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1.
Margret Scholz Brigitte Ruge-Wehling Antje Habekuß Otto Schrader Galina Pendinen Kristin Fischer Peter Wehling 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(5):837-849
Barley yellow dwarf virus (BYDV) causes high yield losses in most of the major cereal crops worldwide. A source of very effective
resistance was detected within the tetraploid wild species of Hordeum bulbosum. Interspecific crosses between a resistant H. bulbosum accession and H. vulgare cv. ‘Igri’ were performed to transfer this resistance into cultivated barley. Backcrosses to H. vulgare resulted in offspring which carried a single subterminal introgression of H. bulbosum chromatin on barley chromosome 3HL and proved to be fully resistant to BYDV-PAV, as inferred by ELISA values of zero or close
to zero and lack of BYDV symptoms. Genetic analysis indicated a dominant inheritance of the BYDV-PAV resistance factor, which
we propose to denote Ryd4
Hb
. The identity and effect of Ryd4
Hb
are discussed in relation to other known genes for BYDV resistance or tolerance, as well as the relevance of this gene for
resistance breeding in barley. 相似文献
2.
Riedel C Habekuss A Schliephake E Niks R Broer I Ordon F 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,123(1):69-76
Barley yellow dwarf virus (BYDV) is an economically important pathogen of barley, which may become even more important due to global warming. In barley,
several loci conferring tolerance to BYDV-PAV-ASL-1 are known, e.g. Ryd2, Ryd3 and a quantitative trait locus (QTL) on chromosome 2H. The aim of the present study was to get information whether the level
of tolerance against this isolate of BYDV in barley can be improved by combining these loci. Therefore, a winter and a spring
barley population of doubled haploid (DH) lines were genotyped by molecular markers for the presence of the susceptibility
or the resistance encoding allele at respective loci (Ryd2, Ryd3, QTL on chromosome 2H) and were tested for their level of BYDV-tolerance after inoculation with viruliferous (BYDV-PAV-ASL-1)
aphids in field trials. In DH-lines carrying the combination Ryd2 and Ryd3, a significant reduction of the virus titre was detected as compared to lines carrying only one of these genes. Furthermore,
spring barley DH-lines with this allele combination also showed a significantly higher relative grain yield as compared to
lines carrying only Ryd2 or Ryd3. The QTL on chromosome 2H had only a small effect on the level of tolerance in those lines carrying only Ryd2, or Ryd3 or a combination of both, but the effect in comparison to lines carrying no tolerance allele was significant. Overall, these
results show that the combination of Ryd2 and Ryd3 leads to quantitative resistance against BYDV-PAV instead of tolerance. 相似文献
3.
Niks RE Habekuss A Bekele B Ordon F 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(7):1536-1543
In a mapping population derived from the Ethiopian barley line L94 × Vada, natural infection by barley yellow dwarf virus (BYDV) occurred. While line L94 hardly showed symptoms, Vada was severely affected. The 103 recombinant inbred lines segregated bimodally. The major gene responsible for this resistance mapped to chromosome 6H. We propose to name the locus Ryd3. A subset of recombinant inbred lines, L94, and Vada were planted in a subsequent field test which confirmed the previous field observations. Double antibody sandwich enzyme-linked immunosorbent assays (DAS-ELISA) indicated that the epidemic was due to a combination of the serotypes BYDV-PAV and BYDV-MAV. In the accessions with the least BYDV symptoms no virus was detected, justifying the consideration of the gene as conferring true resistance rather than tolerance to these viruses. In a laboratory/gauze house trial a near-isogenic line carrying the Vada chromosome 6H fragment in an L94 background was affected as much as Vada. The effect of Ryd3 was quantified, and compared with that of the only other known major gene for resistance to BYDV, Ryd2, which is also of Ethiopian origin and is located on chromosome 3H. Both genes seemed to reduce the chance of the viral isolate used in this study to establish infection. In plants in which it became established, the virus concentration reached a similar level as in susceptible accessions, but with less dramatic symptom development. Inoculated plants in which the virus failed to multiply tended to show an increase in the number of ears per plant, resulting in higher grain yield per plant. Ryd3 co-segregates with several PCR-based molecular markers that may serve for marker assisted selection. 相似文献
4.
