Genomics research has been central of biological sciences in recent years. A high-throughput, high-information content BAC fingerprinting (HICF) technology that we developed has continually drawn wide attention and has been used for genomics projects of various species, including plants, animals, and fungi. With this technology in place, we have been constructing physical maps for wheat and its relatives, papaya, citrus, walnut, Brachypodium, musa, cassava, cowpea, chickpea, trout, duckweed, etc. Our work suggested that it is feasible to construct contigs and physical maps using global BAC libraries of wheat and almost certainly also of other plant polyploid species with genome sizes comparable to that of wheat.

The evolution of wheat species and forms is of great interest of scientific community as well as germplasm conservation and application. Emmer was likely domesticated in the Diyarbakir region in southeastern Turkey, which was followed by subsequent hybridization and introgression from wild to domesticated emmer in southern Levant. Durum wheat is closely related to domesticated emmer in the eastern Mediterranean and may have originated there. Hexaploid wheat (Triticum aestivum, genomes AABBDD) originated by hybridization of tetraploid Triticum turgidum (genomes AABB) with Aegilops tauschii (genomes DD). A population in the southwestern and southern Caspian appears to be the main source of the wheat D genome. Gene flow from Ae. tauschii was an important source of wheat genetic diversity and shaped its distribution along the D-genome chromosomes.

Comparative genome analyses reveal that the reduction of the basic chromosome number from 12 to 7 in the Triticeae has taken place by insertional dysploidy, in which an entire chromosome is inserted by its telomeres into a break in the centromeric region of another chromosome. The original centromere-telomere polarity of the chromosome arms is maintained in the new chromosome. Insertional dysploidy has been recorded in four grass subfamilies and appears to be the dominant mechanism of basic chromosome number reduction in grasses; Synteny was reduced in the vicinity of the termini of modern Ae. tauschii chromosomes but not in the vicinity of the ancient termini embedded in the Ae. tauschii chromosomes by insertional dysploidy, suggesting that the dependence of synteny erosion on gene location along the centromere-telomere axis either evolved recently in the Triticeae phylogenetic lineage or its evolution was recently accelerated.

This page was last updated 25 April 2014.