Molecular genetic mapping of chromosomes 6A and 6B of tetraploid wheat (Triticum turgidum L.) /
Triticum turgidum var durum cv 'Langdon'-T. t. var
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1997.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=739891041&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Triticum turgidum var durum cv 'Langdon'-T. t. var 'dicoccoides' chromosomes 6A and 6B recombinant substitution lines (RSLs) and F3 families derived from a 'Langdon- dicoccoides' disomic chromosome 6A substitution line were analyzed with the objective of increasing the number of markers assigned to and the resolution of previously constructed 6A and 6B linkage maps. Fifty-seven markers were added to the 6A RSL-population map, which now consists of 73 markers that span 111 cM, and 40 markers were added to the 6B RSL-population map, which now consists of 56 markers that span 123 cM. The 6A and 6B markers were assigned to 40 and 34 loci, respectively, and except for two 6B loci, all loci on the two RSL-population maps were ordered at a LOD > 3.0. Thirty-seven orthologous markers were assigned to the 6A and 6B maps and colinearity between the two chromosomes is strongly indicated. Colinearity with markers in barley chromosome 6H and with other Triticum group 6 chromosomes is also indicated, and a consensus Triticeae group 6 map was produced. In addition, homoeology between a long segment in rice chromosome 2 and parts of 6A and 6B was demonstrated. The high degree of similarity between the 6A RSL population map and the 6A F2-population map indicates that the former population, which consists of 66 lines, can be reliably used for mapping, as was previously demonstrated for the 6B RSL population. An unexpected finding was that 18% of the RFLPs did not map to the chromosomes of interest, i.e., to 6A in the two 6A mapping populations and to 6B in the 6B RSL mapping population. Most of these markers were shown to be located in the homoeologue of the substituted/recombined chromosome. A T. dicoccoides allele, or in some cases a Chinese Spring allele, is fixed in many RSLs for 26 of these markers and, given that distorted segregation in favor of the non-Langdon allele is apparent for all but six of these markers, eventual fixation of the non-Langdon allele in most RSLs for markers that are presently heterozygous seems probable. |
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| Item Description: | Vita. "Major Subject: Genetics". In title, numerals are used. |
| Physical Description: | xi, 95 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 83-94. |