Molecular breeding for grain yield in barley: an evaluation of QTL effects in a spring barley cross 总被引:8,自引:0,他引:8
H. Zhu G. Briceño R. Dovel P. M. Hayes B. H. Liu C. T. Liu S. E. Ullrich 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(5):772-779
We report results from a breeding strategy designed to accumulate favorable QTL alleles for grain yield identified in the
SteptoeבMorex’ (SM) barley germplasm. Two map lines (SM73 and SM145) from the original mapping population were selected based
on their marker genotype and QTL structure. When crossed, these lines would be expected to produce progeny with most favorable
QTL alleles. One hundred doubled haploid (DH) lines from the F1 hybrid of this cross were genotyped with ten RFLP markers and one morphological marker defining grain yield to monitor QTL
segregation. A subset of 24 lines representing various combinations of putatively favorable and unfavorable QTL alleles, together
with Steptoe, ‘Morex’, SM73, and SM145, were phenotyped for grain yield in five environments. Multiple regression procedures
were used to explore phenotype and genotype relationships. Most target QTLs showed significant effects. However, significance
and magnitude of QTL effects and favorable QTL allele phase varied across environments. All target QTLs showed significant
QTL-by-environment interaction (QTL×E), and the QTL on chromosome 2 expressed alternative favorable QTL alleles in different
environments. Digenic epistatic effects were also detected between some QTL loci. For traits such as grain yield, marker-assisted
selection efforts may be better targeted at determining optimum combinations of QTL alleles rather than pyramiding alleles
detected in a reference mapping population.
Received: 2 June 1998 / Accepted: 17 September 1998 相似文献
5.
Thomas Lüpken Nils Stein Dragan Perovic Antje Habekuß Albrecht Serfling Ilona Krämer Urs Hähnel Burkhard Steuernagel Uwe Scholz Ruvini Ariyadasa Mihaela Martis Klaus Mayer Rients E. Niks Nicholas C. Collins Wolfgang Friedt Frank Ordon 《Molecular breeding : new strategies in plant improvement》2014,33(2):477-488
Barley yellow dwarf disease (BYD) is transmitted by aphids and is caused by different strains of Barley yellow dwarf virus (BYDV) and Cereal yellow dwarf virus (CYDV). Economically it is one of the most important diseases of cereals worldwide. Besides chemical control of the vector, growing of tolerant/resistant cultivars is an effective way of protecting crops against BYD. The Ryd3 gene in barley (Hordeum vulgare L.) confers tolerance to BYDV-PAV and BYDV-MAV and the locus was previously mapped on the short arm of barley chromosome 6H near the centromere. We applied a strategy for high-resolution mapping and marker saturation at the Ryd3 locus by exploiting recent genomic tools available in barley. In a population of 3,210 F2 plants, 14 tightly linked markers were identified, including 10 that co-segregated with Ryd3. The centromeric region where Ryd3 is located suffers suppressed recombination or reduced recombination rate, suggesting potential problems in achieving (1) map-based cloning of Ryd3 and (2) marker selection of the resistance in breeding programmes without the introduction of undesirable traits via linkage drag. 相似文献
6.
S. Kicherer G. Backes U. Walther A. Jahoor 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(6):881-888
The Hordeum vulgare accession ’HOR 1063’ was crossed with the barley cultivar Krona, and 220 doubled haploid lines were produced based on this
cross. A molecular map was constructed based on RFLP markers. Field trials were performed over 2 years and at two locations.
In field trials, resistance to leaf rust by means of artificial infection, heading date, plant height and Kernel weight were
assessed. For leaf rust resistance, 4 QTLs were localised, that explained 96.1% of the genetic variation. One QTL on chromosome
4H confirmed a position found in another genetic background and one mapped to the same position as Rph16 on chromosome 2H. All digenic effects decreased the effects of the respective QTLs. In addition to the denso-locus and the hex-v locus, other QTLs influencing heading date, plant length and kernel weight were found in this cross.
