Spontaneum Accessions Research Articles

Discovery and assay of single-nucleotide polymorphisms in barley (Hordeum vulgare).

The least ambiguous genetic markers are those based on completely characterized DNA sequence polymorphisms. Unfortunately, assaying allele states by allele sequencing is slow and cumbersome. The most desirable type of genetic marker would be unambiguous, inexpensive to assay and would be assayable singly or in parallel with hundreds of other markers (multiplexable). In this report we sequenced alleles at 54 barley (Hordeum vulgare ssp. vulgare) loci, 38 of which contained single-nucleotide polymorphisms (SNPs). Many of these 38 loci contained multiple polymorphisms, and a total of 112 polymorphisms were scored in five barley genotypes. The polymorphism data set was analyzed both by using the individual mutations as cladistic characters and by reducing data for each locus to haplotypes. We compared the informativeness of these two approaches by consensus tree construction and bootstrap analysis. Both approaches provided similar results. Since some of the loci sequenced contained insertion/deletion events and multiple point mutations, we thought that these multiple-mutated loci might represent old alleles that predated the divergence of barley from H. spontaneum. We evaluated sequences from a sample of H. spontaneum accessions from the Eastern Mediterranean, and observed similar alleles present in both cultivated barley and H. spontaneum, suggesting either multiple domestication events or multiple transfers of genes between barley and its wild ancestor.

Variation in utilization efficiency and tolerance to reduced water and nitrogen supply among wild and cultivated barleys

Broad genotypic variation in the response to low soilmoisture and reduced nitrogen supply was found amongthe wild Hordeum spontaneum accessions and thelandraces and modern cultivars of H. vulgare ofdifferent geographic origin. Measurements at the endof vegetative growth in plants grown in soil culturesrevealed genotypically specific responses to the usedenvironmental factors. Cultivars and breeding linesfrom Syria and Ethiopian landraces combined bothdrought resistance and tolerance to low nitrogen. TheSyrian barleys were also distinguished by a highnitrogen utilization efficiency (NUE) under low Nnutrition. European cultivars indicated a pooradaptation to N shortage, but some of them wereresistant to soil drought. No stress resistant barleyswere found among the wild accessions and Sardinianlandraces. Genotypic differences in the relativevalues of NUE and water use efficiency were associatedwith low N-tolerance. Some Syrian selections,Ethiopian landraces and the modern German cv. Maresiwere found to be most drought resistant. Maintenanceof a relatively high photosynthetic activity of theuppermost leaves was associated with droughtresistance. As far as concerning with the vegetativegrowth phase, the modern Syrian germplasm andEthiopian landraces may be recommended as donors ofadaptative characters for local barley breeding.

Production and Characterization of a Complete Set of Wheat-Wild Barley (Hordeum vulgare ssp. spontaneum) Chromosome Addition Lines.

A wild barley, Hordeum vulgare L. ssp. spontaneum (C. Koch.) Thell. (syn. H. spontaneum C. Koch.) is considered to be the progenitor of cultivated barley (H. vulgare L. ssp. vulgare). A complete set of Triticum aestivum L. cv. ‘Shinchunaga’-H. spontaneum OUH602 whole chromosome addition lines, and 5 telosomic addition lines were developed. Chromosome constitutions of the addition lines were confirmed by C-banding and genomic in situ hybridization. Addition lines for the entire 1H chromosome and its long arm are only available as monosomic and monotelosomic additions, respectively, because of sterility. All other lines were recovered as disomic or ditelosomic additions. Self-sterile monosomic 1H and monotelosomic 1HL addition lines can be reproduced by backcrossing the plants having simultaneous addition of the long arm of barley chromosome 6H, because the plants with such chromosome constitutions recover partial female fertility. In general, the phenotypic alternations observed in each of the wheat-H. spontaneum OUH602 addition lines were similar to those previously noted in the corresponding lines of the ‘Chinese Spring’ wheat-‘Betzes’ barley addition series and the primary trisomic series of the H. spontaneum accession OUH602. Monotelosomic 1HL addition and ditelosomic 1HS addition are especialy valuable for unequivocal chromosome arm localization of barley genes and markers clustered around the centromeric region of 1H. The utility of the wheat-H. spontaneum addition lines is discussed.

