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1.
Application of marker-assisted selection with RFLP based markers has been constrained by high cost and time requirements in situations involving a large number of plants. RFLP markers mapped on a Harrington/TR306 population have been identified elsewhere as linked to quantitative trait loci (QTL) governing malting quality. The probes ABG610, ABC622, as well as probes for the Nar1, Amy1 and Nar7 were sequenced and locus specific primers developed. These locus specific primers were applied to genomic DNA from both Harrington and TR306. Sequence analysis of the resultant monomorphic fragments revealed sequence divergence for the Xabg610, Xabc622, Amy1 and Nar1 loci, but not for the Nar7 locus. Application of a set of Hor2 primers to genomic DNA from the barley lines Harrington and TR306 led to the direct amplification of codominant alleles. Allele-specific primers were designed based on the sequence divergence identified among the Xabg610, Xabc622 and Nar1 alleles. Amplification conditions were optimized for each of these alleles such that only the favourable allele from Harrington was amplified. The usefulness of these primers for selecting Harrington alleles was demonstrated by their failure to amplify the corresponding alleles from the lines, Sterling, Stella and WM872. The Amy1 allele-specific amplicon was only capable of differentiating this locus between Harrington and TR306. The conversion of these markers into PCR amplifiable, allele-specific amplicons would greatly facilitate their application to barley breeding programs.  相似文献   

2.
Australia and Canada are major exporters of malting barley (Hordeum vulgare L.), with Baudin from Australia and AC Metcalfe from Canada being the benchmark varieties for premium malting quality in the past 10 years. We used the barley doubled haploid population derived from a cross of Baudin and AC Metcalfe to map quantitative trait loci (QTLs) for malting quality. The results revealed different genetic architectures controlling malting quality for the two cultivars. Sixteen QTLs were identified and located on chromosomes 1H, 2H, 5H and 7H. The Australian barley Baudin mainly contributed to the malting quality QTL traits of high diastatic power and high β-glucanase on chromosome 1H, while Canadian barley AC Metcalfe mainly contributed to the QTL traits of high hot water extract, high free amino nitrogen, high α-amylase and low malt yield in chromosome 5HL telomere region. This study demonstrated the potential to breed new barley varieties with superior malting quality by integrating genes from Australian and Canadian malting barley varieties. This paper also provides methods to anchor traditional molecular markers without sequence information, such as amplified fragment length polymorphism markers, into the physical map of barley cv. ‘Morex’.  相似文献   

3.
The terminal region of barley chromosome 5HL controls malt extract, diastatic power, free amino acid nitrogen, alpha-amylase activity, seed dormancy and pre-harvest sprouting. Comparative analysis of the barley and rice maps has established that the terminal region of barley chromosome 5HL is syntenic to rice chromosome 3L near the telomere end. The rice BAC (Bacterial Artificial Chromosome) sequences covering the region of chromosome 3L were used to search barley expressed sequenced tags database. Thirty-three genes were amplified by PCR (polymerase chain reaction) with the primers designed from barley ESTs (expressed sequence tag). Comparison of the sequences of the PCR generated DNA fragments revealed polymorphisms including single nucleotide polymorphism (SNP), insertions or deletions between the barley varieties. Seven new PCR based molecular markers were developed and mapped within 10 cM in three doubled haploid barley populations (Stirling × Harrington, Baudin × AC Metcalfe and Chebec × Harrington). The mapped genes maintain the micro-syntenic relationship between barley and rice. These gene specific markers provide simple and efficient tools for germplasm characterization and marker-assisted selection for barley malting quality, and ultimately lead to isolation and identification of the major gene(s) controlling multiple quality traits on barley chromosome 5HL.  相似文献   

4.
Malting barley is of high economic and scientific importance. Determining barley grains that are suitable for malting involves measuring malting quality, which is an expensive and complex process. In order to decrease the cost of phenotyping and accelerate the process of developing superior malting barley cultivars, markers for marker-assisted breeding are needed. In this study, we identified quantitative trait loci (QTLs) for malting traits in a Stellar/01Ab8219 F6:8 recombinant inbred line population grown at Aberdeen and Tetonia, Idaho, USA in 2009 and 2010. We identified QTLs associated with malt extract (ME), wort protein, soluble/total protein (S/T), diastatic power (DP), alpha-amylase, beta-glucan (BG) and free amino nitrogen (FAN) at a logarithm of odds score ≥2.5 using a high-density genetic map produced by merging Diversity Arrays Technology markers with the current single nucleotide polymorphism map. Novel QTLs were identified for DP and FAN on chromosome 5H, S/T on 6H, and BG and ME on 7H. Dissection of the genetic regions associated with malting traits suggests the involvement of multiple molecular pathways. The resulting molecular markers may prove useful for barley improvement.  相似文献   

