Genetic map of lps3: a new short petiole gene in soybeans

The short petiole trait is valuable for the development of plant ideotypes with high yield by improving the plant canopy. The soybean breeding line SS98206SP has shown extremely short petioles in the greenhouse and fields. A new single recessive gene designated as lps3 confers the short petiole trait in SS98206SP. The objectives of this study were to map the short petiole gene in SS98206SP with PCR-based markers. In total, 187 F(2) plants and their F(2:3) families from a cross between the short petiole line SS98206SP and the long petiole cultivar 'Taekwang' along with the two parental lines were evaluated for their petiole lengths in a greenhouse. An SSR marker from each 10-cM section of a consensus soybean map was selected for bulked segregant analysis (BSA) to identify the tentative genomic location of the gene. The BSA technique was useful to localize the gene to a genomic region in the soybean linkage group F (chromosome 13). A linkage map with six SSR and two SNP markers flanking the gene was constructed. We positioned the gene between two SSR markers, Sat_234 and Sct_033, at distances of 8.5 and 3.5 cM from the marker, respectively. The makers flanking the gene (lps3) were located within 3-4 cM of the gene. These markers will be useful for maker-assisted selection in the development of new ideotype soybean plants.