Agronomy Department, Purdue University, 915 W State Street, West Lafayette, IN 47907-2054, USA.
Theor Appl Genet. 2010 Sep;121(5):961-70. doi: 10.1007/s00122-010-1365-y. Epub 2010 Jun 5.
Thinopyrum intermedium translocations derived from the wheat (Triticum aestivum L.) substitution line P-29 were previously characterized by RFLP. We have further analyzed these lines and additional related germplasm with publicly available STS and SSRs. Primers which showed a polymorphism between wheat and P-29, were tested in all recombinant and nulli-tetrasomic lines confirming their position on chromosome 7D. The resulting 7D/7E chromosome maps appeared as a mosaic of wheat and Th. intermedium chromatin sections. To verify the composition of the translocation lines suggested by the RFLP-PCR map, F(2) progeny of two crosses (CS/216-1 and CS/260-1) were analyzed with molecular markers. Both populations gave an unexpectedly diverse number of recombinant individuals, suggesting that interstitial translocations occur more frequently than previously thought. This analysis also showed that there is a wide range in the number and position of the interstitial translocations within a given line such as the mosaic chromosome in recombinant line 260-1/CS-26, which has four Th. intermedium chromosome segments. Phenotypic data of the two populations suggested the presence of one gene which we have called Bdv3 to differentiate it from the previously reported orthologous gene Bdv2. Using the PCR-based molecular markers identified in this study, 5 out of 12 elite lines that showed good yields and no YDV symptoms contained Th. intermedium chromatin. Due to the multiple components involved in the YDV disease complex, combining selection for YDV resistance with the molecular markers and maps identified in this study will increase the efficiency of introgressing Th. intermedium chromatin containing YDV resistance or other beneficial traits into elite wheat germplasm.
中间偃麦草易位系是从小麦（Triticum aestivum L.）代换系 P-29 通过 RFLP 分析得到的。我们利用已公开的 STS 和 SSR 进一步分析了这些系及其它相关的种质资源。在所有的重组和单体-四体中检测到在小麦和 P-29 之间表现多态性的引物，证实了它们在 7D 染色体上的位置。由此产生的 7D/7E 染色体图谱呈现出小麦和中间偃麦草染色质节段的镶嵌图。为了验证由 RFLP-PCR 图谱所建议的易位系的组成，用分子标记对两个杂交种（CS/216-1 和 CS/260-1）的 F2 后代进行了分析。这两个群体都产生了出乎意料的多样化重组个体，这表明易位发生的频率比以前认为的要高。该分析还表明，在给定的系中，易位的数量和位置存在广泛的变化，例如在重组系 260-1/CS-26 中出现的嵌合染色体，它有四个中间偃麦草染色体片段。两个群体的表型数据表明存在一个基因，我们称之为 Bdv3，以将其与以前报道的同源基因 Bdv2 区分开来。利用本研究中基于 PCR 的分子标记，在 12 个表现出良好产量且无 YDV 症状的优良系中，有 5 个含有中间偃麦草染色质。由于 YDV 病害复合体内涉及多个成分，因此结合对 YDV 抗性的选择以及本研究中鉴定的分子标记和图谱，将有助于将含有 YDV 抗性或其它有益性状的中间偃麦草染色质导入优良小麦种质资源中。
