Characterisation of the late blight resistance in potato differential MaR9 reveals a qualitative resistance gene, R9a, residing in a cluster of Tm-2 (2) homologs on chromosome IX.
Characterisation of the late blight resistance in potato differential MaR9 reveals a qualitative resistance gene, R9a, residing in a cluster of Tm-2 (2) homologs on chromosome IX.
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DOI：
10.1007/s00122-015-2480-6
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发表时间：
2015-05
期刊：
影响因子：
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通讯作者：
Vossen JH
中科院分区：
文献类型：
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作者：
Jo KR;Visser RG;Jacobsen E;Vossen JH
马铃薯植株马R9的持久晚疫病抗性具有遗传特征。定位了一个新的R基因。否定和纠正了R9的单基因性质和图谱位置。马铃薯晚疫病菌(Solanum tuberosum，Solanum tuberosum)是由马铃薯晚疫病菌(Phytophthora Infestans)引起的晚疫病，可通过遗传抗性有效控制。MaR9差异植物对广泛的晚疫病菌株提供持久的抗性。这种抗性是由至少7个来自防疫链霉菌的基因引起的，包括R1、Rp1-abpt1、R3a、R3b、R4、R8和迄今尚未鉴定的抗性基因(S)。在这里，我们开始研究MaR9中这种额外的抗性的遗传学特征。从MaR9衍生的三个Bc1群体被鉴定为分离了IPO-C抗性，但缺乏R8。一个Bc1群体表现出连续规模的抗性表型，表明多个数量抗性基因正在分离。在另外两个Bc1群体中，抗性和感病以1：1的比例分离，这表明一个质量抗性基因(R9a)。一个与R9a完全共分离的九号染色体PCR标记184-81。利用聚合酶链式反应标记GP101和Stm1021确定了R9a在第九染色体小臂末端的定位。随后，进行了聚类分析，发现了6个紧密连锁的标记。CDPSw58、CDPSw59和CDPSw510位于R9a基因的末端(5.8 cM)，与Sw-5高度同源。CDPTm22位于R9a的近侧(2.9 cm)。CDPTm26和CDPTm27与抗性完全共分离，与TM-2 2有很高的同源性，表明R9a位于与TM-2 2同源的NBS-LRR基因簇中。MaR9除R9a外，还存在数量抗性，其遗传特征有待进一步研究。本文的在线版本(doi：10.1007/s00122-0152480-6)包含补充材料，授权用户可以使用。
The durable late blight resistance in potato plant Ma R9 is genetically characterized. A novel R -gene is mapped. The monogenic nature and map positions of R9 are negated and rectified. Late blight of potato (Solanum tuberosum), caused by Phytophthora infestans, can effectively be managed by genetic resistance. The MaR9 differential plant provides durable resistance to a broad spectrum of late blight strains. This resistance is brought about by at least seven genes derived from S. demissum including R1, Rpi-abpt1, R3a, R3b, R4, R8 and, so far uncharacterized resistance gene(s). Here we set out to genetically characterize this additional resistance in MaR9. Three BC1 populations derived from MaR9 were identified that segregated for IPO-C resistance but that lacked R8. One BC1 population showed a continuous scale of resistance phenotypes, suggesting that multiple quantitative resistance genes were segregating. In two other BC1 populations resistance and susceptibility were segregating in a 1:1 ratio, suggesting a single qualitative resistance gene (R9a). A chromosome IX PCR marker, 184-81, fully co-segregated with R9a. The map position of R9a on the distal end of the lower arm of chromosome IX was confirmed using PCR markers GP101 and Stm1021. Successively, cluster-directed profiling (CDP) was carried out, revealing six closely linked markers. CDPSw58, CDPSw59 and CDPSw510 flanked the R9a gene at the distal end (5.8 cM) and, as expected, were highly homologous to Sw-5. CDPTm22 flanked R9a on the proximal side (2.9 cM). CDPTm26 and CDPTm27 fully co-segregated with resistance and had high homology to Tm-2 2, showing that R9a resides in a cluster of NBS–LRR genes with homology to Tm-2 2. Besides R9a, additional resistance of quantitative nature is found in MaR9, which remains to be genetically characterized. The online version of this article (doi:10.1007/s00122-015-2480-6) contains supplementary material, which is available to authorized users.