Study on breeding Wx wheat lines by rolling convergent backcross in combination with pollen and endosperm staining with I2 -KI solution.

A waxy wheat line Caiwx was used as a donor parent,and some elite lines or varieties such as Yangmai 9,Yangmai 15,Yangmai 17 were used as recurrent parents.A series of waxy wheat lines including Yangnuo 615,Yangnuo 09,Yangnuo 6733,Yangnuo 465,Yangnuo06 and Yangnuo 05G68 were developed by using rolling convergent backcross method combined with pollen and endosperm staining with I2-KI solution.The results indicated that the developed waxy wheat lines could overcome the defects such as high stem,little spike,late heading and muturing,and bad muturing phases,derived from the donor parent Caiwx.The disease resistances were also improved,especially the resistances to powdery mildew and Fusarium head blight.The grains per spike,thousand kernel weight and yield of all the lines were higher than that of Caiwx.And compared with Yangmai 11,the yield of Yangnuo 09,Yangnuo 6733,Yangnuo 465,Yangnuo 06 and Yangnuo 05G68 increased by 11.75%,1.99%,1.99%,0.6% and 2.19%,respectively.Yangnuo 05G68 has now entered the regional test and production test of Jiangsu province.The water absorption of Wx lines was higher.Their development time and breakdown time was longer.The results proved that it is feasible and effective to breed waxy wheat varieties with high yield,high disease resistances,and broad environmental adaptability through the rolling convergent backcross method combined with pollen and endosperm staining with I2-KI solution.