Enhancement of wheat distant hybridization germplasm

The related species of Triticinae are important and valuable gene resources for molecular improvement of wheat (Triticum aestivum L.). These species have a number of distinct characteristics that common wheat varieties simply do not have. Through distant hybridization and chromosome engineering in the past years, a number of new germplasms, including wheat ("Xiaoyan 6")-rye ("German white") addition, substitution and translocation lines, have been developed and characterized. The sequential genome in situ hybridization (GISH) and multi-color fluorescence in situ hybridization (FISH), specific molecular markers, combining with disease resistance evaluation and nutrition, quality and yield identification had screened 10 kinds of new wide hybrid germplasms, including sterile lines. The screened germplasms were highly resistant to stripe rust, leaf rust and powdery mildew. Some hybrid germplasms were also of high quality, enriched Zn and Fe, high nutrient efficiency and desirable agronomic traits. These traits made the germplasms new and valuable for effective wheat breeding. Also 414 new EST (expressed sequence tag) markers specific to rye genome and 31 new markers specific to rye chromosome arms had been developed. These molecular markers could be used in marker-assisted selection breeding or to rapidly detect corresponding rye chromosomes or chromosome segments introgressed into wheat background. The identification and mapping of new resistant genes derived from wheat relatives were ongoing. Some new advanced lines of wheat-rye and wheat-Agropyron cristatum were being developed for release as new cultivars.