Received: 16 July 1999 / Accepted: 7 September 1999 相似文献
7.
J. -L. Molina-Cano M. Moralejo M. Elía P. Muñoz J. R. Russell A. M. Pérez-Vendrell F. Ciudad J. S. Swanston 《Molecular breeding : new strategies in plant improvement》2007,19(3):275-284
To determine the genetic factors influencing grain β-glucan content, that were effective in a population of two-row barley
grown in very contrasting environments, 102 doubled haploid lines from the cross Beka × Logan were sown at two sites, Lleida
(N.E. Spain) and Dundee (E. Scotland) in 2002. Following harvest, grain samples were assessed for total β-glucan content.
Beka had lower β-glucan content than Logan at both sites but, while there was transgressive segregation among the DH lines,
this was primarily amongst lines with higher β-glucan than Logan. In addition to differences between DH lines, there were
differences between the sites and there was also genotype × site interaction. Three QTLs for β-glucan content were detected
at both sites, but their contribution to β-glucan content was, in all cases, higher at Lleida compared to Dundee. One QTL
was located in the distal end of the long arm of chromosome 1H, in the same region as a gene for UDP-glucose-4-epimerase,
an enzyme known to be involved in the synthesis of cell wall polysaccharides, while another was located in the same area of
chromosome 5H as a genetic factor shown previously, in the same cross, to influence grain protein content. The third was in
the centromeric region of chromosome 7H, close to the gene for naked (hulless) grain. These findings will be important in
designing crosses and devising selection strategies in breeding of both low β-glucan, malting barley and high β-glucan, hulless
barley for human food use. 相似文献
8.
P. Y. Jui T. M. Choo K. M. Ho T. Konishi R. A. Martin 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(5):549-556
A study was conducted on a two-row/six-row cross of barley to (1) determine the yield potential, (2) detect epistasis and
genetic correlations, (3) estimate the heritabilities of six agronomic traits, and (4) study the effect of the V locus on the agronomic traits in the barley cross. The effects of five other marker loci (Re2, s, R, Est1, and Est5) on the six agronomic traits were also studied. One hundred and ninety doubled-haploid (DH) lines were derived from a ‘Leger’/CI9831
cross using the bulbosum method. The DH lines and the two parents were tested for grain yield, test weight, seed weight, plant
height, lodging, and heading/maturity at two locations in Eastern Canada in 1993. Additive×additive epistasis and genetic
correlations were detected for some of the agronomic traits. Many of the heritability estimates were high; however, significant
progress in yield improvement would be difficult to achieve because of a low mean yield of the DH lines. Under the growing
conditions in Eastern Canada, six-row lines outyielded two-row by 20–27%. Six-row lines, however, were associated with low
test weight, low seed weight, and severe lodging. Some two-row lines yielded higher than the two-row parent CI9831, but none
of the six-row lines yielded higher than the six-row parent ‘Leger’. The R, s, and Est5 loci were associated with the six agronomic traits, but the Est1 locus was apparently not associated with the agronomic traits. The effect of the Re2 locus was probably due to its close linkage with the V locus. Further studies are needed to determine if superior six-row lines can be developed from two-row/six-row crosses.
Received: 19 September 1996 / Accepted: 18 October 1996 相似文献
9.
Reinheimer JL Barr AR Eglinton JK 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(6):1267-1274
Spring radiation frost is a major abiotic stress in southern Australia, reducing yield potential and grain quality of barley by damaging sensitive reproductive organs in the latter stages of development. Field-based screening methods were developed, and genetic variation for reproductive frost tolerance was identified. Mapping populations that were segregating for reproductive frost tolerance were screened and significant QTL identified. QTL on chromosome 2HL were identified for frost-induced floret sterility in two different populations at the same genomic location. This QTL was not associated with previously reported developmental or stress-response loci. QTL on chromosome 5HL were identified for frost-induced floret sterility and frost-induced grain damage in all three of the populations studied. The locations of QTL were coincident with previously reported vegetative frost tolerance loci close to the vrn-H1 locus. This locus on chromosome 5HL has now been associated with response to cold stress at both vegetative and reproductive developmental stages in barley. This study will allow reproductive frost tolerance to be seriously pursued as a breeding objective by facilitating a change from difficult phenotypic selection to high-throughput genotypic selection. 相似文献
10.
