Yd2 Gene Research Articles

Ethiopian barley landraces: useful resistant sources to manage Barley yellow dwarf and other foliar diseases constraining productivity

One hundred sixty-five advanced lines were subjected to marker-assisted selection using Cleaved amplified polymorphic sequence-polymerase chain reaction (CAPS-PCR) primer against Barley yellow dwarf (BYD) resistant Yd2 gene. In addition, phenotypic evaluation was employed to screen the advanced lines for multiple disease resistance. Effect of host growth rate and incubation period on BYD development was also assessed. Results of marker PCR showed that Yd2 gene was detected in 96 (58.2%) out of 165 accessions tested. Data on relationships of days to heading (DtH) and BYD symptoms development revealed that barley accessions having shorter DtH (66 days), BYD severity appeared low, and vice versa on accessions having longer DtH (79–83 days). Screening for multiple disease resistance gave interesting results. Among 11 accessions (with Yd2) selected as the best for multiple diseases, 6 accessions [Chelia local, 4304–2(2), 4818(1.3), 1822–1(1), 1831–2-2(2), and 4915–1(1.2)] were highly resistant to leaf rust and net blotch, while other five lines had moderately resistant reaction. Study on the relationship of host resistance and incubation period showed that BYDV was detectable 5 days earlier in susceptible than in resistant lines. This can be used as an alternative method in preliminary screening of large number of genotypes against BYDV. From this study, it was evident that the identified resistant genotypes are a good resource for barley improvement program targeting BYDV and other important foliar pathogens. Barley breeders are encouraged to take advantage of this opportunity in producing multi-disease resistant barley genotypes in an agronomically enhanced genetic background in the country and beyond.

Possibility of exploiting the Yd2 resistance to BYDV in spring barley breeding

AbstractThe effects of the Yd2 gene on tolerance to barley yellow dwarf virus (BYDV) and other agronomically important characters in spring barley were evaluated in a set of randomly selected doubled haploid (DH) lines of an‘Igri’/‘Atlas 68’ cross and three crosses between CIMMYT Yd2 materials and the Czech malting barley ‘Akcent’. The cleaved amplified polymorphic site (CAPS) diagnostic marker Yd2 was used for identification of the Yd2 gene and this analysis showed high agreement with the results of field infection tests. Yd2 lines exhibited significantly lower symptom scores and lower reductions of some grain yield characters, but their resistance level was not consistent over the years. The presence of secondary stresses (high temperature/drought) in 2000 led to relatively higher sensitivity to BYDV infection, strengthened by the long life cycle of genotypes. In cases where secondary stresses were mild (in 2002), the longer life cycle significantly increased sensitivity to BYDV infection only in the absence of the Yd2 gene (in susceptible genotypes). The examination of different vegetative, grain yield and malting quality characters separately for groups of Yd2 and non‐ Yd2 lines did not show any evidence of adverse effect of the Yd2 gene on any character.

Marker‐assisted backcross introgression of the Yd2 gene conferring resistance to barley yellow dwarf virus in barley

AbstractYLM, a codaominant polymerase chain reaction (PCR) marker linked to Yd2, could substantially improve the precision and efficiency of barley yellow dwarf virus (BYDV) resistance breeding. The aim of this study was to assess the effectiveness of YLM in a marker‐assisted introgression programme and to quantify associations between the presence of Yd2 and other agronomic and quality traits. The Yd2 gene was introgressed into a BYDV‐susceptible background through two cycles of marker‐assisted backcrossing. BC2 F2‐derived lines, either carrying or not carrying the YLM allele associated with resistance, were compared in the presence and absence of BYDV. The YLM marker was shown to be effective in the introgression of Yd2. Lines carrying the YLM allele associated with resistance produced significantly fewer leaf symptoms and showed a reduction in yield loss when infected with BYDV. There were no deleterious effects associated with the introgression of Yd2 on grain yield, grain size or malting quality. The implications of marker‐assisted selection for Yd2 on barley improvement are discussed.

