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1.
W. Cao G. R. Hughes H. Ma Z. Dong 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(4):551-554
The development of Septoria nodorum blotch-resistant cultivars has become a high priority objective for durum wheat breeding programs. Marker-assisted selection
enables breeders to improve selection efficiency. In order to develop markers for resistance to Septoria nodorum blotch, a set of F5 recombinant inbred lines, derived from the crosses Sceptre/3–6, Sceptre/S9–10 and Sceptre/S12–1, was developed based on the
F2-derived family method. Two RAPD markers, designated UBC521650 and RC37510, were detected by bulked segregant analysis and located approximately 15 and 13.1 centiMorgans (cM) from the resistance gene
snbTM, respectively. A SCAR marker was also successfully developed for marker-assisted selection in breeding programs based on
the sequence of the RAPD marker UBC521650. This is the first report of DNA-based markers linked to resistance for Septoria nodorum blotch in durum wheat.
Received: 8 March 2000 / Accepted: 25 June 2000 相似文献
2.
Pawel C Czembor Edward Arseniuk Andrzej Czaplicki Qijiang Song Perry B Cregan Peter P Ueng 《Génome》2003,46(4):546-554
Stagonospora nodorum blotch is an important foliar and glume disease in cereals. Inheritance of resistance in wheat appears to be quantitative. To date, breeding of partially resistant cultivars has been the only effective way to combat this pathogen. The partial resistance components, namely length of incubation period, disease severity, and length of latent period, were evaluated on a population of doubled haploids derived from a cross between the partially resistant Triticum aestivum 'Liwilla' and susceptible Triticum aestivum 'Begra'. Experiments were conducted in a controlled environment and the fifth leaf was examined. Molecular analyses were based on bulked segregant analyses using 240 microsatellite markers. Four QTLs were significantly associated with partial resistance components and were located on chromosomes 2B, 3B, 5B, and 5D. The percentage of phenotypic variance explained by a single QTL ranged from 14 to 21% for incubation period, from 16 to 37% for disease severity, and from 13 to 28% for latent period, 相似文献
3.
Ghaffary SM Robert O Laurent V Lonnet P Margalé E van der Lee TA Visser RG Kema GH 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,123(5):741-754
The ascomycete Mycosphaerella graminicola is the causal agent of septoria tritici blotch (STB), one of the most destructive foliar diseases of bread and durum wheat
globally, particularly in temperate humid areas. A screening of the French bread wheat cultivars Apache and Balance with 30
M. graminicola isolates revealed a pattern of resistant responses that suggested the presence of new genes for STB resistance. Quantitative
trait loci (QTL) analysis of a doubled haploid (DH) population with five M. graminicola isolates in the seedling stage identified four QTLs on chromosomes 3AS, 1BS, 6DS and 7DS, and occasionally on 7DL. The QTL
on chromosome 6DS flanked by SSR markers Xgpw5176 and Xgpw3087 is a novel QTL that now can be designated as Stb18. The QTLs on chromosomes 3AS and 1BS most likely represent Stb6 and Stb11, respectively, and the QTLs on chromosome 7DS are most probably identical with Stb4 and Stb5. However, the QTL identified on chromosome 7DL is expected to be a new Stb gene that still needs further characterization. Multiple isolates were used and show that not all isolates identify all QTLs,
which clearly demonstrates the specificity in the M. graminicola–wheat pathosystem. QTL analyses were performed with various disease parameters. The development of asexual fructifications
(pycnidia) in the characteristic necrotic blotches of STB, designated as parameter P, identified the maximum number of QTLs. All other parameters identified fewer but not different QTLs. The segregation of
multiple QTLs in the Apache/Balance DH population enabled the identification of DH lines with single QTLs and multiple QTL
combinations. Analyses of the marker data of these DH lines clearly demonstrated the positive effect of pyramiding QTLs to
broaden resistance spectra as well as epistatic and additive interactions between these QTLs. Phenotyping of the Apache/Balance
DH population in the field confirmed the presence of the QTLs that were identified in the seedling stage, but Stb18 was inconsistently expressed and might be particularly effective in young plants. In contrast, an additional QTL for STB
resistance was identified on chromosome 2DS that is exclusively and consistently expressed in mature plants over locations
and time, but it was also strongly related with earliness, tallness as well as resistance to Fusarium head blight. Although
to date no Stb gene has been reported on chromosome 2D, the data provide evidence that this QTL is only indirectly related to STB resistance.
