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1.
A. De Bustos P. Rubio N. Jouve 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(5):733-742
The visco-elastic properties of bread flour are firmly associated with the presence or absence of certain HMW subunits coded
by the Glu-1 genes. Identifying allelic specific molecular markers (AS-PCR) associated with the presence of Glu-1 genes can serve as a valuable tool for the selection of useful genotypes. This paper reports the use of primers designed
from nucleotide sequences of the Glu-D1 gene of wheat (AS-PCR for Glu-D1y10) that recognise and amplify homologous sequences of the Glu-R1 gene subunits of rye. The primers amplify the complete coding regions and provided two products of different size in rye,
in wheats carrying the substitution 1R(1D) and in rye-wheat aneuploid lines carrying the long arm of chromosome 1R. The location,
the molecular characterisation of these sequences and their expression during grain ripening seem to demonstrate that the
amplification products correspond to structural genes encoding the high-molecular-weight (HMW) glutenins of rye. The homology
of the rye gene to subunits encoding HMW glutenins in wheat was confirmed by Southern blots and sequencing. The amplification-products
were cloned, sequenced and characterised, and the sequences compared with the main glutenin subunits of wheat and related
species. Further, an RT-PCR experiment was performed using primers designed from the sequence of both amplified products.
This assay demonstrated that both sequences are expressed in endosperm during grain ripening. The results of these analyses
suggest that both gene subunits correspond to x- and y-type genes of the Glu-R1 locus of rye.
Received: 11 December 2000 / Accepted: 17 April 2001 相似文献
2.
Molecular characterization of a LMW-GS gene located on chromosome 1B and the development of primers specific for the Glu-B3 complex locus in durum wheat 总被引:13,自引:0,他引:13
R. D’Ovidio M. Simeone S. Masci E. Porceddu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(7):1119-1126
Low-molecular-weight glutenin subunits (LMW-GS) represent a specific class of wheat storage proteins encoded at the Glu-3 loci. Particularly interesting are the LMW-GS encoded at the Glu-B3 locus because they have been shown to play an important role in determining the pasta-making properties of durum wheat. Genes
encoding LMW-GS have been characterized but only a few of them have been assigned to specific loci. Notably, no complete LMW-GS
gene encoded at the Glu-B3 locus has yet been described. The present paper reports the isolation and characterization of a lmw-gs gene located at the Glu-B3 locus. The clone involved, designated pLDNLMW1B, contains the entire coding region and 524 bp of the 5′ upstream region.
A nucleotide comparison between the pLDNLMW1B clone and other LMW-GS genes showed the presence of some peculiar structural
characteristics, such as short insertions in the promoter region, the presence of a cysteine codon in the repetitive domain,
and a more regular structure of this region, which could be important for its tissue-specific expression and for the functional
properties of the encoded protein, respectively.
Received : 30 May 1997 / Accepted : 29 July 1997 相似文献
3.
PCR analysis of x- and y-type genes present at the complex Glu-A1 locus in durum and bread wheat 总被引:4,自引:0,他引:4
D. Lafiandra G. F. Tucci A. Pavoni T. Turchetta B. Margiotta 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(2):235-240
Genes (x-type) corresponding to different high-molecular-weight glutenin subunits encoded at the Glu-A1 locus present in bread- and durum-wheat cultivars have been selectively amplified by the polymerase chain reaction (PCR).
DNA fragments corresponding to an unexpressed x-type gene were also amplified. As unexpressed y-type genes may or may not
contain an 8-kb transposon-like insertion, two different sets of primers were designed to obtain amplification of DNA fragments
corresponding to these genes. Amplified DNA fragments were also digested with restriction enzymes. The digestion patterns
of amplified fragments corresponding to unusual x-type subunits showed similarities with genes encoding the most common subunits
2* and 1. The unexpressed amplified x-type gene showed a restriction pattern similar to the one obtained with the allelic gene
encoding high-molecular-weight glutenin subunit 1; homologies were also found within the repetitive region of the linked y-type
genes. On the basis of these observations it is postulated that an ancestral active x-type gene, most likely corresponding
to subunit 1, was silenced following the insertion of the 8-kb transposon-like fragment into the linked y-type gene.
