Identification Of Molecular Cytogenetics Of Wheat "China Spring"-Thinopyrum Elongatum7E Translocations

E group chromosomes of Thinopyrum elongatum， an important wild relativespecies of wheat，contain superior resistance genes to various diseases which can beused to increase wheat genetic resources, especially in chromosome7E. Due to thelarge size and complex of genome, it is very difficult to obtain the sequence informationof wheat. Chromosome7E translocation to common wheat chromosome in the progenyof the Th.elongatum disomic addition line7E hybrid with Chinese spring were inducedby the gametocidal (Gc) chromosome originated from Aegilops Linn. in this article. Toidentify the translocations of progeny, E group were preliminary screened bynon-specific primers; and then GISH were carried out using Th.elongatum E-genomicDNA as probe, CS genomic DNA as blocking, in in root tip cells of positive plants;lastly, The plants appeared signals in GISH were determined using six pairs of SSRprimers (three pairs of7E long arm and three pairs of7E short arm).Obtained the F1F2and F3of Chinese spring-Th.elongatum disomic addition line7E (CS-7E) crossed to a disomic addition line with gametocidal chromosome2C ofAe.cylindryca. PCR, GISH, SSR results as following: percentage of chromosomeaberrations was18.5%(10out of54plants) in F3. Among them,2plants were long armheterozygosity translocation,6plants were short arm heterozygosity translocation,1plant was short arm of terminal fragment of7E and1plant was short arm homozygoustranslocation.BC1F1progeny were obtained from F1backcrossed to the7E addition line, fromwhich12plants disomic for the7E chromosome and monosomic for the Gcchromosome(2n=45) were selected. BC1F2were obtained from self-pollinated of these12plants. Identify results as following: percentage of chromosome aberrations were14.47%(23out of159plants). Among them,3plants were long arm heterozygositytranslocation,11plants were short arm heterozygosity translocation,4plants were shortarm of terminal fragment of7E and1plant was short arm homozygous translocation.On one hand, this study provided innovative genetic improvement of germplasm towheat resistance; on the other hand, laid the foundation for Th.elongatum7Echromosome physical map mapping and resistance genes cloning.