Genetic analysis of resistance in barley to barley yellow dwarf virus

AbstractThe inheritance of resistance to barley yellow dwarf virus (BYDV) was studied in the selected 24 spring and winter barley cultivars that showed a high or intermediate resistance level in 1994‐97 field infection tests. The polymerase chain reaction diagnostic markers YLM and Ylp were used to identify the resistance gene Yd2. The presence of the Yd2 gene was detected with both markers in all the resistant spring barley cultivars and lines from the CIMMYT/ICARDA BYDV nurseries. The results of field tests and genetic analyses in winter barley corresponded with marker analyses only when the Ylp marker was used. Genes non‐allelic with Yd2 were detected by genetic analyses and the Ylp marker in moderately resistant spring barley cultivars ‘Malvaz’, ‘Atribut’ and ‘Madras’, and in the winter barley cultivars ‘Perry’ and ‘Sigra’. Significant levels of resistance to BYDV were obtained by combining the resistance gene Yd2 with genes detected in moderately resistant cultivars. The utilization of analysed resistance sources in barley breeding is discussed.

Development of YLM, a codominant PCR marker closely linked to the Yd2 gene for resistance to barley yellow dwarf disease

The Yd2 gene in barley provides protection against barley yellow dwarf luteovirus (BYDV), the most economically devastating virus of cereals worldwide. Because resistance assays to identify Yd2-containing individuals from breeding populations are often difficult, we have developed a closely linked, codominant PCR-based marker for Yd2 using AFLP marker technology. The marker, designated YLM, can be amplified from barley genomic DNA prepared using a rapid and simple extraction procedure and, in a survey of more than 100 barley genotypes, was found to be polymorphic between most Yd2 and non-Yd2 lines. The YLM therefore shows excellent potential as a tool for selecting Yd2-carrying segregants in barley breeding programmes.

Rapid and informative assays for Yd2, the barley yellow dwarf virus resistance gene, based on the nucleotide sequence of a closely linked gene

This paper describes the isolation of the cDNA encoding a protein previously shown to be indicative of the disease-resistance phenotype mediated by the Yd2 gene in barley (Hordeum vulgare L.). Amino acid sequences of four peptides obtained after isolation of the protein on two-dimensional polyacrylamide gels were completely homologous to sequences occurring within subunit E of barley vacuolar proton-translocating ATPase. Nucleotide sequence data of cloned cDNAs from both Yd2 and non-Yd2 barley varieties showed an amino acid change arising from a single-base-pair polymorphism. This was predicted to result in the shift in isoelectric point used previously to differentiate the protein in Yd2 and non-Yd2 barleys. Earlier work had indicated very close linkage between the gene from which this cDNA is derived, which we have named Ylp, and Yd2, the barley yellow dwarf virus resistance gene. We report here the development of PCR-based assays which discriminate between the two alleles of Ylp and thereby act as valuable predictors of Yd2 for barley breeders and others looking to study this important gene in cereal crops. The validity of each assay was tested with an extensive survey of over 100 barley varieties currently under cultivation in Australia or of importance to Australian barley breeding programmes. Complete agreement was observed between the allele of Ylp detected by the assay and the known Yd2 status of the barleys. A dominant PCR marker for the Yd2-associated allele of Ylp was subsequently developed using an allele-specific primer pair. This fast and economical assay will have broad application in the marker-assisted selection of Yd2-containing lines.

The Yd2 gene for barley yellow dwarf virus resistance maps close to the centromere on the long arm of barley chromosome 3

Barley yellow dwarf luteovirus (BYDV) causes serious yield losses in all cereals worldwide. The Yd2 gene from a number of Ethiopian barleys (Hordeum vulgare L.) has been the most effective means of providing resistance against BYDV in cultivated barley. Isolation of the Yd2 gene will enable characterisation of the molecular basis of the Yd2-BYDV interaction. This paper describes the first stage in a project to isolate the gene: the construction of a detailed linkage map of the Yd2 region. The map encompasses 27.6 centiMorgans (cM) of chromosome 3 and contains 19 RFLPs, 2 morphological marker loci, the centromere and Yd2. In the mapping population of 106 F2 individuals, Yd2 perfectly cosegregated with the RFLP loci Xwg889 and XYlp, which were located on the long arm, 0.5 cM from the centromere. The two morphological marker loci, uzu dwarfand white stripe j, both mapped distal to Yd2. The protein product of the gene at the XYlp locus will provide a convenient assay for the selection of Yd2 during the breeding of BYDV-resistant barley varieties.

