Creation Of Wheat-rye 5R(5B) Substitution Line With Resistance To Stripe Rust And Development Of Specific Molecular Markers For Specific Segments Of 5R Chromosome

Rye 5R chromosome contains wheat stripe rust resistance gene that is useful for wheat breeding program.In this study,SLAF-sequence technology and wheat-rye MA1R^Ku-MA7R^Kumonosomic addition lines were used to develop specific molecular markers of rye 5R^Kuchromosome.Non-denaturative fluorescence in situ hybridization?ND-FISH?was used to identify wheat-rye 5R^Ku?5B?disomic substitution lines and rye 5R^Kuu deletion lines.The 5R^Kudeletion lines were used to locate the 5R^Kuspecific marker and stripe rust resistance gene.In addition,the meiosis behavior of chromosomes of the 5R^Ku?5B?disomic substitution line was observed,and its self-fertilized progeny were analyzed using ND-FISH.The following is summary of the results:1.114 pairs of 5R^Kuchromosome specific molecular markers were developed.2.Wheat-rye disomic addition lines DA1R^I-7R^I,DA1R^Ki-7R^Kiand monosomic addition lines MA1R^PI613196-7R^PI613196and their parental rye were used to verify the polymorphism of5R^Kuspecific molecular markers,and 100 of the 114 markers displayed polymorphism.3.The 5R^Ku?5B?disomic substitution line,5RL^Ku?5B?ditelosomic substitution line,5RS^Ku?5B?monotelosomic substitution line,5RS^Ku.5BL translocation line and four 5R^Kuu deletion lines were identified.The 5R^Kuchromosome was divided into nine segments including S1,S2.1,S2.2,L1.1,L1.2,L2.1,L2.2,L3.1 and L3.2 according to the signal sites of Oligo-pSc119.2-1,Oligo-pSc200 and Oligo-pSc250 probes as well as the breakpoints of the deletion lines.S1-S2.1,L1.2-L3.2,L2.2-L3.2 and L3.2 segments were deleted respectively from four 5R^Kudeletion lines DEL5RS^S1-S2.1,DEL5RL^L1.2-L3.2,DEL5RL^L2.2-L3.2and DEL5RL^L3.2.Using these deletion lines,5R^Kuspecific molecular markers were located in six sections,S1-S2.1,S2.2,L1.1,L1.2-L2.1,L2.2-L3.1 and L3.2,respectively.4.Stripe rust resistance testing indicated that the 5R^Kumonosomic additional line,5R^Ku?5B?disomic substitution line,5RL^Ku?5B?ditelosomic substitution line,deletion lines DEL5RS^S1-S2.1,DEL5RL^L2.2-L3.2and DEL5RL^L3.2displayed moderate resistance to stripe rust.5RS^Ku.5BL translocation line,5RS^Ku?5B?monotelosomic substitution line and deletion line DEL5RL^L1.2-L3.2were high susceptible to stripe rust.Therefore the stripe rust resistance gene was initially located in the L1.2-L2.1 segment.5.During the meiosis of 5R^Ku?5B?disomic substitutio line,5R^Kumonovalent in metaphase I was observed,and lagging wheat chromosomes could also be observed in anaphase I and telophase I.In the self-fertilized progeny of the 5R^Ku?5B?disomic substitutio line,the 1A/1B,5A/5D,1B/1D,4B/7D,4B/4D and 5R/6A translocation chromosomes were found.The translocation frequency between wheat chromosomes was 5.94%,and that between wheat and rye was 0.50%.These results indicates that this substitution line can induce homeologous chromosome recombination.The results in this study provide a new stripe rust resistance gene resource for wheat breeding program.The developed molecular markers,the 5R^Ku?5B?disomic substitution line and the 5R^Kudeletion lines provide a foundation for the further application of the stripe rust resistance gene on 5RL^Kuarm.