Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
enabled [disable] Abstract
Number of results

Results found: 13

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
|
|
issue 3
283-295
EN
At present two separate nomenclature systems exist for wheat and rye. This paper provides a proposed common catalogue of wheat, rye and triticale resistance gene symbols. More than 130 postulated wheat resistance genes are listed. Over 39 rye and 6 triticale resistance (R) genes have been identified and named. Genes responsible for reaction to powdery mildew and to leaf, stem and yellow rusts are the best-represented group of resistance genes. From the common catalogue it can be concluded that there exists a potential for further transfer of rye resistance genes to wheat and triticale. Many molecular markers can be applied for marker-assisted gene transfer, but the expression of the R genes in the new genetic background of triticale remains to be investigated.
EN
Three approaches to identification of powdery mildew resistance genes in wheat - comparison of reaction patterns based on host-pathogen interaction, chromosomal location of resistance genes by means of genetic and cytogenetic assessment, and molecular identification - are reviewed in this paper. The paper covers publications published mostly in the nineties. The derivation and current status of twenty-five Pm genes in wheat are presented. RAPD, RFLP and STS markers closely linked to some specific resistance genes, from recent reports, are listed. These can be useful to phytopathologists and breeders who are interested in the practical application of wheat powdery mildew resistance genes.
EN
Following completion of Arabidopsis thaliana sequencing projects, multiple resistance gene analogues (RGAs) have been identified. In this work a review of the current state of knowledge available in protein databases and scientific articles is presented. Putative resistance genes were identified by using BLAST searches as well as HMM fingerprints (the latter to infer existence of characteristic domains). The representation of all five classes of putative resistance genes in Col-0 ecotype was examined, along with the statistics on RGAs present on all five chromosomes of Arabidopsis thaliana.
EN
Sequences of two recently cloned genes playing a role in resistance against wheat pathogens (receptor-like kinase Lrk10 and Cre3 genes) were used to search for similarity of cereal clones included in the NCBI database. We found 23 clones with similarity to the Cre3 gene with predicted NBS and LRR domains, and 50 clones with serine/threonine kinase function and similarity to the new receptor-like kinase gene Lrk10 from wheat. In those two groups of clones some conservative nucleotide sequences were identified. Two sequences are identical between the majority of resistance gene candidate clones with a high similarity to Lrk10, and two sequences are identical between the majority of resistance gene candidate clones with similarity to the Cre3 gene.
EN
Current information on barley resistance genes available from scientific papers and on-line databases is summarised. The recent literature contains information on 107 major resistance genes (R genes) against fungal pathogens (excluding powdery mildew), pathogenic viruses and aphids identified in Hordeum vulgare accessions. The highest number of resistance genes was identified against Puccinia hordei, Rhynchosporium secalis, and the viruses BaYMV and BaMMV, with 17, 14 and 13 genes respectively. There is still a lot of confusion regarding symbols for R genes against powdery mildew. Among the 23 loci described to date, two regions Mla and Mlo comprise approximately 31 and 25 alleles. Over 50 R genes have already been localised and over 30 mapped on 7 barley chromosomes. Four barley R genes have been cloned recently: Mlo, Rpg1, Mla1 and Mla6, and their structures (sequences) are available. The paper presents a catalogue of barley resistance gene symbols, their chromosomal location and the list of available DNA markers useful in characterising cultivars and breeding accessions.
EN
Thirty-seven wheat cultivars originating from seven European countries were examined by using sequence tagged site (STS) markers for seven Lr (leaf rust = brown rust) resistance genes against the fungal pathogen of wheat Puccinia recondita f. sp. tritici (Lr9, Lr10, Lr19, Lr24, Lr26 and Lr37). Additionally, 22 accessions with various Lr genes from two germplasm collections were tested. A Scar (sequence-characterized amplified region) marker for Lr24 and a CAPS (Cleaved Amplified Polymorphic Sequence) marker for Lr47 were also used to identify those genes in the wheat accessions. Each marker amplified one specific DNA fragment. Three Lr gene markers were identified in wheat cultivars (Lr10, Lr26 and Lr37). Another four markers (Lr9, Lr19, Lr24 and Lr47) were found in breeding lines carrying leaf rust resistance genes. The results were compared with leaf rust resistance gene postulations made in previous studies, based on multipathotype testing. Markers for Lr10, Lr26 and Lr37 may be useful in marker-assisted breeding.
