Session 2 Breeding Methodologies i Mapping

 

Oral Presentation

 

 

Experiences with Marker-Assisted Selection for Quantitative Traits in Barley

S. E. Ullrich1, A. Kleinhofs1, I. Romagosa2, F. Han1, W. Gao1 and D. Schmierer1

1Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99164-6420, USA,
E-mail: ullrich@wsu.edu;
2Centre UdL-IRTA, 25198 Lleida, Spain

Molecular marker-assisted selection (MMAS) is a proven breeding and genetics strategy for simply inherited (13 gene) traits. MMAS for complexly inherited true quantitative traits is less certain. Research through the North American Barley Genome Project concentrated on malting quality and grain yield traits. These traits are difficult to evaluate and select for due to number of genes, genotype (G), environment (E), GXG, and GXE effects, and cost. For malting quality, major QTL regions on chromosomes 1 (7H) (QTL1) and 4H (QTL2) with multi-trait QTLs (malt extract, alpha-amylase, diastatic power, beta-glucan) were MMAS targets in Steptoe/Morex (S/M) crosses. MMAS for QTL1 was effective but not for QTL2. Fine mapping of QTL2 improved its selectability. For yield in S/M, MMAS for QTLs on chromosomes 3H and 6H was more effective than for QTLs on chromosomes 2H and 7 (5H). Another S/M MMAS study resulted in lines with improved yield-related traits but not yield per se. MMAS resulted in improved yield and malting quality in Harrington/Baronesse backcross lines. Lessons learned include: (1) genotypic and/or tandem genotypic-phenotypic selection was as good as or better than phenotypic selection, (2) response of single QTLs can be complicated by epistasis and cross-over GXE, (3) optimum QTL allele composition is difficult to predict, (4) QTL fine mapping can improve MMAS.

 

 

A Large Scale Mapping of ESTs on Barley Genome

K. Sato1, N. Nankaku1,2 , Y. Motoi1,2 and K. Takeda1

1Research Institute for Bioresources, Okayama University, Kurashiki 710-0046, Japan,
E-mail: kazsato@rib.okayama-u.ac.jp; 2CREST,
Japan Science and Technology Cooperation,
Kawaguchi 332-0012, Japan

ESTs are the most informative sources of genetic markers on the linkage map in barley. We have generated ca. 60,000 ESTs from 3ends from nine different cDNA libraries. Each EST sequence was basecalled by phred and trimmed by QV = 20. Unigenes were developed by phrap (contig 8,753, singlet 6,686) to process primers by Primer3. Ca. 11,000 primer sets were generated. Our strategy of mapping ESTs are (1) polymorphisms appear on agarose gel (2) SNP analysis after direct sequencing of parental PCR amplicons either using PCR-RFLP or SNP typing system. The project aims to localize several thousands of ESTs on the barley linkage map.

 

 

Poster Presentation

Genetic Diversity of Barley Cultivars from Kazakhstan and Europe

S. I. Abugalieva1, Y. Turuspekov1, E. Noli2, A. Abugalieva3; V. Talame2 and R. Tuberosa2

1Institute of Plant Physiology, Genetics & Bioengineering, Almaty, 480090, Kazakhstan;
2Department of Agroenvironmental Sciences and Technology, 40127-Bologna, Italy;
3enter for Crop Science and Farming, Almalybak, 483133, Kazakhstan,
E-mail: research@nursat.kz; absaule@yahoo.com

 Hordeins, isozymes, RAPD, SSR, and AFLP markers were used for studying the genetic diversity in 34 barley cultivars widely grown in Europe and 34 commercial varieties grown in Kazakhstan. The varieties also were divided in the following groups: old, moderately new, and modern. From 26 to 50 hordein components were observed from storage protein analysis. While 46, 44, 40 were identified in all cultivars, 42 and 37 were present only in European cultivars. Fifteen polymorphic isozyme loci were analyzed. The average number of alleles per locus was 1.20, with 1.34 in Kazakh and 1.05 in European cultivars, respectively. Proportion of polymorphic loci accounted as average for all varieties was 0.18, with 0.28 in Kazakhstan and 0.08 in Europe. Six RAPD primers, which produced 67 loci, were revealed to be informative. A total of 161 AFLP bands produced with 6 MseI-EcoRI primer combinations and 31 SSR loci were analyzed in all accessions. The number of AFLP bands per primer combination ranged from 83 to 95. One primer combination discriminated almost all varieties indicating the informativity of AFLP markers. SSRs revealed an average of 4.8 alleles per locus. The correlation between the SSR and AFLP similarity matrices computed for all the possible pairwise comparison among cultivars was equal to 0.51. In the cluster analyses carried out with AFLP and SSR markers, the accessions were separated according to ear type, geographic origin and growth habit. A multivariate analysis separated the accessions according to ear type and geographic origin. In general, our results did not indicate a sizeable loss of genetic diversity both within the European and Kazakhstan genetic pool.

 

 

Differences between South American H Haplome Diploids
and I Haplome Diploids, from the Perspective of the 5S rDNA Gene in the Genus Hordeum

B. R. Baum1 and D. A. Johnson2

1Agriculture and Agri-Food Canada, Ottawa, Ontario, ON K1A 0C6, Canada, E-mail: baumbr@agr.gc.ca; 2Ottawa-Carleton Institute of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada

Twelve South American diploid Hordeum species belonging to the H genome and three diploid species belonging to the I genome (including cultivated barley), were investigated for their 5S rDNA sequence diversity. The ca. 500 sequenced clones were assigned to classes which were further assigned to haplomes. Two classes were found to be present in each haplome. These were labelled accordingly long H1 and short I1 for the I haplome diploids, and long H2 and long Y2 for the South American diploids. The aligned sequences were subjected to a series of Maximum likelihood analyses and various tests, including molecular clock, which will be presented and discussed.

 

 

Use of the Functional Map to Identify QTLs
and Explore the Genetics of Biometric Agronomic Traits
in the
Oregon Wolfe Barleys

G. H. Buck-Sorlin1,2, R. K. Varshney3, M. Prasad3, R. Kota3, A. Graner3
and A. Boerner3

1Department of Cytogenetics and 3Genebank Department, Institute of Plant Genetics and Crop
Plant Research (IPK), D-06466 Gatersleben, Germany, E-mail: buck@ipk-gatersleben.de;
2Department of Computer Science, Brandenburg University of Technology Cottbus (BTU),
D-03013 Cottbus, Germany

The Oregon Wolfe Barleys (OWBs) are a well-characterised, phenotypically polymorphic mapping population that has been used for a whole range of mapping and QTL studies. The population was grown in the greenhouse twice in 1999/2000 and 2003, and biometric (organ lengths and ratios), meristic (number of leaves per main stem, number of tillers) and phenological traits (flowering time) were established in a systematic fashion. Additionally, the mapping population was used to prepare a functional map by employing ESTs in different marker assays like RFLPs, SSRs and SNPs. The functional map (or transcript map) based on the OWB population contains > 500 genes. This map has been used for QTL analysis for the above traits. The combination of the functional map with information on biometric morphological traits promises to give new insights into the nature and quantitative inheritance of these traits and is hoped to provide a decisive progress in the field of expression mapping.

