Abstract: Sugarcane mosaic virus (SCMV) causes considerable damage to maize (Zea mays L.) in China. Understanding the genetic of resistance gene(s) is the basis for effective selection in resistance breeding program. The objective of the present study
was to identify the new resistance gene to SCMV in China maize germplasm. Twenty-one BC₂F₃ populations derived from eight
maize intercross combinations were planted in field trials under artificial inoculation. The number of resistant and susceptible
plants in one BC₂F₃ population (Ye 478 ´ Hai 9-21) was found to be in accordance with the theoretical 1:3 ratio．A recessive gene
derived from the resistant parent Hai 9-21 was supposed to control the resistance to SCMV. With the aid of BSA (bulked segregant
analysis) and SSR marker analyses, a new recessive resistance gene to maize SCMV was identified, designated as scm3. The scm3 gene was located in the bin3.04/05, flanked by the SSR markers umc1965 and bnlg420 with the genetic distances of 45.7 and 6.5 cM, respectively. The other linked markers include umc1307, umc2265, bnlg2241, and umc2166. These linked markers are in the order of umc1965–scm3–bnlg420–umc1307–umc2265–bnlg2241–umc2166. Resistant germplasm to SCMV in maize was en-riched with the identification and mapping of scm3.

Key words: Maize dwarf mosaic, SCMV, Resistance gene, Molecular marker, Gene mapping