Identification of wheat-Agropyron cristatum 6P translocation lines and localization of 6P-specific EST markers

Abstract

To improve genetic diversity of wheat and produce chromosome translocation lines with chromatin from Agropyron cristatum, this study screened progenies of a wheat line SM2-244 known to carry a reciprocal wheat-A. cristatum 5A. 6P chromosome translocation with increased fertile tiller number and grain number per spike. Genomic in situ hybridization (GISH) showed that these progenies contained four new types of translocation chromosomes, labeled as TC-A, TC-L, TC-S and TC-T. The long arm of chromosome 6P originally present in the 5A. 6P translocation was subdivided into three segments between relative arm length points 0–0.32, 0.32–0.69, 0.69–1 on the centromere to telomere axis. Screening with 6P-specific EST markers allocated 24, 30, 20 and 56 EST markers to segments C-6PL-0.32, 6PL-0.32-0.69, 6PL-0.69-1, and 6PS, respectively, and markers specific to individual arms were also identified. This study provides experimental resources and tools for mining of desirable genes on the A. cristatum chromosome 6P that can be exploited in wheat breeding.