Application of genomics in assessing biodiversity in wild and cultivated barley

AbstractBiodiversity, the substrate for natural selection and adaptation to the environment, is of foremost importance in species conservation. Genomics, the study of the structure and function of complex genomes, can be applied to the assessment of the genetic component of biodiversity in animals and plants. Genomic analysis within the genus Hordeum, in cultivars of H. vulgare and in wild accessions of H. spontaneum, was performed by different types of molecular markers, such as restriction fragment length polymorphisms (RFLP) and long primer–polymerase chain reaction (LP–PCR), and simple sequence repeats (SSR). The aim of this approach was to compare the correlation existing between genotypic variation at specific regions of the genome, as targeted with the different probes obtained from stress‐responsive genes, and phenotypic variation, as shown by adaptation to different environments and climates. H. vulgare cultivars with contrasting growth habits (spring or winter) and H. spontaneum accessions adapted to different locations in Israel have been analysed. The results showed the existence of some tight associations between adaptive traits and markers (RFLP, LP–PCR) derived from specific genes induced in response to environmental stress. The correlation between adaptive phenotypes and genetic variation obtained with these markers was similar to that observed with SSRs. However, a considerable amount of the global genetic variation (83% in H. vulgare and 65% in H. spontaneum) seemed to have no direct correlation with the particular genetic traits involved in differentiating the individuals. Molecular markers are therefore a useful tool to target genomic regions involved in adaptation to the environment.

Genetic resources of salt tolerance in wild Hordeum species

Salt tolerance was evaluated in 340 accessions of Hordeum, consisting of 41 brittle-rachis forms of Hordeum vulgare L. subsp. vulgare (H. agriocrithon) accessions, 154 H. vulgare L. subsp. spontaneum (H. spontaneum) accessions, and 145 accessions of ten other species or subspecies of wild Hordeum. Germination was carried out at concentrations of 171, 257, and 342 mM NaCl. The levels of salt tolerance for seed germination in wild Hordeum species were generally lower than those found by Mano et al. (1996) in cultivated barley; the NaCl tolerance level of the different species were as follows: H. agriocrithon > H. spontaneum > other wild Hordeum species. In addition, leaf injury index was used to assess tolerance at the seedling stage after treatment with 500 mM NaCl solution for four weeks. The levels of salt tolerance at the seedling stage in wild Hordeum species were generally higher than those found by Mano & Takeda (1995) in cultivated barley. Most wild Hordeum species showed high NaCl tolerance at the seedling stage and are considered good sources of germplasm for salt tolerance breeding.

Assessment of the genetic relatedness of barley accessions (Hordeum vulgare s.l.) resistant to soil-borne mosaic-inducing viruses (BaMMV, BaYMV, BaYMV-2) using RAPDs

Thirty-six Hordeum vulgare varieties and 12 H. spontaneum germplasms originating from different parts of the world and showing different reactions to the barley yellow mosaic virus complex (BaMMV, BaYMV, BaYMV-2) were analyzed for genetic similarity using RAPDs. On the basis of an analysis of 20 selected RAPD-primers corresponding to 544 bands genetic similarity according to Nei and Li (1979) was estimated to be between 0.685 and 0.964. Associations between the 48 genotypes were calculated using UPGMA-clustering and principal coordinate analysis. By applying these methods we were able to separate H. spontaneum accessions from H. vulgare varieties, and within these groups all the genotypes were clustered correctly according to their origin. Consequently, RAPD analysis can be considered a very useful and efficient tool for the fast estimation of genetic relationships in barley. The correlation between genetic similarity with respect to German varieties and adaptation of exotic barley varieties to German growing conditions is discussed.

Net blotch resistance in wild species of Hordeum.

Resistance to net blotch was evaluated in 175 Hordeum vulgare subsp. spontaneum (H. spontaneum) accessions and 149 accessions of thirteen species or subspecies of wild Hordeum. Most H. spontaneum accessions showed resistance to each of the four Pyrenophora teres f. teres (P. teres) isolates tested. However, H. spontaneum accessions showed different resistance reactions, depending upon their origin. In particular, some accessions from Afghanistan and Russia showed a high level of resistance, and accessions from Morocco were susceptible. Among the four P. teres isolates, the virulence spectra on the H. spontaneum accessions were more different between isolates from different countries than between those from the same country. Hordeum spontaneum accessions susceptible to the Canadian isolate WRS102, but resistant to the other three isolates were found in Iraq suggesting the geographical differentiation of resistance genes in H. spontaneum. All accessions of the other wild Hordeum species, especially some accessions of H. marinum subsp. gussoneanum, showed high levels of resistance. These resistance genes may be useful candidates for incorporation into cultivated barley.