This study shows that detailed genetic analysis of contemporary commercial bread wheat cultivars can unveil novel Stb genes that can be readily applied in marker-assisted breeding programs. 相似文献
4.
Tabib Ghaffary SM Faris JD Friesen TL Visser RG van der Lee TA Robert O Kema GH 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(1):125-142
Septoria tritici blotch (STB), caused by the ascomycete Mycosphaerella graminicola, is one of the most devastating foliar diseases of wheat. We screened five synthetic hexaploid wheats (SHs), 13 wheat varieties
that represent the differential set of cultivars and two susceptible checks with a global set of 20 isolates and discovered
exceptionally broad STB resistance in SHs. Subsequent development and analyses of recombinant inbred lines (RILs) from a cross
between the SH M3 and the highly susceptible bread wheat cv. Kulm revealed two novel resistance loci on chromosomes 3D and
5A. The 3D resistance was expressed in the seedling and adult plant stages, and it controlled necrosis (N) and pycnidia (P) development as well as the latency periods of these parameters. This locus, which is closely linked to the microsatellite
marker Xgwm494, was tentatively designated Stb16q and explained from 41 to 71% of the phenotypic variation at seedling stage and 28–31% in mature plants. The resistance locus
on chromosome 5A was specifically expressed in the adult plant stage, associated with SSR marker Xhbg247, explained 12–32% of the variation in disease, was designated Stb17, and is the first unambiguously identified and named QTL for adult plant resistance to M. graminicola. Our results confirm that common wheat progenitors might be a rich source of new Stb resistance genes/QTLs that can be deployed in commercial breeding programs. 相似文献
5.
W. Wicki M. Messmer M. Winzeler P. Stamp J. E. Schmid 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(7-8):1273-1280
This study was carried out to develop an in vitro test for the identification of genotypes resistant to Septoria nodorum blotch. The basis for this project was a previous study in which a crude extract of S. nodorum was used as a selective agent (Keller et al. 1994). It was possible to distinguish resistant and susceptible cultivars in
an in vitro test with zygotic embryos. In our project we wanted to test whether this in vitro test can also be used to detect
resistant and susceptible genotypes in early segregating populations. Specific crosses between eight winter wheat lines showing
contrasting resistance reaction for S. nodorum blotch on leaves and ears were made. The resistance level of both leaf and ear was evaluated after artificial inoculation
in the field for the parental lines, the F1 progenies, as well as for segregating F3 and F4 populations. In addition, this plant material was tested in vitro using methods similar to those described by Keller et al.
(1994), i.e. culturing immature zygotic embryos and mature seeds on selective media. A good agreement between in vitro screening
and field resistance on the ear was found for the parental lines, the F1 and F4 generation but not for the F3 generations. This leads to the conclusion that the in vitro screening might be integrated into wheat breeding programs. Populations
showing a high susceptibility to the pathogen metabolites in vitro could be discarded. Another promising implementation for
wheat breeding would be the screening of advanced breeding material or candidate partners in a crossing program for resistance
on the ear. However, the in vitro screening is not precise enough to select single plants in early segregating populations.
Received: 18 January 1999 / Accepted: 30 April 1999 相似文献
6.
PETER S. SOLOMON ROHAN G. T. LOWE KAR-CHUN TAN ORMONDE D. C. WATERS RICHARD P. OLIVER 《Molecular Plant Pathology》2006,7(3):147-156
Stagonospora nodorum is an important pathogen of wheat and related cereals, causing both a leaf and glume blotch. This review summarizes recent advances in our understanding of taxonomy, control and pathogenicity of this species.
Taxonomy: Stagonospora (syn. Septoria ) nodorum (Berk.) Castell. and Germano [teleomorph: Phaeosphaeria (syn. Leptosphaeria ) nodorum (Müll.) Hedjar.], kingdom Fungi, phylum Ascomycota, subphylum Euascomycota, class Dothideomycetes, order Pleosporales, family Phaeosphaeriaceae, genus Phaeosphaeria , species nodorum .
Host range: Wheat, Triticum aestivum , T. durum , Triticale, are the main hosts but other cereals and wild grasses have been reported to harbour S. nodorum. Disease symptoms are lens-shaped necrotic lesions on leaves, girdling necrosis on stems (especially the nodes, hence ' nodorum ') and lesions on glumes. Mature lesions produce pycnidia scattered throughout the lesions, especially as tissue senesces.
