A new dominant locus, E11, controls early flowering time and maturity in soybean

Abstract

Flowering time, as an important ecological trait related to photoperiod response, maturity, and final yield, is a complex trait conferred by multiple genes. To further elucidate the genetic mechanism for the flowering time, quantitative trait loci (QTLs) related to the flowering time and maturity were identified utilizing specific-locus amplified fragment sequencing (SLAF-Seq) technology. In total, we identified three QTLs on chromosomes 5, 6, and 7 from a recombinant inbred line (RIL) population of 171 individuals derived from a cross between Minsoy and Archer soybeans. Of these QTLs, one new QTL on chromosome 7, called E11, was simultaneously detected in an ~ 1.03 Mb region from the F6 and F8 generations of the RIL population, and accounted for ~ 15% of the total phenotypic variation over 2 years. The gene symbol E11e11 had been approved by the soybean genetic committee. The segregation patterns observed in residual heterozygous lines (RHLs) at the E11 locus revealed that early flowering was controlled by a single dominant gene. The gene was fine-mapped to an ~ 138 kb interval, including 11 genes based on the reference genome. Through amino acid sequence analysis, three most likely candidate genes, Glyma.07 g048500, Glyma.07 g049000, and Glyma.07 g049200, were identified. The phenotypes detected from two near-isogenic lines (NILs) revealed that NILs for E11 allele significantly promoted the flowering time and maturity than NILs for the e11 under the long-day (LD) conditions. These results suggest that E11 is a new flowering time gene that will be valuable in improving our understanding of the mechanism for the flowering time and molecular breeding.