Improving efficiency of spring wheat breeding through combination of hybridization and radiation

The progress of spring wheat breeding through the combination of hybridization and irradiation in the last 30 years was reviewed.From 1974 up to now,F1 seeds were equally divided into two parts,one part was irradiated by γ-ray,and the other part was planted without any treatment.And these two parts were equally selected by pedigree method.Seven varieties were developed,and four of them became leading varieties with largest acreage in Xinjiang.Our data showed that the middle or low dose γ-ray irradiation on F1 dry seeds could enlarge the variation of most agronomic traits in hybrid progenies and reduce the correlation coefficient between plant height and kernel plumpness,which may increase the opportunity to breed varieties with combination of drought resistance and lodging resistance.Varieties such as Xinchun 2 and Xinchun 6 with high yield potential and drought resistance were developed,which were successively leading varieties with the largest production area from 1986 to 2009 in Xinjiang.New varieties,such as Xinchun 26 with high quality,were released in recent years.Our experiences showed that hybridization combined with irradiation treatment could significantly improve breeding efficiency.In addition,utilization of CIMMYT germplasm has played a key role for the variety development.