QTL Mapping and Inheritance of Clubroot Resistance Genes Derived FromBrassica rapasubsp.rapifera(ECD 02) Reveals Resistance Loci and Distorted Segregation Ratios in TwoF2Populations of Different Crosses
QTL Mapping and Inheritance of Clubroot Resistance Genes Derived FromBrassica rapasubsp.rapifera(ECD 02) Reveals Resistance Loci and Distorted Segregation Ratios in TwoF2Populations of Different Crosses
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DOI：
10.3389/fpls.2020.00899
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发表时间：
2020-07-03
影响因子：
5.6
通讯作者：
Strelkov, Stephen E.
中科院分区：
文献类型：
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作者：
Fredua-Agyeman, Rudolph;Jiang, Junye;Strelkov, Stephen E.
在本研究中，对许多加拿大油菜根结线虫分离物表现广谱抗性的油菜新品系ECD 02与两个根瘤病敏感菌株B杂交。油菜材料产生两个F(2)群体。对F(2)株进行了抗P.油菜病型为3H型、5X型和5G型。卡方拟合检验表明，绝大多数(约75%)产生F(2)群体的组合表现出9R：7S、7R：9S、13R：3S、3R：13S、5R：11S、11R：5S和1R：15S的分离比。这是对来自ECD 02的两个显性主要根瘤病(CR)基因遗传所预期的15R：1S比率的修改。扭曲的分离比表明，这两个抗性基因位于不同的染色体上，并且两个基因以上位性方式相互作用来传递抗性。用144个基于聚合酶链式反应的标记对两个F(2)群体进行基因分型。利用这些多态标记进行连锁分析和QTL分析，在A03染色体上定位到两个与抗顶相关的QTL。Popl#1中的5X和5G型油菜致病基因与Popl#1中的5X和5G型油菜致病相关，而在Popl#2中只有A03染色体上的第二个QTL与5X和5G型抗病相关。其中CRa/CRb(Kato)基因(S)被定位在RAPA中。此外，B染色体A08上的Crr1基因。在两个F(2)群体中检测到PAPA。因此，表型和分子数据证实了ECD02中存在两个CR基因。这是首次研究表明甘蓝型油菜中的主要显性基因以非加性方式互作以赋予对不同P的抗性。甘蓝型油菜病型。关键信息：这项研究提供了关于甘蓝型油菜根瘤病抗性基因作用的遗传和类型的知识(ECD 02)。结果表明，A03上的CRa/CRb(Kato)基因(S)和B染色体上的Crr1基因之间存在重复的隐性和隐性抑制上位性互作、双基因加性和互补基因作用。Rapactrol控制的杆状阻力顶部。油菜病型为3H型、5X型和5G型。
In this study,Brassica rapasubsp.rapifera(ECD 02) which exhibits broad-spectrum resistance to many CanadianPlasmodiophora brassicaeisolates was crossed with two clubroot-susceptibleB. rapaaccessions to produce twoF(2)populations. TheF(2)plants were screened againstP. brassicaepathotypes 3H, 5X, and 5G. The Chi-square goodness of fit test showed that the vast majority (approximate to 75%) of the crosses that produced theF(2)populations showed segregation ratios of 9R:7S, 7R:9S, 13R:3S, 3R:13S, 5R:11S, 11R:5S, and 1R:15S. These were modifications of the 15R:1S ratio expected for the inheritance of two dominant major clubroot resistance (CR) genes from ECD 02. The distorted segregation ratios suggest that the two resistance genes are on different chromosomes and that two genes interact in an epistatic manner to confer resistance. Genotyping was conducted with 144 PCR-based markers in the twoF(2)populations. Linkage and QTL analysis with the polymorphic markers identified two QTLs on chromosome A03 to be associated with resistance toP. brassicaepathotypes 5X and 5G in Popl#1 while only the second QTL on chromosome A03 was associated with resistance to pathotypes 5X and 5G in Popl#2. The QTLs clustered in genomic regions on the A03 chromosome ofB. rapawhere theCRa/CRb(Kato)gene(s) are mapped. In addition, theCrr1gene on the A08 chromosome ofB. rapawas detected in the twoF(2)populations. Therefore, the phenotypic and molecular data confirm the existence of two CR genes in ECD 02. This is the first study that shows that major dominant genes inBrassicainteract in a non-additive manner to confer resistance to differentP. brassicaepathotypes. Key Message:This study provides knowledge on the inheritance and type of gene action for clubroot resistance derived fromBrassica rapasubsp.rapifera(ECD 02). The results indicated that duplicate recessive and recessive suppression epistatic interactions, digenic additivity and complementary gene action between theCRa/CRb(Kato)gene(s) on the A03 and theCrr1gene on the A08 chromosome ofB. rapacontrolled clubroot resistance toP. brassicaepathotypes 3H, 5X and 5G.