The taxonomic status of Hystrix and phylogenetic relationships among Hystrix and its related genera of Pseudoroegneria (St), Hordeum (H), Psathyrostachys (Ns), Elymus (StH), Leymus (NsXm), Thinopyrum bessarabicum (E(b)) and Lophopyrum elongatum (E(e)) were estimated from sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. The type species of Hystrix, H. patula, clustered with species of Pseudoroegneria, Hordeum, Elymus, Th. bessarabicum and Lo. elongatum, while H. duthiei ssp. duthiei, H. duthiei ssp. longearistata, H. coreana and H. komarovii were grouped with Psathyrostachys and Leymus species. The results indicate that: (i) H. patula is distantly related to other species of Hystrix, but is closely related to Elymus species; (ii) H. duthiei ssp. duthiei, H. duthiei ssp. longearistata, H. coreana and H. komarovii have a close affinity with Psathyrostachys and Leymus species, and H. komarovii might contain the NsXm genome of Leymus; and (iii) the St, H and Ns genomes in Hystrix originate from Pseudoroegneria, Hordeum and Psathyrostachys, respectively, while the Xm in Hystrix and Leymus has a complex relationship with the E or St genomes. According to the genomic system of classification in Tiritceae, it is reasonable to treat Hystrix patula as Elymus hystrix L, and the other species of Hystrix as species of a section of Leymus, Leymus Sect. Hystrix.
Hybrids including Hystrix patula, H. duthiei and H. longearistata were obtained and genetic relationships among them were studied. Meiotic pairing in hybrids of H. duthiei × Psathyrostachys juncea (Ns), H. longearistata × Psa. juncea (Ns), Leymus multicaulis (NsXm) × H. duthiei, L. multicaulis (NsXm) × H. longearistata, Elymus sibiricus (StH) × H. patula, Roegneria ciliaris (StY) × H. patula, R. ciliaris (StY) × H. duthiei and R. ciliaris (StY) × H. longearistata averaged 5.76, 5.44, 11.94, 10.88, 10.08, 3.57, 0.46 and 0.90 bivalents per cell, respectively. The results indicated that H. duthiei and H. longearistata had the NsXm genomes of Leymus, while H. patula contained the StH genomes and had a low genome affinity with the StY genomes of Roegneria. Results of genome-specific RAPD assay were comparable with the chromosome pairing data. According to the genomic system of classification in Triticeae, H. patula should be considered as Elymus hystrix L., while H. duthiei and H. longearistata as Leymus duthiei and Leymus duthiei ssp. longearistata, respectively.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.