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由SCMV引起的矮花叶病是我国的主要玉米病害之一,鉴定和发掘新的抗病基因对于玉米抗病遗传育种具有重要意义。以抗病自交系海9-21和感病自交系掖478杂交的一个BC2F3群体为试验材料,通过人工接种矮花叶病毒进行抗病性鉴定,发现该分离群体中抗病植株与感病植株数符合1∶3的分离比例,推测其抗病基因是由1对隐性基因控制。抗感池和SSR标记连锁分析表明,存在一个新的玉米矮花叶病隐性抗病基因(或等位基因),将该基因命名为scm3。scm3基因来源于抗病玉米自交系海9-21,位于第3染色体短臂3.04～3.05区域,在SSR标记umc1965和bnlg420之间,遗传距离分别为45.7cM和6.5cM。连锁的标记还有umc1307、umc2265、bnlg2241和umc2166,它们与scm3之间的遗传距离分别是8.3、13.3、15.5和19.7cM,这些SSR标记与scm3基因在染色体上的排列顺序为umc1965—scm3—bnlg420—umc1307—umc2265—bnlg2241—umc2166。
Dwarf mosaic disease caused by SCMV is one of the main maize diseases in China. Identification and exploration of new disease-resistance genes are of great significance for genetic breeding of maize disease resistance. A BC2F3 population of resistant inbred line Ha 9-21 and susceptible inbred line Ye 478 was used as experimental material to identify the disease resistance by artificial inoculation of dwarf mosaic virus and it was found that the resistant plants and the susceptible lines The number of diseased plants was in line with the ratio of 1: 3, suggesting that the resistance gene was controlled by a pair of recessive genes. The analysis of resistance pools and SSR markers showed that there was a new recessive resistance gene (or allele) to maize dwarf mosaic disease, which was named as scm3. The scm3 gene was originated from the resistant maize inbred line Ha9-21 and located in the 3.04-3.05 region on the short arm of chromosome 3. The genetic distance between SSR markers umc1965 and bnlg420 was 45.7cM and 6.5cM, respectively. The linkage markers umc1307, umc2265, bnlg2241 and umc2166, their genetic distances to scm3 were 8.3, 13.3, 15.5 and 19.7 cM respectively. The sequence of these SSR markers and scm3 genes on the chromosomes was umc1965-scm3-bnlg420 -umc1307-umc2265-bnlg2241-umc2166.