Received: 8 April 1996 / Accepted: 30 August 1996 相似文献
4.
Conservation in wheat high-molecular-weight glutenin gene promoter sequences: comparisons among loci and among alleles of the GLU-B1-1 locus 总被引:2,自引:0,他引:2
O. D. Anderson F. A. Abraham-Pierce A. Tam 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(5):568-576
The high-molecular-weight glutenin (HMW) genes and encoded subunits are known to be critical for wheat quality characteristics
and are among the best-studied cereal research subjects. Two lines of experiments were undertaken to further understand the
structure and high expression levels of the HMW-glutenin gene promoters. Cross hybridizations of clones of the paralogous
x-type and y-type HMW-glutenin genes to a complete set of six genes from a single cultivar showed that each type hybridizes
best within that type. The extent of hybridization was relatively restricted to the coding and immediate flanking DNA sequences.
Additional DNA sequences were determined for four published members of the HMW-glutenin gene family (encoding subunits Ax2*, Bx7, Dx5, and Dy10) and showed that the flanking DNA of the examined genes diverge at approximately −1200 bp 5′ to the start
codon and 200–400 bp 3′ to the stop codon. These divergence sites may indicate the boundaries of sequences important in gene
expression. In addition, promoter sequences were determined for alleles of the Bx gene (Glu-B1-1), a gene reported to show higher levels of expression than other HMW-glutenin genes and with variation among cultivars. The
sequences of Bx promoters from three cultivars and one wild tetraploid wheat indicated that all Bx alleles had few differences
and contained a duplicated portion of the promoter sequence “cereal-box” previously suspected as a factor in higher levels
of expression. Thus, the “cereal-box” duplication preceeded the origin of hexaploid wheat, and provides no evidence to explain
the variations in Bx subunit synthesis levels. One active Bx allele contained a 185-bp insertion that evidently resulted from
a transposition event.
Received: 5 August 1997 / Accepted: 6 November 1997 相似文献
5.
The development of a nuclear male sterility system in wheat. Expression of the barnase gene under the control of tapetum specific promoters 总被引:14,自引:0,他引:14
M. De Block D. Debrouwer T. Moens 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(1-2):125-131
Nuclear male sterility within Triticum aestivum is considered as the ideal basis for the development of a hybridization system for wheat. We engineered nuclear male sterility
in wheat by introducing the barnase gene under the control of tapetum-specific promoters derived from corn and rice. A biolistic-mediated transformation method,
based on the use of the poly(ADP-ribose)polymerase inhibitor niacinamide, was set up which enriched for low-copy integrations
(1–3 copies). Most of these copies were not linked and segregated in the next generation.
Received: 22 January 1997 / 7 February 1997 相似文献
6.
M. Tahir A. Pavoni G. F. Tucci T. Turchetta D. Lafiandra 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(6):654-659
A hexaploid wheat landrace collected from the Baluchistan province of Pakistan was found to possess a novel high-molecular-weight glutenin subunit (HMW-GS). The subunit has a very slow electrophoretic mobility as revealed by SDS-PAGE, and its molecular weight is comparable to that of the highest molecular weight glutenin subunit (2.2 encoded in the D-genome) reported so far in hexaploid wheat varieties and landraces of Japanese origin. Evidence obtained from (PCR) gene amplification studies using the primers specific for Glu-1 loci proved that the gene coding for this novel subunit belongs to the Glu-A1 locus located on the long arm of chromosome 1A. Digestion of the amplified gene (PCR product) with restriction enzymes indicated that the novel gene differs from prevailing Glu-A1 alleles (null, 1 and 2*) by an extra DNA fragment of approximately 600 base pairs. The results also indicated that the novel subunit is most probably a derivative of subunit 2* that has very likely incorporated the 600-bp fragment following a process of unequal crossing over. The present findings were further substantiated by reserved phase high performance liquid chromatography (RP-HPLC) analysis. 相似文献
7.
