The Construction of a Standard Karyotype of Intermediate Wheatgrass and Its Potential Progenitor Species.

The genome composition of intermediate wheatgrass (IWG; (Host) Barkworth and D.R. Dewey; 2n = 6x = 42) is complex and remains to be a subject of ongoing investigation. This study employed fluorescence in situ hybridization (FISH) to analyze the karyotype of and its related species. With the St-80 probe derived from and the pDb12H probe from , FISH analysis classified the chromosomes of as . FISH karyotype was established using pSc119.2-1, (GAA), AFA-3, AFA-4, pAs1-1, pAs1-3, pAs1-4, and pAs1-6 as a combined multiplex oligonucleotide probe. MATO software was used to analyze chromosome length, arm ratio, and karyotype structure. The karyotype formula of is K(2n) = 6X = 42 = 36m + 6sm, and that of is K(2n) = 4X = 28 = 22m + 6sm. The karyotype formula of and is K(2n) = 2X = 14 = 12m + 2sm, of is K(2n) = 2X = 14 = 2M + 12m, and of is K(2n) = 2X = 14 = 12m + 2sm. Based on the results of FISH, standard karyotypes of and its potential progenitor species were constructed. These standard karyotypes revealed that there was evolutionary parallelism between genome and karyotype, but due to the complexity of evolution, the FISH signal of was abundant and asymmetrical.