 

A Consensus Molecular Genetic Map of Barley

M. Cakir1, R. Appels1,2, A. Hunter3, D. Schibeci3, C. D. Li2 and M. Bellgard3

1Molecular Plant Breeding CRC and WA State Agricultural Biotechnology Centre, Murdoch University, Murdoch, WA 6150, Australia, E-mail: mcakir@central.murdoch.edu.au; 2Crop Improvement Institute, Department of Agriculture, Bentley Delivery Centre, WA 6983, Australia; 3Centre for Bioinformatics
and Biological Computing, Murdoch University, Murdoch, WA 6150, Australia

An extensive international collaboration allowed us to compile a consensus map of barley. The consensus map was formed using four barley maps produced in our laboratory as well as a number of other Australian and international published genetic maps and includes over 2000 markers. c-MAP software was used to view the consensus map and validate marker order by comparison of the consensus map to the individual maps that contributed to the consensus map. The options in c-MAP such as the matrix were found useful for quickly assessing the occurrence of duplicate loci. The alignment of different genetic maps was generally unambiguous with respect to the order of loci and examples of alignments will be presented together with an estimate of the error inherent in producing the consensus map. QTLs were also inserted into map in a searchable format within the software and this has enhanced the value of the map considerably. This map serves the purpose of summarising extensive datasets in the area of molecular genetic mapping as well as in the application of molecular markers in plant breeding programs.

 

Characterization and Mapping of a Wild Barley eibi1 Mutation Identifying a Gene Essential for Leaf Water Conservation

G. Chen1, M. Sagi2, S. Weining1, T. Krugman1, T. Fahima1, A. B. Korol1 and E. Nevo1

1Institute of Evolution, University of Haifa, Haifa 31905, Israel,
E-mail: nevo@research.haifa.ac.il;
2Institute for Applied Research,
Ben-Gurion University of the Negev, Beer Sheva 84105, Israel

A spontaneous wilty mutant (eibi1) hypersensitive to drought was identified in wild barley, Hordeum spontaneum Koch. Mutant eibi1 had a highest relative water loss rate among the known wilty mutants, indicating that eibi1 is one of the most drought sensitive mutants. When compared with wild type, eibi1 had the same ABA level, the same ability to accumulate stress-induced ABA, and the same stomatal movement in response to light, dark, drought, and exogenous ABA, revealing that eibi1 was neither an ABA -deficient nor an ABA-insensitive mutant. eibi1 leaves had a larger chlorophyll efflux rate in 80% ethanol than the wild-type leaves; demonstrating that eibi1 was defective in an actual barrier layer in cuticle that limits water loss of the plant. An approximately 3:1 segregation ratio of wild type to mutant among 158 F2 plants derived from a cross of eibi1 by Morex revealed that the eibi1 high water loss rate was caused by a single recessive nuclear mutation. This mutation was mapped on chromosome 3H short arm between simple sequence repeat markers (SSR) Bmag0603 and Bmac0067, and cosegregating with Bmac0828.

 

Molecular Marker Validation and Physiological Determinants
of QTL Effect on Grain Protein Concentration of Two-Rowed Barley

L. C. Emebiri and D. B. Moody

Department of Primary Industries, Victorian Institute for Dryland Agriculture, Horsham Victoria 3401, Australia, E-mail: livinus.emebiri@dpi.vic.gov.au

With the advent of DNA markers, it has become possible to locate quantitative trait loci (QTL) for numerous phenotypes in plants. Beyond QTL identification, however, a number of issues still need to be addressed in order to integrate quantitative genetic information into genome-based breeding programs. Among these include validation of QTL effects and a determination of the possible physiological basis of gene action. In previous studies, QTLs that influenced variations in barley grain protein concentration (GPC) were identified on chromosome 5H and 7H. The objectives of the present studies were
(1) to verify marker-trait associations across genetic backgrounds, and (2) to establish the morphological and physiological basis for differences in GPC among doubled haploid lines selected for allelic variation at identified QTLs. In the first study, QTL effects were confirmed using 3 independent doubled haploid populations with different combinations of low and high GPC parental lines. In the second study, doubled haploid lines with allelic variation at these QTL were grown at Horsham, Victoria, in 2001 and 2002, at 0 and 80 kg/ha of nitrogen application, and assessed for phenotypic differences. On average, lines with low-protein alleles were lower in GPC by 1.2% units. There were no significant differences in tillering or dry matter accumulation during vegetative growth, and at anthesis, there were also no significant differences in nitrogen content of the straw or spikes. At maturity, however, highly significant (P 0.01) differences were observed for traits associated with spike morphology (spike weight, spike length and kernels per spike), indicating that lower GPC was achieved by the distribution of a similar amount of nitrogen to a larger number of grains. The implications on germplasm utilisation were discussed.

 

 

Identifying Genes Controlling Heading Date in Spring Barley

J. D. Franckowiak, N. N. Krasheninnik and G. T. Yu

Department of Plant Sciences, North Dakota State University, Fargo, ND 58105, USA,
E-mail: j.franckowiak@ndsu.nodak.edu

Heading date determines in part the adaptation of barley to specific production areas. Most barley breeding programs use some exotic germplasm; thus, knowledge of expected photoperiod responses is desirable. Photoperiod sensitive genes in barley are commonly called early maturity (Eam) genes. Heading date is also affected by temperature and vernalization requirements (the Sgh1, Sgh2, and sgh3 genes for spring growth habit). The Eam1 gene, which is expressed only under long-day conditions (13 hours or longer), is frequently present in wild barley, winter cultivars, and spring cultivars grown during the winter or at high latitudes. Many two-rowed spring cultivars have the long-day gene Eam11 (effective at 12 to 13 hours only). The Eam6 gene confers early heading under both long- and short-day conditions. The Eam5 and eam9 genes confer earliness under short-day conditions. The eam8 gene shows a day length-neutral response. The eam10, mat-f, and mat-i genes produce early plants in most tests. The long-day genes Eam1, Eam6, and Eam11 can cause breeding problems because they are located in chromosome 2H near QTLs for resistance to Fusarium head blight. The Eam6 and Eam11 loci are near the six-rowed spike type 1 (vrs1) locus. The Eam6 gene exhibits additive interactions with Eam1, Eam5, and eam9. Three or more unidentified genes can enhance or inhibit the expression of some, but not all, Eam genes.

