Genetic mapping of the wheat leaf rust resistance gene Lr60 (LrW2)
Genetic mapping of the wheat leaf rust resistance gene Lr60 (LrW2)
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DOI：
10.2135/cropsci2007.08.0480
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发表时间：
2008-05-01
期刊：
影响因子：
2.3
通讯作者：
Somers, Daryl J.
中科院分区：
文献类型：
--
作者：
Hiebert, Colin W.;Thomas, Julian B.;Somers, Daryl J.
叶锈病（由小麦柄锈菌（Puccinia triticina Eriks）引起）是小麦（Triticum aestivum L.）在北美本研究的目的是评估未鉴定的抗性基因Lr 60（以前的LrW 2）的实用性，通过展示其新奇，遗传位置和抗性的广度，它赋予的抗性品种的发展。将携带Lr 60（RL 6172）的单基因系的单倍体与感病品种授粉，以产生具有由单倍体的不规则减数分裂产生的随机染色体缺陷的杂种。在488个杂交种中，有4个对叶锈病敏感。所有的易感杂交种都缺乏RL 6172的几个多态性微卫星等位基因，这些等位基因对染色体1D具有特异性。对F-2群体的分析证实，Lr 60位于1D的短臂上，距离微卫星BARC 149 8.4 cM。由于Lr 21也位于1DS上，因此在Lr 21和Lr 60的单基因系之间进行杂交;在所测试的1141个个体中的F-2中回收的5个易感植物用后代测试进行确认。该比率（5：1136）给出了Lr 21和Lr 60之间的估计重组频率为13%。RL 6172用37个小麦疫霉菌分离株进行了测试，包括在北美发现的毒力多样性;一个分离株是有毒的。Lr 60是一个新的抗叶锈基因，代表了小麦遗传资源的多样性，可用于培育抗叶锈品种。
Leaf rust (caused by Puccinia triticina Eriks.) is an important disease of wheat (Triticum aestivum L.) in North America. This study was conducted to assess the utility of the uncharacterized resistance gene Lr60 (formerly LrW2) for the development of resistant cultivars by demonstrating its novelty, genetic location, and the breadth of resistance that it confers. Haploids of a single gene line carrying Lr60 (RL6172) were pollinated with a susceptible cultivar to generate hybrids with random chromosome deficiencies arising from irregular meiosis of the haploid. Out of 488 hybrids, four were susceptible to leaf rust. All susceptible hybrids lacked several polymorphic microsatellite alleles from RL6172 that are specific to chromosome 1D. Analysis of an F-2 population confirmed that Lr60 was located on the short arm of 1D, 8.4 cM distal to the microsatellite BARC149. Since Lr21 is also located on 1DS a cross was made between single gene lines of Lr21 and Lr60; five susceptible plants recovered in F-2 out of 1141 individuals tested were confirmed with progeny tests. This ratio (5:1136) gives an estimated recombination frequency of 13% between Lr21 and Lr60. RL6172 was tested with 37 isolates of P. triticina, encompassing a diversity of virulence found in North America; one isolate was virulent. Lr60 is a novel resistance gene and represents a useful diversification of the genetic resources available in wheat for development of leaf rust resistant cultivars.