EN
Sequence tagged site (STS) markers have been developed recently to identify resistance genes in wheat. A number of wild relatives have been used to transfer resistance genes into wheat cultivars. Accessions of wild species of Triticeae: Aegilops longissima (4), Ae. speltoides (6), Ae. tauschii (8), Ae. umbellulata (3), Ae. ventricosa (3), Triticum spelta (2), T. timopheevi (3), T. boeoticum (4) and T. monococcum (1), 34 in total, were examined using PCR-STS markers for resistance genes against Puccinia recondita f.sp. tritici (Lr) and Erysiphe graminis (Pm). Additionally, a set of cv. Thatcher near-isogenic lines conferring resistance genes Lr 1, Lr 9, Lr 10, Lr 24, Lr 28, Lr 35 and Lr 37 were examined with the same procedure. Twenty-two accessions were tested using the inoculation test for resistance to Erysiphe graminis, Puccinia recondita, P. striiformis and P. graminis. The most resistant entries were those of Aegilops speltoides and Triticum timopheevi and among T. boeoticum accession #5353. Markers of all mentioned Lr resistance genes were identified in all corresponding cv. Thatcher near-isogenic lines (except Lr 35 gene marker). The following resistance gene markers were identified in wild Triticeae accessions: Lr 1 in two accessions of Ae. tauschii and one accession of Ae. umbellulata, Lr 9 in one accession of Ae. umbellulata, Lr 10 in one accession of T. spelta, Lr 28 in 11 accessions: Ae. speltoides (4), Ae. umbellulata (2), T. spelta (2) and T. timopheevi (3), Lr 37 in 3 accessions of Ae. ventricosa, Pm 1 in all 34 accessions, Pm 2 in 28 accessions, Pm 3 in all 4 accessions of T. boeoticum, 1 accession of T. spelta and 1 of T. timopheevi, and Pm 13 in 5 out of 6 accessions of Ae. speltoides. Reliability and usefulness of STS markers is discussed.
EN
Three Fusarium species: F. graminearum, F. culmorum and F. cerealis were identified in laboratory cultures and in sporodochia from spikelets of scabby wheat. SCAR (sequence characterized amplified region) primers were used to identify Fusarium species and nivalenol (NIV) and deoxynivalenol (DON) chemotypes within species in laboratory cultures and field collected heads harvested in 2006. Results from PCR analyses confirmed preliminary identifications of species on the basis of examination of macroconidia under a light microscope and identification of cultures on agar media. NIV and DON (3Ac-DON and 15Ac-DON) chemotypes were identified using PCR assay. Among samples and isolates of F. graminearum, the 15Ac-DON chemotype dominated, and among those where F. culmorum was identified, the 3Ac-DON chemotype prevailed. Only 5 of the 41 isolates of F. graminearum tested, displayed the NIV chemotype. An increase in the frequency of F. graminearum and a decrease in the frequency of F. culmorum were found during 1998 to 2006.
EN
Sequence tagged site (STS) markers for eight resistance genes against Puccinia recondita f. sp. tritici were used to screen a set of near-isogenic lines of wheat cv. Thatcher containing in total 40 different Lr genes and their alleles. Polymerase chain reaction (PCR) analysis was carried out by using STS, SCAR and CAPS primers specific for the leaf rust resistance genes Lr1, Lr9, Lr10, Lr19, Lr24, Lr28, Lr37 and Lr47. The STS, CAPS and SCAR markers linked to resistance genes Lr9, Lr10, Lr19, Lr24, Lr37 and Lr47 were found to be reliable in diverse genetic backgrounds. The amplification product of the Lr1 gene marker was detected in the susceptible cv. Thatcher and in all of the near-isogenic lines examined except Lr2a, Lr2b, Lr2c and Lr19. The sequence analysis of PCR products amplified in lines Lr1, Lr10, Lr28 and in cv. Thatcher indicated that the near-isogenic lines and cv. Thatcher contained in the targeted chromosome region an allele that differed from the original alleles corresponding to Lr1/6*Thatcher (TLR621) and susceptible Thatcher (TH621). The amplification product specific to the STS marker of the Lr1 gene was amplified in almost all Thatcher near-isogenic lines and in cv. Thatcher because their alleles possessed primer sequences identical to the original allele TLR621. The marker for the Lr28 resistance gene was identified in line Lr28, carrying gene Lr28, and in 21 other near-isogenic lines. The sequencing of PCR products specific to Lr28 and generated in lines Lr1, Lr10 and Lr28 indicated that the lines Lr1, Lr10 and Lr28 are heterozygous in this region.