 

 

Development of Functional Genetic Markers by Combination of cDNA-AFLP Based Expression Profiling and Marker
Assisted Genotype Pooling

M. Herz1, S. Mikolajewski1, L. Hartl2, M. Baumer2 and G. Schweizer1

1Research Group of Genome Analysis and 2Research Group of Barley Breeding ,
Institute for Crop Production and Plant Breeding, Bavarian State Research Centre for Agriculture,
D-85354 Freising-Weihenstephan, Germany, E-mail: markus.herz@lfl.bayern.de

Malting quality of barley represents the manifestation of the well-adjusted interaction of several different genes. Due to this complex genetic basis, quantitatively inherited traits and in particular malting quality require sophisticated methods to be tagged by genetic markers. Induction of gene expression by a standardised micromalting process was used to identify differentially expressed genes both in varieties and in segregating populations. Based on a DH-population which was previously used to construct a QTL map for malting quality, phenotypic pools were constructed utilising the information about markers which flank significant QTL intervals for malting quality traits and the observations of the traits. cDNA- AFLP analysis was performed with a selected subpopulation of the segregating progeny and differential TDFs were integrated into the linkage map. Several polymorphic fragments could be assigned to QTL intervals of the reference map and their correlation to malting quality traits was calculated. The favourite alleles of differential TDFs increased the means of malting quality parameters significantly compared to the means of the entire subpopulation. Differential TDFs which are located within significant QTL intervals represent candidates for functional genetic markers for malting quality and are therefore well suitable for efficient selection in early stages of plant breeding.

 

 

Flowering Time Markers for Barley Breeding

E. Igartua1, A. Cuesta1, M. P. Gracia1, J. M. Lasa1, F. J. Ciudad2 and A. M. Casas1

1Department of Genetics and Plant Production, Aula Dei Experimental Station, CSIC, 50080 Zaragoza, Spain, E-mail: igartua@eead.csic.es;
2IInstituto de Tecnología Agraria de Castilla y
Leon, Zamaduenas, Crta. Burgos km 119,
47071-Valladolid,
Spain

Adjustment of crop phenology to the resources of the production environment is among the most important traits for barley adaptation. Three genes, Sgh, Sgh2 and Sgh3, are responsible for winter/spring growth habit and vernalization response. Two more genes, Ppd-H1 and Ppd-H2, control photoperiod response. In most studies, the main photoperiod and vernalization QTL coincide with the putative location of the corresponding major genes. There are also a number of QTLs with lesser effects on flowering, known as earliness per se loci, more abundant, but showing less consistency across studies. All these loci have been detected in a number of studies involving biparental progenies. But their use in MAS requires knowledge of their effects and interactions at the germplasm-pool level. For this reason, 17 populations of up to 20 doubled haploids each, made of combinations of 14 parents routinely used in a Spanish breeding program, are being phenotyped for heading time, and genotyped with markers located in the vicinity of major photoperiod and vernalization response loci. The objective is to identify a set of markers that can be used to make predictions of flowering time of genotypes and candidate crosses. These predictions would also be useful to perform MAS towards favorable loci combinations. A progress report on association between markers and field flowering time determinations will be presented.

 

The Distribution of Retrotransposon-Based (S-SAP) Markers
in European Barley Cultivars

F. J. Leigh, J. R. Law, V. J. Lea, E. Chiapparino, P. Donini and J. C. Reeves

Molecular Research Group, National Institute of Agricultural Botany, Cambridge, CB3 0LE, UK,
E-mail: fiona.leigh@niab.com

The retrotransposon based S-SAP technique has been shown to be a highly informative method for genetic analysis. We have evaluated primers designed from the LTRs of six retrotransposon families in conjunction with a large number of selective MseI primers to evaluate the most informative primer combinations that generate high quality profiles. Following extensive screening, we selected six of these primer combinations from four of the retrotransposon families for wider application. This subset of primer combinations has been used to profile a set of over 500 barley cultivars using the S-SAP technique. The barley cultivars were chosen to represent the barley germplasm cultivated across Europe during the past 50 years. This has allowed us to determine the relationships among and between a range of genotype/germplasm classes at these loci. Thus, our research gives insight into trends and events that have shaped barley breeding programmes over the past 50 years.


 

 

Giving the Right Gene Barley will Germinate on Time

C. D. Li, R. Lance, A. N. Tarr, R. Appeals and M. Cakir

Western Australia Department of Agriculture, South Perth, WA 6151, Australia,
E-mail: cli@agric.wa.gov.au

Pre-harvest sprouting results in significant economic loss for grain industry around the world. Lack of adequate dormancy is the major reason for pre-harvest sprouting in field under wet weather conditions. On the other hand, too much dormancy also has detrimental effect in the malting house. A doubled haploid population, derived from a cross of an Australian barley Chebec and a Canadian Malting barley Harrington, was used to search for gene(s) controlling seed dormancy and pre-harvest sprouting. The population was tested for pre-harvest sprouting under high rainfall condition and tested for seed dormancy under rain-shelter. One major locus was identified on chromosome 5H to control pre-harvest sprouting, which could explain over 70% of the phenotypic variation. The same locus also controls seed dormancy. Comparative genomics approaches were used to identify the candidate gene(s) controlling seed dormancy and pre-harvest sprouting. The barley dormancy/pre-harvest sprouting locus showed high micro-synteny with the terminal end of rice chromosome 3. The rice DNA sequences were annotated and a gene encoding GA20-oxidase was identified as the gene controlling seed dormancy and pre-harvest sprouting. This gene is specifically expressed in the developing and germinating seeds. Different alleles of this gene with various levels of dormancy were cloned and sequenced. Diagnostic molecular markers were developed to distinguish the different alleles of the seed dormancy gene.

 

Identification and Mapping of Disease Resistance-Related DNA Sequences in Barley

Z. Liu, R. M. Biyashev, J. A. Mammadov and M. A. Saghai-Maroof

Department of Crop and Soil Environmental Sciences, Virginia Tech, Blacksburg, VA 24061-0404, USA, E-mail: biyashe@vt.edu

The objective of this study was to identify disease resistance gene analogs (RGAs) from barley based on the use of conserved motifs among cloned disease resistance genes. Over 150 barley RGA clones were generated by using two pairs of degenerate primers designed from nucleotide binding domain (NBD) of several previously cloned disease resistance genes. The resultant RGAs were characterized based on both DNA sequence data and RFLP patterns after Southern hybridization. Representative clones were mapped using NABGMP mapping populations and disease resistance near-isogenuc Imes. Thirteen different barley RGA classes were identified. The encoding amino acids indicated that all these 13 clones, except one, contained continuous open reading frames and had characteristic regions of NBD. RGA-related clones were mapped to all barley chromosomes except chromosome 7. One RGA mapped to chromosome 4 and at least 2 markers mapped to each of the remaining barley chromosomes. Almost all of the RGAs mapped to barley chromosomal regions which previously had been reported to contain known disease resistance factors. DNA sequence comparisons showed that a diverse group of RGAs has been identified.

