High-resolution mapping and new marker development for adult plant stripe rust resistance QTL in the wheat cultivar Kariega
High-resolution mapping and new marker development for adult plant stripe rust resistance QTL in the wheat cultivar Kariega
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DOI：
10.1007/s11032-014-0158-4
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发表时间：
2014-12-01
影响因子：
3.1
通讯作者：
Prins, R.
中科院分区：
文献类型：
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作者：
Agenbag, G. M.;Pretorius, Z. A.;Prins, R.
在优质面包小麦品种Kariega中，有3个主要的数量性状位点（QTL）对成株持久抗条锈性起作用：QYr.sgi-2B. 1和QYr.sgi-4A. 1，以及多效抗性基因Lr 34/Yr 18/Sr 57。虽然标记辅助选择目前被用于将卡列加条锈病成株抗性纳入新的南非小麦育种系，但有效选择大QTL间隔仍然是一项具有挑战性的任务。在这项研究中，我们描述了表达序列标签（EST）衍生的标记的发展，作为一种有效的策略，增加标记密度在选定的QTL间隔和多样性阵列技术（DArT）和EST衍生的标记序列标签位点（STS）标记的转换，使高通量筛选。为了减少QTL间隔，从Kariega × Avocet S杂交中开发了由1，020个F-2个体组成的高分辨率作图群体。通过重组选择，QYr.sgi-2B.1显示位于2B染色体短臂上标记位点Xbarc 55和Xwmc 344之间的6.1 cM间隔内，比先前的23 cM间隔大小减小。以前，QYr.sgi-4A.1的定义不明确，但通过定位QYr.sgi-4A.1区间的选定重组体，QTL区域缩小到4A染色体长臂上标记位点Xbarc 78、Xwmc 313和Xwmc 219之间的16.3-cM区间。利用EST-STS标记Xufs 1 -4A对QYr.sgi-4A.1进行了定位，提高了对该慢锈QTL的选择效率。EST标记策略有助于提高标记密度，有助于提高Kariega QTL在抗病育种中的选择。此外，还开发了BC 4F 2家系，以研究QYr.sgi-2B.1和QYr.sgi-4A.1单独以及与Lr 34/Yr 18/Sr 57组合在Avocet S.
Three major quantitative trait loci (QTL) contribute to the durable adult plant stripe rust resistance in the high-quality bread wheat cultivar Kariega; QYr.sgi-2B.1 and QYr.sgi-4A.1, and the pleiotropic resistance gene Lr34/Yr18/Sr57. While marker-assisted selection is currently being used to incorporate the Kariega stripe rust adult plant resistance into new South African wheat breeding lines, effective selection of the large QTL intervals remains a challenging task. In this study, we describe the development of expressed sequence tag (EST)-derived markers as an effective strategy for increasing the marker density in the selected QTL intervals and the conversion of Diversity Arrays Technology (DArT) and EST-derived markers to sequence tagged site (STS) markers to enable high-throughput screening. To reduce the QTL intervals, a high-resolution mapping population was developed, consisting of 1,020 F-2 individuals, from the cross Kariega x Avocet S. Through recombinant selection, QYr.sgi-2B.1 was shown to reside within a 6.1 cM interval on the short arm of chromosome 2B, between marker loci Xbarc55 and Xwmc344, a reduction from the previous interval size of 23 cM. Previously, QYr.sgi-4A.1 was poorly defined, but by mapping selected recombinants for the QYr.sgi-4A.1 interval, the QTL region was narrowed to a 16.3-cM interval between marker loci Xbarc78, Xwmc313 and Xwmc219 on the long arm of chromosome 4A. An EST-STS marker, Xufs1-4A, was also developed for QYr.sgi-4A.1, which improved selection for this slow-rusting QTL. The EST marker strategy was useful in increasing marker density and contributed to improved selection for the Kariega QTL in resistance breeding. In addition, BC4F2 families were developed to study the expression of QYr.sgi-2B.1 and QYr.sgi-4A.1 individually, and in combination with Lr34/Yr18/Sr57 in the common, stripe rust susceptible background of Avocet S.