| Powdery mildew,caused by Blumeria graminis f.sp.tritici(Bgt),is one of the major fungal diseases of wheat,which seriously threatens the safety in production of wheat in China.As a result of long-term use of interspecific hybrids,genetic basis of wheat is increasingly narrow,easily lead to the rapid occurrence of powdery mildew and pandemic.Therefore,it is necessary to prevent the disease from greater harm effectively by excavating various channels to fully tap the disease-resistant resources,expanding the genetic basis of wheat and proceed to the rational distribution of disease resistance genes from a macroscopic view.China has a wealth of wheat local varieties of resources.A large number of excellent traits including disease resistance genes has been accumulated in the long-term domesticated cultivation process,which are the excellent gene source of wheat resistance breeding in China.This experiment was carried out in three hundred and twenty-four wheat varieties from domestic and foreign,and landraces which were inoculated with pathotypes E09 and E20.The objectives of the study were to fully explore and to make use of the useful gene resources,to expand the genetic basis of modern wheat breeding for disease resistance breeding of wheat genetic improvement and to provide new source resistance and excellent germplasm resources by seeding to characterize the resistance to powdery mildew.At the same time,molecular markers linked to seven effective powdery mildew resistant genes Pm21,Pm52,PmLk906,PmLx66,PmTm4,PmJm22 and PmHNK were used to detect the disease resistance genes to explore the new disease resistance genes through gene postulation,and to provide further material for resistance to powdery mildew gene locating.The results are as follows:(1)The results of seedling inoculation showed that there were 20 resistant varieties to only E09,40 resistant varieties to only E20 and 59 resistant varieties to both E09 and E20,accounting for 6.2%,12.3%,and 18.2%,respectively.Among them,22 resistant varieties were high resistance to the two races,accounting for 6.8%.These materials can be used as an effective source of disease resistance breeding,which are introduced into the cultivars with good adaptability and agronomic traits to expand the genetic basis of wheat breeding and accelerate the process of wheat breeding.(2)The results of molecular markers showed that the varieties carried the gene PmLk906,PmHNK,Pm52,PmLx66 and PmTm4 were more than others,which were 39,30,29,28 and 22,respectively.The varieties carried the gene PmJm22 and Pm21 genes were less than others,which were 6 and 5,respectively.The varieties carried two or more genes were very few.The data indicated that it is badly in need of improving the efficiency of breeding and accelerating the molecular breeding process because of the low efficiency of conventional breeding gene polymerization varieties.(3)Combined the resistance reaction with the molecular detection for gene derivation,we found that in 17 materials of immunization and near immunization,Heze 2,Zhongmai 175 and Zhongyou 9507 might carry Pm52,Mianmai 37 and Mianmai 39 may carry PmTm4,Linkang16 and Zhoumai 27 may carry PmJm22.According to literature,Am9,Fuzhuang 30,03W262 carries PmP55 d,Pm5E,Pm51,respectively The other 7 materials,which means MR-125,MR-1252,Mianmai 41,Shijiazhuang 8,CA0455,028079 and 04W223,did not detect molecular markers linked to disease resistance genes or reports of genes resistant to powdery mildew,it indicated that these varieties may carry new disease resistance genes,which can be used to carry out the research on the gene resistance to powdery mildew and gene storage and technical reserve for wheat gene cloning and transgenic breeding. |
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