QUANTITATIVE AND MORPHOLOGICAL CHARACTERISTICS OF NP9BR RANDOM-MATING POPULATION OF SORGHUM AFTER NINE CYCLES OF SELECTION (MALE-STERILITY, DROUGHT, HERITABILITY, ARIZONA).

Persistent Link:
http://hdl.handle.net/10150/187642
Title:
QUANTITATIVE AND MORPHOLOGICAL CHARACTERISTICS OF NP9BR RANDOM-MATING POPULATION OF SORGHUM AFTER NINE CYCLES OF SELECTION (MALE-STERILITY, DROUGHT, HERITABILITY, ARIZONA).
Author:
CHIGWE, CHARLES FRANCISCO BRADLEY.
Issue Date:
1984
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:
This study sought to determine the effects of reselection on the adaptation of a grain sorghum (Sorghum bicolor (L.) Moench) population to heat and drought. A random-mating population, NP9BR, was subjected to selection under heat and moisture stress for nine generations to improve its resistance to drought. One hundred single plants selected from the original (C₀) and the reselected (C₉) population were grouped by maturity and evaluated for drought resistance by measuring morphological and agronomic characters under wet (normal irrigation) and dry (restricted irrigation) conditions at the University of Arizona, Marana Agricultural Center, Arizona. Eighty of the selections were grown under a sprinkler irrigation gradient system at Yuma Mesa Agricultural Center, Arizona. Selection under drought conditions reduced plant height, head exsertion, leaf width and length, and seed weight of the population. Blooming was evened out from predominantly early in C₀ to early, medium and late maturing in C₉. Moisture stress reduced grain yield by an overall 16%. The medium maturing selections suffered less yield reduction than the early and late. Although C₉ progenies showed a greater reduction in grain yield, several of them produced equal yields in wet and dry treatments. Leaf width and length were significantly correlated (p = .1%) with yield under dry conditions in all maturity groups. Most selections with very short narrow leaves had small heads and low yields. Some with medium leaf width and length out-yielded broad-leaved ones especially under dry conditions. Forty percent of the selections from C₉ had good head production characteristics under the irrigation gradient system, compared to only 20% from C₀. There were four times as many selections in C₀ unable to produce heads under the system as there were in C₉. The majority of genotypes with good head production in both populations came from the early maturing group. The highest grain yields came from C₀ selections but some C₉ selections with comparable yields were observed. This study indicates that phenotypic selection may still have potential for isolating high-yield genotypes from random-mating populations but may be inadequate for separating differences in drought tolerance among genotypes.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Sorghum -- Breeding.; Sorghum -- Drought tolerance.; Sorghum -- Climatic factors.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Plant Sciences; Graduate College
Degree Grantor:
University of Arizona

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleQUANTITATIVE AND MORPHOLOGICAL CHARACTERISTICS OF NP9BR RANDOM-MATING POPULATION OF SORGHUM AFTER NINE CYCLES OF SELECTION (MALE-STERILITY, DROUGHT, HERITABILITY, ARIZONA).en_US
dc.creatorCHIGWE, CHARLES FRANCISCO BRADLEY.en_US
dc.contributor.authorCHIGWE, CHARLES FRANCISCO BRADLEY.en_US
dc.date.issued1984en_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.abstractThis study sought to determine the effects of reselection on the adaptation of a grain sorghum (Sorghum bicolor (L.) Moench) population to heat and drought. A random-mating population, NP9BR, was subjected to selection under heat and moisture stress for nine generations to improve its resistance to drought. One hundred single plants selected from the original (C₀) and the reselected (C₉) population were grouped by maturity and evaluated for drought resistance by measuring morphological and agronomic characters under wet (normal irrigation) and dry (restricted irrigation) conditions at the University of Arizona, Marana Agricultural Center, Arizona. Eighty of the selections were grown under a sprinkler irrigation gradient system at Yuma Mesa Agricultural Center, Arizona. Selection under drought conditions reduced plant height, head exsertion, leaf width and length, and seed weight of the population. Blooming was evened out from predominantly early in C₀ to early, medium and late maturing in C₉. Moisture stress reduced grain yield by an overall 16%. The medium maturing selections suffered less yield reduction than the early and late. Although C₉ progenies showed a greater reduction in grain yield, several of them produced equal yields in wet and dry treatments. Leaf width and length were significantly correlated (p = .1%) with yield under dry conditions in all maturity groups. Most selections with very short narrow leaves had small heads and low yields. Some with medium leaf width and length out-yielded broad-leaved ones especially under dry conditions. Forty percent of the selections from C₉ had good head production characteristics under the irrigation gradient system, compared to only 20% from C₀. There were four times as many selections in C₀ unable to produce heads under the system as there were in C₉. The majority of genotypes with good head production in both populations came from the early maturing group. The highest grain yields came from C₀ selections but some C₉ selections with comparable yields were observed. This study indicates that phenotypic selection may still have potential for isolating high-yield genotypes from random-mating populations but may be inadequate for separating differences in drought tolerance among genotypes.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectSorghum -- Breeding.en_US
dc.subjectSorghum -- Drought tolerance.en_US
dc.subjectSorghum -- Climatic factors.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.committeememberBriggs, Robert E.en_US
dc.contributor.committeememberRay, Dennis T.en_US
dc.contributor.committeememberStith, Lee S.en_US
dc.contributor.committeememberNutting, William L.en_US
dc.contributor.committeememberWatson, Theo F.en_US
dc.identifier.proquest8412660en_US
dc.identifier.oclc690914544en_US
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