Accessions Of Cultivated Barley Research Articles

The evolutionary relationship between bere barley and other types of cultivated barley

We used genotyping-by-sequencing to investigate the evolutionary history of bere, the oldest barley variety still cultivated in Britain and possibly in all of Europe. With a panel of 203 wild and 401 cultivated barley accessions, including 35 samples identified as bere, we obtained filtered datasets comprising up to 1,946,469 single nucleotide polymorphisms (SNPs). The beres formed two genetically-distinct groups, the larger of which included beres from Orkney and the Scottish Western Isles, as well as varieties not identified as bere from the Faroe Islands. This group of beres was distinct from other British barleys, but had a close genetic affiliation with Scandinavian accessions. Although the data were partly compatible with the traditional view that bere was introduced to Scotland by the Vikings during the eighth century AD, the evidence as whole suggested that the bere and Scandinavian barleys are sister groups descended from a more distant common progenitor, possibly dating to the Bronze Age when hulled barleys first become common in northern Europe. More recently, there has been gene flow from these beres into Polish barleys, possibly following export of grain to the Baltic region during periods when Orkney was under Norwegian or Danish rule. A second, smaller group of beres, which included a traditional Welsh variety, was genetically distinct from the main group and probably represents a more recent introduction of barley from central Europe. Our results emphasize the uniqueness of bere barley and its importance as a heritage crop and a potential source of germplasm for breeding programmes.

Molecular diversity of Azerbaijani wild and cultivated barley genotypes

In this study the genetic diversity of Azerbaijan barley, nuclear genomes of 13 cultivated and 9 wild barley accessions were analyzed at population and individual levels using twenty ISSR primers. In total, 304 fragments were amplified, of which 263 were found to be polymorphic. High genetic diversity indices for ISSR markers (0.714) suggested that this method was equally effective in determining genetic variation in barley accessions. The highest and the lowest similarity indexes were equal to 0.92 and 0.20, respectively. Cluster analysis based on Nei’s genetic distance values showed that genotypes could be grouped into seven main clusters. Furthermore, no differences between the wild and cultivated barley accessions were revealed. Screening a higher number of anonymous loci in barley using ISSR markers will enable the selection of the best parent cultivars for the development of novel varieties

Evaluating the genetic effects of seed dormancy regulatory genes Qsd1 and Qsd2 in a global collection of cultivated barley (Hordeum vulgare ssp. vulgare) with functional kompetitive allele‐specific PCR markers

AbstractSeed dormancy is agronomically important trait that associates with plant survival and seed production. Wild species present long dormancy to protect their seeds from unfavourable climate conditions until the next growing season. In contrast, shortened dormancy extends crop adaptability and promotes crop rotation in agriculture. However, the shortened dormancy brought about the risk of preharvest sprouting (PHS) on cereal crops in temperate and subtropical regions. Recently, two major quantitative genetic loci Qsd1 and Qsd2 that control the seed dormancy in barley have been cloned. In this study, two kompetitive allele‐specific PCR (KASP) markers were developed and applied in a genotypic survey among 859 accessions of cultivated barley. Long‐dormancy‐associated alleles at both loci were over‐represented within East Asian accessions. Both Qsd1 and Qsd2 had significant genetic effects on seed dormancy variations in cultivated barley. Thus, the two KASP markers could be applied in selecting favourable alleles in breeding practice to optimize the seed dormancy duration.

History and future perspectives of barley genomics.

