Dry matter partitioning of bean (Phaseolus vulgaris L.) and cowpea (Vigna unguiculata (L.) Walp.) under water deficit conditions.

Persistent Link:
http://hdl.handle.net/10150/185649
Title:
Dry matter partitioning of bean (Phaseolus vulgaris L.) and cowpea (Vigna unguiculata (L.) Walp.) under water deficit conditions.
Author:
Castro Neto, Manoel Teixeira de.
Issue Date:
1991
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Productivity of legume crops grown in semi-arid regions of the world is limited by drought. This study was conducted to determine the effect of drought on the physiological and morphological factors associated with productivity of cowpea (Vigna unguiculata (L.) Walp) and bean (Phaseolus vulgaris L.) grown under reduced water levels. Physiological factors measured were photosynthesis, water and osmotic potential, translocation, RGR and dry matter partitioning. Morphological traits of pods and seeds were studied with scanning electron microscope. Water stress reduced seed yield in cowpea and bean plants by decreasing total biomass and photosynthesis. The source leaf, pod and seed water potential of stressed cowpea was lower than water potential of nonstressed plants. Bean water potential and turgor of source leaf, pod walls, and seed were similar for both stressed and nonstressed plants over the reproductive period. No differences in water potential and turgor were observed between pod walls and seed and source leaves of either cowpea or bean plants. In both bean and cowpea, partitioning of the total above ground dry matter was similar for both stressed and nonstressed plants. However, more dry matter accumulated in seeds than in other plant structures. Photosynthetic rates of single leaves from either cowpea or bean were greater for nonstressed than stressed plants. The duration of seed growth of cowpea and bean was not different between stressed and nonstressed plants; however, rate of seed growth at the end of seed filling period was greater in nonstressed plants. Seed RGR of both stressed and nonstressed cowpea and bean plants declined at about the same time photosynthesis of the source leaf declined. LAI and NAR were greatest in nonstressed cowpea and bean plants. Sixty-one percent of ¹⁴C sucrose taken up by the leaves was translocated to the seeds whereas only about 80% ended up in the pod walls. Pod funiculus of stressed bean plants had more scalariform xylem vessels than nonstressed plants.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Dissertations, Academic; Plant physiology.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Plant Sciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Bartels, Paul G.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleDry matter partitioning of bean (Phaseolus vulgaris L.) and cowpea (Vigna unguiculata (L.) Walp.) under water deficit conditions.en_US
dc.creatorCastro Neto, Manoel Teixeira de.en_US
dc.contributor.authorCastro Neto, Manoel Teixeira de.en_US
dc.date.issued1991en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractProductivity of legume crops grown in semi-arid regions of the world is limited by drought. This study was conducted to determine the effect of drought on the physiological and morphological factors associated with productivity of cowpea (Vigna unguiculata (L.) Walp) and bean (Phaseolus vulgaris L.) grown under reduced water levels. Physiological factors measured were photosynthesis, water and osmotic potential, translocation, RGR and dry matter partitioning. Morphological traits of pods and seeds were studied with scanning electron microscope. Water stress reduced seed yield in cowpea and bean plants by decreasing total biomass and photosynthesis. The source leaf, pod and seed water potential of stressed cowpea was lower than water potential of nonstressed plants. Bean water potential and turgor of source leaf, pod walls, and seed were similar for both stressed and nonstressed plants over the reproductive period. No differences in water potential and turgor were observed between pod walls and seed and source leaves of either cowpea or bean plants. In both bean and cowpea, partitioning of the total above ground dry matter was similar for both stressed and nonstressed plants. However, more dry matter accumulated in seeds than in other plant structures. Photosynthetic rates of single leaves from either cowpea or bean were greater for nonstressed than stressed plants. The duration of seed growth of cowpea and bean was not different between stressed and nonstressed plants; however, rate of seed growth at the end of seed filling period was greater in nonstressed plants. Seed RGR of both stressed and nonstressed cowpea and bean plants declined at about the same time photosynthesis of the source leaf declined. LAI and NAR were greatest in nonstressed cowpea and bean plants. Sixty-one percent of ¹⁴C sucrose taken up by the leaves was translocated to the seeds whereas only about 80% ended up in the pod walls. Pod funiculus of stressed bean plants had more scalariform xylem vessels than nonstressed plants.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectDissertations, Academicen_US
dc.subjectPlant physiology.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplinePlant Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorBartels, Paul G.en_US
dc.contributor.committeememberVoigt, R.L.en_US
dc.contributor.committeememberO'Leary, J.W.en_US
dc.contributor.committeememberBriggs, R.E.en_US
dc.contributor.committeememberKatterman, F.R.en_US
dc.identifier.proquest9208048en_US
dc.identifier.oclc711880579en_US
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