Genetic studies on the powdery mildew resistance of winter barley lines derived from Hordeum spontaneum accessions collected in Israel

The genetics of the powdery mildew resistance of 15 Hordeum spontaneum-derived winter barley lines were studied in testcrosses with selected cultivars carrying the MIa12 and MIa13 resistance alleles, in order to identify the inheritance of the resistance and to test for linkage with the MIa locus on chromosome 1H (5). A total of 27 genes were identified. Only one of these genes (in line ‘1–12 x Dura’) could eventually be allelic to a gene previously identified in H. spontaneum Koch. A monofactorial dominant inheritance was identified in the majority of the lines. Three of the tested lines possessed recessively inherited genes and in one line a dominant and a recessive gene were identified. In respect to the reaction of the lines against European mildew cultures, lines with a bifactorially inherited resistance had a broader resistance spectrum than those with a monofactorial inheritance, while lines carrying recessive factors showed a moderately expressed resistance. In three cases a linkage with the MIa locus was found, while in two further lines a possible allelism to this locus was indicated by the absence of recombinant progeny plants. By using more than two isolates for linkage analysis, it was possible to identify additional genes for mildew resistance, reaching a maximum number of four genes in the same line. In some cases, a different inheritance was observed for the resistance of the same line against different isolates. It was assumed that different genes exist, each being effective against a different isolate.

Evaluation of cultivated and wild barley for resistance to pathotypes ofPuccinia hordei with wide virulence

An isolate ofPuccinia hordei (ND89-3) originally collected in Morocco is virulent on most barley genotypes reported to possess resistance, except cultivar Estate (CI 3410), which possesses theRph3 gene and exhibits a low to intermediate level of resistance (infection type 12). Isolate ND89-3 possesses one of the widest virulence spectrums reported forP. hordei. Accessions ofHordeum vulgare (1,997 in total) andH. spontaneum (885 in total), mostly originating from the Mediterranean region and parts of North Africa, were evaluated with isolate ND89-3 at the seedling stage to identify new sources of leaf rust resistance. Fifty-eight accessions ofH. vulgare, and 222 accessions ofH. spontaneum exhibited low infection types to this isolate. Further evaluations of these resistant accessions with isolates ofP. hordei virulent forRph3,Rph7, andRph12 suggested that most of the resistantH. vulgare accessions possess theRph3 gene. Data suggested additional sources of effective resistance inH. vulgare are rather limited. FiveH. vulgare accessions and 167H. spontaneum accessions were identified as possible sources of new genes for leaf rust resistance. These accessions likely possess resistance genes that are different fromRph1 toRph12, or gene combinations thereof based on their reaction to four leaf rust isolates. Utilization of these accessions in barley breeding will broaden the germplasm resources available for genetic control ofP. hordei.

Reactions of Hordeum spontaneum to infection with two cultures of Puccinia hordei from Israel and United States

The reactions to infection with two cultures of Puccinia hordei were determined for 292 Hordeum spontaneum (syn. H. vulgare ssp. spontaneum) accessions, collected at 16 sites which encompassed the ecological range of H. spontaneum in Israel. Culture Tel-Aviv was from Israel and culture 57.19 was from the United States. Fifty-two percent of the accessions were resistant to culture Tel-Aviv and 67% were resistant to culture 57.19. Forty-three percent of the accessions were resistant to both cultures. The average infection type (IT) of accessions within sites ranged from 2.7 to 7.5 on a 0–9 rating scale. The results showed that the presence of Ornithogalum species, the alternate hosts of P. hordei, may increase the percentage of H. spontaneoum accessions resistant to P. hordei. More accessions were resistant at sites where humidity at 1400 was higher, the annual evaporation was lower, and where the glumes were shorter. Kernel weight and annual rainfall was not correlated with resistance. A lower percentage of H. spontaneum accessions were resistant to P. hordei culture Tel-Aviv from Israel than to culture 57.19 from the United States. In a previous study a lower percentage of H. spontaneum accessions also was found to be resistant to a culture of Erysiphe graminis hordei from Israel than to cultures from other countries. Previous studies also have shown that cultures of P. hordei and E. graminis hordei from Israel have many genes for virulence on barley, and that H. spontaneum accessions from Israel have many genes for resistance to these two pathogens. Previous results and the results reported in this paper support the hypothesis of coevolution of resistant host genes and virulent pathogen genes where hosts and pathogens have coexisted for many thousand years.