Barley (Hordeum vulgare), one of the most widely cultivated cereal crops, possesses a large genome of 5.1 Gbp. Through various international collaborations, the genome has recently been sequenced and assembled at the chromosome-scale by exploiting available genetic and genomic resources. Many wild and cultivated barley accessions have been collected and preserved around the world. These accessions are crucial to obtain diverse natural and induced barley variants. The barley bioresource project aims to investigate the diversity of this crop based on purified seed and DNA samples of a large number of collected accessions. The long-term goal of this project is to analyse the genome sequences of major barley accessions worldwide. In view of technical limitations, a strategy has been employed to establish the exome structure of a selected number of accessions and to perform high-quality chromosome-scale assembly of the genomes of several major representative accessions. For the future project, an efficient annotation pipeline is essential for establishing the function of genomes and genes as well as for using this information for sequence-based digital barley breeding. In this article, the author reviews the existing barley resources along with their applications and discuss possible future directions of research in barley genomics.

Detection of QTLs controlling alpha-amylase activity in a diversity panel of 343 barley accessions

The α–amylase activity of cultivated barley is critically important to the brewing industry. Here, we surveyed variation in malt α–amylase activity in 343 cultivated barley accessions from around the world. Population structure analysis based on genotype data at 1536 SNPs clustered these accessions into two groups, one comprising South-East Asian and Ethiopian accessions and one group containing the other accessions. A genome-wide association study identified significant quantitative trait loci (QTLs) for α–amylase activity on all seven chromosomes of barley. Accessions showing high and low α–amylase activity were crossed with the high-quality Japanese malting barley cv. Harun Nijo to develop F2 mapping populations. We identified two QTLs on chromosome 6H in a cross between Haruna Nijo (high activity) × Weal (highest activity). Single QTLs were identified each on 3H, 4H, and 5H from a cross between Haruna Nijo (high activity) × VLB-1 (low activity), indicating that the high α–amylase activity in Haruna Nijo might be derived from loci on these chromosomes. The addition of the high α–amylase activity QTL alleles from chromosome 6H in cv. Weal further increased the α–amylase activity conferred by alleles of Haruna Nijo. These results demonstrate that a target haplotype can be successfully improved using a strategy comprising diversity analysis of ex situ collections followed by introducing effective new alleles.

Vulnerability of Barley to African Pathotypes of Puccinia graminis f. sp. tritici and Sources of Resistance.

The emergence of widely virulent pathotypes (e.g., TTKSK in the Ug99 race group) of the stem rust pathogen (Puccinia graminis f. sp. tritici) in Africa threatens wheat production on a global scale. Although intensive research efforts have been advanced to address this threat in wheat, few studies have been conducted on barley, even though pathotypes such as TTKSK are known to attack the crop. The main objectives of this study were to assess the vulnerability of barley to pathotype TTKSK and identify possible sources of resistance. From seedling evaluations of more than 1,924 diverse cultivated barley accessions to pathotype TTKSK, more than 95% (1,844) were found susceptible. A similar high frequency (910 of 934 = 97.4%) of susceptibility was found for the wild progenitor (Hordeum vulgare subsp. spontaneum) of cultivated barley. Additionally, 55 barley lines with characterized or putative introgressions from various wild Hordeum spp. were also tested against pathotype TTKSK but none was found resistant. In total, more than 96% of the 2,913 Hordeum accessions tested were susceptible as seedlings, indicating the extreme vulnerability of the crop to the African pathotypes of P. graminis f. sp. tritici. In total, 32 (1.7% of accessions evaluated) and 13 (1.4%) cultivated and wild barley accessions, respectively, exhibited consistently highly resistant to moderately resistant reactions across all experiments. Molecular assays were conducted on these resistant accessions to determine whether they carried rpg4/Rpg5, the only gene complex known to be highly effective against pathotype TTKSK in barley. Twelve of the 32 (37.5%) resistant cultivated accessions and 11 of the 13 (84.6%) resistant wild barley accessions tested positive for a functional Rpg5 gene, highlighting the narrow genetic base of resistance in Hordeum spp. Other resistant accessions lacking the rpg4/Rpg5 complex were discovered in the evaluated germplasm and may possess useful resistance genes. Combining rpg4/Rpg5 with resistance genes from these other sources should provide more durable resistance against the array of different virulence types in the Ug99 race group.

