An Extended Linkage Map of Sugar Beet (Beta vulgaris L.) Including Nine Putative Lethal Genes and the Restorer Gene X |
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| Authors: | K Pillen G Sleinrücken R G Herrmann C Jung |
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| Institution: | Institut für Botanik, Ludwig-Maximilians Universität München, Menzinger Str. 67, D-80638 München, Germany;Department of Plant Breeding and Biometry, Cornell University, 252 Emerson Hall, Ithaca 14853, Ny, Usa;A. Dieckmann-Heimburg, Saatzucht Sülbeck, Kirchhorsterstr. 2, D-31688 Nienstädt, Germany |
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| Abstract: | An extended genetic map of sugar beet (Beta vulgaris L.) is presented encompassing 177 segregating markers (2 morphological traits, 7 isozymes, and 168 RFLP markers) on 9 linkage groups. The linkage map comprises 1057.3 cM equivalent to an average genetic spacing of 6.0 cM/marker. The length of individual linkage groups varies between 80.7 (group VIII) and 167.4 cM (group VIII). The number of markers per linkage group ranges between 13 and 24. No indication of duplicate regions was found, confirming the true diploid nature of B. vulgaris. Twenty-six markers (15 %) deviated significantly (a = 0.01) from the expected segregation ratio. This distorted segregation was probably caused by linkage with lethal genes. Four such genes (designated Let Ib, Let 5b, Let 6b, Let 8) could be located at discrete positions due to their absolute linkage to skewed RFLP markers. The restorer gene X has been located terminally on linkage group ÜI, 9.6 cM distant from RFLP marker pKP1238. |
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| Keywords: | Beta vulgaris RFLP linkage map lethal genes male sterility restorer gene |
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