13. Linkage relations between Adh-1 and two morphological markers

A. C. Sanchez, G. S. Khush and D. S. Brar

International Rice Research Institute, P. 0. Box 933, Manila, Philippines

The Adh-1 gene for alcohol dehydrogenase was assigned to linkage group 11 by Ranjhan et al. (1988). In order to map this gene on the linkage group we crossed marker stock (RGS1132) having linked markers v-4 (virescent), la (lazy), and Adh- 12 with an isozyme tester stock (IRRI Acc. 6245) having Adh-13. As the data of Table 1 show, Adh-1 was found to be linked with both v-4 and la. Recombination values were calculated using maximum likelihood formula (Allard 1956) and found to be 21+/-3.35 between Adh-1 and v-4 and 29+/-0.15 between Adh-1 and la. The map distance between v-4 and la was calculated to be 10+/-2.37 cM. These data show that v-4 is located between la and Adh-1 (Fig. 1). The linkage intensities between v-4 and la and Adh-1 and v-4 are similar to those reported by Ishikawa and Morishima (1989) did not detect and linkage between la and Adh-1.

Table 1. Segregation of three genes, v-4, la and Adh-1 in the F2 population of RGS 1132 X Acc. 6245

================================================================
                          Adh-1                    Recombination
Marker          =============================Total  value
                 3/3        3/2        2/2
================================================================
v-4     normal   47         84         17    148
        mutant    1         14         18     33   21+/-3.35
        total    48         98         35    181
================================================================
la      normal   45         80         20    145
        mutant    3         18         15     36   29+/-0.15
        total    48         98         35    181
================================================================
                normal             virescent
        normal  138                     7    145
        lazyant  10                    26     36   10+/-2.37
        total   148                    33    181
================================================================

Fig. 1. Relative positions of the three loci in linkage group 11.

References

Allard, R. W. 1956. Formulas and tables to facilitate the calculation of recombination values in heredity. Hilgardia 24(10): 235-278.

Ishikawa, R., T. Kinoshita and H. Morishima, 1988. Linkag analysis of the Pgd-1 locus. RGN 5: 81-82.

Ishikawa, R. and H. Morishima, 1989. Linkage analysis for four isozyme loci. Adh-1, Acp-1, Pox-2 and Pgd-2. RGN 6: 109-112.

Ranjhan, S., J. C. Glaszmann and G. S. Khush, 1988, Chromosomal location of four isozyme loci by trisomic analysis in rice (Oryza sativa L.). Theor. Appl. Genet. 75: 541-545.