Genetic diversity in barley (Hordeum vulgare) for traits associated with feed and forage purposes

Barley (Hordeum vulgare L.) is an important coarse cereal cultivated in many parts of the world since ancient times and mostly used as cattle & poultry feed. However, in India due to climate change and frequent drought especially in drier areas barley offers a better alternative to extreme climate such as drought and winter. In the present study 220 cultivated barley accessions of indigenous and exotic origin were evaluated for different agro-morphological traits. The material was evaluated during the 2011-12 growing season at DWR, Karnal where observations were recorded on 13 agro-morphological traits. The results showed high variability among the accessions for grain per spike, green fodder yield, grain yield, grain yield of regenerated crop, biological yield and harvest index (HI). Based on K-mean clustering pattern, the genotypes were grouped into five clusters having significant inter-cluster distances. Shannon-Weaver's diversity index (H) and Simpson's index (1/D) was used to assess the phenotypic diversity of traits for each cluster genotypes and overall. Shannon's diversity index revealed large diversity for most traits. The average H for the whole population was 0.91 with the lowest 0.74 for HI, the highest (1.01) for days to heading. The simple correlation coefficients among traits were estimated, which showed significant positive relations between grain yield with plant height (r = 0.25**), green fodder yield (r = 0.15*), grain yield of regenerated crop (r = 0.13*) and HI (0.19**), while negative correlation with days to heading (r = –0.35**). Sources for individual traits in different genotypes of barley clusters were identified which can be used as donors in hybridization programme for dual purpose barley improvement programme.

Development and characterization of polymorphic EST-SSR and genomic SSR markers for Tibetan annual wild barley.

Tibetan annual wild barley is rich in genetic variation. This study was aimed at the exploitation of new SSRs for the genetic diversity and phylogenetic analysis of wild barley by data mining. We developed 49 novel EST-SSRs and confirmed 20 genomic SSRs for 80 Tibetan annual wild barley and 16 cultivated barley accessions. A total of 213 alleles were generated from 69 loci with an average of 3.14 alleles per locus. The trimeric repeats were the most abundant motifs (40.82%) among the EST-SSRs, while the majority of the genomic SSRs were di-nuleotide repeats. The polymorphic information content (PIC) ranged from 0.08 to 0.75 with a mean of 0.46. Besides this, the expected heterozygosity (He) ranged from 0.0854 to 0.7842 with an average of 0.5279. Overall, the polymorphism of genomic SSRs was higher than that of EST-SSRs. Furthermore, the number of alleles and the PIC of wild barley were both higher than that of cultivated barley, being 3.12 vs 2.59 and 0.44 vs 0.37. Indicating more polymorphism existed in the Tibetan wild barley than in cultivated barley. The 96 accessions were divided into eight subpopulations based on 69 SSR markers, and the cultivated genotypes can be clearly separated from wild barleys. A total of 47 SSR-containing EST unigenes showed significant similarities to the known genes. These EST-SSR markers have potential for application in germplasm appraisal, genetic diversity and population structure analysis, facilitating marker-assisted breeding and crop improvement in barley.

Resequencing Data Indicate a Modest Effect of Domestication on Diversity in Barley: A Cultigen With Multiple Origins

The levels of diversity and extent of linkage disequilibrium in cultivated species are largely determined by diversity in their wild progenitors. We report a comparison of nucleotide sequence diversity in wild and cultivated barley (Hordeum vulgare ssp. spontaneum and ssp. vulgare) at 7 nuclear loci totaling 9296bp, using sequence from Hordeum bulbosum to infer the ancestral state of mutations. The sample includes 36 accessions of cultivated barley, including 23 landraces (cultivated forms not subject to modern breeding) and 13 cultivated lines and genetic stocks compared to either 25 or 45 accessions of wild barley for the same loci. Estimates of nucleotide sequence diversity indicate that landraces retain >80% of the diversity in wild barley. The primary population structure in wild barley, which divides the species into eastern and western populations, is reflected in significant differentiation at all loci in wild accessions and at 3 of 7 loci in landraces. "Oriental" landraces have slightly higher diversity than "Occidental" landraces. Genetic assignment suggests more admixture from Occidental landraces into Oriental landraces than the converse, which may explain this difference. Based on θπ for silent sites, modern western cultivars have ~73% of the diversity found in landraces and ~71% of the diversity in wild barley.

