules by tracer experiment with 15N2 gas. The results indicate that major part of fixed N in bacteroids (a symbiotic state of rhizobia) is excreted rapidly to cytosol of infected cells in the form of ammonia, then the ammonia is assimilated into amino acids via GS/GOGAT pathway. Then the fixed nitrogen is assimilated into ureides, allantoin and allantoic acid, and then transported to the shoots via xylem. A small portion of fixed N was assimilated in the bacteroids directly into glutamate and alanine. On the other hand, nitrate absorbed from the roots are mainly assimilated into asparagine. The characteristics of nitrate absorption and metabolism was studied. It is well known that nitrate is a potent inhibitor to nodulation and nitrogen fixation, although the inhibitory mechanism is not fully understood. The authors recently found that nitrate depresses individual nodule growth and nitrogen fixation activity rapidly and reversibly when nodules were in direct contact with nitrate. The indirect effects of nitrate on nodule growth and nitrogen fixation activity were different among treatment concentration and period of supply. The continuous supply of low levels of nitrate from the lower part of roots promoted the nodulation and nitrogen fixation of the upper part of the roots. Hypernodulation mutant lines of soybean were isolated which have profuse nodulation compared with parents. They also exhibit partial-nitrate tolerant to nodulation. The characteristics of hypernodulation mutant lines were studied in relation to nitrate inhibition. The results suggest that lower nitrate absorption and assimilation activity in hypernodulation mutants may be one reason to milder inhibition by nitrate on hypernodulation mutant lines.
![Evaluation of Di-nitrogen Fixation in Early and Late Developmental Stages of Soybean (Glycine Max [L.] Merr.) PDF](https://books.google.com/books/content/images/frontcover/_Jj2wQEACAAJ?fife=w80-h100)
Author: Raphael Lemes Hamawaki
Publisher:
ISBN:
Category : Nitrogen
Languages : en
Pages : 300
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Book Description
Nitrogen (N) is present in proteins, enzymes, cell structures, purines and pyrimidines in DNA and RNA molecules, photosynthetic pigments, and several other types of molecules in all living organisms. Nonetheless, even though N makes up more than 78% of the atmosphere, it is reported to be the most frequent deficient nutrient in plants. Nitrate (NO3- ) and ammonium (NH4+) are the N forms absorbed by plants from soil, but legume crops can establish symbiotic relationships with rhizobia bacteria, and fix N2 from the atmosphere. In soybean, increasing yield and protein content are raising the crop's N requirement; therefore, enhanced N2 fixation is seen as a reliable path to avoid the use of N fertilizers. In this study, the objective was to perform a comprehensive screening in greenhouse and field conditions of soybean genotypes for traits related to N2 fixation. The purpose was to identify among the soybean genotypes different N2 fixation profiles at early and late stages, as well as to investigate their capacity to accumulate above-ground N and supply carry-over N to following crops. The results showed different profiles among the soybean genotypes for early and late N2 fixation capacity, both in greenhouse and field evaluations. Different traits were correlated to either early or late N2 fixation activity. Soybean and winter-rye shoot dry mass were evaluated in the field to assess above-ground N accumulation and carry-over N, respectively. Soybean genotypes were identified with specific capacities to accumulate N in above-ground biomass or supply N to winter-rye. The patterns of N2 fixation identified in this study, as well as the different abilities to accumulate N above-ground or supply N to following crops, could assist in the selection of superior lines with improved N2 fixation capacity.
