Identification and Mapping of a Novel Sugarcane Mosaic Virus Resistance Gene in Maize

Sugarcane mosaic virus (SCMV) causes considerable damage to maize (Zea mays L.) in China. Characterization of resistance gene(s) serves as the basis for effective selection in resistance breeding programs. The objective of this study was to identify novel genes conferring resistance to SCMV from maize germplasm in China. A total of 21 BC2F3 populations derived from 8 maize intercross combinations were artificially inoculated with SCMV under field conditions. The numbers of resistant and susceptible plants in the BC2F3 population Ye 478 × Hai 9-21 were consistent with the theoretical 1:3 phenotypic ratio, suggesting that a recessive gene derived from the resistant parent Hai 9-21 was responsible for resistance to SCMV. Bulked segregant analysis (BSA) and simple sequence repeat (SSR) marker analysis were used to verify the recessive resistance gene that was designated scm3. Gene scm3 was located in bin 3.04–3.05, flanked by SSR markers umc1965 and bnlg420 with genetic distances of 45.7 and 6.5 cM, respectively. Four additional linked markers were detected, which were associated with scm3 gene in the order of umc1965–scm3–bnlg420–umc1307–umc2265–bnlg2241–umc2166.