Useful websites: http://ocid.nacse.org/research/deephyphae/htmls/asco_taxlist_spat.html (taxonomic information), http://ohioline.osu.edu/ac-fact/0002.html (disease information), http://wwwacnfp.murdoch.edu.au/ (ACNFP homepage), http://www.broad.mit.edu/annotation/fungi/stagonospora_nodorum/index.html (genome sequence homepage), http://cogeme.ex.ac.uk/efungi/ (genome sequence annotation and analysis). 相似文献
Taxonomy: Stagonospora (syn. Septoria ) nodorum (Berk.) Castell. and Germano [teleomorph: Phaeosphaeria (syn. Leptosphaeria ) nodorum (Müll.) Hedjar.], kingdom Fungi, phylum Ascomycota, subphylum Euascomycota, class Dothideomycetes, order Pleosporales, family Phaeosphaeriaceae, genus Phaeosphaeria , species nodorum .
Host range: Wheat, Triticum aestivum , T. durum , Triticale, are the main hosts but other cereals and wild grasses have been reported to harbour S. nodorum. Disease symptoms are lens-shaped necrotic lesions on leaves, girdling necrosis on stems (especially the nodes, hence ' nodorum ') and lesions on glumes. Mature lesions produce pycnidia scattered throughout the lesions, especially as tissue senesces.
Useful websites: http://ocid.nacse.org/research/deephyphae/htmls/asco_taxlist_spat.html (taxonomic information), http://ohioline.osu.edu/ac-fact/0002.html (disease information), http://wwwacnfp.murdoch.edu.au/ (ACNFP homepage), http://www.broad.mit.edu/annotation/fungi/stagonospora_nodorum/index.html (genome sequence homepage), http://cogeme.ex.ac.uk/efungi/ (genome sequence annotation and analysis). 相似文献
7.
W. Wicki M. Winzeler J. E. Schmid P. Stamp M. Messmer 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(7-8):1265-1272
Sixteen crosses between eight winter wheat cultivars were screened for resistance to Septoria nodorum leaf and glume blotch in the F1 and F4 generations using artificial inoculation in the field. The F1 of most crosses showed dominance for susceptibility on both ear and leaf. The effects of general combining ability were of
similar magnitude as the effects for specific combining ability. On the basis of the phenotypic difference of the parents,
no prediction was possible about the amount and the direction of genetic variance in the segregating populations. The variation
observed in this study both within and among the segregating populations suggests a quantitative inheritance pattern influencing
the expression of the two traits. The components of variance between F2 families within a population were as high as (for S. nodorum blotch on the ear) or higher (for S. nodorum blotch on the leaf) than those between populations. Therefore, strong selection within a few populations may be as effective
to obtain new resistant genotypes as selection in a large number of populations. In almost all crosses, progenies were found
that were more resistant than the better parent. Thus transgression breeding may be a tool to breed for higher levels of resistance
to S. nodorum blotch. Highly resistant genotypes were found even in combination with two susceptible parents. The genetic source for Septoria resistance is probably broader than is generally assumed and could be used to improve S. nodorum resistance by combination breeding followed by strong selection in large populations.
Received: 18 January / Accepted: 30 April 1999 相似文献
8.
Chartrain L Joaquim P Berry ST Arraiano LS Azanza F Brown JK 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,110(6):1138-1144
We report the genetics of resistance of the Portuguese wheat breeding line TE 9111 to septoria tritici blotch (STB), which is caused by Mycosphaerella graminicola. TE 9111 is the most resistant line known in Europe and combines isolate-non-specific, partial resistance with several isolate-specific resistances. We show that, in addition to high levels of partial resistance to STB, TE 9111 has a new gene for resistance to M. graminicola isolate IPO90012, named Stb11, that maps on chromosome 1BS, the Stb6 gene for resistance to isolate IPO323 and, probably, the Stb7 gene for resistance to isolate IPO87019. All of these genes are closely linked to microsatellite markers, which can be used for marker-assisted selection. TE 9111 may therefore be a valuable source of resistance to STB for wheat breeding, especially in Mediterranean environments. 相似文献
9.