5.
Quantitative trait loci (QTLs) associated with grain weight, grain width, kernel hardness and malting quality were mapped in a doubled haploid population derived from two elite Australian malting barley varieties, Navigator and Admiral. A total of 30 QTLs for grain weight, grain width and kernel hardness were identified in three environments, and 63 QTLs were identified for ten malting quality traits in two environments. Three malting quality traits, namely β-amylase, diastatic power and apparent attenuation limit, were mainly controlled by a QTL linked to the Bmy1 gene at the distal end of chromosome 4H encoding a β-amylase enzyme. Six other malting quality traits, namely α-amylase, soluble protein, Kolbach index, free amino-acid nitrogen, wort β-glucan and viscosity, had coincident QTL clustered on chromosomes 1HS, 4HS, 7HS and 7HL, which demonstrated the interdependence of these traits. There was a strong association between these malt quality QTL clusters on chromosomes 1HS and 7HL and the major QTL for kernel hardness, suggesting that the use of this trait to enable early selection for malting quality in breeding programs would be feasible. In contrast, the majority of QTLs for hot-water extract were not coincident with those identified for other malt quality traits, which suggested differences in the mechanism controlling this trait. Novel QTLs have been identified for kernel hardness on chromosomes 2HL and 7HL, hot-water extract on 7HL and wort β-glucan on 6HL, and the resulting markers may be useful for marker-assisted selection in breeding programs.  相似文献   

6.

Key message

An effective approach for the further evolution of QTL markers, may be to create mapping populations for locally adapted gene pools, and to phenotype the studied trait under local conditions.

Abstract

Mapping populations of Polish fodder and malting spring barleys (Hordeum vulgare L.) were used to analyze traits describing short-time drought response at the seedlings stage. High-throughput genotyping (Diversity Array Technology (DArT) markers) and phenotyping techniques were used. The results showed high genetic diversity of the studied populations which allowed the creation of high-density linkage maps. There was also high diversity in the physiological responses of the barleys. Quantitative trait locus (QTL) analysis revealed 18 QTLs for nine physiological traits on all chromosomes except 1H in malting barley and 15 QTLs for five physiological traits on chromosomes 2H, 4H, 5H and 6H in fodder barley. Chromosomes 4H and 5H contained QTLs which explained most of the observed phenotypic variations in both populations. There was a major QTL for net photosynthetic rate in the malting barley located on chromosome 5H and two major QTLs for overall photochemical performance (PI) located on 5H and 7H. One major QTL related to photochemical quenching of chlorophyll fluorescence was located on chromosome 4H in fodder barley. Three QTL regions were common to both mapping populations but the corresponding regions explained different drought-induced traits. One region was for QTLs related to PSII photosynthetic activity stress index in malting barley, and the corresponding region in fodder barley was related to the water content stress index. These results are in accordance with previous studies which showed that different traits were responsible for drought tolerance variations in fodder and malting barleys.  相似文献   

7.
Molecular marker-assisted selection for enhanced yield in malting barley   总被引:1,自引:0,他引:1  
Brewers are reluctant to change malting barley (Hordeum vulgare ssp. vulgare L.) cultivars due to concerns of altered flavor and brewing procedures. The U.S. Pacific Northwest is capable of producing high yielding, high quality malting barley but lacks adapted cultivars with desirable malting characteristics. Our goal was to develop high yielding near isogenic lines that maintain traditional malting quality characteristics by transferring quantitative trait loci (QTL) associated with yield, via molecular marker-assisted backcrossing, from the high yielding cv. Baronesse to the North American two-row malting barley industry standard cv. Harrington. For transfer, we targeted Baronesse chromosome 2HL and 3HL fragments presumed to contain QTL that affect yield. Analysis of genotype and yield data suggests that QTL reside at two regions, one on 2HL (ABG461C-MWG699) and one on 3HL (MWG571A-MWG961). Genotype and yield data indicate that additional Baronesse genome regions are probably involved, but need to be more precisely defined. Based on yield trials conducted over 22 environments and malting analyses from 6 environments, we selected one isogenic line (00-170) that has consistently produced yields equal to Baronesse while maintaining a Harrington-like malting quality profile. We conclude there is sufficient data to warrant experiments testing whether the 2HL and 3HL Baronesse QTL would be effective in increasing the yield of other low yielding barley cultivars.  相似文献   

