Lan Caixia, Basnet Bhoja R, Singh Ravi P, Huerta-Espino Julio, Herrera-Foessel Sybil A, Ren Yong, Randhawa Mandeep S
International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6-641, 06600, Texcoco, México D.F., Mexico.
Campo Experimental Valle de México INIFAP, Apdo. Postal 10, 56230, Chapingo, Texcoco, Edo. de México, Mexico.
Theor Appl Genet. 2017 Mar;130(3):609-619. doi: 10.1007/s00122-016-2839-3. Epub 2016 Dec 21.
New leaf rust adult plant resistance (APR) QTL QLr.cim - 6BL was mapped and confirmed the known pleotropic APR gene Lr46 effect on leaf rust in durum wheat line Bairds. CIMMYT-derived durum wheat line Bairds displays an adequate level of adult plant resistance (APR) to leaf rust in Mexican field environments. A recombinant inbred line (RIL) population developed from a cross of Bairds with susceptible parent Atred#1 was phenotyped for leaf rust response at Ciudad Obregon, Mexico, during 2013, 2014, 2015 and 2016 under artificially created epidemics of Puccinia triticina (Pt) race BBG/BP. The RIL population and its parents were genotyped with the 50 K diversity arrays technology (DArT) sequence system and simple sequence repeat (SSR) markers. A genetic map comprising 1150 markers was used to map the resistance loci. Four significant quantitative trait loci (QTLs) were detected on chromosomes 1BL, 2BC (centromere region), 5BL and 6BL. These QTLs, named Lr46, QLr.cim-2BC, QLr.cim-5BL and QLr.cim-6BL, respectively, explained 13.5-60.8%, 9.0-14.3%, 2.8-13.9%, and 11.6-29.4%, respectively, of leaf rust severity variation by the inclusive composite interval mapping method. All of these resistance loci were contributed by the resistant parent Bairds, except for QLr.cim-2BC, which came from susceptible parent Atred#1. Among these, the QTL on chromosome 1BL was the known pleiotropic APR gene Lr46, whereas QLr.cim-6BL, a consistently detected locus, should be a new leaf rust resistance locus in durum wheat. The mean leaf rust severity of RILs carrying all four QTLs ranged from 8.0 to 17.5%, whereas it ranged from 10.9 to 38.5% for three QTLs (Lr46 + 5BL + 6BL) derived from the resistant parent Bairds. Two RILs with four QTLs combinations can be used as sources of complex APR in durum wheat breeding.
新的叶锈病成株抗性（APR）QTL QLr.cim - 6BL被定位，并证实了已知的多效性APR基因Lr46对硬粒小麦品系拜尔德斯叶锈病的影响。国际玉米小麦改良中心（CIMMYT）培育的硬粒小麦品系拜尔德斯在墨西哥田间环境中对叶锈病表现出足够水平的成株抗性（APR）。由拜尔德斯与感病亲本Atred#1杂交产生的重组自交系（RIL）群体，于2013年、2014年、2015年和2016年在墨西哥奥布雷贡市，在人工创造的小麦叶锈菌（Pt）小种BBG/BP流行条件下，对叶锈病反应进行了表型鉴定。利用50K多样性阵列技术（DArT）序列系统和简单序列重复（SSR）标记对RIL群体及其亲本进行基因分型。使用包含1150个标记的遗传图谱来定位抗性位点。在1BL、2BC（着丝粒区域）、5BL和6BL染色体上检测到四个显著的数量性状位点（QTL）。这些QTL分别命名为Lr46、QLr.cim - 2BC、QLr.cim - 5BL和QLr.cim - 6BL，通过包容性复合区间作图法分别解释了叶锈病严重程度变异的13.5 - 60.8%、9.0 - 14.3%、2.8 - 13.9%和11.6 - 29.4%。除QLr.cim - 2BC来自感病亲本Atred#1外，所有这些抗性位点均由抗性亲本拜尔德斯贡献。其中，1BL染色体上的QTL是已知的多效性APR基因Lr46，而QLr.cim - 6BL作为一个一直被检测到的位点，应该是硬粒小麦中一个新的叶锈病抗性位点。携带所有四个QTL的RIL的平均叶锈病严重程度在8.0%至17.5%之间，而来自抗性亲本拜尔德斯的三个QTL（Lr46 + 5BL + 6BL）组合的平均叶锈病严重程度在10.9%至38.5%之间。两个具有四个QTL组合的RIL可作为硬粒小麦育种中复杂APR的来源。