 

 

Genetic Mapping of Genes Affecting Interactions between Barley
and Pyrenophora teres-Fungus

O. Manninen1, M. Serenius1, N. Mironenko2, O. Afanasenko2 and M. Jalli3

1Department Crops and Biotechnology, MTT Agrifood Research Finland, Plant Production Research Unit,
FIN-31600 Jokioinen, Finland, E-mail: outi.manninen@mtt.fi; 2All-Russian Institute for Plant Protection, St-Petersburgh-Pushkin, 196606
Russia; 3Boreal Plant Breeding Ltd., FIN-31600 Jokioinen, Finland

Net blotch is a common and economically important barley disease worldwide, especially in the temperate and humid production areas. Net blotch is caused by the fungal phytopathogen Pyrenophora teres Drechsler. The most cost-effective and environment-friendly way to control the net blotch disease is by using resistant cultivars. We have used a well known resistance source, the Ethiopian two-row barley line CI 9819, as the donor of resistance in our net blotch resistance mapping progeny. A major resistance gene against net type isolates was located on chromosome 6H, explaining up to 88% of the phenotypic variation of seedling resistance. In addition, several epistatic minor genes were detected on chromosomes 1H, 2H, 3H, 5H and 7H. The effect of the major resistance locus on chromosome 6H has been verified in advanced backcross lines in both greenhouse and field conditions. We also located a major resistance gene against the Finnish spot type isolates on chromosome 5H, explaining up to 84% of the variation in seedling resistance. We are currently aiming to map P. teres avirulence genes corresponding the resistance genes we have earlier mapped in barley. We have crossed P. teres isolates differing in their virulence against the resistance source CI 9819. The single ascospore progeny isolates have been analysed with AFLP markers and a preliminary linkage map has been constructed. Genetic mapping or tagging of avirulence genes with the aid of bulked segregant analysis is ongoing in several net blotch crosses.

 

 

A Technology for Ultra Rapid Mapping of Complex Genomes

A. Masoudi-Nejad1, P. H. Dear2 and R. Waugh1

1Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, UK,
E-mail: rwaugh@scri.sari.ac.uk;
2MRC Laboratory of Molecular Biology,
Cambridge, CB2 2QH, UK

Uncovering the location and order of genes in a genome has fundamentally altered the framework within which biological research is conducted. In humans and model species this has been largely achieved through advances in DNA sequencing chemistry, instrumentation and computational analysis. Though possible in theory now for all organisms, financial realities dictate that for non-models this objective is simply a pipedream. In this project we are extending a generic technology we have pioneered on various species to barley. The approach reduces the cost of locating and ordering genes on genomes to an estimated 0.11% of the current cost of a whole genome shotgun project. This is possible using our current technology, which is based on liquid-handling. However, an attainable challenge is to make the transition to automated solid phase technology, which will further reduce the cost by ca. 90% and slash individual project completion times to a matter of a few weeks. The approach integrates well with other genomic technologies it can be used to greatly accelerate the creation of physical (BAC- or other clone-based) maps, to guide sequencing efforts, or to greatly refine genetic maps and thereby provide, for the first time, a link between high-resolution physical maps and genetically-mapped traits the bridge between genomics and genetics.

 

 

Identification of Marker Trait Associations in a Barley
Four Way Cross

G. L. McMichael1, J. K. Eglinton1, A. R. Barr2 and K. J. Chalmers3

1School of Agriculture and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia, E-mail: gai.mcmichael@adelaide.edu.au;
2Australian Grain Technology, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia; 3Molecular Plant Breeding CRC, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia

Genetic mapping in cereals has been exclusively applied to populations derived from simple crosses.Genetic studies are now beginning to target broader population structures to take advantage of association mapping and whole genome analysis techniques.This paper presents the preliminary results from the genetic analysis of a population of 841 DH lines derived from the complex cross Chieftan/Barque//Manley/VB9104.This cross is a significant departure from typical mapping population structures. The population has been extensively phenotyped for malt quality and adaptation characteristics, through evaluation as a mainstream breeding population within the SA Barley Improvement Program (SABIP). Of the 841 doubled haploid (DH) lines, 837 lines were evaluated in double row trials, with 350 individuals promoted to stage one, 70 individuals to stage two and ten individuals to stage three.One line (WI3408) has subsequently progressed to pilot scale malting and brewing trials, with potential for commercial release.Due to the large size of this population, high throughput technology will be required for the genotyping. There were 290 microsatellite markers (SSRs), 90 of which were EST derived that were selected for the initial parental screening, based on their association with the traits of interest for this population.Of these combined markers, 60% were polymorphic between one or more parents. An initial skeletal map is to be constructed using a minimum of 48 SSRs from the parental screens. The 350 stage one lines will be screened more comprehensively as will the 70 stage two lines and the ten stage three lines respectively. The Gene Flow database will be the method of recording and analysing the data.

 

 

The Multivariate Data Analysis Revolution in Genetics,
Plant Breeding and Biotechnology

L. Munck and B. Moeller

Department of Dairy and Food Science, The Royal Veterinary and Agricultural University,
DK-1958
Frederiksberg C, Denmark, E-mail: lmu@kvl.dk; www.models.kvl.dk

The main focus in biology since the rediscovering of the laws of Mendel 100 years ago has been centered around the gene. This is also reflected in the choice of mathematical equations in genetics and biotechnology focusing on gene effects and sequences by probability calculus. As the classic geneticist Waddington in 1969 pointed out: They say nothing what so ever about the actual phenotypes concerned. Classic statistics is set up for studying populations and has difficulties in characterizing phenotypes as individuums. This is now possible thanks to the computer by the pattern recognition methods of multivariate data analysis using a graphic interface for classification (Principal Component Analysis PCA) and for correlation (Partial Least Squares Regression PLSR). These methods are now extensively used in near infrared screening analyses and in the food and brewing industry. Based on literature and the latest results from our international research group on applied multivariate data analysis and spectroscopy, this review paper aims at proving that multivariate data analysis, now still in an introductory stage, will be able to revolutionise the mutual connections between the genome and phenome aspects of data in genetics, plant breeding and biotechnology. Thus whole spectroscopic fingerprints of the physics and chemistry of barley seeds classified by PCA are differentiating between carbohydrate and regulatory mutants and alleles and can as well be used as specific multivariate selection criteria for improving a multigene quality complex in e.g. malting barley breeding.

 

 

Identification of RAPD Markers Linked to Salt Tolerance
in Cultivated and Wild Barleys

H. Pakniyat1, A. Namayandeh1 and B. P. Forster2

1Department of Crop Production and Plant Breeding, Shiraz University, Shiraz, Iran;
2Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, UK, E-mail: bforst@scri.sari.ac.uk

Randomly amplified polymorphic DNAs (RAPDs) were used to search for markers associated with salt tolerance in barley. Initial screens involved growing 63 cultivated and wild barley genotypes in saline conditions and testing for shoot sodium content along with other physiological traits. From these tests 5 tolerant and 5 non-tolerant genotypes were selected. DNA from the tolerant and non-tolerant genotypes were formed into two contrasting bulks and interrogated using 30 different 10-mer RAPD primers. One primer (P15) produced a band found only in tolerant lines, and additionally produced a smaller product found only in the non-tolerant group. Primer P10 produced a band specific to the tolerant bulk and P22 produced a band specific to the non-tolerant group.