Relationship between leaf stages and epistasis for resistance to Stagonospora nodorum in durum wheat
Ten varieties and eight generations (2F1, 2F2, 2B1 and 2B2) of durum wheat derived from two crosses were evaluated for resistance to natural infection by Stagonospora nodorum blotch (SNB) at the 2-3 and 6-7 leaf stages at two sites over two years. There were significant differences in the incidence of SNB between leaf stages in most of the wheat varieties, with resistance being most evident at the 6-7 leaf stage. Separate analyses of the mean values for each generation showed that the genetic mechanism of defense against the pathogen depended upon the leaf stage. At the 2-3 leaf stage, only additive and dominance effects were implicated in the control of SNB for the two crosses at the two sites and for the two replications. For the 6-7 leaf stage, inheritance was more complicated and an epistatic effect was involved. Narrow-sense heritability values (range: 0.63-0.67) were consistent between crosses and leaf stages. These findings indicate a lack of resistance to SNB at the 2-3 leaf stage whereas resistance was observed at the 6-7 leaf stage and involved the genetic mechanisms of plant defense such as epistasis. 相似文献
10.
Using hybrid analysis and test-clone method, 102 accessions of Triticum monococcum L. from the collection of the Vavilov All-Russia Institute of Plant Industry have been studied. This species of wheat has been found to by considerably polymorphic with respect to the resistance to the fungus Erysiphe graminis DC. f. sp. tritici Marchal. causing powdery mildew. The resistance of most accessions to the fungus population and clones is determined by dominant genes. In rare cases, the resistance was determined by recessive genes or one, two, or three oligogenes. A group of einkorn wheat accessions has been found in which the resistance to powdery mildew was determined by the same dominant factor or different but closely linked ones. Recessive resistance genes of T. monococcum differ from the recessive gene pm5 determining the resistance of T. aestivum plants. The genome of T. monococcum contains various genes of resistance to powdery mildew and is a potential source of effective genes to be used when selecting cultivated species of wheat for immunity. 相似文献
11.
Using hybrid analysis and test-clone method, 102 accessions of Triticum monococcum L. from the collection of the Vavilov All-Russia Institute of Plant Industry have been studied. This species of wheat has been found to by considerably polymorphic with respect to the resistance to the fungus Erysiphe graminis DC. f. sp. tritici Marchal. causing powdery mildew. The resistance of most accessions to the fungus population and clones is determined by dominant genes. In rare cases, the resistance was determined by recessive genes or one, two, or three oligogenes. A group of einkorn wheat accessions has been found in which the resistance to powdery mildew was determined by the same dominant factor or different but closely linked ones. Recessive resistance genes of T. monococcum differ from the recessive gene pm5 determining the resistance of T. aestivum plants. The genome of T. monococcum contains various genes of resistance to powdery mildew and is a potential source of effective genes to be used when selecting cultivated species of wheat for immunity. 相似文献
12.
13.
Aguilar V Stamp P Winzeler M Winzeler H Schachermayr G Keller B Zanetti S Messmer MM 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,111(2):325-336
Breeding for wheat varieties resistant to Stagonospora nodorum blotch (SNB) is the most sustainable strategy for controlling the disease. In order to map quantitative trait loci (QTLs) for SNB resistance we analysed 204 recombinant inbred lines of the cross between the winter wheat (Triticum aestivum L.) variety Forno and the winter spelt (Triticum spelta L.) variety Oberkulmer. We determined the level of resistance of adult plants to leaf blotch (SNL) and glume blotch (SNG) as well as morphological traits for 2 years after artificial inoculation with S. nodorum. Using composite interval mapping and LOD > 3.7, we detected ten QTLs for SNG blotch resistance (six inherited from the susceptible parent Forno) and 11 QTLs for SNL resistance (four inherited from Forno) across 2 years. Both resistance traits were moderately correlated (r = 0.52) and had only one common QTL. For SNL resistance, seven QTLs were not associated with QTLs for morphological traits. Among them, QSnl.eth-2D, QSnl.eth-4B and QSnl.eth-7B3 had major effects (R(2) > 13%) and were potential candidates for marker-assisted selection. For SNG, the major QTL on chromosome 5A, explaining 36% of the phenotypic variance for resistance, was associated with the q locus conferring the spelt morphology (long lax ear, long culm and hard glumes). Only QSng.eth-1BS, which explained 7% of the variance for resistance to SNG blotch, was not associated with QTLs for morphological traits. The consequences for breeding programmes are discussed. 相似文献
14.
Wheat samples described in literature as resistant to septoria glume blotch were assessed for their response to inoculation with Septoria nodorum Berk. Three days after inoculation with the infectious agent, samples Klein Titan (k-41772), Mian Jang (k-61568), Walter (k-54585), Reisler (k-59505), Rempart (k-59493), PIN/BOW (k-62838), MN81330 (k-60785), Frondoso (k-46736), Sokrates (k-58179) were classified as resistant to infection. Seven days after inoculation, only samples Reisler and Mian Jang were regarded as resistant. The genetic control of glume blotch resistance was studied by hybridological analysis in sample MN81330. Resistance of this sample manifested in a longer latent period of the disease is controlled by two dominant complementary genes not linked to the gene Lr24 responsible for resistance to brown rust, to the gene responsible for coleoptile coloration, and to minor genes that improve expression of the major ones. 相似文献
15.