T. Krugman A. Korol E. Nevo J. W. Snape O. Levy B. Rubin 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):46-51
Chlorotoluron is a selective phenylurea herbicide widely used for broad-leaved and annual grass weed control in cereals. Variation in the response to chlorotoluron (CT) was found in both hexaploid bread wheat (Triticum aestivum L.) and wild tetraploid wheat (Triticum dicoccoides KöRN.). Here, we describe the comparative mapping of the CT resistance gene (Su1) on chromosome 6B in bread and wild wheat using RFLP markers. In bread wheat, mapping was based on 58 F4 single-seed descent (SSD) plants of the cross between a genotype sensitive to chlorotoluron, ‘Chinese Spring’ (CS), and a resistant derivative, the single chromosome substitution line, CS (‘Cappele-Desprez’ 6B) [CS (CAP6B). In T dicoccoides, mapping was based on 37 F2 plants obtained from the cross between the CT-susceptible accession B-7 and the resistant accession B-35. Nine RFLP probes spanning the centromere were chosen for mapping. In bread wheat Su1 was found to be linked to α-Amy-1 (9.84 cM) and Xpsr371 (5.2 cM), both on the long arm of 6B, and Nor2 (2.74 cM) on the short arm. In wild wheat the most probable linkage map was Nor2-Xpsr312-Su1-Pgk2, and the genetic distances between the genes were 24.8cM, 5.3cM, and 6.8cM, respectively. These results along with other published map data indicate that the linear order of the genes is similar to that found in T. aestivum. The results of this study also show that the Su1 gene for differential response to chlorotoluron has evolved prior to the domestication of cultivated wheat and not in response to the development and use of chemicals. 相似文献
8.
X. Shan T. K. Blake L. E. Talbert 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(6-7):1072-1078
Conversion of amplified fragment length polymorphisms (AFLPs) to sequence-specific PCR primers would be useful for many genetic-linkage
applications. We examined 21 wheat nullitetrasomic stocks and five wheat-barley addition lines using 12 and 14 AFLP primer
combinations, respectively. On average, 36.8% of the scored AFLP fragments in the wheat nullitetrasomic stocks and 22.3% in
the wheat-barley addition lines could be mapped to specific chromosomes, providing approximately 461 chromosome-specific AFLP
markers in the wheat nullitetrasomic stocks and 174 in the wheat-barley addition lines. Ten AFLP fragments specific to barley
chromosomes and 16 AFLP fragments specific to wheat 3BS and 4BS chromosome arms were isolated from the polyacrylamide gels,
re-amplified, cloned and sequenced. Primer sets were designed from these sequences. Amplification of wheat and barley genomic
DNA using the barley derived primers revealed that three primer sets amplified DNA from the expected chromosome, five amplified
fragments from all barley chromosomes but not from wheat, one amplified a similar-sized fragment from multiple barley chromosomes
and from wheat, and one gave no amplification. Amplification of wheat genomic DNA using the wheat-derived primer sets revealed
that three primer sets amplified a fragment from the expected chromosome, 11 primer sets amplified a similar-sized fragment
from multiple chromosomes, and two gave no amplification. These experiments indicate that polymorphisms identified by AFLP
are often not transferable to more sequence-specific PCR applications.
Received: 30 June 1998 / Accepted: 26 October 1998 相似文献
9.
Cloning and characterisation of a family of disease resistance gene analogs from wheat and barley 总被引:7,自引:0,他引:7
S. Seah K. Sivasithamparam A. Karakousis E. S. Lagudah 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(5-6):937-945
The most common class of plant disease resistance (R) genes cloned so far belong to the NBS-LRR group which contain nucleotide-binding
sites (NBS) and a leucine-rich repeat (LRR). Specific primer sequences derived from a previously isolated NBS-LRR sequence
at the Cre3 locus, which confers resistance to cereal cyst nematode (CCN) in wheat (Triticum aestivum L.) were used in isolating a family of resistance gene analogs (RGA) through a polymerase chain reaction (PCR) cloning approach.
The cloning, analysis and genetic mapping of a family of RGAs from wheat (cv ‘Chinese Spring’) and barley (Hordeum vulgare L. cvs ‘Chebec’ and ‘Harrington’) are presented. The wheat and barley RGAs contain other conserved motifs present in known
R genes from other plants and share between 55–99% amino acid sequence identity to the NBS-LRR sequence at the Cre3 locus. Phylogenetic analysis of the RGAs with other cloned R genes and RGAs from various plant species indicate that they
belong to a superfamily of NBS-containing genes. Two of the barley derived RGAs were mapped onto loci on chromosomes 2H (2),
5H (7) and 7H (1) using barley doubled haploid (DH) mapping populations. Some of these loci identified are associated with
regions carrying resistance to CCN and corn leaf aphid.