 

Marker-Assisted Selection and Resistance Gene Pyramiding
in Barley

N. Pecchioni2, E. Francia1, D. Barabaschi1, G. Delogu1, J. Ovesna3, L. Kucera3,
J. Vacke3
and V. Sip3

1Experimental Institute for Cereal Research, 29017 Fiorenzuola dArda (PC), Italy,
E-mail: pecchioni.nicola@unimore.it;
2Universit degli Studi di
Modena e Reggio, Facolt di Agraria, 42100 Reggio Emilia, Italy;
3Research
Institute of Crop Production, 161 06 Prague-Ruzyne, Czech Republic

The soil-borne barley yellow mosaic virus complex (BaMMV-BaYMV), the aphid-borne barley yellow dwarf virus (BYDV) and the seed-borne fungus Pyrenophora graminea (leaf stripe) are the most serious diseases for the barley crop in Southern Europe. Moreover, resistance to BaYMV, still not present in Czech Republic, is a target of quarantine breeding for this as well as for other Eastern European countries, and resistance to leaf stripe an increasingly important trait for organic barley crop in Europe. Nevertheless, breeding for multiple diseases encounters several economical and technical problems, and cultivars resistant to all the former diseases are not yet available. In this view, two schemes of marker-assisted selection (MAS) have been followed in winter barley to develop high yielding advanced lines: an assisted pedigree by introducing the two virus resistances, and a gene pyramiding scheme to introduce four loci of resistance two to leaf stripe, and one each to BYDV and BaYMV. STS and SSR markers have been selected for the aim and applied to segregating progenies together with phenotypic selection for agronomic traits. Results of the two MAS processes are here presented, including yield performances of the advanced breeding lines.

 

 

A Gene Mapped to Chromosome 7H in Barley (Hordeum vulgare) Causes Necrotic Leaf Spots and Less Susceptibility to the Pathogen Puccinia hordei

M. Persson, A. Djurle and A. Falk

Department of Plant Biology and Forest Genetics, The Swedish University of Agricultural Sciences,
75007,
Uppsala, Sweden, E-mail: mattias.persson@vbsg.slu.se

Barley plants defense themselves with different reactions such as cell-wall appositions, accumulation of pathogenesis related proteins, production of reactive oxygen species and hypersensitive cell death. In this study we used a mutant line originally made from Bowman-Rph 3, mutated with fast neutrons. The phenotype of the mutant is dark brown spots on the leaves that are visible from the one leaf stage until the old senescent plant. Microscopic analysis reveled autofluorescence in the dark spots. To locate the gene responsible to this dramatic phenotype we used BSA (bulked segregant analysis) in combination with a large number of AFLP (Amplified Fragment Length Polymorphism) primer combinations. PstI enzyme was used instead of EcoRI, due to its methylation sensitivity. To perform a high-resolution genetic mapping a mapping population of 719 mutated F2 plants from the cross Mutant × Proctor were used. As a reference, 12 wildtype F2 plants from the same cross were used. The gene has been mapped to chromosome 7H by the use of AFLP and Proctor-Nudinka mapping populations. The mutant supported growth of the biotrophic barley pathogen Puccinia hordei significantly less than the wildtype. In this study we will investigate resistance qualities to the necrotrophic barley pathogen Bipolaris sorokiniana.

 

 

Small Mapping Crosses and Their Use to Establish a Broad Based QTL Map for Barley

S. J. Rae1, R. Keith1, F. J. Leigh2, A. Mackie3, D. Matthews2, G. Felix3, P. C. Morris3,
P. Donini2
and W. T. B. Thomas1

1Scotish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, UK, E-mail: srae@scri.sari.ac.uk;
2Molecular Research Group, NIAB, Cambridge, CB3 0LE, UK; 3School of Life Sciences, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS, UK

Quantitative traits (QTLs) are identified by selecting and hybridising parental lines that differ in one or more QTL. Thus to examine numerous agronomic traits many different crosses are required: This cross specific nature limits the adoption of marker assisted breeding (MAS) in barley. We propose to maximise the number of cross specific populations thereby enabling the production of one robust, broad based QTL map: We have used 23 small mapping populations of a target size of 20 individuals. These F1 doubled haploid (DH) populations were derived from pairs of crosses made from UK national list trial entries in 1999 and 2000. The populations were grown at two locations (SCRI and NIAB) to account for genotype and environment interactions. Microsatellite markers from the SCRI barley framework map, supplemented with S-SAP markers, have genotyped the 400+ DH lines; facilitating the construction of one combined linkage map. To this marker map we propose to add barley malting quality quantitative traits (found by agronomic and biochemical assessments) from each cross specific population and then to create a combined QTL map from all the populations. It is anticipated such a combined QTL map should provide a tool for MAS and identify more consistent candidate gene regions.

 

 

Genetic Control of Grain Damage in a Spring Barley Mapping Population

R. Rajasekaran, W. T. B. Thomas, A. Wilson, P. E. Lawrence, G. R. Young and R. P. Ellis

Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, UK,
E-mail: wthoma@scri.sari.ac.uk

A genetic map was constructed, using a wide range of DNA-based markers, in a barley mapping population developed to explore the genetic control of traits concerned in grain damage of spring barley cultivars. Quantitative trait loci (QTL) were located for husk skinning, gape between the lemma and palea and splitting of the fused pericarp/testa/aleurone tissues. QTLs for the traits were clustered at loci on chromosomes 1H, 4H, 5H, 6H and 7H along with QTL for grain shape parameters. Historical changes in grain size and shape therefore appear to have resulted in a greater propensity for grain splitting in some modern cultivars. QTL analysis indicates the possibility of transgressive segregation for grain splitting in random inbred lines from the Tankard × Livet population as some Tankard alleles decrease splitting. The breeding of more extreme lines is of potential concern to the malting industry as, without extensive phenotypic assessment of splitting, such lines could potentially be commercialised and thus put malting barley supplies at risk. Our genetic mapping highlights regions of the genome that confer a splitting risk and identifies potential markers for selection against the potential for grain to split. Validation of the markers in a wider range of germplasm will establish their potential value in marker-assisted selection.