S. R. Larson K. A. Young A. Cook T. K. Blake V. Raboy 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(1-2):141-146
This study describes the inheritance and linkage map positions of two low phytic acid barley (Hordeum vulgare) mutations, lpa1-1 and lpa2-1, that dramatically reduce grain phytic acid content and increase inorganic seed phosphorus (P). Wide-cross, F2 mapping populations were constructed by mating six-rowed varieties, ‘Steptoe’ and/or ‘Morex’, with two-rowed ‘Harrington’lpa donor lines homozygous for either lpa1-1 or lpa2-1. The barley lpa1-1 mutation showed normal inheritance patterns, whereas a deficiency of homozygous lpa2-1/lpa2-1 F2 plants was observed. We identified a codominant, STS-PCR marker (aMSU21) that cosegregated with lpa1-1 in a population of 41 F2 plants. The aMSU21 marker was then mapped to a locus on barley chromosome 2H, using a North American Barley Genome Mapping
Project (NABGMP) doubled haploid population (‘Harrington’בMorex’). We determined that lpa2-1 is located within a recombination interval of approximately 30 cM between two AFLP markers that were subsequently mapped
to barley chromosome 7H by integration with the same NABGMP population. Recent comparative mapping studies indicate conserved
genetic map orders of several homologous molecular marker loci in maize and the Triticeae species that also show corresponding
linkage to the biochemically similar lpa2 mutations of maize and barley. This observation suggests that barley and maize lpa2 mutations may affect orthologous genes. No such evidence for correspondence of the phenotypically similar lpa1 mutations of barley and maize has been revealed.
Received: 22 September 1997 / Accepted: 2 December 1997 相似文献
11.
12.
H. Zhu L. Gilchrist P. Hayes A. Kleinhofs D. Kudrna Z. Liu L. Prom B. Steffenson T. Toojinda H. Vivar 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(7-8):1221-1232
Fusarium head blight (FHB), an important disease of barley in many areas of the world, causes losses in grain yield and quality. Deoxynivalenol
(DON) mycotoxin residues, produced by the primary pathogen Fusarium graminearum, pose potential health risks. Barley producers may not be able to profitably market FHB-infected barley, even though it has
a low DON level. Three types of FHB resistance have been described in wheat: Type I (penetration), Type II (spread), and Type
III (mycotoxin degradation). We describe putative measures of these three types of resistance in barley. In wheat, the three
resistance mechanisms show quantitative inheritance. Accordingly, to study FHB resistance in barley, we used quantitative
trait locus (QTL) mapping to determine the number, genome location, and effects of QTLs associated with Type-I and -II resistance
and the concentration of DON in the grain. We also mapped QTLs for plant height, heading date, and morphological attributes
of the inflorescence (seeds per inflorescence, inflorescence density, and lateral floret size). QTL analyses were based on
a mapping population of F1-derived doubled-haploid (DH) lines from the cross of the two-rowed genotypes Gobernadora and CMB643, a linkage map constructed
with RFLP marker loci, and field evaluations of the three types of FHB resistance performed in China, Mexico, and two environments
in North Dakota, USA. Resistance QTLs were detected in six of the seven linkage groups. Alternate favorable alleles were found
at the same loci when different inoculation techniques were used to measure Type-I resistance. The largest-effect resistance
QTL (for Type-II resistance) was mapped in the centromeric region of chromosome 2. All but two of the resistance QTLs coincided
with QTLs determining morphological attributes of the inflorescence and/or plant height. Additional experiments are needed
to determine if these coincident QTLs are due to linkage or pleiotropy and to more clearly define the biological basis of
the FHB resistance QTLs. Plant architecture should be considered in FHB resistance breeding efforts, particularly those directed
at resistance QTL introgression and/or pyramiding.
