首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Tritordeum (X Tritordeum Ascherson et Graebner) is a synthetic amphiploid belonging to the Triticeae tribe, which resulted from crosses between Hordeum chilense and wheat. It presents useful agronomic traits that could be transferred to wheat, widening its genetic basis. In situ hybridisation with total genomic DNA from H. chilense and cloned, repetitive DNA sequences (pTa71 and pAs1) probes were used to discriminate the parental origin of all chromosomes, to analyse the chromosome pairing and to identify the chromosomes in pollen mother cells (PMCs) at metaphase I of the tritordeum line HT251 (HchHchDD, 2n = 4x = 28). The H. chilense total genomic DNA and the ribosomal sequence pTa71 probes, allowed the unequivocal discrimination of the 14 chromosomes of Hch genome-origin and the 14 chromosomes of D genome-origin. Chromosome pairing analysis revealed meiotic irregularities such as reduced percentage of PMCs with complete homologous pairing, high frequency of univalents, most of H. chilense-origin and a reduced frequency of intragenomic multivalents from both genomes. The H. chilense genome revealed high meiotic instability. After individual chromosome identification at metaphase I with the pAs1 probe, we found the occurrence of pairing between chromosomes of different homoeology groups. The possible interest of the tetraploid tritordeum in the improvement of other Triticeae species is also discussed.  相似文献   

2.
Summary Hexaploid and octoploid tritordeums and their parents Hordeum chilense and Triticum spp. were screened for resistance to isolates of wheat and barley yellow and brown rusts. All H. chilense lines were highly resistant to both wheat and barley brown rust, few lines were susceptible to wheat yellow rust while susceptibility to barley yellow rust was common. In general the resistance of tritordeum is predominantly contributed by the wheat parent and apparently the genes for resistance in H. chilense are inhibited in their expression by the presence of the wheat genome.Abbreviations WYR wheat yellow rust - WBR wheat brown rust - BYR barley yellow rust - BBR barley brown rust  相似文献   

3.
Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.  相似文献   

4.
Summary Hordeum chilense is a wild barley with high crossability with Triticum, Hordeum and Secale. Its amphiploid with wheat, tritordeum, has potential as a new crop. H. chilense is highly resistant to the powdery mildew diseases of both wheat and barley. Whereas tritordeum is resistant to barley powdery mildew, its reaction to wheat powdery mildew is similar to that of its wheat parent. However H. chilense contributes to a reduced density of mildew colonies. This quantitative resistance of tritordeum is diluted at higher ploidy levels.  相似文献   

5.
D. Rubiales  A. Moral  A. Martín 《Euphytica》2001,122(2):369-372
Septoria leaf blotch and common bunt are important diseases of wheat to which Hordeum vulgare is resistant. Addition lines of H. vulgare in wheat were utilized to determine which H. vulgare chromosomes carry resistance genes. Resistance to septoria leaf blotch was conferred by gene(s) present all over the barley genome, but more strongly by those located on chromosomes 7 and 4. Almost complete resistance to common bunt was conferred by gene(s) present in chromosomes 6 and a slight but significant level of resistance was conferred by chromosome 7. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

6.
×Tritordeum (Ascherson et Graebner, an amphiploid between Triticum turgidum conv. durum and Hordeum chilense), and chromosome substitution lines of tritordeum where chromosomes 2 H ch or 3 H ch H. chilense were replaced with chromosome 2 D of T. aestivum or 3 H v chromosome of H. vulgare, respectively, were used to assess the effect of specific chromosomes on the rachis. ×Tritordeum has brittle rachis while the 2 D(2 H ch) and 3 H v (3 H ch) substitution lines have non-brittle rachis. Both lines also have compact spikes, a character highly desirable for the improvement of tritordeum threshability. Different combinations of 2 D and 3 H v translocations were developed in tritordeum. In this article we present information on the identification and characterisation of all these introgression lines by the fluorescent in situ hybridisation.  相似文献   