8.
Aluminium (Al) toxicity is an important limitation to barley (Hordeum vulgare L.) on acid soil. Al-resistant cultivars of barley detoxify Al externally by secreting citrate from the roots. To link the genetics and physiology of Al resistance in barley, genes controlling Al resistance and Al-activated secretion of citrate were mapped. An analysis of Al-induced root growth inhibition from 100 F2 seedlings derived from an Al-resistant cultivar (Murasakimochi) and an Al-sensitive cultivar (Morex) showed that a gene associated with Al resistance is localized on chromosome 4H, tightly linked to microsatellite marker Bmag353. Quantitative trait locus (QTL) analysis from 59 F4 seedlings derived from an F3 plant heterozygous at the region of Al resistance on chromosome 4H showed that a gene responsible for the Al-activated secretion of citrate was also tightly linked to microsatellite marker Bmag353. This QTL explained more than 50% of the phenotypic variation in citrate secretion in this population. These results indicate that the gene controlling Al resistance on barley chromosome 4H is identical to that for Al-activated secretion of citrate and that the secretion of citrate is one of the mechanisms of Al resistance in barley. The identification of the microsatellite marker associated with both Al resistance and citrate secretion provides a valuable tool for marker-assisted selection of Al-resistant lines.  相似文献   

9.
A population comprising 102 doubled haploid lines were produced from a cross between Beka, a barley cultivar widely grown in Spain, and Logan, a north American cultivar with inherently low protein content, a character considered to derive from the cultivar Karl. The intentions were to determine whether low-nitrogen malting barleys could be developed in Spain, and if genetic factors that influenced protein content were similarly expressed in widely diverse environments, i.e. northeastern Spain and eastern Scotland. An extensive map comprising 187 molecular markers was developed. Expressed sequence-tagged-derived markers were used in addition to anonymous simple sequence repeats to determine the potential for identifying candidate genes for quantitative trait loci (QTLs), and 22 such markers were mapped for the first time. There was transgressive segregation for both yield and protein content, and the gene for low protein from Logan was not expressed in the Scottish environment. In 2002, high yield was associated with earlier heading date in Spain, while late heading at the Scottish site was associated with greater lodging and lower thousand-kernel weight. These appeared to be possible pleiotropic effects of a factor detected on chromosome 2H. Using information from a consensus map, it was shown that this locus on 2H was in the region of the photoperiod response gene Eam6. A QTL explaining 18% of the variation in grain protein content was detected on chromosome 5H in a region in which a gene for nitrate reductase was previously observed. No effect on grain protein was associated with chromosome 6H, which has been suggested as the location of the low protein gene from Karl. However, it is likely that Karl contained more than one genetic factor reducing protein, and we postulate that the gene on 6H may have been lost during the breeding of Logan.  相似文献   

10.
Single nucleotide polymorphism (SNP) genotyping is useful for assessing genetic variation in germplasm collections, genetic map development and detection of alien chromosome substitutions. In this study, a diversity analysis using 1,301 SNPs on a set of 37 barley accessions was conducted. This analysis showed a high polymorphism rate between the malting barley cultivar 'Haruna Nijo' and the food barley cultivar 'Akashinriki'. Haruna Nijo and Akashinriki are donors of the barley expressed sequence tag (EST) collections. A doubled haploid (DH) population derived from the cross between Haruna Nijo and Akashinriki was genotyped with 1,448 SNPs. Of these 1,448 SNPs, 734 were polymorphic and distributed on barley linkage groups (chromosomes) as follows: 1H (86), 2H (125), 3H (120), 4H (100), 5H (127), 6H (88) and 7H (88). By using cMAP, we integrated the SNP markers across high-density maps. The SNPs were also used to genotype 98 BC(3)F(4) recombinant chromosome substitution lines (RCSLs) developed from the same cross (Haruna Nijo/Akashinriki). These data were used to create graphical genotypes for each line and thus estimate the location, extent and total number of introgressions from Akashinriki in the Haruna Nijo background. The 35 selected RCSLs sample most of the Akashinriki food barley genome, with only a few missing segments. These resources bring new alleles into the malting barley gene pool from food barley.  相似文献   

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