Whole-genome analysis with SNPs from BOPA1 shows clearly defined groupings of Western Mediterranean, Ethiopian, and Fertile Crescent barleys

The discovery of Hordeum spontaneum C. Koch, a wild ancestor of cultivated barley, in Morocco in 1978 led to the proposal of a multicentric origin for this crop, as an alternative to the widely accepted theory of a single centre of domestication in the Fertile Crescent. Since this discovery, we have tested this hypothesis using the most advanced genetic techniques available at the time, from CM-proteins to RFLP and DNA-chloroplast markers. Nowadays, the availability of single nucleotide polymorphism (SNP) markers that are spread densely over the barley genome provides us with another powerful tool to give further support for the above. We have used 1,536 SNPs from the Barley Oligo Pool Assay 1 (BOPA1) of Illumina to characterize 107 wild and cultivated barley accessions from the Western Mediterranean, Fertile Crescent, Ethiopia, and Tibet. The results have confirmed that each location of the above-mentioned germplasm groups clusters separately. Analysis of molecular variance enabled us to focus on the chromosomal regions and loci that differentiated these groups of barley germplasm. Some of these regions contain vernalization and photoperiod response genes, some of the so-called domestication genes, as well as the most important quantitative trait locus for flowering time in the Mediterranean region. We have combined these results with other genetic evidence, and interpreted them in the framework of current theories on the onset of the Neolithic revolution in the Mediterranean region, to conclude that neither Ethiopia nor the Western Mediterranean can be ruled out as centres of barley domestication, together with the Fertile Crescent.

Geographical differentiation and diallel analysis of seed dormancy in barley

Seed dormancy is one of the most important parameters affecting the malting process and pre-harvest sprouting in barley (Hordeum vulgare L.). Variation of seed dormancy in 4365 cultivated and 177 wild barley (ssp. spontaneum) accessions derived from different regions of the world was investigated in Okayama University, Kurashiki, Japan. Seed dormancy of each accession was estimated from their germination percentages at 0, 5, 10 and 15 weeks post-harvest after-ripening periods. All of the wild barley accessions showed less than 10% germination at 0 week after-ripening period. Level of seed dormancy in 4365 cultivated barley accessions showed a clear geographical differentiation. Seventy seven percent of Ethiopian accessions showed high germination percentages, while 86% of Japanese, Turkish and North African accessions showed low germination percentages at 0 week after-ripening period. A half diallel cross using eleven barley accessions with different level of dormancy revealed that seed dormancy was predominately controlled by additive gene effects. These results suggest that large genetic diversity for seed dormancy in barley is explained as different levels of additive accumulation of genetic factors. Barley varieties showing appropriate dormancy could be developed by crossing among barley germplasm accessions used in the present study.

Haplotype diversity in the endosperm specific β-amylase gene Bmy1 of cultivated barley (Hordeum vulgare L.)

Five single nucleotide polymorphism (SNP) sites corresponding to substitutions in the protein sequence of the β-amylase gene Bmy1 at amino acid (AA) positions 115, 165, 233, 347 and 430 were genotyped in 493 cultivated barley accessions by Pyrosequencing and a CAPS assay. A total of 6 different haplotypes for the Bmy1 gene were discovered of which 4 haplotypes were identified as previously described alleles Bmy1-Sd1, Bmy1-Sd2L, Bmy1-Sd2H and Bmy1-Sd3, while 2 haplotypes were new. A broad spectrum of haplotypes was found in spring barleys, while the winter barleys were dominated by the newly described haplotype Bmy1-Sd4. Individual haplotype frequencies varied between the geographic regions.

