Molecular And Cytological Identification Of New Wheat-thinopyrum Intermedium Alien Lines

Thinopyrum intermedium(2n=6x=42,JJJsJsStSt)is one of the most important wild relatives of wheat,distributing in many countries in the world.Th.intermedium is easy to hybrid with wheat and it also have tolance to salt,cold,drought and resistance to powdery mildew,yellow rust,stripe rust,stem rust,and yellow dwarf.Combined with other superior characterizations,Th.intermedium has been widely used in the genetic improvement of wheat and has become an important source of broadening the genetic basis of wheat.In addition,Th.intermedium is a cross-pollination plant which leads to the complicated composition of cross progeny's chromosomes.Therefore,identification of the chromosomes composition of Th.intermedium in wheat backgroune is still in progress.In this researches,Th.intermedium hybridizes with common wheat,MianYang26.After several generations' self-crossing,95083 series were developed.201501165 series were developed from the progenies of the cross between 95083 and Mianyang26.Using morphology,cytology,molecular biology and biochemistry methods,characterization and identification on 95083 and 201501165 series were analysed,results are shown below:(1)Using cytology,identification on parents,partial amphidiploid 89074,shows that it adds 7(A-G)pairs chromosomes in wheat background.Three typical Th.intermedium addition lines were identified from 95083 series: 95083-1(42+?+?),95083-2(41+?+?),95083-3(42+?+?),which have three different additional Th.intermedium chromosomes(“number 1,number 2,number 3”)belonging to Js.Three typical Th.intermedium addition lines were identified from 201501165 series:201601165-1(42+?+?),201501165-3-2(41+?),which have two different additional Th.intermedium chromosomes(“number 3 and number 4”)belonging to Js.(2)Identification on additional chromosomes' homologous groups by TNAC molecular marker and Native-PAGE shows that: the long chromosome in 95083-1“number 1” is 4Js,and the short segment chromosomes “number 2” comes from 7th homologous group.In 2015-1165-6-1,the short “number 4” is the long arm of 4Js.The alien chromosome in 201501165-3-2's “number 3” is 7Js.(3)Identification on disease-resistance in fields shows a series of progenis which have high resistance to stripe rust.TNAC molecular markers identified that the resistance to stripe rust was associated with chromosome homologous group 7.After FISH using Oligo-pSc119.2 and Oligo-pTa535 probes,materials which have resistance to stripe rust all add one or two 7Js chromosomes from Th.intermedium.Therefore,the resistance to stripe rust comes from 7Js.(4)Aibian 1 has a dwarf gene Rht10 which displayed insensitive to gibberellin.Therefore,the 95083 series plants and 201501165 series plants with dwarf character were selected for gibberellin susceptibility test.Chinese Spring was used as sensitive control and Wanmai38 as insensitive control.A total of three gibberellin-insensitive materials were available for future dwarf breeding for reducing plant height.(5)In salt tolerance test,Qingmai 6 was used as insensitive control and the Chinese Spring as sensitive control.The moderate salt-resistant material 201501165-35-1 was obtained.This material has a significant increase in the relative seedling height after 20 days at the re-growth experiment after removing of salt stress.So the material can be used as a potential material in the saline soil of about 1.00%.