A ¹⁵N study of the effects of nitrate, ammonium and nitrate plus ammonium nutrition on nitrogen assimilation in Hordeum vulgare

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dc.contributor.advisorLewis, O A Men_ZA
dc.contributor.authorChadwick, Susan Glynnisen_ZA
dc.date.accessioned2016-11-16T13:24:58Z
dc.date.available2016-11-16T13:24:58Z
dc.date.issued1985en_ZA
dc.descriptionBibliography: pages 98-112.en_ZA
dc.description.abstractA review of the recent literature concerning the assimilation and utilisation of nitrate and ammonium nitrogen within plants has been presented. Barley plants (Hordeum vulgare L.cv. Clipper) were grown hydroponically under controlled environmental conditions. The aerated nutrient solutions contained 2mM inorganic ¹⁴N supplied as either nitrate alone, ammonium alone, a 1:1 nitrate plus ammonium mixture or a 3:1 nitrate plus ammonium mixture. After 20 days of growth ¹⁵N nutrient solutions were substituted. The plant material was harvested four and eight hours after the commencement of the ¹⁵N feeding experiment and prepared for analysis. Xylem sap was also collected for a period of one hour beginning half an hour before each harvest and continuing for half an hour after harvesting. Separate batches of plants were used for harvesting and sap collection. In nitrate-fed plants the shoot was shown to be the main organ of nitrate assimilation. Xylem sap analysis indicated that 66% of the ¹⁵N supply to the shoot was in the form of nitrate and the majority of the absorbed and assimilated ¹⁵N was located in this region. In ammonium-fed plants, however, ¹⁵N-ammonium accumulated in the root with only a very small amount detectable in the xylem sap. Some 93% of the ¹⁵N exported from root to shoot in the xylem stream was in the form of organic nitrogen (mainly glutamine). This indicated that the root was the major organ of ammonium assimilation and that the shoot was the main destination of root assimilated nitrogen.en_ZA
dc.identifier.apacitationChadwick, S. G. (1985). <i>A ¹⁵N study of the effects of nitrate, ammonium and nitrate plus ammonium nutrition on nitrogen assimilation in Hordeum vulgare</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/22563en_ZA
dc.identifier.chicagocitationChadwick, Susan Glynnis. <i>"A ¹⁵N study of the effects of nitrate, ammonium and nitrate plus ammonium nutrition on nitrogen assimilation in Hordeum vulgare."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 1985. http://hdl.handle.net/11427/22563en_ZA
dc.identifier.citationChadwick, S. 1985. A ¹⁵N study of the effects of nitrate, ammonium and nitrate plus ammonium nutrition on nitrogen assimilation in Hordeum vulgare. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Chadwick, Susan Glynnis AB - A review of the recent literature concerning the assimilation and utilisation of nitrate and ammonium nitrogen within plants has been presented. Barley plants (Hordeum vulgare L.cv. Clipper) were grown hydroponically under controlled environmental conditions. The aerated nutrient solutions contained 2mM inorganic ¹⁴N supplied as either nitrate alone, ammonium alone, a 1:1 nitrate plus ammonium mixture or a 3:1 nitrate plus ammonium mixture. After 20 days of growth ¹⁵N nutrient solutions were substituted. The plant material was harvested four and eight hours after the commencement of the ¹⁵N feeding experiment and prepared for analysis. Xylem sap was also collected for a period of one hour beginning half an hour before each harvest and continuing for half an hour after harvesting. Separate batches of plants were used for harvesting and sap collection. In nitrate-fed plants the shoot was shown to be the main organ of nitrate assimilation. Xylem sap analysis indicated that 66% of the ¹⁵N supply to the shoot was in the form of nitrate and the majority of the absorbed and assimilated ¹⁵N was located in this region. In ammonium-fed plants, however, ¹⁵N-ammonium accumulated in the root with only a very small amount detectable in the xylem sap. Some 93% of the ¹⁵N exported from root to shoot in the xylem stream was in the form of organic nitrogen (mainly glutamine). This indicated that the root was the major organ of ammonium assimilation and that the shoot was the main destination of root assimilated nitrogen. DA - 1985 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1985 T1 - A ¹⁵N study of the effects of nitrate, ammonium and nitrate plus ammonium nutrition on nitrogen assimilation in Hordeum vulgare TI - A ¹⁵N study of the effects of nitrate, ammonium and nitrate plus ammonium nutrition on nitrogen assimilation in Hordeum vulgare UR - http://hdl.handle.net/11427/22563 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/22563
dc.identifier.vancouvercitationChadwick SG. A ¹⁵N study of the effects of nitrate, ammonium and nitrate plus ammonium nutrition on nitrogen assimilation in Hordeum vulgare. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 1985 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/22563en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Biological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherBotanyen_ZA
dc.titleA ¹⁵N study of the effects of nitrate, ammonium and nitrate plus ammonium nutrition on nitrogen assimilation in Hordeum vulgareen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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