Analysis of molecular diversity, population structure and linkage disequilibrium in a worldwide survey of cultivated barley germplasm (Hordeum vulgare L.).

BackgroundThe goal of our study was a systematic survey of the molecular diversity in barley genetic resources. To this end 953 cultivated barley accessions originating from all inhabited continents except Australia were genotyped with 48 SSR markers. Molecular diversity was evaluated with routine statistics (allelic richness, gene diversity, allele frequency, heterozygosity and unique alleles), Principal Coordinate Analysis (PCoA), and analysis of genome-wide linkage disequilibrium.ResultsA genotyping database for 953 cultivated barley accessions profiled with 48 SSR markers was established. The PCoA revealed structuring of the barley population with regard to (i) geographical regions and (ii) agronomic traits. Geographic origin contributed most to the observed molecular diversity. Genome-wide linkage disequilibrium (LD) was estimated as squared correlation of allele frequencies (r2). The values of LD for barley were comparable to other plant species (conifers, poplar, maize). The pattern of intrachromosomal LD with distances between the genomic loci ranging from 1 to 150 cM revealed that in barley LD extended up to distances as long as 50 cM with r2 > 0.05, or up to 10 cM with r2 > 0.2. Few loci mapping to different chromosomes showed significant LD with r2 > 0.05. The number of loci in significant LD as well as the pattern of LD were clearly dependent on the population structure. The LD in the homogenous group of 207 European 2-rowed spring barleys compared to the highly structured worldwide barley population was increased in the number of loci pairs with r2 > 0.05 and had higher values of r2, although the percentage of intrachromosomal loci pairs in significant LD based on P < 0.001 was 100% in the whole set of varieties, but only 45% in the subgroup of European 2-rowed spring barleys. The value of LD also varied depending on the polymorphism of the loci selected for genotyping. The 17 most polymorphic loci (PIC > 0.80) provided higher LD values as compared to 19 low polymorphic loci (PIC < 0.73) in both structured (all accessions) and non-structured (European 2-rowed spring varieties) barley populations.ConclusionA global population of cultivated barley accessions was highly structured. Clustering highlighted the accessions with the same geographic origin, as well as accessions possessing similar agronomic characters. LD in barley extended up to 50 cM, and was strongly dependent on the population structure. The data on LD were summarized as a genome-wide LD map for barley.

Molecular and Structural Characterization of Barley Vernalization Genes

Vernalization, the requirement of a period of low temperature to induce transition from the vegetative to reproductive state, is an evolutionarily and economically important trait in the Triticeae. The genetic basis of vernalization in cultivated barley (Hordeum vulgare subsp. vulgare) can be defined using the two-locus VRN-H1/VRN-H2 model. We analyzed the allelic characteristics of HvBM5A, the candidate gene for VRN-H1, from ten cultivated barley accessions and one wild progenitor accession (subsp. spontaneum), representing the three barley growth habits - winter, facultative, and spring. We present multiple lines of evidence, including sequence, linkage map location, and expression, that support HvBM5A being VRN-H1. While the predicted polypeptides from different growth habits are identical, spring accessions contain a deletion in the first intron of HvBM5A that may be important for regulation. While spring HvBM5A alleles are typified by the intron-localized deletion, in some cases, the promoter may also determine the allele type. The presence/absence of the tightly linked ZCCT-H gene family members on chromosome 4H perfectly correlates with growth habit and we conclude that one of the three ZCCT-H genes is VRN-H2. The VRN-H2 locus is present in winter genotypes and deleted from the facultative and spring genotypes analyzed in this study, suggesting the facultative growth habit (cold tolerant, vernalization unresponsive) is a result of deletion of the VRN-H2 locus and presence of a winter HvBM5A allele. All reported barley vernalization QTLs can be explained by the two-locus VRN-H1/VRN-H2 model based on the presence/absence of VRN-H2 and a winter vs. spring HvBM5A allele.

