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dc.contributor.advisorMuramotoen_US
dc.contributor.authorSHERMAN, RICHARD ALAN.
dc.creatorSHERMAN, RICHARD ALAN.en_US
dc.date.accessioned2011-10-31T16:52:18Zen
dc.date.available2011-10-31T16:52:18Zen
dc.date.issued1986en_US
dc.identifier.urihttp://hdl.handle.net/10150/183873en
dc.description.abstractA breeding program was begun to transfer the caducous bract trait from the wild cotton diploid species Gossypium armourianum Kearney (D genome, 2n = 26) to the cultivated tetraploid species G. hirsutum (AD genomes, 2n = 4x = 52). The sterile triploids were then doubled with colchicine to obtain fertile hexaploid plants. These plants and their open pollinated progeny varied in their chromosome number from 73 to 82 chromosomes, the majority being the expected 78 chromosomes. Chromosome associations included bivalents, trivalents, quadrivalents, and hexavalents. The caducous bract trait varied from being similar to each parent species to intermediate expression. Backcrossed to G. hirsutum, progeny with 61 to 67 chromosomes were obtained with associations including frequent trivalents, quadrivalents, and one hexavalent. The caducous bract trait was not expressed in most plants and only variable in others. Progeny from open pollination or backcrossing these plants gave chromosome numbers closer to the tetraploid parent, with ranges of 56 to 64 chromosomes in open pollinated progeny and 52 to 58 for backcrossed plants. Again, the caducous bract trait was variable, possibly due to the influence of the A and D genomes of the New World cottons. Tetraploids recovered from the progeny had bivalent pairing and chiasma frequencies similar to G. hirsutum. Further backcrossing is hoped to increase the expression of the caducous bract trait.
dc.language.isoenen_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.subjectCotton -- Genetics.en_US
dc.subjectCotton -- Varieties.en_US
dc.titleCHROMOSOMAL INHERITANCE IN A BACKCROSS PROGRAM BETWEEN A HEXAPLOID COTTON LINE AND TETRAPLOID COTTON (CYTOGENETICS).en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.identifier.oclc697659406en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.contributor.committeememberEndrizzi, J. E.en_US
dc.contributor.committeememberRay, D. T.en_US
dc.contributor.committeememberBriggs, R. E.en_US
dc.contributor.committeememberMatsuda, K.en_US
dc.identifier.proquest8623862en_US
thesis.degree.disciplinePlant Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.namePh.D.en_US
refterms.dateFOA2018-06-27T22:12:51Z
html.description.abstractA breeding program was begun to transfer the caducous bract trait from the wild cotton diploid species Gossypium armourianum Kearney (D genome, 2n = 26) to the cultivated tetraploid species G. hirsutum (AD genomes, 2n = 4x = 52). The sterile triploids were then doubled with colchicine to obtain fertile hexaploid plants. These plants and their open pollinated progeny varied in their chromosome number from 73 to 82 chromosomes, the majority being the expected 78 chromosomes. Chromosome associations included bivalents, trivalents, quadrivalents, and hexavalents. The caducous bract trait varied from being similar to each parent species to intermediate expression. Backcrossed to G. hirsutum, progeny with 61 to 67 chromosomes were obtained with associations including frequent trivalents, quadrivalents, and one hexavalent. The caducous bract trait was not expressed in most plants and only variable in others. Progeny from open pollination or backcrossing these plants gave chromosome numbers closer to the tetraploid parent, with ranges of 56 to 64 chromosomes in open pollinated progeny and 52 to 58 for backcrossed plants. Again, the caducous bract trait was variable, possibly due to the influence of the A and D genomes of the New World cottons. Tetraploids recovered from the progeny had bivalent pairing and chiasma frequencies similar to G. hirsutum. Further backcrossing is hoped to increase the expression of the caducous bract trait.


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