Liang Guohua

Molecular mapping of two semidwarf genes in an indica rice variety Aitaiyin3 (Oryza sativa L.)

Genetic analysis established that Aitaiyin3, a dwarf rice variety derived from a semidwarf cultivar Taiyin1, carries two recessive semidwarf genes. By using simple sequence repeat (SSR) markers, we mapped the two semidwarf genes, sd-1 and sd-t2 on chromosomes 1 and 4, respectively. Sd-t2 was thus named because the semidrawf gene sd-t has already been identified from Aitaiyin 2 whose origin could be traced back to Taiyin1. The result of the molecular mapping of sd-1 gene revealed it is linked to four SSR markers found on chromosome 1. These markers are: RM297, RM302, RM212, and OSR3 spaced at 4.7 cM, 0 cM, 0.8cM and 0 cM, respectively. Sd-t2 was found to be located on chromosome 4 using five SSR markers: two markers, SSR332 and RM1305 located proximal to sd-t2 are spaced 11.6 cM, 3.8 cM, respectively, while the three distally located primers, RM5633, RM307, and RM401 are separated by distances of 0.4 cM, 0.0 cM, and 0.4 cM, respectively.