Received: 22 November 1998 / Accepted: 2 June 1999 相似文献
13.
S. Moharramipour H. Tsumuki K. Sato H. Yoshida 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(5):592-596
A set of 150 doubled-haploid (DH) barley (Hordeum vulgare L.) lines derived from the cross of Harrington/TR306 was used to determine the number and chromosomal location of quantitative
trait loci (QTLs) controlling resistance to cereal aphids. The experiments were conducted under natural infestation in the
field during two growing seasons: 1994 and 1995. Aphid resistance was measured by counting the number of aphids per plot.
Counts were made on a weekly basis. Each year at the time of maximum aphid density there was an obvious difference in reaction
between the parental genotypes. The DH lines showed continuous variation for aphid density. Simple interval mapping and simplified
composite interval mapping revealed that the principal QTL determining cereal aphid resistance is on the distal region of
the short arm of chromosome 1. This aphid-resistance QTL is linked with a heading-date QTL. At the time of highest aphid infestation,
this QTL accounted for 31% and 22% of the total variance of aphid density in 1994 and 1995, respectively. A QTL on chromosome
5 was also detected but only by simplified composite interval mapping. However, the largest consistent effect was due to the
QTL on the short arm of chromosome 1. This QTL may be a useful target for marker-assisted selection for adult plant cereal
aphid resistance in barley.
Received: 10 September 1996/Accepted: 11 October 1996 相似文献
14.
T. Toojinda L. H. Broers X. M. Chen P. M. Hayes A. Kleinhofs J. Korte D. Kudrna H. Leung R. F. Line W. Powell L. Ramsay H. Vivar R. Waugh 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(4):580-589
Stripe rust, leaf rust, and Barley Yellow Dwarf Virus (BYDV) are important diseases of barley (Hordeum vulgare L). Using 94 doubled-haploid lines (DH) from the cross of Shyri x Galena, multiple disease phenotype datasets, and a 99-marker
linkage map, we determined the number, genome location, and effects of genes conferring resistance to these diseases. We also
mapped Resistance Gene Analog Polymorphism (RGAP) loci, based on degenerate motifs of cloned disease resistance genes, in
the same population. Leaf rust resistance was determined by a single gene on chromosome 1 (7H). QTLs on chromosomes 2 (2H),
3 (3H), 5 (1H), and 6 (6H) were the principal determinants of resistance to stripe rust. Two- locus QTL interactions were
significant determinants of resistance to this disease. Resistance to the MAV and PAV serotypes of BYDV was determined by
coincident QTLs on chromosomes 1 (7H), 4 (4H), and 5 (1H). QTL interactions were not significant for BYDV resistance. The
associations of molecular markers with qualitative and quantitative disease resistance loci will be a useful information for
marker-assisted selection.
Received: 2 February 1999 / Accepted: 30 December 1999 相似文献
15.
Comparative mapping of the wheat chromosome 5A Vrn-A1 region with rice and its relationship to QTL for flowering time 总被引:3,自引:0,他引:3
R. N. Sarma B. S. Gill T. Sasaki G. Galiba J. Sutka D. A. Laurie J. W. Snape 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(1-2):103-109
The vernalization gene Vrn-A1 on chromosome 5A is the predominant gene determining the spring/winter habit difference in bread wheat. Vrn-A1 was physically mapped using a set of deletion lines which located it to the region of chromosome 5A flanked by deletion breakpoints
0.68 and 0.78. This interval was shown to be homoeologous to a region of rice chromosome 3 that contains the flowering-time
QTL Hd-6, previously mapped in a Nipponbare×Kasalath cross, and FLTQ1, a novel QTL identified by analysis of 78 F3 families derived from a cross of ‘IR20’ב63–83’. Possible relationships between Vrn-A1 and rice QTL are discussed. Analysis of the chromosome 5A deletion lines showed evidence for a second, more proximal flowering-time
effect located between deletion breakpoints 0.56 and 0.64. The proximal part of chromosome 5A is homoeologous to rice chromosome
9, on which two QTL were detected in the ‘IR20ב63–83’ cross. The possible relationship between these effects is also discussed.