Received: 6 January 1998 / Accepted: 1 April 1998 相似文献
10.
Sequence similarity between allelic Glu-B3 genes related to quality properties of durum wheat 总被引:14,自引:0,他引:14
R. D’Ovidio C. Marchitelli L. Ercoli Cardelli E. Porceddu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(3-4):455-461
Low-molecular-weight glutenin subunits (LMW-GSs) are wheat endosperm proteins mostly encoded by genes located at the Glu-3 loci. These proteins are of particular interest in durum wheat because a correlation between LMW-GSs encoded by genes at
the Glu-B3 locus and the pasta-making quality of durum wheat semolina has been shown. We isolated and characterized two allelic lmw-gs genes located at the Glu-B3 locus and present in durum wheat lines displaying different qualitative properties. The clones pLMW1CL and λLMW3.1 were found
to contain allelic sequences encoding LMW-GSs belonging to the good and poor quality-related groups named LMW-2 and LMW-1,
respectively. The LMW-GSs specified by these genes have very large repetitive domains which are composed of repeats regularly
distributed along the domain. The main difference between these two proteins is an insertion of 13 amino acids within the
repetitive domain which, by itself, seems insufficient to explain the qualitative differences between LMW-2 and LMW-1. These
results further support the hypothesis that the greater amount of LMW-2, rather than sequence peculiarities, accounts for
the better quality observed in durum wheat cultivars possessing these subunits. The characterization of the complete primary
structure of these alleles, other than providing information for an understanding of the structure-function relationship among
LMW-GSs and furnishing basic material for wheat engineering, should also assist in our understanding of the evolutionary relationship
between the different lmw-gs genes.
Received: 8 May 1998 / Accepted: 5 August 1998 相似文献
11.
Development of wheat scab symptoms is delayed in transgenic wheat plants that constitutively express a rice thaumatin-like protein gene 总被引:21,自引:0,他引:21
W. P. Chen P. D. Chen D. J. Liu R. Kynast B. Friebe R. Velazhahan S. Muthukrishnan B. S. Gill 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(5):755-760
The possibility of controlling wheat scab (caused by Fusarium graminearum Schw.) was explored by engineering wheat plants for constitutive expression of pathogenesis-related (PR) protein genes. A
rice thaumatin-like protein (TLP) gene (tlp) and a rice chitinase gene (chi11) were introduced into the spring wheat cultivar ’Bobwhite’ by co-transformation of the plasmids pGL2ubi-tlp (ubiquitin/tlp//CaMV 35S/hpt) and pAHG11 (CaMV 35S/chi11//ubiquitin/bar). The transformation was by biolistic bombardment. Bialaphos was used as the selection reagent. The integration and expression
of the tlp, bar, chi11 and hpt genes were analyzed by Southern, Northern and Western blot analyses. The four transgenes co-segregated in the T1 progeny of the transgenic plant and were localized at the telomeric region of the chromosome 6A long arm by sequential N-banding
and fluorescent in situ hybridization (FISH) using pAHG11 or pGL2ubi-tlp as the probes. Only the transgenes tlp and bar, under the control of the ubiquitin promoter-intron, were expressed. No expression of the chi11 and hpt genes, controlled by the CaMV 35S promoter, was detected in T1 plants. After inoculation with conidia of F. graminearum, the symptoms of scab developed significantly slower in transgenic plants of the T1, T2 and T3 generations expressing the tlp gene than in non-transformed control plants. This is the first report of enhanced resistance to F. graminearum in transgenic wheat plants with constitutive expression of TLP.
Received: 15 December 1998 / Accepted: 30 January 1999 相似文献
12.
