Searching for novel sources of field resistance to Ug99 and Ethiopian stem rust races in durum wheat via association mapping
Searching for novel sources of field resistance to Ug99 and Ethiopian stem rust races in durum wheat via association mapping
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DOI：
10.1007/s00122-013-2050-8
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发表时间：
2013-05-01
影响因子：
5.4
通讯作者：
Tuberosa, Roberto
中科院分区：
文献类型：
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作者：
Letta, Tesfaye;Maccaferri, Marco;Tuberosa, Roberto
小麦锈菌(Puccinia graminis f.sp.)小麦条锈病是硬粒小麦的一种毁灭性病害，是小麦茎锈病的病原。虽然已在小麦中鉴定出50多个抗茎锈病(Sr)基因座，但只有几个基因座对UG99(TTKSK小种)和其他硬质粒专化的埃塞俄比亚小种仍然有效。以183份不同的硬粒小麦种质为材料，利用关联作图(AM)方法，在4个田间评价季节，人工接种UG99和硬粒小麦特定小种的混合物，对埃塞俄比亚的茎锈病抗性基因座进行了鉴定。用简单序列重复、多样性阵列技术和序列标记位点标记(总共1,253个)对小组进行了描述。结果表明，抗性是低基因的，有12个QTL标记标记在三到四个季节都有显著意义(P<；0.05)。R(2)值在1.1%~11.3%之间。在两个季节中发现了24个额外的单标记/QTL区域。AM的结果证实了之前在双亲作图研究中描述的SR13的作用，以及推测含有SR9、Sr14、Sr17和Sr28的染色体区域的作用。3个微效QTL与六倍体小麦中报道的QTL一致，5个与Sebatel×Kristal硬粒作图群体中最近报道的QTL重叠。13个单标记/QTL区域位于染色体上未见报道的sr基因/QTL区域。本研究中确定的等位基因变异很容易获得，并可用于标记辅助选择，从而为田间条件下获得更持久的抗茎锈病提供了额外的机会。
Puccinia graminis f. sp. tritici, the causative agent of stem rust in wheat, is a devastating disease of durum wheat. While more than 50 stem rust resistance (Sr) loci have been identified in wheat, only a few of them have remained effective against Ug99 (TTKSK race) and other durum-specific Ethiopian races. An association mapping (AM) approach based on 183 diverse durum wheat accessions was utilized to identify resistance loci for stem rust response in Ethiopia over four field-evaluation seasons and artificial inoculation with Ug99 and a mixture of durum-specific races. The panel was profiled with simple sequence repeat, Diversity Arrays Technology and sequence-tagged site markers (1,253 in total). The resistance turned out to be oligogenic, with twelve QTL-tagging markers that were significant (P < 0.05) across three or four seasons. R (2) values ranged from 1.1 to 11.3 %.Twenty-four additional single-marker/QTL regions were found to be significant over two seasons. The AM results confirmed the role of Sr13, previously described in bi-parental mapping studies, and the role of chromosome regions putatively harbouring Sr9, Sr14, Sr17 and Sr28. Three minor QTLs were coincident with those reported in hexaploid wheat and five overlapped with those recently reported in the Sebatel x Kristal durum mapping population. Thirteen single-marker/QTL regions were located in chromosome regions where no Sr genes/QTLs have been previously reported. The allelic variation identified in this study is readily available and can be exploited for marker-assisted selection, thus providing additional opportunities for a more durable stem rust resistance under field conditions.