Development of Chromosome Specific Molecular Markers for Thinopyrum elongatum and their Applications in Gene Introgression

It is necessary to develop specific markers of Th. elongatum for useful genes to be transferred into wheat. The eighty nine chromosome specific molecular markers  for 7E were developed by Specific Length Amplified Fragment Sequencing (SLAF-seq) with a successful rate of 65.9%, The thirteen specific markers   to 1E~7E chromosome of Th. elongatum by Retrotransposon microsatellite amplified polymorphism (REMAP) and thirty one molecular markers specific to each E-chromosome of Th. elongatum were developed by Target region amplification polymorphism (TRAP) technologies. These chromosome-specific molecular markers were applied to detect chromosomes and /or fragments of Th. elongatum in wheat background.The results of this study have provided with important theoretical and practical basis for the study and utilization of Th. elongatum involved wheat germplasm.

The Durum- Th. elongatum addition lines were established based  on combined techniques of cytology and molecular marker selection.  The 2E, 7E chromosome disomic addition lines and, 4E,5E chromosome monsomic addition lines in F₄ progeny were identified by specific molecular markers and GISH. The wheat-Th. elongatum 7E chromosome long arm translocation  was obtained using 7E chromosome specific molecular markers and genomic in situ hybridization (GISH).The result of FHB reaction evaluation indicated that the 7EL translocation lines had a higher level of resistance than that of the 7ES.

The progenies of synthetized hexaploid  (AABBEE) crossed with triticale (AABBRR) to were analyzed by specific molecular marker and GISH for introgression of Th. elongatum chromosomes. The results of GISH revealed that several triticale lines had E chromosomes and/or E-R chromosome translocation.  Analyses of R and E chromosome-specific molecular marker confirmed the above results. This investigation leads to conclude that specific molecular marker can track each E and R genome chromosomes and /or fragments introgression.