title: Genetic relationships of tetraploid Elymus species and their genomic donor species inferred from polymerase chain reaction-restriction length polymorphism analysis of chloroplast gene regions.
abstract: The genetic relationships of 38 individuals from 13 Elymus tetraploid species, two Pseudoroegneria species and one Hordeum species were examined using polymerase chain reaction-restriction length polymorphism analysis of chloroplast gene regions. The 13 Elymus species contain SH and SY genomes with either a single spikelet or multiple spikelets per rachis node. The Pseudoroegneria and Hordeum species contain an S genome with single spikelet per rachis node and an H genome with multiple spikelets per rachis node, respectively. Four chloroplast gene regions, trnD-trnT intron, trnK [tRNA-Lys (UUU) exon1]- trnK [tRNA-Lys (UUU) exon2], trnC-trnD, and rbcL were amplified with specific primers and subsequently digested with up to 16 different restriction enzymes. Interspecific variation was detected in the four regions. A dendrogram based on similarity matrices using the unweighted pair group method with arithmetic average algorithm separated the 38 individuals into two distinct groups: the Elymus and Pseudoroegneria species as one group and Horduem as a second group. This result corresponded well with previous findings, and strongly suggested that a Pseudoroegneria species is the maternal donor to tetraploid Elymus species. Unlike previous studies using nuclear genes, the chloroplast DNA used in this study could not clearly separate the SY-genome species from SH-genome species. No clear separation between the species with a single spikelet per rachis node and the species with multiple spikelets per rachis node was found. Intra-specific variation was detected for the species studied. These observations provide molecular evidence for the highly diverse nature of the Elymus gene pool based on morphological characteristics.
mesh_terms: D016000:Cluster Analysis; D017931:DNA Primers; D018742:DNA, Chloroplast / Q000235:genetics; D031749:Elymus / Q000235:genetics*; D014644:Genetic Variation; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D011123:Polyploidy; D025341:Principal Component Analysis
chemical_list: D017931:DNA Primers; D018742:DNA, Chloroplast