M. Helguera I. A. Khan J. Dubcovsky 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(7):1137-1143
The leaf rust resistance gene Lr47 confers resistance to a wide spectrum of leaf rust strains. This gene was recently transferred from chromosome 7 S of Triticum speltoides to chromosome 7 A of hexaploid wheat Triticum aestivum. To facilitate the transfer of Lr47 to commercial varieties, the completely linked restriction fragment length polymorphism (RFLP) locus Xabc465 was converted into a PCR-based marker. Barley clone ABC465 is orthologous to the type-I wheat sucrose synthase gene and primers
were designed for the conserved regions between the two sequences. These conserved primers were used to amplify, clone and
sequence different alleles from T. speltoides and T. aestivum. This sequence information was then used to identify the T. speltoides sequence, detect allele-specific mutations, and design specific primers. Cosegregation of the PCR product of these primers
and the T. speltoides chromosome segment was confirmed in four backcross-populations. To complement this dominant marker, a cleavage amplified polymorphic
sequence (CAPS) was developed for the 7 A allele of Xabc465. This CAPS marker is useful to select homozygous Lr47 plants from F2or backcross-F2 segregating populations, and in combination with the T. speltoides-specific primers is expected to facilitate the deployment of Lr47 in new bread wheat varieties.
Received: 7 June 1999 / Accepted: 30 September 1999 相似文献
13.
Molecular mapping of the wheat powdery mildew resistance gene Pm24 and marker validation for molecular breeding 总被引:23,自引:0,他引:23
X. Q. Huang S. L. K. Hsam F. J. Zeller G. Wenzel V. Mohler 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(3):407-414
Molecular markers were identified in common wheat for the Pm24 locus conferring resistance to different isolates of the powdery mildew pathogen, Erysiphe graminis DM f. sp. tritici (Em. Marchal). Bulked segregant analysis was used to identify amplified fragment length polymorphism (AFLP) markers and microsatellite
markers linked to the gene Pm24 in an F2 progeny from the cross Chinese Spring (susceptible)× Chiyacao (resistant). Two AFLP markers XACA/CTA-407 and XACA/CCG-420, and three microsatellite markers Xgwm106, Xgwm337 and Xgwm458, were mapped in coupling phase to the Pm24 locus. The AFLP marker locus XACA/CTA-407 co-segregated with the Pm24 gene, and XACA/CCG-420 mapped 4.5 cM from this gene. Another AFLP marker locus XAAT/CCA-346 co- segregated in repulsion phase with the Pm24 locus. Pm24 was mapped close to the centromere on the short arm of chromosome 1D, contrary to the previously reported location on chromosome
6D. Pm24 segregated independently of gene Pm22, also located on chromosome 1D. An allele of microsatellite locus Xgwm337 located 2.4±1.2 cM from Pm24 was shown to be diagnostic and therefore potentially useful for pyramiding two or more genes for powdery mildew resistance
in a single genotype.
Received: 25 August 1999 / Accepted: 16 December 1999 相似文献
14.
H. Zhang J. Jia M. D. Gale K. M. Devos 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(1):69-75
A comparative genetic map of Aegilops umbellulata with wheat was constructed using RFLP probes that detect homoeoloci previously mapped in hexaploid bread wheat. All seven
Ae. umbellulata chromosomes display one or more rearrangements relative to wheat. These structural changes are consistent with the sub-terminal
morphology of chromosomes 2 U, 3 U, 6 U and 7 U. Comparison of the chromosomal locations assigned by mapping and those obtained
by hybridization to wheat/Ae. umbellulata single chromosome addition lines verified the composition of the added Ae. umbellulata chromosomes and indicated that no further cytological rearrangements had taken place during the production of the alien-wheat
aneuploid lines. Relationships between Ae. umbellulata and wheat chromosomes were confirmed, based on homoeology of the centromeric regions, for 1 U, 2 U, 3 U, 5 U and 7 U. However,
homoeology of the centromeric regions of 4 U with wheat group-6 chromosomes and of 6 U with wheat group-4 chromosomes was
also confirmed, suggesting that a re-naming of these chromosomes may be pertinent. The consequences of the rearrangements
of the Ae. umbellulata genome relative to wheat for gene introgression are discussed.
Received: 10 July 1997 / Accepted: 19 September 1997 相似文献
15.