EN
The aim of the present study was to detect candidate DNA markers for selected leaf rust resistance genes. A total number of 286 loci in the ?Thatcher' near-isogenic lines carrying resistance gene Lr1, Lr9, Lr10, Lr13, Lr19, Lr21, Lr24, Lr26, Lr28, Lr35, and Lr37 were screened for DNA polymorphism by the PstIAFLP method. A survey with 33 selective primers yielded 16 candidate markers. Further validation studies on cultivars characterized for the presence and absence of selected resistance genes confirmed specificity of markers for Lr24, Lr26 and Lr37. The AFLP-based marker P42-530 was successfully converted into an STS marker. The new marker was linked with the Lr37-specific marker (CslVrga13) at the distance of 1.7 cM. The PstIAFLP method was found to be effective in the identification of DNA changes induced in hexaploid wheat by translocations from Agropyron elongatum, Secale cereale and Aegilops ventricosa.
EN
Thirty doubled haploid (DH) lines of barley derived from F1 of a cross between the six-rowed cultivar Pomo and two-rowed cultivar Maresi were examined for susceptibility to Fusarium seedling blight (SB) and head blight (FHB), measured by mycotoxin (nivalenol) content of kernels. RAPD (random amplified polymorphic DNA) polymorphism was analysed by using 53 decamer primers. Amplification products (APs) were 200 bp up to 2000 bp in size on average 5.7 per primer and the total number of APs was 284, 51.06% of which were polymorphic. Only 32 APs differentiated the examined DH lines ? 19 APs for nivalenol content of kernels and 13 for seedling resistance. DH lines segregated with continuous distribution of resistance to FHB and SB. At the seedling stage all DH lines exhibited lower susceptibility than parental cultivars, but in the adult stage only two lines (MP 2 and MP 7) appeared to be more resistant to FHB, i.e. accumulated in kernels a lower amount of mycotoxin than cultivars Maresi and Pomo.
EN
Barley doubled haploids (DH) were examined for their susceptibility to Fusarium head blight caused by Fusarium culmorum. DH lines were derived from F1 Maresi (two-rowed) ? Pomo (six-rowed) hybrids by the 'H. bulbosum' method. Doubled haploids, parental cultivars and F1 and F2 hybrids were inoculated with Fusarium culmorum (W.G.Sm.) Sacc., isolate KF350 under field conditions. The kernel infection score, number of kernels per ear, kernel weight per ear, 1000-kernel weight, and kernel fractions were recorded in inoculated and control plants. Samples of kernels were analysed for presence of nivalenol and deoxynivalenol. In the inoculated plants a reduction of kernel number, kernel weight per ear, 1000-kernel weight and percentage of plump kernels was observed. Generally, inoculation caused a significant decrease in the kernel fraction > 2.5 mm, and increase in the fractions 2.5-2.2 and < 2.2 mm. This tendency was more visible in 2-rowed than in 6-rowed lines. The nivalenol content of inoculated doubled haploids ranged from 0.16 to 7.61 mg/kg, whereas their deoxynivalenol content ranged from 0.000 to 0.253 mg/kg. Significant relationships between the kernel infection score and nivalenol content, kernel yield per ear, 1000-kernel weight and kernel fraction > 2.5 mm were observed. Transgression effects were noted in some DH lines, in which the reduction of kernel characters was lower than in parental cultivars. Doubled haploids with a positive and negative transgression for nivalenol and deoxynivalenol content were also recorded.
EN
The genetic determination of variability of barley doubled haploid (DH) lines in regard of their susceptibility to Fusarium head blight caused by Fusarium culmorum was studied. The susceptibility was evaluated in a 3-year field experiment on the basis of reduction in yield traits and mycotoxin accumulation in infected kernels. The following traits were analysed in inoculated and control plants: kernel number and weight per ear, 1000-kernel weight, percentage of plump kernels (>2.5 mm), deoxynivalenol (DON) content and nivalenol (NIV) content of kernels. On the basis of the obtained data, heritability coefficient (ratio of genotypic to phenotypic variance) was assesed, and genetic parameters as well as the number of effective factors were estimated. Heritability coefficients calculated from two-way analysis of variance, i.e. regarding the influence of years and year ? genotype interaction, appeared to be exceptionally low and ranged from 5.2% for the reduction in plump kernels to 38.2% for the reduction in 1000-kernel weight. In the case of mycotoxin accumulation about 60% of the observed variability in NIV concentration and 30% in DON concentration resulted from genetic differences among lines. Additive effects of genes were important for all the analysed traits. Significant effects of dominance and dominance ? dominance were observed for 1000-kernel weight and percentage of plump kernels. Moreover, it was found that the observed variability in yield trait reduction resulted from the segregation of 5-6 effective factors, DON content from 4 factors, while NIV content from 5 factors.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.