Water deficit responses of non-nodulated and nodulated Vicia faba (broad bean) when supplied with various forms on concentrations of medium nitrogen nutrition

2.50
Hdl Handle:
http://hdl.handle.net/10547/610788
Title:
Water deficit responses of non-nodulated and nodulated Vicia faba (broad bean) when supplied with various forms on concentrations of medium nitrogen nutrition
Authors:
McCabe, Victoria B.
Abstract:
V. faba fixes nitrogen effectively (Richards & Soper, 1979), however nitrogen fixation is reportedly energetically expensive and water deficit sensitive. Research was designed to determine whether medium nitrogen applications would result in increased productivities in V. faba, particularly during water deficits. Non-nodulated and nodulated V. faba were subjected to gradual water deficit imposition, and were supplied with a variety of medium nitrogen nutrition. Nitrogen fixing V. faba exhibited greater productivities than V. faba which were supplied with low medium nitrate concentrations (0.8 roM N), even during water deficits. Plant performance parameters (growth; net photosynthesis; nitrogen assimilatory enzyme activities; osmotic adjustment) were greater in nodulated than in non-nodulated 'no nitrate' supplied V. faba throughout water deficits, inferring water deficit tolerance for nitrogen fixation. However significantly greater plant performance paramaters were exhibited in V. faba when supplied with increasingly concentrated medium nitrogen nutrition (> 0.8 roM N) than when reliant on nitrogen fixation. In contrast to the bulk of previous literature, NR activities were maintained in V. faba until water deficits became severe, inferring a role for nitrate assimilation in nitrogenous osmotica production. Medium ammonia additions resulted in the exhibition of significantly increased root biomasses; cumulative leaf areas (important for a green manure crop); heights; and nitrogen assimilation in V. faba throughout water deficits, and accordingly in increased osmotic adjustment (including compatible solute accumulation), protein concentrations and vegetative yields. Greater plant productivities in v. faba when supplied with medium ammonia additions were attributed in part to lower associated assimilatory costs for ammonia than nitrate nutrition (Raven, 1992). Results indicated increased metabolism as opposed to storage of medium ammonia, and therefore potentially alleviated 'sink size' feedback inhibition of photosynthesis and nitrogen metabolism in V. faba when supplied with medium ammonia additions. Furthermore ammonia supplied V. faba may have been predisposed towards water deficit tolerance. In summary V. faba exhibited significantly greater nitrogen assimilation; osmotic adjustment; net photosynthesis; and growth when supplied with increasingly concentrated medium nitrogen nutrition (and particularly with medium ammonia additions) than when reliant on nitrogen fixation, both during periods of adequate irrigation and during water deficits.
Citation:
McCabe, V. B. (2000) 'Water deficit responses of non-nodulated and nodulated Vicia faba (broad bean) when supplied with various forms on concentrations of medium nitrogen nutrition'. PhD thesis. University of Luton.
Publisher:
University of Bedfordshire
Issue Date:
Mar-2000
URI:
http://hdl.handle.net/10547/610788
Type:
Thesis or dissertation
Language:
en
Description:
A Thesis submitted to the Faculty of Science, Technology & Design, University of Luton, in partial fulfilment of the requirements for the Degree of Doctor of Philosophy
Appears in Collections:
PhD e-theses

Full metadata record

DC FieldValue Language
dc.contributor.authorMcCabe, Victoria B.en
dc.date.accessioned2016-05-26T12:07:20Zen
dc.date.available2016-05-26T12:07:20Zen
dc.date.issued2000-03en
dc.identifier.citationMcCabe, V. B. (2000) 'Water deficit responses of non-nodulated and nodulated Vicia faba (broad bean) when supplied with various forms on concentrations of medium nitrogen nutrition'. PhD thesis. University of Luton.en
dc.identifier.urihttp://hdl.handle.net/10547/610788en
dc.descriptionA Thesis submitted to the Faculty of Science, Technology & Design, University of Luton, in partial fulfilment of the requirements for the Degree of Doctor of Philosophyen
dc.description.abstractV. faba fixes nitrogen effectively (Richards & Soper, 1979), however nitrogen fixation is reportedly energetically expensive and water deficit sensitive. Research was designed to determine whether medium nitrogen applications would result in increased productivities in V. faba, particularly during water deficits. Non-nodulated and nodulated V. faba were subjected to gradual water deficit imposition, and were supplied with a variety of medium nitrogen nutrition. Nitrogen fixing V. faba exhibited greater productivities than V. faba which were supplied with low medium nitrate concentrations (0.8 roM N), even during water deficits. Plant performance parameters (growth; net photosynthesis; nitrogen assimilatory enzyme activities; osmotic adjustment) were greater in nodulated than in non-nodulated 'no nitrate' supplied V. faba throughout water deficits, inferring water deficit tolerance for nitrogen fixation. However significantly greater plant performance paramaters were exhibited in V. faba when supplied with increasingly concentrated medium nitrogen nutrition (> 0.8 roM N) than when reliant on nitrogen fixation. In contrast to the bulk of previous literature, NR activities were maintained in V. faba until water deficits became severe, inferring a role for nitrate assimilation in nitrogenous osmotica production. Medium ammonia additions resulted in the exhibition of significantly increased root biomasses; cumulative leaf areas (important for a green manure crop); heights; and nitrogen assimilation in V. faba throughout water deficits, and accordingly in increased osmotic adjustment (including compatible solute accumulation), protein concentrations and vegetative yields. Greater plant productivities in v. faba when supplied with medium ammonia additions were attributed in part to lower associated assimilatory costs for ammonia than nitrate nutrition (Raven, 1992). Results indicated increased metabolism as opposed to storage of medium ammonia, and therefore potentially alleviated 'sink size' feedback inhibition of photosynthesis and nitrogen metabolism in V. faba when supplied with medium ammonia additions. Furthermore ammonia supplied V. faba may have been predisposed towards water deficit tolerance. In summary V. faba exhibited significantly greater nitrogen assimilation; osmotic adjustment; net photosynthesis; and growth when supplied with increasingly concentrated medium nitrogen nutrition (and particularly with medium ammonia additions) than when reliant on nitrogen fixation, both during periods of adequate irrigation and during water deficits.en
dc.language.isoenen
dc.publisherUniversity of Bedfordshireen
dc.subjectC200 Botanyen
dc.subjectVicia fabaen
dc.subjectbroad beanen
dc.subjectnitrogen fixationen
dc.subjectwater deficit responseen
dc.titleWater deficit responses of non-nodulated and nodulated Vicia faba (broad bean) when supplied with various forms on concentrations of medium nitrogen nutritionen
dc.typeThesis or dissertationen
dc.type.qualificationnamePhDen_GB
dc.type.qualificationlevelPhDen
dc.publisher.institutionUniversity of Bedfordshireen
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