Thomas Miedaner Yusheng Zhao Manje Gowda C Friedrich H Longin Viktor Korzun Erhard Ebmeyer Ebrahim Kazman Jochen C Reif 《BMC genomics》2013,14(1)
Background
Septoria tritici blotch is an important leaf disease of European winter wheat. In our survey, we analyzed Septoria tritici blotch resistance in field trials with a large population of 1,055 elite hybrids and their 87 parental lines. Entries were fingerprinted with the 9 k SNP array. The accuracy of prediction of Septoria tritici blotch resistance achieved with different genome-wide mapping approaches was evaluated based on robust cross validation scenarios.Results
Septoria tritici blotch disease severities were normally distributed, with genotypic variation being significantly (P < 0.01) larger than zero. The cross validation study revealed an absence of large effect QTL for additive and dominance effects. Application of genomic selection approaches particularly designed to tackle complex agronomic traits allowed to double the accuracy of prediction of Septoria tritici blotch resistance compared to calculation methods suited to detect QTL with large effects.Conclusions
Our study revealed that Septoria tritici blotch resistance in European winter wheat is controlled by multiple loci with small effect size. This suggests that the currently achieved level of resistance in this collection is likely to be durable, as involvement of a high number of genes in a resistance trait reduces the risk of the resistance to be overcome by specific pathogen isolates or races.Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-14-858) contains supplementary material, which is available to authorized users. 相似文献16.
L. S. Arraiano A. J. Worland C. Ellerbrook J. K. M. Brown 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(5):758-764
Septoria tritici blotch, caused by the fungus Mycosphaerella graminicola,is currently the major foliar disease of wheat world-wide, and new sources of resistance and knowledge about the genetics
of resistance are needed to improve breeding for resistance to this disease. Sears’s ’Synthetic 6x’ hexaploid wheat, derived from a hybrid of Triticum dicoccoides and Triticum tauschii, was resistant to 12 of 13 isolates of M. graminicola tested. Chromosome 7D of ’Synthetic 6x’ was identified as carrying resistance to all 12 isolates in tests of seedlings of inter-varietal chromosome substitution
lines of ’Synthetic 6x’ into ’Chinese Spring’ and to two isolates in tests of adult plants. A septoria tritici blotch resistance gene, named Stb5, was identified using the M. graminicola isolate IPO94269 and mapped on the short arm of chromosome 7D, near the centromere, in a population of single homozygous
chromosome-recombinant lines for the 7D chromosome.
Received: 1 February 2001 / Accepted: 17 April 2001 相似文献
17.
Huyen T. T. Phan Kasia Rybak Stefania Bertazzoni Eiko Furuki Eric Dinglasan Lee T. Hickey Richard P. Oliver Kar-Chun Tan 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2018,131(6):1223-1238
Key message
The fungus Parastagonospora nodorum causes Septoria nodorum blotch (SNB) of wheat. A genetically diverse wheat panel was used to dissect the complexity of SNB and identify novel sources of resistance.Abstract
The fungus Parastagonospora nodorum is the causal agent of Septoria nodorum blotch (SNB) of wheat. The pathosystem is mediated by multiple fungal necrotrophic effector–host sensitivity gene interactions that include SnToxA–Tsn1, SnTox1–Snn1, and SnTox3–Snn3. A P. nodorum strain lacking SnToxA, SnTox1, and SnTox3 (toxa13) retained wild-type-like ability to infect some modern wheat cultivars, suggesting evidence of other effector-mediated susceptibility gene interactions or the lack of host resistance genes. To identify genomic regions harbouring such loci, we examined a panel of 295 historic wheat accessions from the N. I. Vavilov Institute of Plant Genetic Resources in Russia, which is comprised of genetically diverse landraces and breeding lines registered from 1920 to 1990. The wheat panel was subjected to effector bioassays, infection with P. nodorum wild type (SN15) and toxa13. In general, SN15 was more virulent than toxa13. Insensitivity to all three effectors contributed significantly to resistance against SN15, but not toxa13. Genome-wide association studies using phenotypes from SN15 infection detected quantitative trait loci (QTL) on chromosomes 1BS (Snn1), 2DS, 5AS, 5BS (Snn3), 3AL, 4AL, 4BS, and 7AS. For toxa13 infection, a QTL was detected on 5AS (similar to SN15), plus two additional QTL on 2DL and 7DL. Analysis of resistance phenotypes indicated that plant breeders may have inadvertently selected for effector insensitivity from 1940 onwards. We identify accessions that can be used to develop bi-parental mapping populations to characterise resistance-associated alleles for subsequent introgression into modern bread wheat to minimise the impact of SNB.18.