Disease and Insect Resistance in Cultivated Barley Accessions from the USDA National Small Grains Collection

Cultivated barley (Hordeum vulgare subsp. vulgare L.) accessions from the USDA‐ARS National Small Grains Collection (NSGC) have been tested systematically for the past 20 yr for disease and insect resistance. In this study, we analyzed the resistance to barley yellow dwarf (BYD), spot blotch (SB) caused by Cochliobolus sativus (Ito and Kuribayashi) Drechs. ex Dastur, net blotch (NB) caused by Pyrenophora teres f. teres Drechs., stripe rust (SR) caused by Puccinia striiformis Westend. f. sp. hordei, and Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), with respect to (i) geographic origin of resistant accessions, (ii) relationship to other NSGC descriptor data, and (iii) relationships among resistances. “Centers of concentration” for certain resistances were identified: eastern Africa for several diseases, western Turkey and the Caucasus for SR resistance, eastern Asia for adult plant resistance to NB, and south‐central Asia for RWA resistance. Stripe rust resistance was also associated with accessions originating from high altitude in eastern Africa (Ethiopia). Various associations between resistances and grain descriptors, plant habit, and landrace status were also found. Forty‐eight accessions showed multiple resistances on the basis of the field disease data and the RWA greenhouse data. Many of these resistant accessions were from Ethiopia, and many were of unknown origin. Stripe rust testing in California and Bolivia supported the conclusion that winter‐habit accessions were more resistant to the disease than were spring‐habit accessions. Information from this study will be used to guide future NSGC acquisition and evaluation efforts.

Characterisation of Genetic Diversity in ICARDA Core Collection of Cultivated Barley (Hordeum vulgare L.)

Out of the total accessions of cultivated barley, held at ICARDA, a subset core collection consisting of 153 accessions originating from different countries was established. Genetic diversity of the core collection was studied using AFLP markers. The accessions were grouped into different geographic sub-regions and the total genetic variation was estimated using Popgene software. Genetic distance matrix was computed and hierarchical unrooted tree was performed using Phylip software package. Our results demonstrate that the AFLP markers were highly informative and were useful in generating a meaningful classification of the cultivated barley that we determined as a subset of core collection. &amp;nbsp; &amp;nbsp;

Differentiation of β‐Amylase Phenotypes in Cultivated Barley

β‐Amylase types coded by the Bmy1 locus were investigated by analyzing the thermostability and isoelectric focusing (IEF) patterns in 8270 accessions of cultivated barley (Hordeum vulgare L.) from different regions of the world. The β‐amylase types were classified into three main thermostability types (A, high; B, medium; C, low) and three major IEF patterns (I, Ia, and II) together with several rare mutant types. By combined analysis of the thermostability types and IEF patterns, we found 14 β‐amylase phenotypes. Among them, A‐II, B‐I, B‐Ia, B‐II, and C‐II were confirmed to be the major types comprising more than 99% of cultivated barley, and accessions belonging to types A‐Ia, A‐IIa, C‐I, C‐Ia, and C‐IV were reported here for the first time. We also confirmed a clear geographical differentiation of β‐amylase phenotypes: In East Asia, nearly 90% of the accessions were of the A‐II type, while 97% of the Ethiopian accessions were of the C‐II type. The B‐I type accessions were mostly restricted to the former USSR and Europe. In Nepal, Bhutan, India, and Pakistan, 90% of the B type accessions were of the B‐Ia type. The B‐II type barley seems to have originated in Turkey and then mainly spread to North Africa, Europe, and the former USSR.

Polymorphism at rDNA loci in barley and its relation with climatic variables.

