Summary
Genotypes of sorghum and millet have previously been found to have different amounts of root-associated acetylene reduction activity. Isotope dilution experiments using15N have been carried out to evaluate the amount of nitrogen fixed by bacteria which is incorporated into the different genotypes when grown in vermiculite in the glasshouse. Isotope dilution result indicated that the content of shoot nitrogen derived from biological nitrogen fixation varied by up to 27% between sorghum genotypes and 17% between millet genotypes. Considerable isotope dilution also resulted from uptake of non-exchangeable-N (as NH +4 ) in the vermiculite. It is possible that the genotypic differences in isotope dilution may reflect differences in the ability of plants to take up non-exchangeable-N, and that vermicultite is therefore an unsuitable growth medium for such studies.
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References
Beauchamp E G 1982 Fixed ammonium and potassium release from two soils. Comm. in Soil Sci. Plant Anal. 13, 927–943.
Broughton W J and Dilworth M J 1971 Control of leghaemoglobin synthesis in snake beans. Biochem. J. 125, 1075–1080.
Brown J C and Bell W D 1969 Iron uptake dependant upon genotype of corn. Proc. Soil. Sci. Soc. Am. 83, 99–101.
Dabin B 1965 Application des dosages automatiques a l'analyse des sols. Cahiers ORSTOM Serie Pedologie 111 No. 4, 335–366.
Dart P J and Wani S P 1982 Non-symbiotic nitrogen fixation and soil fertility.In Nonsymbiotic nitrogen fixation and organic matter in the tropics. Symposia papers I Transactions of the 12th International Congress of Soil Science, New Delhi, India.
Döbereiner J and Day J M 1975 Nitrogen fixation in the rhizosphere of tropical grasses.In Nitrogen Fixation by Free-living Micro-organisms Ed. W D P Stewart IBP Vol. 6, pp 39–56.
Fried M and Broeshart H 1975 An independant measurement of the amount of nitrogen fixed by a legume crop. Plant and Soil 43, 713–715.
Giller K E, Day J M, Dart P J and Wani S P 1984 A method for measuring the transfer of fixed nitrogen from free-living bacteria to higher plants using15N2. J. Microb. Methods 2, 307–316.
Nommik H 1965 Ammonium fixation and other reactions involving a nonenzymatic immobilization of mineral nitrogen in soil.In Soil Nitrogen. Eds. W V Bartholomew and F E Clark. Am. Soc. Agron. No. 10, Madison, USA, pp 198–258.
van Berkum P and Bohlool B B 1980 Evaluation of nitrogen fixation by bacteria in association with roots of tropical grasses. Microb. Rev. 44, 491–517.
Varley J A 1966 Automatic methods for the determination of nitrogen, phosphorus and potassium in plant materials. Analyst 91, 119–126.
Wani S P, Upadhyaya M N and Dart P J 1984 An intact plant assay for estimating nitrogenase activity (C2H2 reduction) of sorghum and millet plants grown in pots. Plant and Soil 85, 15–29.
Witty J F 1983 Estimating N2-fixation in the field using15N-labelled fertilizer: some problems and solutions. Soil Biol. Biochem. 15, 631–639.
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Published as Journal Article No. 493 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru P.O., Andhra Pradesh 502 324, India.
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Giller, K.E., Wani, S.P. & Day, J.M. Use of isotope dilution to measure nitrogen fixation associated with the roots of sorghum and millet genotypes. Plant Soil 90, 255–263 (1986). https://doi.org/10.1007/BF02277402
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DOI: https://doi.org/10.1007/BF02277402