Identification of QTL underlying somatic embryogenesis capacity of immature embryos in soybean (Glycine max (L.) Merr.)

High embryogenesis capacity of soybean (Glycine max (L.) Merr.) in vitro possessed potential for effective genetic engineering and tissue culture. The objects of this study were to identify quantitative trait loci (QTL) underlying embryogenesis traits and to identify genotypes with higher somatic embryogenesis capacity. A mapping population, consisting of 126 F_5:6 recombinant inbred lines, was advanced by single-seed-descent from cross between Peking (higher primary and secondary embryogenesis) and Keburi (lower primary and secondary embryogenesis). This population was evaluated for primary embryogenesis capacity from immature embryo cultures by measuring the frequency of somatic embryogenesis (FSE), the somatic embryo number per explant (EPE) and the efficiency of somatic embryogenesis (ESE). A total of 89 simple sequence repeat markers were used to construct a genetic linkage map. Six QTL were associated with somatic embryogenesis. Two QTL for FSE were found, QFSE-1 (Satt307) and QFSE-2 (Satt286), and both were located on linkage group C2 that explained 45.21 and 25.97% of the phenotypic variation, respectively. Four QTL for EPE (QEPE-1 on MLG H, QEPE-2 on MLG G and QEPE-3 on MLG G) were found, which explained 7.11, 7.56 and 6.12% of phenotypic variation, respectively. One QTL for ESE, QESE-1 (Satt427), was found on linkage group G that explained 6.99% of the phenotypic variation. QEPE-2 and QESE-1 were located in the similar region of MLG G. These QTL provide potential for marker assistant selection of genotypes with higher embryogenesis.