| Wheat(Triticum aestivum L.)is one of the most important food crops in China,and its safety production has very important significance.Stripe rust,caused by Puccinia striiformis Westend.f.sp.tritici Eriks.(Pst),is a devastating disease on wheat in world,especially in China.Growing resistant cultivars is the most economic,effective and environment-friendly approach to control the disease.However,due to the simplification of wheat stripe rust resistant sources and high speed variation of Pst races,the resistance in wheat cultivars was often overcome by new Pst races after they were grown 3~5 years as commercial production.Therefore,it will provide the basis for wheat disease resistant breeding and utilization of wheat cultivars to detect the stripe rust resistance gene in wheat commercial cultivars and advanced lines.Also,identification of new resistance genes from wheat breeding resources and development of closely linked markers for these gene(s)is very important for marker-assisted selection breeding.To clear the frequences of all-stage resistance genes Yr5,Yr9,Yr10,Yr15,Yr26 and adult-plant resistance gene Yr18 in wheat from Yellow & Huai River Valley Facultative Wheat Region,we detected 115 wheat cultivars and advanced lines with the closely linked markers of these genes.In addition,using conventional hybridization analysis and simple sequence repeats(SSR)markers,the genetic linkage map of stripe rust resistance gene in wheat cultivar Zhongliang 31 collected form Gansu Province was constructed.The main results are as follows:1.115 wheat cultivars(lines)were evaluated with Chinese most prevalent Pst races CYR32 and CYR33 both in seedling and adult-plant stage.The results indicated that 72(62.6%)and 75(65.2%)genotypes were resistant to CYR32 and CYR33 in seedling stage,respectively,and 75(65.2%)genotypes were resistant to mixed races of CYR32 and CYR33 in the adult-plant stage.Taken the seedling and adult-plant evaluation together,a total of 71(61.7%)genotypes confer all-stage resistance to CYR32 and CYR33,and 16(13.9%)genotypes show adult-plant resistance.2.The potential stripe rust resistance gene(s)in these 115 genotypes were detected by theclosely linked markers of Yr5,Yr9,Yr10,Yr15,Yr26 and Yr18.The results suggested that Yr9 may exist in 38(33.0%)genotypes,and 5(4.4%),1(0.9%),3(2.6%)and 8(7.0%)genotypes may contain Yr5,Yr10,Yr18 and Yr26 gene,respectively.No genotype can be detected Yr15.3.Zhongliang 31 was evaluated with Chinese prevalent Pst races CYR29,CYR31,CYR32,CYR33,Su11-4,Su11-6 and V26 in the seedling stage.The results showed that Zhongliang 31 was highly resistant to the seven Pst races.Seedlings of resistant and susceptible parents,F2 and F3 generations were inoculated with CYR33.And the genetic analysis results indicated that a single dominant gene(temporarily designated as Yrzl31)coffers resistance to CYR33 in Zhongliang 31.4.The mapping population was constructed by 115 F2 plants of the cross Mingxian169/Zhongliang 31 inoculated with CYR33.Among 351 pairs of screened SSR primers,four SSR markers,Barc181,Barc120,Wmc269 and Barc187,were linked to Yrzl31.And the gene was located on wheat chromosome 1B.Disease resistance and molecular tests suggested that Yrzl3 maybe a new gene. |