The Yd2 gene for barley yellow dwarf virus resistance maps close to the centromere on the long arm of barley chromosome 3

The Yd2 gene for barley yellow dwarf virus resistance maps close to the centromere on the long arm of barley chromosome 3

The Yd2 gene and enhanced resistance to barley yellow dwarf virus (BYDV) in winter barley

AbstractA breeding programme was developed to obtain barley yellow dwarf virus (BYDV)‐resistant winter genotypes using the Yd2 gene. The aim was to incorporate the Yd2 allele into the new high‐yielding genotypes to release cultivars that allow barley cultivation in areas where BYDV is endemic.The resistant lines were developed using pedigree selection. An ICARDA resistant line (83RCBB130) carrying the Yd2 gene was crossed with three susceptible, high‐yielding winter varieties and their F1 lines were either selfed or backcrossed to the matching susceptible parent. The best lines selected from subsequent selfing generations were evaluated in replicated trials in the presence or absence of BYDV, starting from F6 and BC1F5 to F8 and BC1F7 generations. Four genotypes with superior agronomic traits and BYDV resistance were selected.

Parial resistance in the barley (Hordeum vulgare L.) cultivar ‘Chikurin Ibaraki 1’ to two PAV‐like isolates of barley yellow‐dwarf virus: allelic variability at the Yd2 gene locus

AbstractThe Japanese barley cultivar, ‘Chikurin Ibaraki 1’, is partially resistant to the PAV serotype of barley yellow‐dwarf virus (BYDV), but its induced mutant line, Ea52, is susceptible. The inheritance of resistance in cv. ‘Chikurin Ibaraki 1’ to BYDV‐PAV was investigated. The F, and F2 plants of crosses of cvs ‘Chikurin Ibaraki 1’, Ea52, ‘Vixen’, carrying the Yd2 gene of resistance, and ‘Plaisant’, a susceptible French cultivar, were tested in growth chamber and field conditions. Isolate RG, against which ‘Chikurin Ibaraki 1’ is partially resistant in growth chamber and field conditions, and isolate 2t, which overcomes the partial resistance of ‘Chikurin Ibaraki 1’ in field conditions (Chalhoub et al. 1994) were used. The segregation of F2 plants of crosses between ‘Chikurin Ibaraki 1’ and the susceptible cultivars to isolate RG (one resistant to three susceptible) suggests that the resistance of ‘Chikurin Ibaraki 1’ is controlled by a single recessive gene. All 537 F2 plants of ‘Chikurin Ibaraki 1’בVixen’ tested with isolate RG in growth chamber and field conditions were resistant. The F2 plants of this cross were all resistant to isolate 2t in growth chamber conditions but segregated with a ratio of one resistant to three susceptible in field conditions owing to the susceptibility of ‘Chikurin Ibaraki 1’ to this isolate. Results suggest that the resistance gene in ‘Chikurin Ibaraki 1’ is tightly linked or allelic with the Yd2 gene in ‘Vixen’. However, it differs from this gene in ‘Vixen’ in that it can be overcome by isolate 2t in field conditions.

Complexity in evaluating resistance of barley (Hordeum vulgare L) to 2 pathotypes of BYDV-PAV: allelic variability at the Yd2 gene locus

Complexity in evaluating resistance of barley (Hordeum vulgare L) to 2 pathotypes of BYDV-PAV: allelic variability at the Yd2 gene locus

The Yd2 resistance to barley yellow dwarf virus is effective in barley plants but not in their leaf protoplasts

SummaryThe Yd2 gene for “resistance” to barley yellow dwarf virus (BYDV) has been widely used in barley (Hordeum vulgare). We have tested Australian isolates of BYDV of varying severity against barley genotypes with and without the Yd2 gene and report here a positive relationship between symptoms and virus levels determined by ELISA. Cultivar Shannon is the result of backcrossing the resistant line CI 3208 to cultivar Proctor, a susceptible line. It appears to be intermediate in reaction to BYDV between Proctor and CI 3208, although it carries the major gene, Yd2. Unlike the whole plant studies, no significant differences were observed with regard to the ability of protoplasts derived from these various genotypes to support BYDV replication. It is therefore demonstrated for the first time that the Yd2 gene is not among the small number of resistance genes which are effective against virus replication in isolated protoplasts.

