The Molecular Identification of Powerdery Mildew Resistance Genes in the Cultivars in Henan Province and Application of Molecular Marker-assisted Breeding

The phenotype of thirty cultivars against powdery mildew,those cultivars widely-used in Henan province during the past fifty years,was evaluated.Pm gene contained in these cultivars was identified by the PCR-based markers tightly linked with Pm2,Pm4,Pm8,Pm13,Pm21 and Pm24.Among these cultivars there were only three resistant(against) powdery mildew.Before 80s nearly none of these Pm genes were used.After 80s Pm8 was widely-used,with the limited use of Pm2,Pm4 and Pm24,while Pm13 and Pm21 did not exist in these cultivars.With the same markers above,the cultivars used more than 6.67×10~(4) ha during 2004-2005 were also analyzed.Back-cross breeding combined with molecular marker selection was taken to transfer Pm genes such as Pm13,Pm21,Pm30 and Pm33 to Zheng 9023 which is now widely-used.Lines and NILs of Zheng 9023 resistant against powdery mildew were obtained.Combined hybrid breeding with molecular marker selection,Zheng mai 835 and Zheng mai 863,pyramids of different Pm genes,and Zheng mai 883 containing Pm21 were bred.