Mapping of Resistance Genes to Powdery Mildew in Barley

J. Repkova1, Z. Kyjovska1,3, P. Lizal1, A. Dreiseitl2 and A. Jahoor3

1Department of Genetics and Molecular Biology, Faculty of Sciences, Masaryk University Brno,
611 37
Brno, Czech Republic, E-mail: repkova@sci.muni.cz;
2Agricultural Research Institute Kromeriz, Ltd., 767 01
Kromeriz, Czech Republic; 3Risoe National Laboratory, Roskilde, DK-4000, Denmark

The introduction of fully effective resistance genes from the wild barley Hordeum vulgare ssp. spontaneum (PI354949 and PI466495) into H. vulgare was performed by the cross with the variety Tiffany. Powdery mildew resistance tests on plants of F2 generation revealed the segregation ratio 15:1 in Tiffany × PI354949 and 3 : 1 in Tiffany × PI466495, which indicated presence of 2 and 1 dominant resistance genes, respectively. To identify individual R genes, technology of microsatellite DNA markers and linkage recombination analysis was applied. One of resistance genes to Blumeria graminis f.sp. hordei in PI354949 was determined to be located in Mla locus linked with Bmac0213 and the other on chromosome 1(7H) linked with Bmag0507 (14.0 cM in proximal position). In PI466495, R gene was linked with Bmac0213 (8.4 cM in distal position) and it is also located in Mla locus. The perspective aim of this work is fine-mapping of the promising gene located on 7H chromosome and identification of tightly linked DNA markers for marker assisted selection.

 

Single Nucleotide Polymorphism Mapping of the Barley Genes Involved in Abiotic Stresses

N. Rostoks1, L. Cardle1, S. Mudie1, J. T. Svensson2, H. Walia2, E. M. Rodriguez2,
S. Wanamaker2, P. E. Hedley1, H. Liu1, L. Ramsay1, J. Russell1, T. J. Close2,
D. F. Marshall1
and R. Waugh1
1Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, UK, E-mail: rwaugh@scri.sari.ac.uk; 2Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA

Changes in environmental conditions and need for increased agricultural production require plant varieties tolerant to various abiotic stresses. Recently, numerous genome-wide transcription profiling studies have emerged identifying large number of genes involved in plant response to abiotic stresses. In order to facilitate associations of these genes with known plant traits, the information about genetic map location is crucial. The advent of large-scale EST sequencing projects has provided information about significant proportion of expressed plant genes and, thus, offers an opportunity to identify mappable polymorphisms at the nucleotide sequence level. As an additional benefit, Single Nucleotide Polymorphism (SNP) markers are amenable to automation and high-throughput. Our aim is to identify and characterize SNPs in 1000 barley genes known to be associated with responses to abiotic stress in barley or homologous to such genes in other plant species. The SNPs are discovered by sequencing 3 regions of the genes from the parent lines of Steptoe × Morex, Owb D × Owb R and Lina × HS92 mapping populations. The discovered SNPs are assembled into haplotypes which are mapped in one or several of the mapping populations. The co-localization of the haplotypes and known barley Quantitative Trait Loci (QTL) is investigated. Here we report preliminary results on SNP discovery, mapping and SNP database creation.

 

 

Development of Gene Based Molecular Markers in Barley

J. R. Russell, L. Ramsay, A. Booth, M. MACaulay, L. Cardle, D. F. Marshall,
W. Powell
and R. Waugh

Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, UK,
E-mail: rwaugh@scri.sari.ac.uk

Novel gene based markers have an enormous potential for exploitation in barley. Uses include the dense coverage of the genome in genetic linkage maps through to the development of diagnostic markers for agronomic and quality traits of interest. To date many of the markers used successfully to delineate the barley genome have been based primarily on anonymous DNA sequences, and therefore give little information on the underlying genes that control traits. With the advent of large-scale EST sequencing projects in barley there exists a rapidly expanding database of gene sequences for the cereals, which can be used to develop molecular markers that are associated with genes of interest. In order to construct a highly defined gene map in barley, existing sequences can be mined for slight variations such as single base changes (SNPs), repeat sequence expansion and contraction (SSRs) and insertion and deletion events (indels) or alternatively variants can be discovered from additional sequencing guided by existing information. The resultant sequence-based genetic map will form the basic platform for many applications including candidate gene isolation, marker-assisted selection, genetic diversity studies, molecular taxonomy and association genetics studies. Here we report results of ongoing work on the gene-based marker discovery, mapping and utilisation with emphasis on a number of genes identified in grain development and germination.

 

 

Identification of Barley Semi-Dwarf Gene uzu

D. Saisho1, K. Tanno1, M. Chono2, I. Honda3, H. Kitano4 and K. Takeda1

1Research Institute for Bioresources, Okayama University of Science, Okayama 710-0046, Japan,
E-mail: saisho@rib.okayama-u.ac.jp;
2Department of Wheat and Barley, National Institute of Crop Science, National Agricultural Research Organization, Tsukuba 305-8518, Japan; 3Department of Physiology and Quality Science, National Institute of Vegetables and Tea Science, National Agricultural Research Organization, Ano, Mie 514-2392, Japan, 4Graduate School of Bioagricultural Science, Nagoya University, Nagoya, 464-8601, Japan

Semi-dwarf varieties of cereal crops have contributed to high yield and resistance to lodging. The adaptation of these varieties is well known as the green revolution in rice and wheat since 1960s. In barley, there is a single recessive gene, called uzu, which shows a plant type similar to semi-dwarf varieties of rice and wheat. The uzu lines are distributed only in Far East involving southern part of Japan and Korean peninsula. In 1930s, the majority of cultivars in these regions possessed uzu gene. On the basis of comprehensive morphological and physiological studies, we found that uzu line was insensitive mutant to exogenous brassinolide. The insensitivity was ascribed to single substitution of amino acid residue in the Brassinosteroid insensitive 1 gene homologue (HvBRI1), which completely co-segregated with uzu locus in F2 segregating population. Furthermore, the mutation was commonly observed in more than 250 uzu accessions. We propose that uzu is responsible to mutation in HvBRI1.

 

QTL Analysis in Hordeum bulbosum L. for Interspecific Crossability and Hybrid Formation with Barley

H. Salvo-Garrido, L. Fish, D. A. Laurie and J. W. Snape

John Innes Centre, Norwich Research Park, Colney lane, Norwich, NR4 7UH, UK,
E-mail: john.snape@bbsrc.ac.uke

H. bulbosum is important in barley breeding for haploid production and for the introgression of useful genes. An RFLP map has been created which covers about 90 of the H. bulbosum genome (Salvo-Garrido et al. 2001). The two parents of this mapping population also produce very different results when used as pollinators onto barley. PB1 has high crossability and gives high rates of haploid production; in contrast, PB11 has a lower crossability and gives a high frequency of hybrids. Experiments were carried out to map QTL involved in these different responses. To phenotype the 75 recombinant clones, all were pollinated onto a barley cultivar, Triumph, under controlled environmental conditions. For QTL mapping, MapQTL, version-3 was used. QTLs for crossability were mapped in chromosomes 2Hb, 3Hb, 6Hb and 7H6. A novel QTL promoting hybrid formation, heterozygous in the PB11 parent, was mapped in chromosome 6HA, and explained about 40 of the phenotypic variation for this trait. This QTL would enable more efficient selection of H. bulbosum clones for use in introgressing traits from H. bulbosum into barley. The QTLs for crossability identified will enable the identification of more efficient clones for haploid production by MAS.