Jemanesh K. Haile Miloudi M. Nachit Karl Hammer Ayele Badebo Marion S. R?der 《Molecular breeding : new strategies in plant improvement》2012,30(3):1479-1493
Stem rust caused by Puccinia graminis f. sp. tritici was historically one of the most destructive diseases of wheat worldwide. The evolution and rapid migration of race TTKSK (Ug99) and derivatives, first detected in Uganda in 1999, are of international concern due to the virulence of these races to widely used stem rust resistance genes. In attempts to identify quantitative trait loci (QTL) linked with resistance to stem rust race Ug99, 95 recombinant inbred lines that were developed from a cross between two durum wheat varieties, Kristal and Sebatel, were evaluated for reaction to stem rust. Seven field trials at two locations were carried out in main and off seasons. In addition to the natural infection, the nursery was also artificially inoculated with urediniospores of stem rust race Ug99 and a mixture of locally collected stem rust urediniospores. A genetic map was constructed based on 207 simple sequence repeat (SSR) and two sequence tagged site loci. Using composite interval mapping, nine QTL for resistance to stem rust were identified on chromosomes 1AL, 2AS, 3BS, 4BL, 5BL, 6AL 7A, 7AL and 7BL. These results suggest that durum wheat resistance to stem rust is oligogenic and that there is potential to identify previously uncharacterized resistance genes with minor effects. The SSR markers that are closely linked to the QTL can be used for marker-assisted selection for stem rust resistance in durum wheat. 相似文献
19.
Olfa Ayed-Slama Imen Bouhaouel Zoubeir Chamekh Youssef Trifa Ali Sahli Nadhira Ben Aissa Hajer Slim-Amara 《Journal of Genetic Engineering and Biotechnology》2018,16(1):161-167
Agriculture has new challenges against the climate change: the preservation of genetic resources and the rapid creation of new varieties better adapted to abiotic stress, specially salinity. In this context, the agronomic performance of 25 durum wheat (Triticum turgidum subsp. durum Desf.) genotypes (nineteen landraces and six improved varieties), cultivated in two semi-arid regions in the center area of Tunisia, were assessed. These sites (Echbika, 2.2?g?l?1; Barrouta, 4.2?g?l?1) differ by their degree of salinity of the water irrigation. The results showed that most of the agronomic traits (e.g. spike per meter square, thousand kernels weight and grain yield) were reduced by salinity. Durum wheat landraces, Mahmoudi and Hmira, and improved varieties, Maali and Om Rabia showed the widest adaptability to different quality of irrigation water. Genotypes including Jneh Kotifa and Arbi were estimated as stable genotypes under adverse conditions. Thereafter, salt-tolerant (Hmira and Jneh Khotifa) and the most cultivated high-yielding (Karim, Razzak and Khiar) genotypes were tested for their gynogenetic ability to obtain haploids and doubled haploid lines. Genotypes with good induction capacity had not necessarily a good capacity of regeneration of haploid plantlets. In our conditions, Hmira and Khiar exhibited the best gynogenetic ability (3.1% and 2.9% of haploid plantlets, respectively). 相似文献
20.
Chromosomal location of a Triticum timopheevii--derived powdery mildew resistance gene transferred to common wheat. 总被引:19,自引:0,他引:19
A dominant powdery mildew resistance gene introduced from Triticum timopheevii in line 146-155-T of common wheat, Triticum aestivum, was located on chromosome 6B by monosomic analysis. Restriction fragment length polymorphism (RFLP) and microsatellite analyses detected the presence of a T. timopheevii segment, translocated to chromosome 6B, with breakpoints between the loci Xpsr8/Xpsr964 on 6BS and Xpsr154/Xpsr546 on 6BL. The novel powdery mildew resistance gene, which has been designated Pm27, was shown to cosegregate with the microsatellite locus Xpsp3131, which is located on the introgressed T. timopheevii segment. The molecular data confirm the location of Pm27 on the translocated 6B chromosome. 相似文献