Location: Forage and Range ResearchTitle: Characterization of chromosome constitution in three wheat - thinopyrum intermedium amphiploids revealed frequent rearrangement of alien and wheat chromosomes
|CUI, YU - Shandong Agricultural University
|XING, PIYI - Shandong Agricultural University
|QI, XIAOLEI - Academy Of Agricultural Science
|BAO, YINGUANG - Shangdong Agricultural University
|WANG, HONGGANG - Shangdong Agricultural University
|LI, XINGFENG - Shangdong Agricultural University
Submitted to: BMC Plant Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/21/2021
Publication Date: 3/4/2021
Citation: Cui, Y., Xing, P., Qi, X., Bao, Y., Wang, H., Wang, R., Li, X. 2021. Characterization of chromosome constitution in three wheat - thinopyrum intermedium amphiploids revealed frequent rearrangement of alien and wheat chromosomes. Biomed Central (BMC) Plant Biology. https://bmcplantbiol.biomedcentral.com/articles/10.1186/s12870-021-02896-9.
Interpretive Summary: Intermediate wheatgrass (IWG) is not only an important perennial forage but also a gene reservoir for wheat improvement. It had been successfully utilized to provide resistance to diseases and insects to wheat cultivars around the world. The genome constitution of IWG had recently been revealed by molecular cytogenetic and chromosome-specific marker studies. Thus, hybrid derivatives of crosses between wheat and IWG can now be accurately characterized using cytogenetic and molecular techniques. We had determined the genome composition in three octoploids of wheat-IWG hybrid that were consisted of 42 wheat chromosomes and 14 IWG chromosomes. However, the three octoploids differed in their 14 IWG chromosomes that were made up by a mixed genome consisting of J-, JS- and St-genome chromosomes rather than a single J, JS or St genome. The homology identity of IWG chromosomes was established based on analyses of molecular markers. The resistance to stripe rust, powdery mildew, and aphids in these hybrid derivatives will be useful in wheat improvement programs.
Technical Abstract: Thinopyrum intermedium (2n=6x=42) is an important wild perennial Triticeae species exhibiting many potentially favorable traits for wheat improvement. Wheat-Th. intermedium partial amphiploids serve as a bridge to transfer desirable genes from Th. intermedium into common wheat. Three octoploid Trititrigia accessions (TE261-1, TE266-1, and TE346-1) with good resistances to stripe rust, powdery mildew and aphids were selected from hybrid progenies between Th. intermedium and the common wheat variety ‘Yannong 15’ (YN15). Genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH) and multicolor GISH (McGISH) analyses demonstrated that the three octoploid Trititrigia possess 42 wheat chromosomes and 14 Th. intermedium chromosomes. The 14 alien (Th. intermedium) chromosomes belong to a mixed genome consisting of J-, JS- and St-genome chromosomes rather than a single J, JS or St genome. Different types of chromosomal structural variation were also detected in the 1A, 6A, 6B, 2D and 7D chromosomes via FISH, McGISH and molecular marker analysis. The identity of the alien chromosomes and the variations in the wheat chromosomes in the three Trititrigia octoploids were also different. Hence, these accessions could be used as genetic resources in wheat breeding for the transfer of pest resistance genes from Th. intermedium to common wheat.