水稻粳型亲籼系的分子标记辅助育种

Molecular Marker-assisted Breeding of indica-compatible japonica Lines in Rice (Oryza sativa L.)

分子标记辅助聚合育种是累加有利基因的有效手段。培育粳型亲籼系是有效克服水稻籼粳亚种间杂种不育性 ,从而利用水稻亚种间杂种优势的重要途径之一。本研究利用以PCR为基础的分子标记进行辅助选择 ,对不同粳型亲籼系中不同分化度的特异亲和基因进行了聚合 ,并将 4个抗白叶枯病基因和来源于IR2 4的两个恢复基因导入粳型亲籼系中。主要结果如下 :1、以粳型亲籼系G2 4 17- 2 - 1和粳型广亲和系G2 6 0 5为亲本构建分离群体 ,利用本研究筛选的与S b ,S c ,S d三个F1花粉不育基因座位紧密连锁的PCR标记进行辅助选择。在F2 共选择到特异亲籼聚合植株 6株 ,它们分别是 5 8号 ,93号 ,94号 ,115号 ,139号 ,2 0 0号 ;广亲和聚合植株 4株 ,它们分别是 11号 ,14号 ,12 1号 ,177号。2、对当选聚合系的亲籼性和亲粳性综合分析表明 :各个特异亲籼聚合系的亲粳性之间及各个广亲和聚合系的亲籼性之间都有显著差异。特异亲籼聚合系的平均亲籼性和平均亲粳性与亲本G2 4 17- 2 - 1相比都没有显著差异。广亲和聚合系的平均亲籼性高于亲本G2 6 0 5 ,平均亲粳性显著低于亲本G2 6 0 5。这些聚合系的亲和性与其MAS基因型相一致。3、利用四类粳型亲籼系与携带有 2个恢复基因和 4个抗白叶枯病基因的品系构建回交群体 ,应用本研究筛?

Molecular marker assisted breeding is an effective method for pyramiding of genes Development of indica compatible japonica lines (ICJLs) is one of the effective ways to exploit the heterosis between indica and japoinca rice by overcoming the F 1 hybrid sterility. In this study, different differentiation degree F 1 pollen sterility genes of two ICJLs were pyramided using PCR markers based MAS. At the same time, four bacterial blight (BB) resistance genes, Xa4, xa5, xa13 and Xa21 and two CMS restorer genes, Rf3, Rf4 from IR24 were also pyramided into four kinds of ICJLs. The main results were as follows: 1 F 2 population was constructed with two ICJLs, G2417-2-1 and G2605. MAS for S b , S c , and S d were carried out using screened polymorphic PCR markers that were tightly linked to three above mentioned F 1 pollen sterility genes. Out of 200 randomly selected plants in F 2, 10 plants with desirable genotypes were obtained. Among them, 6 plants, No 58, No 93, No 94, No 115, No 139 and No 200 belonged to exceptionally indica compatible pyramiding plants (EICPPs) and the other 4 plants, No 11, No 14, No 121 and No 177 were wide compatible pyramiding plants (WCPPs). 2 The japonica compatibilities of the 6 exceptionally indica compatible pyramiding lines (EICPLs) and the indica compatibilities of the 4 wide compatible pyramiding lines (WCPLs) were significantly different from each other, respectively. Both of the average indica compatibility and the average japonica compatibility of the above 6 EICPLs were at the same level as G2417-2-1's, respectively. As far as the 4 WCPLs are concerned, the average indica compatibility of them was higher than G2605's and the average japonica compatibility was found significantly lower than G2605's. 3 Backcross populations were constructed using four kinds of ICJLs and lines with two restorer genes and four bacterial blight (BB) resistance genes. MAS was proceeded using polymorphic PCR markers linked with the above six genes. Plants with six heterozygous genes were selected. The numbers of plants selected from different BC1F 1 populations with four recurrent parents, IC31, IC32, IC33 and IC34 were 5, 11, 2 and 1, respectively. 4 Nineteen BC1F 2 lines were detected with single PCR marker tightly linked with each target gene. A total of 393 plants were obtained for further use. Among them, 158 plants were found to have two homozygous restorer genes and 40 plants have two homozygous restorer genes and two homozygous dominant BB resistance genes. 5 Forty five plants that contained two homozygous restorer genes and two homozygous dominant BB resistance genes or two homozygous restorer genes and three homozygous BB resistance genes were detected to confirm their genotypes using all PCR markers tightly linked with these genes. Three plants were found to contain six homozygous genotypes of Rf3, Rf4, Xa4, Xa21, xa5 , and xa13 In this study, new ICJLs were obtained through pyramiding different differentiation degree F 1 pollen sterility genes. Through introgressing two restorer genes and four BB resistance genes to four kinds of ICJLs, some BB resistance ICJLs with two restorer genes were obtained. The lines not only can overcome the F 1 hybrid sterility, but also restore CMS for producing inter subspecies three lines hybrid rice with improved resistance to BB.