Received: 23 December 1997 / Accepted: 12 January 1998 相似文献
16.
Groos C Gay G Perretant MR Gervais L Bernard M Dedryver F Charmet G 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(1):39-47
In many wheat (Triticum aestivum L.) growing areas, pre-harvest sprouting (PHS) may cause important damage, and in particular, it has deleterious effects on
bread-making quality. The relationship between PHS and grain color is well known and could be due either to the pleiotropic
effect of genes controlling red-testa pigmentation (R) or to linkage between these genes and other genes affecting PHS. In the present work, we have studied a population of 194
recombinant inbred lines from the cross between two cultivars, ’Renan’ and ’Récital’, in order to detect QTLs for both PHS
resistance and grain color. The variety ’Renan’ has red kernels and is resistant to PHS, while ’Récital’ has white grain and
is highly susceptible to PHS. A molecular-marker linkage map of this cross was constructed using SSRs, RFLPs and AFLPs. The
population was evaluated over 2 years at Clermont-Ferrand (France). PHS was evaluated on mature spikes under controlled conditions
and red-grain color was measured using a chromameter. Over the 2 years, we detected four QTLs for PHS, all of them being co-localized
with QTLs for grain color. Three of them were located on the long arm of chromosomes 3 A, 3B and 3D, close to the loci where
the genes R and taVp1 were previously mapped. For these three QTLs, the resistance to PHS is due to the allele of the variety ’Renan’. Another
co-located QTL for PHS and grain color was detected on the short arm of chromosome 5 A. The resistance for PHS for this QTL
is due to the allele of ’Récital’.
Received: 13 December 2000 / Accepted: 24 April 2001 相似文献
17.
X. Qi G. Jiang W. Chen R. E. Niks P. Stam P. Lindhout 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(5):877-884
By using a high-density AFLP marker linkage map, six QTLs for partial resistance to barley leaf rust (Puccinia hordei) isolate 1.2.1. have been identified in the RIL offspring of a cross between the partially resistant cultivar ’Vada’ and
the susceptible line L94. Three QTLs were effective at the seedling stage, and five QTLs were effective at the adult plant
stage. To study possible isolate specificity of the resistance, seedlings and adult plants of the 103 RILs from the cross
L94×’Vada’ were also inoculated with another leaf rust isolate, isolate 24. In addition to the two QTLs that were effective
against isolate 1.2.1. at the seedling stage, an additional QTL for seedling resistance to isolate 24 was identified on the
long arm of chromosome 7. Of the eight detected QTLs effective at the adult plant stage, three were effective in both isolates
and five were effective in only one of the two isolates. Only one QTL had a substantial effect at both the seedling and the
adult plant stages. The expression of the other QTLs was developmental-stage specific. The isolate specificity of the QTLs
supports the hypothesis of Parlevliet and Zadoks (1977) that partial resistance may be based on a minor-gene-for-minor-gene
interaction.
Received: 16 February 1999 / Accepted: 20 February 1999 相似文献
18.
