Data from: Introgression of chromosome segments from multiple alien species in wheat breeding lines with wheat streak mosaic virus resistance

Pyramiding of alien-derived Wheat streak mosaic virus (WSMV) resistance and resistance enhancing genes in wheat is a cost-effective and environmentally safe strategy for disease control. PCR-based markers and cytogenetic analysis with genomic in situ hybridisation were applied to identify alien chromatin in four genetically diverse populations of wheat (Triticum aestivum) lines incorporating chromosome segments from Thinopyrum intermedium and Secale cereale (rye). Out of 20 experimental lines, 10 carried Th. intermedium chromatin as T4DL*4Ai#2S translocations, while, unexpectedly, 7 lines were positive for alien chromatin (Th. intermedium or rye) on chromosome 1B. The newly described rye 1RS chromatin, transmitted from early in the pedigree, was associated with enhanced WSMV resistance. Under field conditions, the 1RS chromatin alone showed some resistance, while together with the Th. intermedium 4Ai#2S offered superior resistance to that demonstrated by the known resistant cultivar Mace. Most alien wheat lines carry whole chromosome arms, and it is notable that these lines showed intra-arm recombination within the 1BS arm. The translocation breakpoints between 1BS and alien chromatin fell in three categories: (i) at or near to the centromere, (ii) intercalary between markers UL-Thin5 and Xgwm1130 and (iii) towards the telomere between Xgwm0911 and Xbarc194. Labelled genomic Th. intermedium DNA hybridised to the rye 1RS chromatin under high stringency conditions, indicating the presence of shared tandem repeats among the cereals. The novel small alien fragments may explain the difficulty in developing well-adapted lines carrying Wsm1 despite improved tolerance to the virus. The results will facilitate directed chromosome engineering producing agronomically desirable WSMV-resistant germplasm.小麦中外源衍生的小麦线条花叶病毒（Wheat streak mosaic virus, WSMV）抗病基因及抗病增效基因的聚合，是一种经济高效且环境友好的病害防控策略。研究采用基于聚合酶链式反应（Polymerase Chain Reaction, PCR）的分子标记技术结合基因组原位杂交（Genomic In Situ Hybridization, GISH）的细胞遗传学分析方法，在4个遗传背景各异的普通小麦（Triticum aestivum）群体中鉴定外源染色质，所涉小麦材料均整合了中间偃麦草（Thinopyrum intermedium）和黑麦（Secale cereale）的染色体片段。在20份试验材料中，10份携带以T4DL*4Ai#2S易位形式存在的中间偃麦草染色质；而意外的是，另有7份材料在1B染色体上检测到外源染色质（来自中间偃麦草或黑麦）。本研究新鉴定的黑麦1RS染色质（其传递可追溯至育种系谱早期）与增强的小麦线条花叶病毒抗性显著相关。田间试验条件下，仅携带1RS染色质的材料即表现出一定抗性；当其与中间偃麦草4Ai#2S染色质聚合时，其抗性水平显著优于已知抗病品种Mace。多数外源小麦材料携带完整的染色体臂，值得注意的是，本研究中的这些材料在1BS染色体臂内发生了臂内重组。1BS染色体臂与外源染色质之间的易位断点可分为三类：(i) 着丝粒处或其邻近区域；(ii) 标记UL-Thin5与Xgwm1130之间的臂内区间；(iii) 位于Xgwm0911与Xbarc194之间的端粒侧区间。在高严谨度杂交条件下，标记的中间偃麦草基因组DNA可与黑麦1RS染色质发生杂交，表明谷类作物间存在共享的串联重复序列。这些新型小型外源片段或可解释为何尽管材料对病毒的耐受性有所提升，但培育携带Wsm1基因且适应性良好的小麦材料仍存在困难。本研究结果将为定向染色体工程育种提供助力，助力培育兼具优良农艺性状与抗小麦线条花叶病毒特性的种质资源。