M. Helguera I. A. Khan J. Dubcovsky 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(4):625-631
The leaf rust resistance gene Lr47 confers resistance to a wide spectrum of leaf rust strains. This gene was recently transferred from chromosome 7S of Triticum speltoides to chromosome 7A of hexaploid wheat Triticum aestivum. To facilitate the transfer of Lr47 to commercial varieties, the completely linked restriction fragment length polymorphism (RFLP) locus Xabc465 was converted into a PCR-based marker. Barley clone ABC465 is orthologous to the type-I wheat sucrose synthase gene and primers
were designed for the conserved regions between the two sequences. These conserved primers were used to amplify, clone and
sequence different alleles from T. speltoides and T. aestivum. This sequence information was used to identify the T. speltoides sequence, detect allele-specific mutations, and design specific primers. Cosegregation of the PCR product of these primers
and the T. speltoides chromosome segment was confirmed in four backcross-populations. To complement this dominant marker, a cleavage amplified
polymorphic sequence (CAPS) was developed for the 7A allele of Xabc465. This CAPS marker is useful to select homozygous Lr47 plants from F2 or backcross-F2 segregating populations, and in combination with the T- speltoides specific primers is expected to facilitate the deployment of Lr47 in new bread wheat varieties.
Received: 11 October 1999 / Accepted: 30 December 1999 相似文献
16.
S. Rahman Z. Li S. Abrahams D. Abbott R. Appels M. K. Morell 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(1):156-163
A genomic DNA fragment from Triticum tauschii, the donor of the wheat D genome, contains a starch branching enzyme-I (SBE-I) gene spread over 6.5 kb. This gene (designated
wSBE I-D4) encodes an amino acid sequence identical to that determined for the N-terminus of SBE-I from the hexaploid wheat (T. aestivum) endosperm. Cognate cDNA sequences for wSBE I-D4 were isolated from hexaploid wheat by hybridisation screening from an endosperm library and also by PCR. A contiguous sequence
(D4 cDNA) was assembled from the sequence of five overlapping partial cDNAs which spanned wSBE I-D4. D4 cDNA encodes a mature polypeptide of 87 kDa that shows 90% identity to SBE-I amino acid sequences from rice and maize and
contains all the residues considered essential for activity. D4 mRNA has been detected only in the endosperm and is at a maximum concentration mid-way through grain development. The wSBE I-D4 gene consists of 14 exons, similar to the structure for the equivalent gene in rice; the rice gene has a strikingly longer
intron 2. The 3′ end of wSBE I-D4 was used to show that the gene is located on group 7 chromosomes. The sequence upstream of wSBE I-D4 was analysed with respect to conserved motifs.
Received: 14 January 1998 / Accepted: 14 July 1998 相似文献
17.
Y. Weng N. A. Tuleen G. E. Hart 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(3-4):519-527
Extended physical maps of chromosomes 6A, 6B and 6D of common wheat (Triticum aestivum L. em Thell., 2n=6x=42, AABBDD) were constructed with 107 DNA clones and 45 homoeologous group-6 deletion lines. Two-hundred and ten RFLP loci
were mapped, including three orthologous loci with each of 34 clones, two orthologous loci with each of 31 clones, one locus
with 40 clones, two paralogous loci with one clone, and four loci, including three orthologs and one paralog, with one clone.
Fifty five, 74 and 81 loci were mapped in 6A, 6B and 6D, respectively. The linear orders of the mapped orthologous loci in
6A, 6B and 6D appear to be identical and 65 loci were placed on a group-6 consensus physical map. Comparison of the consensus
physical map with eight linkage maps of homoeologous group-6 chromosomes from six Triticeaespecies disclosed that the linear
orders of the loci on the maps are largely, if not entirely, conserved. The relative distributions of loci on the physical
and linkage maps differ markedly, however. On most of the linkage maps, the loci are either distributed relatively evenly
or clustered around the centromere. In contrast, approximately 90% of the loci on the three physical maps are located either
in the distal one-half or the distal two-thirds of the six chromosome arms and most of the loci are clustered in two or three
segments in each chromosome.
Received: 19 April 1999 / Accepted: 28 July 1999 相似文献
18.
