Linkage disequilibrium among modern sugarcane cultivars

• Published in: Theoretical and applied genetics Vol. 99; no. 6; pp. 1053 - 1060
• Main Authors: Jannoo, N, Grivet, L, Dookun, A, D'Hont, A, Glaszmann, J.C
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.10.1999; Berlin Springer Nature B.V
• Subjects: Biological and medical sciences; Chromosomes; Classical genetics, quantitative genetics, hybrids; Cloning; Cultivars; DNA probes; Fundamental and applied biological sciences. Psychology; Genetic aspects; genetic markers; Genetic testing; Genetics of eukaryotes. Biological and molecular evolution; genome; Genomes; genomics; Industrial research; linkage disequilibrium; loci; nucleic acid hybridization; Physiological aspects; Plant genetics; Pteridophyta, spermatophyta; restriction fragment length polymorphism; Saccharum; Saccharum officinarum; Saccharum spontaneum; Sugar industry; Sugarcane; Vegetals; Mauritius; Barbados; United States > US; India; Genetic mapping; Monocotyledones; Linkage; Restriction fragment length polymorphism; Saccharum officinarum; Gramineae; Angiospermae; Interspecific hybridization; Spermatophyta; Linkage equilibrium; Sugar plant; Cultivar
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s001220051414

Modern sugarcane cultivars are derived from a few interspecific hybrids created early in this century. Linkage disequilibrium was investigated in a population of 59 cultivars representing the most important commercial clones bred in Mauritius as well as a few old cultivars involved in their genealogy. Thirty-eight probes scattered over the sugarcane genome map were used to reveal RFLPs. Forty-two cases of bilocus associations were observed involving a total of 33 loci. Most of them are separated by less than 10 cM. All the corresponding allele couples were found in at least 1 of the originally created cultivars, suggesting that they depict ancient associations. This global disequilibrium is interpreted as the result of the foundation bottleneck related to the first interspecific crosses; the preferential allele associations thus created have been maintained through subsequent crosses when the loci were closely linked. This phenomenon is likely also to apply to genes of agricultural interest. A practical consequence is that markers can be used to track known QTLs in modern breeding materials without the necessity to repeatedly study segregating progenies. This structure gives high value to the correlation between molecular markers and agricultural traits among cultivars.