High molecular karyotype variation revealed in indigenous Elymus nutans in the Qinghai Plateau

The karyotypes of 27 individuals of Elymus nutans from eight wild populations in the Qinghai Plateau were analyzed using sequential FISH and GISH. High FISH pattern polymorphism and karyotype variation were detected within and among populations. The chromosome variations were mainly characterized as repeat deletions and amplifications along with inter-genomic translocations. The chromosomes of the St and Y genomes demonstrated higher polymorphism than those of the H genome. Six different inter-genomic translocations were identified in 33.3% of individuals; type I and II translocations were detected with higher frequency. Further analysis revealed that type I and II translocations were distributed in different geographic regions. The origin of high karyotype variation of E. nutans in the Qinghai plateau is further discussed.