Li Qiang, Guo Juan, Chao Kaixiang, Yang Jinye, Yue Weiyun, Ma Dongfang, Wang Baotong
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, China.
Tianshui Institute of Agricultural Sciences, Tianshui, China.
Front Plant Sci. 2018 Aug 2;9:1120. doi: 10.3389/fpls.2018.01120. eCollection 2018.
Stripe rust, caused by the biotrophic fungus f. sp. (), is one of the most widespread and destructive wheat diseases worldwide. Growing resistant cultivars is an effective approach for controlling this disease. However, because host resistance genes were easily overcome by new virulent races, there is a continuous demand for identifying new effective wheat stripe rust resistance genes and develop closely linked markers for marker-assisted selection (MAS). Baidatou, an old Chinese wheat landrace, has been grown for several decades in Longnan region, Gansu Province, where stripe rust epidemics are frequent and severe. In our previous study, a single dominant gene in Baidatou was identified to control the adult-plant resistance (APR) to Chinese prevalent race CYR33. And the gene was located on wheat chromosome 6DS by four polymorphic simple sequence repeat (SSR) and two sequence-related amplified polymorphism (SRAP) markers, with the genetic distances of two closely linked markers 3.6 and 5.4 cM, respectively. To further confirm the APR gene in Baidatou and construct the high-density map for the resistance gene, adult plants of F, F, F, and F populations derived from the cross Mingxian169/Baidatou and two parents were inoculated with CYR33 at Yangling field, Shaanxi Province during 2014-2015, 2015-2016, and 2016-2017 crop seasons, respectively. The field evaluation results indicated that a single dominant gene confers the APR to race CYR33 in Baidatou. 92 F lines and parents were sequenced using DArTseq technology based on wheat GBS1.0 platform, and 31 genetic maps consisted of 2,131 polymorphic SilicoDArT and 952 SNP markers spanning 4,293.94 cM were constructed. Using polymorphic SilicoDArT, SNP markers and infection types (ITs) data of F lines, the gene was further located in 0.8 cM region on wheat chromosome 6D. These closely linked markers developed in this study should be useful for MAS for Baidatou in crop improvement and map-based clone this gene.
条锈病由活体营养型真菌小麦条锈菌（Puccinia striiformis Westend. f. sp. tritici）引起，是全球分布最广、危害最大的小麦病害之一。种植抗病品种是防治该病的有效途径。然而，由于寄主抗性基因很容易被新的毒性小种克服，因此持续需要鉴定新的有效小麦抗条锈病基因，并开发紧密连锁的标记用于标记辅助选择（MAS）。白大头是中国古老的小麦地方品种，在甘肃省陇南区种植了几十年，那里条锈病流行频繁且严重。在我们之前的研究中，鉴定出白大头中一个单一显性基因控制对中国流行小种CYR33的成株抗性（APR）。该基因通过四个多态性简单序列重复（SSR）和两个序列相关扩增多态性（SRAP）标记定位在小麦6DS染色体上，两个紧密连锁标记的遗传距离分别为3.6和5.4厘摩。为了进一步确认白大头中的APR基因并构建该抗性基因的高密度图谱，在2014 - 2015年、2015 - 2016年和2016 - 2017年作物生长季，分别在陕西省杨凌田间用CYR33接种了来自杂交组合铭贤169/白大头的F₂、F₃、F₄ 和F₅群体的成株以及两个亲本。田间评估结果表明，一个单一显性基因赋予白大头对CYR33小种的APR。基于小麦GBS1.0平台，使用DArTseq技术对92个F₂株系和亲本进行测序，并构建了由2131个多态性硅芯片DArT和952个SNP标记组成、覆盖4293.94厘摩的31个遗传图谱。利用F₂株系的多态性硅芯片DArT、SNP标记和感染类型（ITs）数据，该基因进一步定位在小麦6D染色体上0.8厘摩的区域。本研究中开发的这些紧密连锁标记对于白大头在作物改良中的MAS以及基于图谱克隆该基因应该是有用的。
