玉米抗粗缩病主效QTL (qMrdd1)的基因多效性分析

前期研究中将主效抗病QTL(qMrdd1)定位在第8染色体分子标记M103.4-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),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。

Gene Pleiotropic Analysis of the Resistance QTL(qMrdd1) to Maize Rough Dwarf Disease

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), seven plants with heterozygous qMrdd1 lociwere selected by MAS for self-pollinated to develop 7 groups of B1, B2, B3, B4, B5, B6 and B7. The resistance lines(B8-Rand 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. The result indicated that there were no genetic multiple-effects and the QTL of qMrdd1 could be used to resistant breeding for maize rough dwarf disease.