Kuchel H Williams KJ Langridge P Eagles HA Jefferies SP 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(8):1029-1041
Grain yield forms one of the key economic drivers behind a successful wheat (Triticum aestivum L.) cropping enterprise and is consequently a major target for wheat breeding programmes. However, due to its complex nature,
little is known regarding the genetic control of grain yield. A doubled-haploid population, comprising 182 individuals, produced
from a cross between two cultivars ‘Trident’ and ‘Molineux’, was used to construct a linkage map based largely on microsatellite
molecular makers. ‘Trident’ represents a lineage of wheat varieties from southern Australia that has achieved consistently
high relative grain yield across a range of environments. In comparison, ‘Molineux’ would be rated as a variety with low to
moderate grain yield. The doubled-haploid population was grown from 2002 to 2005 in replicated field experiments at a range
of environments across the southern Australian wheat belt. In total, grain yield data were recorded for the population at
18 site-year combinations. Grain yield components were also measured at three of these environments. Many loci previously
found to be involved in the control of plant height, rust resistance and ear-emergence were found to influence grain yield
and grain yield components in this population. An additional nine QTL, apparently unrelated to these traits, were also associated
with grain yield. A QTL associated with grain yield on chromosome 1B, with no significant relationship with plant height,
ear-emergence or rust resistance, was detected (LOD ≥2) at eight of the 18 environments. The mean yield, across 18 environments,
of individuals carrying the ‘Molineux’ allele at the 1B locus was 4.8% higher than the mean grain yield of those lines carrying
the ‘Trident’ allele at this locus. Another QTL identified on chromosome 4D was also associated with overall gain yield at
six of the 18 environments. Of the nine grain yield QTL not shown to be associated with plant height, phenology or rust resistance,
two were located near QTL associated with grain yield components. A third QTL, associated with grain yield components at each
of the environments used for testing, was located on chromosome 7D. However, this QTL was not associated with grain yield
at any of the environments. The implications of these findings on marker-assisted selection for grain yield are discussed. 相似文献
19.
F. M. Kirigwi M. Van Ginkel G. Brown-Guedira B. S. Gill G. M. Paulsen A. K. Fritz 《Molecular breeding : new strategies in plant improvement》2007,20(4):401-413
Drought is a major abiotic stress that adversely affects wheat production in many regions of the world. The objective of this
study was to identify quantitative trait loci (QTL) controlling grain yield and yield components under reduced moisture. A
cross between common wheat cultivars ‘Dharwar Dry’ (drought tolerant) and ‘Sitta’ was the source of one hundred twenty-seven
recombinant inbred lines evaluated for two-seasons in a field under differing soil moisture regimes in Ciudad Obregon, Sonora,
Mexico. An SSR/EST-STS marker map was constructed and a grain yield QTL on the proximal region of chromosome 4AL was found
to have a significant impact on performance under reduced moisture. This region was associated with QTL for grain yield, grain
fill rate, spike density, grains m−2, biomass production, biomass production rate, and drought susceptibility index (DSI). Molecular markers associated with these
traits explained 20, 33, 15, 23, 30, 26, and 41% of phenotypic variation, respectively on chromosome 4A. Microsatellite locus
Xwmc89 was associated with all significant QTL covering a 7.7 centiMorgans (cM) region and generally explained the greatest proportion
of phenotypic variation. The alleles associated with enhanced performance under drought stress were contributed by Dharwar
Dry. Microsatellite marker wmc89 may be useful for marker assisted selection to enhance drought tolerance. 相似文献
20.
A. Pan P. M. Hayes F. Chen T. H. H. Chen T. Blake S. Wright I. Karsai Z. Bedö 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,89(7-8):900-910
Winterhardiness in cereals is the consequence of a number of complex and interacting component characters: cold tolerance, vernalization requirement, and photoperiod sensitivity. An understanding of the genetic basis of these component traits should allow for more-effective selection. Genome map-based analyses hold considerable promise for dissecting complex phenotypes. A 74-point linkage map was developed from 100 doubled haploid lines derived from a winter x spring barley cross and used as the basis for quantitative trait locus (QTL) analyses to determine the chromosome location of genes controlling components of winterhardiness. Despite the greater genome coverage provided by the current map, a previously-reported interval on chromosome 7 remains the only region where significant QTL effects for winter survival were detected in this population. QTLs for growth habit and heading date, under 16 h and 24 h light, map to the same region. A QTL for heading date under these photoperiod regimes also maps to chromosome 2. Contrasting alleles at these loci interact in an epistatic fashion. A distinct set of QTLs mapping to chromosomes 1, 2, 3, and 5 determined heading date under 8 h of light. Under field conditions, all QTLs identified under controlled environment conditions were determinants of heading date. Patterns of differential QTL expression, coupled with additive and additive x additive QTL effects, underscore the complexity of winterhardiness. The presence of unique phenotype combinations in the mapping population suggests that coincident QTLs for heading date and winter survival represent the effects of linkage rather than pleiotropy. 相似文献