Development of simple sequence repeat markers specific for the Lr34 resistance region of wheat using sequence information from rice and Aegilops tauschii
Development of simple sequence repeat markers specific for the Lr34 resistance region of wheat using sequence information from rice and Aegilops tauschii
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DOI：
10.1007/s00122-006-0364-5
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发表时间：
2006-10-01
影响因子：
5.4
通讯作者：
Keller, Beat
中科院分区：
文献类型：
--
作者：
Bossolini, Eligio;Krattinger, Simon G.;Keller, Beat
六倍体小麦(Triticum aestivum L.)起源于大约8000年前，由四倍体小麦与二倍体节节麦杂交而成。含有D-基因组。因此，面包小麦D-基因组进化年轻，在面包小麦基因库中表现出较低的多态程度。为了增加位于染色体7DS上的持久叶锈病抗性基因Lr34周围的标记密度，我们利用了来自水稻直系区的分子信息。小麦表达序列标签(WEST)通过与水稻基因的同源性鉴定，但在‘Arina’x‘Forno’作图群体中是单态的。为了获得新的多态标记，从Ae.中分离了代表总物理大小接近1Mb的4个重叠群的细菌人工染色体克隆。节节麦与小麦EST杂交筛选。对几个BAC克隆进行了低通测序，得到了总共类似于560kb的序列。共发现了10个微卫星序列，其中3个在我们的群体中是多态的，并被定位在接近Lr34的遗传图谱上。对标记序列的比较分析表明，水稻基因组和小麦D-基因组之间存在很大的倒位。SWM10微卫星与Lr34紧密连锁，在Lr34的三个独立来源‘Frontana’、‘China Spring’和‘Forno’以及大多数含有Lr34的基因型中具有相同的等位基因。因此，SWM10是一个非常有用的标记，有助于在世界范围内进行Lr34的选择。
Hexaploid wheat (Triticum aestivum L.) originated about 8,000 years ago from the hybridization of tetraploid wheat with diploid Aegilops tauschii Coss. containing the D-genome. Thus, the bread wheat D-genome is evolutionary young and shows a low degree of polymorphism in the bread wheat gene pool. To increase marker density around the durable leaf rust resistance gene Lr34 located on chromosome 7DS, we used molecular information from the orthologous region in rice. Wheat expressed sequence tags (wESTs) were identified by homology with the rice genes in the interval of interest, but were monomorphic in the 'Arina' x 'Forno' mapping population. To derive new polymorphic markers, bacterial artificial chromosome (BAC) clones representing a total physical size of similar to 1 Mb and belonging to four contigs were isolated from Ae. tauschii by hybridization screening with wheat ESTs. Several BAC clones were low-pass sequenced, resulting in a total of similar to 560 kb of sequence. Ten microsatellite sequences were found, and three of them were polymorphic in our population and were genetically mapped close to Lr34. Comparative analysis of marker order revealed a large inversion between the rice genome and the wheat D-genome. The SWM10 microsatellite is closely linked to Lr34 and has the same allele in the three independent sources of Lr34: 'Frontana', 'Chinese Spring', and 'Forno', as well in most of the genotypes containing Lr34. Therefore, SWM10 is a highly useful marker to assist selection for Lr34 in breeding programs worldwide.