Abstract:

YW243 is the new lines of wheat carrying multi-resistance to powdery mildew, yellow dwarf virus and three rusts. Four lines with high yield and good disease resistance，including CB031, CB032, CB034, CB035 were developed By crosses between YW243 and some cultivars with elite agronomic characters. The resistance, resistance genes, grain quality, HWM-GSs and yield of these four lines were analyzed and compared with those of YW243 and the backcrossed parents. The results showed that CB031 possessed genes Pm2+6 controlling the resistance to powdery mildew and HMW-GSs of 1, 7+9, 2+12. CB032 possessed powdery mildew resistance genes Pm4+Pm2+6+Pm21, at lest a stripe rust resistance gene YrX on 2BL and HMW-GSs of 7+9, 2+12.The resistance genes Pm21 and HMW-GSs of 7+9, 5+10 were detected in CB034. CB035 possessed Pm2+6+Pm21，HMW-GSs of 7+8, 2+12. CB031 showed resistance to powdery mildew. CB032 showed immunity to powdery mildew and high resistance to 3 rusts. CB034 showed immunity to powdery mildew and stripe rust. The agronomic characters of these new lines, including kernel characters, ear characters, plant height，yield and quality, were improved compared with those of YW243. The study suggested that the wheat line YW243 is an available resistant parent in wheat breeding program against disease as its good characters could be inherited easily, while its undesirable characters could be improved easily.

Key words: YW243, Powdery mildew, Stripe rust, Resistance gene, Pyramiding line, Improvement