 

Identification of Quantitative Trait Loci Controlling Morphological and Physiological Traits, which Are Characteristic between Oriental and Occidental Barley Cultivars (Hordeum vulgare L.)

M. Sameri and T. Komatsuda

Genetic Diversity Department, National Institute of Agrobiological Sciences (NIAS), Tsukuba 305-8602, Japan, E-mail: mohammad@affrc.go.jp

A total of 99 recombinant inbred lines (RILs) derived from a cross of Oriental six-rowed × Occidental two-rowed cultivars were grown during the two seasons 2001 and 2002 to identify quantitative trait loci (QTL) controlling agronomic traits such as spike characters (length, density, grain number, triplet number, awn length), plant height, tiller number and days to heading. The RILs showed wide variations for each trait, showing the wide range of genetic diversification between Oriental and Occidental varieties and segregation in the progenies. The composite interval mapping identified three QTLs affecting plant height, of which one QTL on chromosome 7HL was newly identified in addition to uzu gene and dsp1 gene. For spike length and density one new QTL was identified on chromosome 2HL, which is closely linked to the cleistogamy gene and Fusarium head blight resistance QTL. For heading date one new major QTL was identified on chromosome 5HL at the same interval covering the Sgh2 locus, however lines with the spring parents allele were later heading. This study showed the Oriental × Occidental barley RILs are good resources for discovering of novel genes with agronomic importance.

 

High-Resolution Mapping of Non-Brittle rachis1 (btr1) in Barley

D. V. Saraswathi, P. Azhaguvel and T. Komatsuda

Department of Genetic Diversity, National Institute of Agrobiological Sciences,Tsukuba, Ibaraka 305-8602, Japan, E-mail: yadhan5vid@rediffmail.com

High-resolution mapping has been crucial for success of map-based cloning and precise placement of the gene of interest. Among abundant variations in barley genome, non-brittle rachis is a valuable trait in study of evolution and domestication pattern of barley. AFLP markers around the btr1 locus previously mapped on 3HS chromosome were converted into sequence tagged sites. Converted STS markers were taken for the high-resolution linkage map study. OUH602 is a wild barley line having Btr1 and Btr2 complementary genes, while Kanto Nakate Gold is non-brittle having btr1btr1Btr2Btr2. 672 F2 plants of KNG × OUH602 were raised in the year 20022003. Brittleness was evaluated 24 weeks after maturity. Linkage analysis showed the btr1 locus is flanked between two STS markers at 0.3 cM proximal and 0.5 cM distal. The order of marker loci was the same in F2 population of Azumamugi × Kanto Nakate Gold with 960 plants. The recombinants were self-pollinated to produce F3 lines for further study. The F2 population of OUH602 × KNG showed good separation of the AFLP markers that were previously mapped as clusters in 99 RILs of Azumamugi × Kanto Nakate Gold. This high-resolution linkage map will serve as basis for map-based cloning of non-brittle rachis locus, with the identification of BAC clones spanning the region.

 

 

Retrotransposons as Genomic Sculptors and Molecular
Markers in Barley

A. H. Schulman1,2, R. Kalendar1, O. Manninen2, C. Stuart-Rogers1, J. Tanskanen1
and C. Vicient1,3

1Plant Genomics Laboratory, Institute of Biotechnology, University of Helsinki, FIN-00014 Helsinki, Finland, E-mail: alan.schulman@helsinki.fi; 2Plant Breeding Biotechnology, MTT Agrifood Research Finland, Plant Production Research Unit, FIN-31600 Jokioinen, Finland; 3Currently Departamento
de Genetica Molecular CID, CSIC, E-08034 Barcelona, Spain

Only a minor fraction, 5 to 10% of the barley genome is genic; most of the rest is composed of retrotransposons and their derivatives. The retrotransposon life cycle resembles the intracellular phase of retroviruses, and new copies are integrated into the genome, without excision of existing copies. We are studying the life cycle of elements representing the major classes retrotransposons in the barley genome: BARE-1, Bagy-2, and two major classes of non-autonomous, parasitic elements, TRIMs and LARDs. Because they represent a major share of the genome, cause easily detectable genetic changes having known ancestral and derived states, and contain conserved regions for which PCR primers may be designed, retrotransposon insertions can be exploited as powerful molecular marker systems. We develop and apply four key retrotransposon-based methods: SSAP, IRAP, REMAP, and RBIP. The SSAP, IRAP, and REMAP methods are multiplex and generate anonymous marker bands; RBIP scores individual loci, much as microsatellite-based marker systems do. The methods are variously suited to marker detection on agarose and polyacrylamide slab gels, slab and capillary sequencing devices, and arrays on solid supports. We apply them to marker-assisted breeding, phylogenetic analyses, biodiversity determinations, and evolutionary studies.

 

Physical Mapping and Identification of Candidate Genes
at the Virus Resistance Gene Locus rym4/5

N. Stein1, D. Perovic1, B. Pellio2, J. Kumlehn1, F. Ordon3 and A. Graner1

1Institute of Plant Genetics and Crop Plant Research (IPK), D-06466 Gatersleben, Germany,
E-mail: stein@ipk-gatersleben.de;
2Institute of Crop Science and Plant Breeding I, Giessen University, D-35392 Giessen, Germany;
3Institute of Epidemiology and Resistance, Federal Centre for Breeding Research on Cultivated Plants (BAZ), D-06449 Aschersleben, Germany

In Europe barley yellow mosaic disease is caused by a complex of three different viruses: BaMMV, BaYMV and BaYMV-2. They belong to the bymovirus group- a subclass of the Potiviridae, and are naturally transmitted via the soilborne fungus Polymyxa graminis. A number of recessive resistance genes has been localised on at least 5 independent loci of the barley genome. The two genes rym4 and rym5 reside at the same locus on chromosme 3HL. While rym4 confers resistance to BaMMV and BaYMV, rym5 confers resistance to all three virus strains. In a map based cloning effort, a physical BAC contig of over 450 kb has been established at this locus and sequencing of over 350 kb has been accomplished. 200 kb of this region co-segregating with the gene in over 5,000 meiotic events harbour two genes. One is a strong candidate for rym4/5 based on the BLASTX annotation. In a set of resistant and susceptible accessions several rym4/5-diagnostic non-synonymous SNPs were detected in two exons. Functional complementation of the candidate gene is in progress.