M. R. Simón 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(2):310-314
Flag-leaf angle (FLAngle), flag-leaf area (FLarea) and flag-leaf area duration (FLADuration) are important traits in determining
yield in wheat (Triticum aestivum L). Genetic studies on these traits are very few. The objective of this study was to determine the gene action controlling
those traits in four wheat crosses. Six generations were available for each cross: parents (P1 and P2), F1, F2 and backcrosses (BC(F1×P1) and BC(F1×P2)). The joint scaling test described by Mather and Jinks was used to test goodness of fit to eight genetic models. Models including
additivity, dominance and interallelic interactions best fitted the data for the three traits and the four crosses. Additive
effects were most prevalent for FLAngle. They were also significant for FLArea and FLADuration. Dominance and epistatic gene
action were also found, but the degree and direction was both trait- and genotype-specific. Heritabilities values were intermediate.
Genetic progress, although slow, can be expected when selecting for these traits; however, selection would be most effective
if delayed to later generations because of dominance and epistatic effects.
Received: 20 April 1998 / Accepted: 14 July 1998 相似文献
19.
Development of a molecular marker for the adult plant leaf rust resistance gene Lr35 in wheat 总被引:14,自引:0,他引:14
R. Seyfarth C. Feuillet G. Schachermayr M. Winzeler B. Keller 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(3-4):554-560
The objective of this work was to develop a marker for the adult plant leaf rust resistance gene Lr35. The Lr35 gene was originally introgressed into chromosome 2B from Triticum speltoides, a diploid relative of wheat. A segregating population of 96 F
2
plants derived from a cross between the resistant line ThatcherLr35 and the susceptible variety Frisal was analysed. Out of 80 RFLP probes previously mapped on wheat chromosome 2B, 51 detected
a polymorphism between the parents of the cross. Three of them were completely linked with the resistance gene Lr35. The co-segregating probe BCD260 was converted into a PCR-based sequence-tagged-site (STS) marker. A set of 48 different
breeding lines derived from several European breeding programs was tested with the STS marker. None of these lines has a donor
for Lr35 in its pedigree and all of them reacted negatively with the STS marker. As no leaf rust races virulent on Lr35 have been found in different areas of the world, the STS marker for the Lr35 resistance gene is of great value to support the introgression of this gene in combination with other leaf rust (Lr) genes into breeding material by marker-assisted selection.
Received: 14 December 1998 / Accepted: 30 January 1999 相似文献
20.
F. C. Ogbonnaya S. Seah A. Delibes J. Jahier I. López-Braña R. F. Eastwood E. S. Lagudah 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(4):623-629
Bread wheat lines introgressed with Aegilops
ventricosa chromosomes were evaluated for their resistance to the Australian cereal cyst nematode (CCN, Heterodera
avenae) pathotype Ha13. Higher levels of resistance relative to the phenotype of the Cre1 CCN resistance gene in wheat were found in the donor Ae. ventricosa parental lines and chromosome-5Nv substitution or addition lines. The newly identified resistance to pathotype Ha13 on chromosome 5Nv, designated, Cre6, was shown to be independent of the Ae. ventricosa-derived Cre2 gene, effective against several European pathotypes. Another Ae. ventricosa derived gene, Cre5, showed partial resistance to pathotype Ha13. Inhibition of Ha13 female nematode reproduction was ranked in the order Cre6 >Cre1 >CreF≥Cre5. Cre6 was inherited as a single dominant locus. Gene sequences encoding nucleotide-binding sites and leucine-rich repeats (NBS-LRR)
from the Cre3 CCN-pathotype Ha13 resistance locus were used as probes to isolate related sequences from one of the donor Ae. ventricosa parents. Related sequences from Ae. ventricosa (71–73% similarity at the amino-acid level to the Cre3-derived sequences) of chromosome 5Nv origin were identified and served as diagnostic molecular markers for the presence of 5Nv. CCN-susceptible plants, found as variants in some of the purported chromosome 5Nv lines, were also found to be missing the diagnostic 5Nv RFLP markers assayed by the NBS-LRR probe. An alloplasmic chromosome-5Nv addition line with Ae. ventricosa cytoplasm in the wheat cultivar, Moisson, background was particularly variable, with 43% CCN-susceptible plants and a corresponding
loss of the diagnostic chromosome-5 molecular markers.
Received: 26 June 2000 / Accepted: 15 July 2000 相似文献