Identification of SSR Marker Linked to y9 Locus in Soybean (Glycine max L.)

Leaf chlorophyll-deficient mutants controlled by y9 locus have been observed frequently and are useful in genetic studies in soybean. The objective of this research was to identify molecular markers linked to the y9 locus. A mapping population consisting of 94 F2 progeny was derived from a cross between normal green leaf Clark (Y9Y9) and chlorophyll-deficient leaf mutant C142 (y9y9). The phenotype of F2 individual plants and parents was recorded at V3 growth stage from field. One-thousand 10-mer oligonucleotide RAPD primers and 42 SSR primers selected from the MLG E of the soybean molecular linkage map were used. A genetic map was constructed from the segregating 6 RAPD, 1 SSR markers and 1 phenotypic (normal green type/chlorophyll-deficient type) marker. The segregation ratios of 3 : 1 observed in the F2 population and the Chi-square values strongly suggest that the chlorophyll-deficient trait is controlled by a single recessive gene. Satt720 marker was linked to y9 locus at a distance of 17.1 cM. Assignment of the y9 locus to molecular linkage group E can be used as an initial step for fine mapping of the y9 gene.