 

 

Molecular Markers and Marker Assisted Selection
in Winter Barley Breeding

V. Sudyova, M. Hudcovicova, L. Klcova and J. Kraic

Division of Applied Genetics and Breeding, Research Institute of Plant Production, 921 68 Piestany, Slovakia, E-mail: sudyova@vurv.sk

Molecular markers linked to BaYMV-1, BaYMV-2, and BaMMV resistance genes ym4 and ym11 was introduced into a winter barley varieties. Acceptors of resistance genes were cultivars Copia and Tiffany. Cultivar Romanze has been used as a donor of ym4 gene and landrace Russia 57 as a gene ym11 donor. Total number of analyzed individuals of F2 progenies was 150. The codominant STS marker MWG838 linked to BaYMV/BaMMV resistance gene ym4 showed a clear differentiation between individuals possessing resistant- and susceptible-linked markers. 37 plants with marker-based genotype ym4ym4 from the crosses Copia × Romanze and Tiffany × Romanze were identified. Calculated values of 2 and probability (P > 0.05) of the observed F2 genotype segregation ratio from the type of crosses indicate that difference between the expected (1:2:1) and observed segregation ratio are not statisticaly significant. Microsatellite marker HVM3 linked to resistance gene ym11 distinguished 30 F2 individuals from the cross Copia × Russia 57. Difference between the expected and observed segregation ratio is not statisticaly significant (23:1 = 2.000, P = 0.1572). New created winter barley lines homozygous at ym4- and ym11-linked marker loci possess with high probability desired resistance genes against BaYMV/BaMMV virus complex. Their effective resistance against virus complex will be further tested.

 

Genetic Analysis of Cleistogamy in Barley

Y. Turuspekov1, Y. Mano2, I. Honda1, Y. Watanabe1 and T. Komatsuda2

1National Institute of Crop Science, Tsukuba 305-8518, Japan,
E-mail: yerlan@affrc.go.jp;
2National Institute of Agrobiological Sciences, Tsukuba 305-8602, Japan

Cleistogamy (CL) in barley could be potentially helpful in resistance to pathogens arising during the flowering time and in restriction of gene flow from genetically modified products. Knowledge of the genetic control of CL can also help better understand important theoretical aspects of biology. In this work we have attempted to study the genetic control of CL using different segregating populations. Using 99 RILs population of Azumamugi × Kanto Nakate Gold, where F1 was chasmogamous (CH), cly1 locus has been mapped on the long arm of chromosome 2H. This locus was co-segregating with AFLP marker e11m19-3 and 3.3 cM proximal to RFLP marker ABC153. Also, mapping analysis of F2 population between Misato Golden and Satsuki Nijo (F1 was CL and in F2 CL dominated over CH with a ratio 3:1) revealed the location of Cly2 locus in the same position of chromosome 2H. In this population, the distances from STS-e11-m19-3 and ABC153 were 1.1 cM and 4.9 cM, respectively. Considering the opposite gene domination in two different mapping populations and that both loci were mapped in the same region, it was concluded that the expression of CL in barley is could be under the control of two closely located genes.

 

 

Genetic and Physical Mapping of Genic Microsatellites
in Barley (Hordeum vulgare L.)

R. K. Varshney1, U. Haehnel1, T. Thiel1, N. Stein1, L. Altschmied1, P. Langridge2 and A. Graner1

1Institute of Plant Genetics and Crop Plant Research (IPK), D-06466 Gatersleben, Germany, E-mail: rajeev@ipk-gatersleben.de; 2University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia

A set of 111,090 barley ESTs (corresponding to 55.9 Mb), generated at IPK, was employed for searching of microsatellites (or simple sequence repeats, SSRs) as a source for the development of SSR markers. With the help of a PERL5 script (MISA, http://pgrc.ipk-gatersleben.de/misa/) 9,564 microsatellites were identified in a total of 8,766 ESTs (SSR-ESTs). Cluster-analysis revealed 2,823 non-redundant SSR-ESTs. From this, a set of 756 primer pairs was designed and as a result, 190 microsatellite (EST-SSRs) loci were placed onto the barley genetic map. These markers show a uniform distribution on all the linkage groups ranging from 22 markers (on 7H) to 36 markers (3H). The polymorphism information content (PIC) for the markers developed ranges from 0.24 to 0.78 with an average of 0.48. Developed markers represent functional class of marker system as they are derived from ESTs (genes). Bioinformatic analyses suggested a putative function for 55.8% (107) markers of which 53.2% (57) SSR-ESTs were assigned to functional categories as per FunCat catalogue of proteins. A total of 74% barley markers showed their transferability in wheat and rye while 41% did so in rice. Furthermore in the direction of physical mapping of barley genome, a PCR-based strategy was established to screen the BAC library with markers. By using this strategy with Morex-BAC library BAC addresses were obtained for a total of 132 mapped EST-SSRs which may provide anchoring points to correlate the barley genetic map with a future physical map. Moreover, eleven groups of markers were recognized on 6 chromosomes of barley which contain one or more BAC clones on which at least two markers of that group representing different genes are located. This analysis leads to the identification of gene-rich regions in barley genome.

 

 

Multi-QTL Mapping of Caryopsis Dormancy and Seedling Desiccation Tolerance of Barley

F. Zhang1,3, G. Chen2, Q. Huang2, O. Orion2, T. Krugman2, T. Fahima2, A. B. Korol2, E. Nevo2
and Y. Gutterman1

1Wyler Department of Dryland Agriculture, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus 84990, Israel; 2Institute of Evolution, University of Haifa,
Haifa 31905, Israel, E-mail: nevo@research.haifa.ac.il;
3Institute of Forestry, Chinese Academy of Forestry, Haidian District, Beijing 100091, P. R. China

The genomic regions controlling caryopsis dormancy and seedling desiccation tolerance were identified with 152 F4 lines derived from a cross between Mona, a Swedish cultivar, and Wadi Qilt, an Israeli wild barley (Hordeum spontaneum). Dormancy, the inability of a viable seed to germinate, and desiccation tolerance, the ability of the desiccated seedlings to revive after rehydration, were characterized by fitting the germination and revival data with growth curves, using three parameters instead of initial scores: minimum, maximum, and speed of germination or revival rate derived by least square method. The genetic map (2040 cM in length) was constructed with Eighty-five genetic markers (SSRs, AFLPs, TSs and Dhn) and the QTL mapping was conducted with MultiQTL package (http://www.multiqtl.com). Seventeen QTLs were detected, and ten out of these affected both dormancy and desiccation tolerance traits. No QTL was identified for germination speed, while six QTLs were for revival speed. More QTLs were for minimum germination than maximum germination, whereas more QTLs were for maximum revival rate than minimum revival rate. Most of the QTLs with strong effects were located on chromosome 4H. Both xeric wild barley and cultivar Mona contributed favorite alleles for caryopsis dormancy and seedling desiccation tolerance. The results revealed that the QTL effects on minimum germination rate underlay the genetic control of caryopsis dormancy, and that the seedling desiccation tolerance was based on the QTL effects on the maximum revival rate and revival speed.