Microsatellite mapping of adult-plant leaf rust resistance gene Lr22a in wheat
Microsatellite mapping of adult-plant leaf rust resistance gene Lr22a in wheat
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DOI：
10.1007/s00122-007-0604-3
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发表时间：
2007-10-01
影响因子：
5.4
通讯作者：
Fox, Stephen L.
中科院分区：
文献类型：
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作者：
Hiebert, Colin W.;Thomas, Julian B.;Fox, Stephen L.
本研究旨在鉴定与成株期叶锈病抗性基因Lr22a连锁的微卫星标记（SSR），并检验它们在不同遗传背景下用于标记辅助选择的通用性。Lr22a先前从粗山羊草（Aegilops tauschii Coss.）渗入到小麦（Triticum aestivum L.）中，并定位在2DS染色体上。将来自Lr22a供体的SSR等位基因与两个回交系及其轮回亲本进行比较，结果表明有2到5个SSR标记与Lr22a共同渗入，粗山羊草渗入片段的大小范围为9 - 20 cM。来自98B34 - T4B×98B26 - N1C01杂交组合的F - 2群体证实了渗入标记与2DS染色体上的Lr22a之间存在连锁。最近的标记GWM296距Lr22a为2.9 cM。用GWM296对118个不同地理来源的品种和育种品系进行了检测。总共扩增出14个等位基因，然而，只有那些被预测或已知携带Lr22a的品系在GWM296处具有独特的粗山羊草等位基因，其片段为121和131 bp。因此，GWM296可用于在不同遗传背景下选择Lr22a。在2002年至2006年期间，携带Lr22a的基因型在田间表现出对叶锈病的强抗性。由于Lr22a具有较强的成株期抗性、在商业应用中的频率较低以及具有独特的标记，它是纳入叶锈病抗性基因组合的理想候选基因。
This study was conducted to identify microsatellite markers (SSR) linked to the adult-plant leaf rust resistance gene Lr22a and examine their cross-applicability for marker-assisted selection in different genetic backgrounds. Lr22a was previously introgressed from Aegilops tauschii Coss. to wheat (Triticum aestivum L.) and located to chromosome 2DS. Comparing SSR alleles from the donor of Lr22a to two backcross lines and their recurrent parents showed that between two and five SSR markers were co-introgressed with Lr22a and the size range of the Ae. tauschii introgression was 9-20 cM. An F-2 population from the cross of 98B34-T4B x 98B26-N1C01 confirmed linkage between the introgressed markers and Lr22a on chromosome 2DS. The closest marker, GWM296, was 2.9 cM from Lr22a. One hundred and eighteen cultivars and breeding lines of different geographical origins were tested with GWM296. In total 14 alleles were amplified, however, only those lines predicted or known to carry Lr22a had the unique Ae. tauschii allele at GWM296 with fragments of 121 and 131 bp. Thus, GWM296 is useful for selecting Lr22a in diverse genetic backgrounds. Genotypes carrying Lr22a showed strong resistance to leaf rust in the field from 2002 to 2006. Lr22a is an ideal candidate to be included in a stack of leaf rust resistance genes because of its strong adult-plant resistance, low frequency of commercial deployment, and the availability of a unique marker.