Location: Forage and Range ResearchTitle: Genome analysis of 7 Kengyilia (Triticeae Poaceae) species with FISH and GISH Author
Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/9/2013
Publication Date: 9/18/2013
Citation: Dou, Q., Wang, R., Lei, Y., Yu, F., Li, Y., Wang, H. 2013. Genome analysis of 7 Kengyilia (Triticeae Poaceae) species with FISH and GISH. Genome. 56:641-649. Interpretive Summary: Species of Kengyilia, a perennial genus in the Triteceae tribe of Poaceae family are commonly distributed in the central Asia and Qinghai-Tibetan plateau, and grow on meadows, in steppes, on fringes of forests, and also in semi-desert or extremely dry desert at altitude from 1100m to 4750m. To date, about 32 species and subspecies were identified in this genus. The origin of Kengyilia was suggested as natural amphiploids between tetraploid Roegneria (StY) and diploid Agropyron (P) species. The evolutionary differentiation of Kengyilia species was suggested to be associated with the geographical variation from Central Asia and the Qinghai-Tibetan plateau. To substantiate evidence from studies using other techniques, we employed molecular cytogenetic techniques GISH and FISH on 7 Kengyilia species to investigate the origin and evoluation of the St, P, and Y genomes in these species. The information obtained can reveal relationships among these species at the chromosomal level, and appropriate species can be selected and utilized for ecological recovery and germplasm enhancement of Kengyilia species.
Technical Abstract: Genome composition of and genetic relationships among seven Kengyilia species were assessed using a technique of sequential FISH (fluorescence in situ hybridization) and GISH (genomic in situ hybridization). Five of these 7 species, K. kokonorica, K. rigidula, K. hirsula, K. grandiglumis, and K. thoroldiana, are native to Qinghai (China). The other two, K. alatavica and K. batalinii, are distributed in Xinjiang (China) and Kyrgyzstan, respectively. Each chromosome of the 7 species could be well identified using chromosome markers 45S rDNA, 5S rDNA, pAS1 and AAG repeats by FISH, and be allocated to the St, P or Y genome by GISH. A complete set each of P genome and Y genome chromosomes were revealed in each species. A set of St genome chromosomes was still unresolved in all species except K. hirsuta, which exhibited an St-P non-Robertsonian translocation in a few individuals. Molecular karyotype comparison indicated that K. alatavica and K. batalinii were distinctly different from Kengyilia species of Qinghai not only in P genome but also in St and Y genome. The results suport that the Kengyilia species from the Central Asia and the Qinghai-Tibetan plateau have independent origins. In spite of the karyotype similarity, the genomic differentiation could still be detected among Qinghai Kengyilia species. Kengyilia kokonorica and K. rigidula shared a highly similar karyotype, while K. hirsuta, K. grandiglumis, and K. thoroldinia appeared more diverged. Specially, a common species-specific pericentric inversion was identified in both K. grandiglumis and K. thoroldinia, and an identical St-P non-Robertsonian translocation was frequently detected in K. hirsuta. The Qinghai species could be genetically grouped into three, namely, K. kokonorica - K. rigidula, K. hirsuta-K grandiglumis, and K. thoroldinia. The possible role of the species-specific inversions and translocations in the evolution of StPY species is discussed.