Genetic data indicated that the land now under the Yellow Sea was a centre of diversity for M. sacchariflorus during the last glacial maximum, followed by a series of migrations as the climate became warmer and wetter. Overall, M. sacchariflorus has greater genetic diversity than M. sinensis, suggesting that breeding and selection within M. sacchariflorus will be important for the development of improved M. × giganteus. Ornamental M. sacchariflorus genotypes in Europe and North America represent a very narrow portion of the species' genetic diversity, and thus do not well represent the species as a whole.

Sinorhizobium meliloti and Sinorhizobium medicae are two closely related species of the genus Sinorhizobium showing a similar host range, nodulating leguminous species of the genera Medicago, Melilotus and Trigonella, but their phylogenic relationship has not been elucidated yet. In this paper we report the application of three different molecular markers, (i) RFLP of nodD genes, (ii) 16S-23S rDNA intergenic gene spacer fingerprinting and (iii) amplification fragment length polymorphism to S. meliloti and S. medicae strains isolated from the Caucasian area, which is the region of origin of the host plant Medicago. The analysis of data could suggest the origin of S. medicae strains from an ancestral S. meliloti population.

Water channel proteins known as aquaporins (AQPs) regulate the movement of water and other small molecules across plant vacuolar and plasma membranes; they are associated with plant tolerance of biotic and abiotic stresses. In this study, a PIP type AQPs gene, designated as GoPIP1, was cloned from Galega orientalis, a high value leguminous forage crop. The GoPIP1 gene consists of an 870 bp open reading frame encoding a protein of 289 amino acids, and belongs to the PIP1 subgroup of the PIP subfamily. The transcript level of GoPIP1 was higher in the root of G. orientalis than in the leaf and stem. The level of GoPIP1 transcript increased significantly when treated with 200 mM NaCl or 20% polyethylene glycol (PEG) 6000. Transient expression of GoPIP1 in onion epidermal cells revealed that the GoPIP1 protein was localized to the plasma membrane. Over-expression of GoPIP1 increased the rosette/root ratio and increased sensitivity to drought in transgenic Arabidopsis plants. However, GoPIP1 over-expression in Arabidopsis had no significant effect under saline condition. The present data provides a gene resource that contributes to furthering our understanding of water channel protein and their application in plant stress tolerance.

Background and aims Miscanthus is a genus of perennial C 4 grasses native to East Asia. It includes the emerging ligno-cellulosic biomass crop M. Âgiganteus, a hybrid between M. sinensis and M. sacchariflorus. Biomass yield and cold tolerance are of particular interest in Miscanthus, given that this crop is more temperate adapted than its C 4 relatives maize, sorghum and sugarcane.Methods A plant exploration was conducted in eastern Russia, at the northern extreme of the native range for Miscanthus, with collections including 174 clonal germplasm accessions (160 M. sacchariflorus and 14 M. sinensis) from 47 sites. Accessions were genotyped by restriction site-associated DNA sequencing (RAD-seq) and plastid microsatellites.Key Results Miscanthus sinensis was found in maritime climates near Vladivostok (43Á6 N) and on southern Sakhalin Island (46Á6 N). Miscanthus sacchariflorus was found inland at latitudes as high as 49Á3 N, where M. sinensis was absent. Most M. sacchariflorus accessions were diploid, but approx. 2 % were tetraploids. Molecular markers revealed little population structure (Jost's D < 0Á007 among diploid groups) but high genetic diversity (expected heterozygosity ¼ 0Á14) within the collection of Russian M. sacchariflorus. Genome-wide association (GWA) analysis for traits measured at the collection sites revealed three M. sacchariflorus single nucleotide polymorphisms (SNPs) significantly associated with the number of stems per unit area, one with height and one with basal stem diameter; three were near or within previously described sorghum quantitative trait loci for related traits.Conclusions This new Miscanthus germplasm collection from eastern Russia will be useful for breeding Miscanthus and sugarcane cultivars with improved adaptation to cold. Moreover, a strategy is proposed to facilitate the rapid utilization of new germplasm collections: by implementing low-cost SNP genotyping to conduct GWA studies of phenotypic data obtained at collection sites, plant breeders can be provided with actionable information on which accessions have desirable traits and alleles.

Miscanthus is a perennial grass with potential for lignocellulosic ethanol production. To ensure its utility for this purpose, breeding efforts should focus on increasing genetic diversity of the nothospecies Miscanthus × giganteus (M×g) beyond the single clone used in many programs. Germplasm from the corresponding parental species M. sinensis (Msi) and M. sacchariflorus (Msa) could theoretically be used as training sets for genomic prediction of M×g clones with optimal genomic estimated breeding values for biofuel traits. To this end, we first showed that subpopulation structure makes a substantial contribution to the genomic selection (GS) prediction accuracies within a 538-member diversity panel of predominately Msi individuals and a 598-member diversity panels of Msa individuals. We then assessed the ability of these two diversity panels to train GS models that predict breeding values in an interspecific diploid 216-member M×g F2 panel. Low and negative prediction accuracies were observed when various subsets of the two diversity panels were used to train these GS models. To overcome the drawback of having only one interspecific M×g F2 panel available, we also evaluated prediction accuracies for traits simulated in 50 simulated interspecific M×g F2 panels derived from different sets of Msi and diploid Msa parents. The results revealed that genetic architectures with common causal mutations across Msi and Msa yielded the highest prediction accuracies. Ultimately, these results suggest that the ideal training set should contain the same causal mutations segregating within interspecific M×g populations, and thus efforts should be undertaken to ensure that individuals in the training and validation sets are as closely related as possible.