Feeding Responses of Rhopalosiphum padi (Homoptera: Aphidae) to Barley Yellow Dwarf Virus Resistant and Susceptible Barley Varieties

The probing and feeding behavior of an important vector of barley yellow dwarf virus (BYDV), the bird cherry-oat aphid, Rhopalosiphum padi was electronically monitored on barley varieties with and without the Yd2 gene, a gene that imparts BYDV resistance to certain cereal cultivars. The presence of the Yd2 gene was shown to have no significant effect on the time elapsed to the first sieve element contact, total number of sieve element contacts, or duration of phloem sieve element ingestion by R. padi . Furthermore, aphid probing and feeding was not greatly affected by BYDV infection in susceptible plants. These data demonstrate that the mechanisms underlying BYDV resistance in plants with the Yd2 gene do not involve factors significantly influencing plant-aphid interactions that invoke alterations in aphid probing or feeding behavior. In addition, the number of sieve element contacts and duration of ingestion from sieve element cells by R. padi indicate that this aphid should be highly efficient in acquiring and transmitting the phloem-delimited BYDV to ‘California Mariout’ barley, with or without the Yd2 gene.

EVALUATION OF NEW AND OLD SOURCES OF TOLERANCE TO EARLY-SEASON BARLEY YELLOW DWARF VIRUS IN OATS

Transgressive segregation has produced oat lines possessing higher levels of barley yellow dwarf virus (BYDV) tolerance than were previously available. Even with inoculation at the earliest growth stages, some oat lines now display a level of tolerance approaching that of Ethiopian barleys possessing the Yd2 gene.

EFFETS D’UNE INFECTION HATIVE VS. TARDIVE DE VIRUS DU NANISME JAUNE DE L’ORGE (BYDV) SUR DES CULTIVARS D’ORGE (HORDEUM VULGARE) AVEC VS. SANS GENE YD2

BYDV (barley yellow dwarf virus) inoculated on the 16th day of growth caused much heavier losses and more grain weight reduction for cultivars without Yd2 gene. Susceptibility is strongly correlated with symptoms for this date of inoculation. Inoculation on the 34th day of growth caused heavier damage in 1974 than in 1973, and no precise symptoms occurred in 1973 despite measurable losses. Maturity is often accelerated by BYDV for cultivars without Yd2, but is generally slowed down for cultivars with Yd2. No relationship was observed between the date of maturity and the susceptibility level of cultivars possessing Yd2.

Inheritance and Linkage of the Yd2 Gene Conditioning Resistance to the Barley Yellow Dwarf Virus Disease in Barley1

Crop ScienceVolume 4, Issue 5 cropsci1964.0011183X000400050034x p. 544-548 Article Inheritance and Linkage of the Yd2 Gene Conditioning Resistance to the Barley Yellow Dwarf Virus Disease in Barley1 C. W. Schaller, C. W. SchallerSearch for more papers by this authorC. O. Qualset, C. O. QualsetSearch for more papers by this authorJ. N. Rutger, J. N. Rutger Professor of Agronomy, formerly Laboratory Technician (now Assistant Professor, University of Tennessee), and formerly Research Assistant (now Assistant Professor, Cornell University), respectively.Search for more papers by this author C. W. Schaller, C. W. SchallerSearch for more papers by this authorC. O. Qualset, C. O. QualsetSearch for more papers by this authorJ. N. Rutger, J. N. Rutger Professor of Agronomy, formerly Laboratory Technician (now Assistant Professor, University of Tennessee), and formerly Research Assistant (now Assistant Professor, Cornell University), respectively.Search for more papers by this author First published: 01 September 1964 https://doi.org/10.2135/cropsci1964.0011183X000400050034xCitations: 38 1 Contribution from the Department of Agronomy, University of California, Davis, Calif. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume4, Issue5September–October 1964Pages 544-548 RelatedInformation