Fig. 1. Part of high density linkage map for chromosome 4, 6 and 7, showing locations of Ph, alk and Rc, respectively. Genetic distance from top end of each map is indicated on the left side.
1) Rice Genome Research Program, Society for Techno-innovation of Agriculture, Forestry and Fisheries, 446-1 ippaizuka, Kamiyokoba, Tsukuba, 305 Japan
2) Rice Genome Research Program, National Institute of Agrobiological Resources, Kannondai 2-1-2, Tsukuba, 305 Japan
Molecular linkage maps of rice have been constructed using DNA markers (McCouch et al. 1988; Saito et al. 1991). We have constructed a high density linkage map including more than 1300 DNA markers (Kurata and coworkers, unpubl.). These finely mapped markers enable us to determine the location of genes for morphological traits precisely. In this paper, we report the identification of DNA markers tightly linked to genes Ph (phenol staining), Rc (brown pericarp) and alk (alkali digestion). For mapping these loci, the F`3` seeds from 186 F`2` plants, which had been used for construction of the high resolution linkage map, were examined phenotypically. The results showed that gene Ph was linked to Ky3 and V17 on chromosome 4, both within a genetic distance of 0.1 cM. On the other hand, gene Rc was tightly linked to C67A and R277, and no recombination was observed. Gene alk was liked to C1478 with 1.1 cM and to R2147, Y2587L and Y4073L with 3.0 cM distance, and was located on chromosome 6 (Fig. 1). These tightly linked DNA markers would be useful to select "Yeast artificial chromosome" (YAC; developed for analysing long fragments) clones carrying these genes.
Fig. 1. Part of high density linkage map for chromosome 4, 6 and 7, showing
locations of Ph, alk and Rc, respectively. Genetic distance from top end of
each map is indicated on the left side.
References
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Saito, A., M. Yano, N. Kishimoto, M. Nakagahra, A. Yoshimura, K. Saito, S. Kuhara, Y. Ukai, M. Kawase, T. Nagamine, S. Yoshimura, O. Ideta, R. Ohsawa, Y. Hayano, N. Iwata and M. Sugiura, 1991. Linkage map of restriction fragment length polymorphism loci in rice. Japan. J. Breed. 41: 665-670.