Abstract:

【Objective】 The AFLP makers linked to rust resistance gene in foxtail millet were studied as they are useful for new resistance genes and the rational usage of marker-assisted selection in millet resistance breeding. 【Method】 A cross between resistant cultivar ‘Shilixiang’ and susceptible cultivar ‘Yugu 1’ was used to map foxtail millet rust resistance gene(s). Based on the identification result of F1 and F2 progenies inoculated with the Uromyces setariae-italicae Yoshino strains 93-5, the resistant and susceptible pools were established. With 128 EcoRⅠ/MseⅠ primer combinations, AFLP analysis was performed on parents and two bulks. AFLP makers were applied to construct a genetic linkage map of resistance gene in an F2 population of 131 individuals, which were sequenced and then converted to stable SCAR markers. 【Result】 The inoculation test showed that the resistance of ‘Shilixiang’ to millet rust was controlled by one dominant gene. In 128 AFLP primer combinations, three markers were found to be linked to the rust resistance gene, with the genetic distance of 7.4, 9., and 27.4 cM, respectively, which was tentatively named Rusi1. A preliminary genetic linkage map was constructed using 3 AFLP markers. Furthermore, the three cloned fragments were sequenced and then E+CTT/M+TAC-256 was successfully converted to a stable SCAR marker. Genetic linkage map of foxtail millet rust resistance gene Rusi1 was constructed. 【Conclusion】 The resistance to millet rust in ‘Shilixiang’ is controlled by a single dominant gene. The gene Rusi, derived from ‘Shilixiang’, is a rust resistance gene found in foxtail millet.

Key words: Setaria italica (L.) Beauv')">Setaria italica (L.) Beauv, millet rust, rust resistance gene, molecular marker, genetic linkage map