The variation in length of the intergenic spacer (IGS) region of the ribosomal DNA repeat unit was examined in 63 accessions of wild barley, Hordeum spontaneum, and seven accessions of cultivated barley, Hordeum vulgare. The accessions of wild barley were collected from ecologically diverse climatic and edaphic microsites in Israel, and the barley cultivars were those grown in India. Sixteen spacer-length variants (slvs) observed in the present study presumably belonged to two known rDNA loci ( Rrn1 and Rrn2). Each accession had one or more variants, which together represented the rDNA phenotype. The rDNA phenotypes of wild barley accessions were widely diverse and differed substantially from those of cultivated barley. The slv phenotypes and the corresponding alleles were shown to be largely correlated with different climatic, edaphic and ecogeographical microsites and niches (the "Evolution Canyon" at Lower Nahal Oren, Mount Carmel; and Tabigha, Eastern Upper Galilee Mountains), so that a particular rDNA phenotype of an accession could be used to predict the climate and soil to which the accession belonged. This sharp microsite ecogeographic variation in ribosomal DNA appears adaptive in nature, and is presumably driven by climatic and edaphic natural selection.

Assessment of Phenotypic Variation in Winter Barley in Scandinavia

Phenotypic diversity for agronomic characteristics was determined in an experiment without fertilizer in 1998 in 41 two-row and 21 six-row winter barley accessions, provided by the Nordic Gene Bank, at Højbakkegård (Denmark). There were significant differences among these 62 accessions for spring establishment, early flowering, covering, plant height, lodging, tillering, spike length, number of kernels per spike and thousand kernel weight. On average, two-row barley accessions had better establishment, covering and standability (although they were slightly taller) but showed lower tillering than six-row barley accessions. Two-row barley accessions also had larger spikes with fewer kernels, but heavier weight, than six-row barley accessions. There were significant phenotypic correlations among the characteristics scored. However, not all of them were common to two- and six-row barley accessions, which suggests the evolution of distinct genetic systems controlling these associations in the two sets of barley accessions. Average linkage cluster analysis and principal component analysis confirmed number of rows as an important characteristic to discriminate among cultivated barley accessions.

Does Indole Alkaloid Gramine Confer Resistance in Barley to Aphid Rhopalosiphum Padi

Accessions of cultivated barley (Hordeum vulgare ssp. vulgare) and its wild progenitor Hordeum vulgare ssp. spontaneum (H. ssp. spont.) were screened for gramine content at the seedling stage. H. ssp. spont. generally had higher gramine concentration compared with cultivated spring barley. Thus gramine concentrations might be raised in modern barley through crossings with selected H. ssp. spont. accessions and repeated back-crossings (BC) of selected offspring to cultivated barley. In the present study, the barley cultivar Lina was used as the recurrent parent. Lina was exceptional among the two-rowed barleys in that it contained moderate levels of gramine, whereas most of the others were very low in gramine. Chromosome-doubled haploid lines (DHs) from the first generation (F1) had a skewed distribution towards higher gramine concentrations and so had the first back-cross generation (BC1F1-DHs). A hairy plant surface, another character proposed to confer resistance to aphids, was also found among some of the plants in the breeding material. BC1F1-DHs with a high proportion of the Lina genome, as determined in an analysis of PCR-based molecular markers, in addition to high gramine concentrations and hairy plant bases in two cases were tested for resistance to the barley pest Rhopalosiphum padi. However, based on aphid performance and preference tests, there were no indications that either high gramine concentrations or hairiness conferred resistance to R. padi when compared with Lina and a variety very low in gramine (Golf). The pattern was the same when the F1 generation was evaluated in aphid performance tests along with Lina, Golf, and the six H. ssp. spont. parents. Aphid weight was consistently low on only one of the six H. ssp. spont. parents. Since previous reports of a positive relationship between gramine concentrations and resistance to R. padi were based on studies in Chile and Japan, a Chilean R. padi population was compared with three Swedish populations, but the responses of all four populations were similar.