Pre- and post-anthesis accumulation of dry matter and nitrogen in wild barley (Hordeum spontaneum) and in barley cultivars (H. vulgare) differing in final grain size and protein content

Four accessions of Hordeum spontaneum and two of Hordeum vulgare were grown in pot conditions, and sampled at intervals before and after anthesis. Dry matter and nitrogen content of leaves, stems, and grains were measured. In general, H. spontaneum was characterized by higher vegetative nitrogen content, and greater allocation of dry matter resources to leaves rather than stems, compared to H. vulgare. The two small grain H. spontaneum accessions of ‘slender’ phenotypic type were much lower in leaf weight and somewhat lower in stem weight, than the two large grain ‘robust’ phenotypic types. Post-anthesis observations showed that large grain H. vulgare (cv. Ruth) accumulated grain dry matter at a greater rate (rather than duration) than the other genotypes. Final dry matter harvest index was about 26% in H. vulgare, but only 14% in all four H. spontaneum accessions. Nitrogen harvest index was low in cv. Ruth (around 35%) and high in H. spontaneum and in the high protein cultivated line 859B (all around 65%).

Morocco as a possible domestication center for barley: biochemical and agromorphological evidence

The distribution of genetic variants of a group of low molecular weight, chloroform-methanol soluble proteins (CM proteins), among Moroccan and non-Moroccan accessions of Hordeum spontaneum and among selections from several Moroccan landraces of H. vulgare and cultivars of the same species with widespread European origin, suggests that domestication of barley might have taken place in Morocco. An agromorphological characterization of the H. spontaneum accessions further supports this hypothesis. The possible Moroccan origin of the French cultivar 'Hatif de Grignon' and of several Spanish 6-rowed barleys is also presented.

Genetics of CM-proteins (A-hordeins) in barley

The CM-proteins, which are the main components of the A-hordeins, include four previously described proteins (CMa-1, CMb-1, CMc-1, CMd-1), plus a new one, CMe-1, which has been tentatively included in this group on the basis of its solubility properties and electrophoretic mobility. The variability of the five proteins has been investigated among 38 Hordeum vulgare cultivars and 17 H. spontaneum accessions. Proteins CMa-1, CMc-1 and CMd-1 were invariant within the cultivated species; CMd was also invariant in the wild one. The inheritance of variants CMb-1/CMb-2 and CMe-1/CMe-2,2' was studied in a cross H. spontaneum x H. vulgare. The first two proteins were inherited as codominantly expressed allelic variations of a single mendelian gene. Components CMe-2,2' were jointly inherited and codominantly expressed with respect to CMe-1. Gene CMb and gene(s) CMe were found to be unlinked. The chromosomal locations of genes encoding CM-proteins were investigated using wheat-barley addition lines. Genes CMa and CMc were associated with chromosome 1, and genes CMb and CMd with chromosome 4. These gene locations further support the proposed homoeology of chromosomes 1 and 4 of barley with chromosomes groups 7 and 4 of wheat, respectively. Gene(s) CMe has been assigned to chromosome 3 of barley. The accumulation of protein CMe-1 is totally blocked in the "high lysine" mutant Riso 1508 and partially so in the high lysine barley Hiproly.

CYTOPLASMIC MALE STERILITY IN BARLEY. XI. THE msm2 CYTOPLASM

A new cytoplasmic male sterility in barley (Hordeum vulgare s.l.) is described and designated as msm2. The cytoplasm was derived from a selection of the wild progenitor of barley (H. vulgare ssp. spontaneum). This selection, 79BS14-3, originates from the Southern Coastal Plain of Israel. The selection 79BS14-3 has a normal spike fertility in Finland. When 79BS14-3 was crossed by cv. Adorra, the F(1) displayed partial male fertility and progeny of recurrent backcrosses with cv. Adorra were completely male sterile. Evidently 79BS14-3 is a carrier of a recessive or semidominant restorer gene of fertility. The dominant restorer gene Rfm1a for another cytoplasmic male sterility, msm1, is also effective in msm2 cytoplasm. The different partial fertility restoration properties of msm2 and msm1 cause these cytoplasms to be regarded as being distinct. Seventy spontaneum accessions from Israel have been studied for their capacity to produce F(1) restoration of male fertility both in msm1 and in msm2 cytoplasms with a cv. Adorra-like seed parent (nuclear gene) background. The msm2 cytoplasm shows partial restoration more commonly than msm1 in these F(1) combinations. The mean restoration percentage per accession for msm2 is 28, and for msm1 4. Most of the F(1) seed set differences of the two cytoplasms are statistically significant. When estimated with partially restored F(1) combinations, msm2 cytoplasm appeared to be about 50 times more sensitive to the male fertility-promoting genes present in the spontaneum accessions. The spontaneum sample from Central and Western Negev, which has been found to be devoid of restoration ability in msm1 cytoplasm, had only low partial restoration ability in msm2 (mean 0.3%). The female fertility of msm2 appears normal. The new msm2 cytoplasm could be useful in producing hybrid barley.