玉米抗粗缩病主效QTL(qMrdd1)的基因多效性分析
玉米粗缩病是一种世界性病毒病,对玉米生产危害极大。前期研究中,我们将主效抗病QTL(qMrdd1)定位在第8染色体分子标记M103.4和M105.3之间。该抗病QTL表现为隐性基因遗传,可降低24.2-39.3%的发病率。通过分子标记检测,在抗病系NT411(供体亲本)和感病系NT409(轮回亲本)回交多代的群体中,选择7个含有抗性QTL(qMrdd1)的杂合单株自交得到分离群体B1、B2、B3、B4、B5、B6、B7和来源于同一回交后代的两对抗感病近等基因系(B8-R、B8-S和B9-R、B9-S),并利用这两对近等基因系与自交系A7110、Q319、CT03、昌7-2、43684、43683、43946组配13对杂交种,在植株整个生育期内无粗缩病病毒接种的条件下,在北京、海南和山东种植不同的材料并对7个分离群体和13对杂交种进行农艺性状调查,结果表明7个分离群体中各基因型植株以及13对杂交种在株高、穗长、穗行数等农艺性状上差异不显著,qMrdd1基因对玉米产量性状不存在多效性现象,可以应用于抗粗缩病育种。
英文摘要:
Maize rough dwarf disease(MRDD)is a kind of virus disease worldwide and may cause great losses in grain yield. We mapped a major resistance QTL, qMrdd1, which flanked by markers M103.4 and M105.3 on chromosome 8. The qMrdd1 acted in a recessive manner to reduce the disease-severity index (DSI) by 24.2-39.3%. In the backcross group of resistance NT411 (donor parent) and susceptible NT409 (recurrent parent), 7 plants with heterozygous qMrdd1 loci were selected by MAS for self-pollinated to develop 7 groups of B1, B2, B3, B4, B5, B6 and B7. The resistance lines(B8-R and B9-R,with qMrdd1)or susceptible(B8-S and B9-S,without qMrdd1)lines were crossed with A7110, Q319, CT03, chang7-2, 43684, 43683, 43946 inbred lines to obtain 13 groups hybrids. The hybrids and 7 segregation populations were planted to investigate agronomic characters without inoculation of the MRDD virus. The results showed that there were no significant difference among the 3 genotype plants of the 7 groups in several agronomic traits such as plant height, ear length, and rows per ear, the same to 13 groups of hybrids. Which indicated that there were no genetic multiple-effects and the QTL of qMrdd1could be used to resistant breeding for maize rough dwarf disease.
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