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GrainGenes Reference Report: FPS-8-318

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Reference
FPS-8-318
Title
TaGW2, a Good Reflection of Wheat Polyploidization and Evolution.
Journal
Frontiers in Plant Science
Year
2017
Volume
8
Pages
318
Author
Qin L
[ Show all 6 ]
Abstract
Hexaploid wheat consists of three subgenomes, namely, A, B, and D. These well-characterized ancestral genomes also exist at the diploid and tetraploid levels, thereby rendering wheat as a good model species for studying polyploidization. Here, we performed intra- and inter-species comparative analyses of wheat and its relatives to dissect polymorphism and differentiation of the TaGW2 genes. Our results showed that genetic diversity of TaGW2 decreased with progression from the diploids to tetraploids and hexaploids. The strongest selection occurred in the promoter regions of TaGW2-6A and TaGW2-6B. Phylogenetic trees clearly indicated that Triticum urartu and Ae. speltoides were the donors of the A and B genomes in tetraploid and hexaploid wheats. Haplotypes detected among hexaploid genotypes traced back to the tetraploid level. Fst and values revealed that the strongest selection on TaGW2 occurred at the tetraploid level rather than in hexaploid wheat. This infers that grain size enlargement, especially increased kernel width, mainly occurred in tetraploid genotypes. In addition, relative expression levels of TaGW2s significantly declined from the diploid level to tetraploids and hexaploids, further indicating that these genes negatively regulate kernel size. Our results also revealed that the polyploidization events possibly caused much stronger differentiation than domestication and breeding.
External Databases
PubMed: 28326096
Gene
TaGW2-6A (Triticum)
Sequence
KY264770
Keyword
genetic differentiation
grain size
nucleotide polymorphism
TaGW2
Triticum aestivum

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