20. Linkage analysis of gene du-1 for low amylose

2)Plant Breed. Lab., Faculty of Agriculture, Kyushu University, Hakozaki, Fukuoka, 812 Japan

Gene du-1 which reduces amylose content in endosperm starch is located on Nishimura's chromosome 7 (Yano et al. 1988). Linkage relations between du-1 and gene markers fgl (faded green leaf) and pgl (pale green leaf) on chromosome 7 were examined in two crosses Em-12 (with du-1)xF1-242 (fgl) and Em-12 (du- 1)xH0775 (pgl). From the segregation pattern for du-1 and pgl observed in F\3\ lines, the maximum likelihood estimate of their recombination value was obtained to be 17.2-17.6% (Table 1), and the mean estimate weighted by the number of parental F\2\ plants was 17.5=+3.6%. Between du-1 and fgl, no recombination was found in both F\2\ and F\3\. The two loci seem to be tightly linked.

Table 1. Linkage relations between du-1 and two marker genes, fgl and pgl located on Nishimura's chromosome 7

Yano, M., K. Okuno, H. Satoh and T. Omura, 1988. Chromosomal location of genes conditioning low amylose content of endosperm starch in rice, Oryza sativa L. Theor. Appl. Genet. 76: 183-189.