7.
Summary Septoria glume blotch, caused by Stagonospora nodorum, is an important disease of wheat (Triticum aestivum). Separate genetic mechanisms were found to control flag leaf and spike resistance. Genes for resistance to S. nodorum were located on different chromosomes in the few wheat cultivars studied. These studies only partially agree on the chromosome locations of gene in wheat for resistance to S. nodorum, and chromosomal arm locations of such genes are not known. The objectives of this study were to determine the chromosome and chromosomal arm locations of genes that significantly influence resistance to S. nodorum in wheat cultivar Cotipora. Monosomic analysis showed that flag leaf resistance was controlled by genes on chromosomes 3A, 4A, and 3B whereas the spike resistance was controlled by genes on chromosomes 3A, 4A, 7A, and 3B (P=0.01). Additionally, genes on chromosomes 6B and 5A influenced the susceptibility of the flag leaf and spike reactions, respectively (P=0.01). Telocentric analysis showed that genes on both arms of chromosome 3A, and the long arms of chromosomes 4A and 3B were involved in the flag leaf resistance whereas genes on both arms of chromosome 4A, the short arm of chromosome 3A, and the long arm of chromosome 3B conferred spike resistance.  相似文献   

8.
Wheat/Hordeum chilense disomic addition lines have been used to locate genes influencing resistance against greenbug (Schizaphis graminum Rond.) in specific chromosomes of H. chilense. H. chilense is a source of antixenosis, antibiosis and host tolerance to the greenbug, being resistant also to the Russian wheat aphid, the two key pests in wheat. For measuring antixenosis, the numbers of aphids per plant were recorded in a host free choice test; antibiotic resistance was determined by measuring the developmental time, the fecundity and the intrinsic rate of population increase of aphids reared on the different hosts, and host tolerance to aphids was evaluated by the leaf damage and the number of expanded leaves on the hosts after 3 weeks of infestation. The greenbugs belonged to a clone of biotype C. Plant genes with positive effects for antixenosis were located on chromosome 1Hch. Genes with positive effects for antibiosis were located on three different chromosomes and those that prolonged aphid developmental time were located on chromosomes 5Hch and 7Hch while those that reduced the total fecundity were on 4Hch. Chromosome 7Hch accounted for host tolerance to greenbug.  相似文献   

9.
A partial genetic linkage map was constructed on 71 doubled-haploid lines derived from a cross between the barley lines Tadmor and WI2291 with 181 molecular markers. The segregating population was used to detect markers linked to the gene Mlg conferring resistance to powdery mildew (Erysiphe graminis f. sp. hordei) and to genes for quantitative resistance to scald (Rhynchosporium secalis). The gene Mlg on chromosome 4H was flanked by two AFLP markers at a distance of 2.0 and 2.4 cM, respectively. QTLs for resistance to scald were detected on chromosomes 2H and 3H. This association of molecular markers with qualitative and quantitative disease resistance loci represents a valuable starting-point for marker-assisted selection. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

10.
Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.  相似文献   

11.
Summary Four newly detected accessions of wild barley (Hordeum vulgare ssp. spontaneum) resistant to powdery mildew caused by Blumeria graminis f. sp. hordei were studied with the aim of finding the number of genes/loci conferring the resistance of individual accessions, the type of inheritance of the genes and their relationships to the Mla locus. F2 populations after crosses between the winter variety ‘Tiffany’ and four wild barley accessions and use of microsatellite DNA markers were focused on the identification of individual resistance genes/loci by means of their chromosomal locations. In PI466495, one locus conferring powdery mildew resistance was identified in highly significant linkage with the marker Bmac0213. This location is consistent with the known locus Mla on chromosome 1HS. In the other three accessions the resistance was determined by two independent loci. In PI466197, PI466297 and PI466461, one locus was identified on chromosome 1HS and three new loci were revealed on chromosomes 2HS (highly significant linkage with Bmac0134), 7HS (highly significant linkage with Bmag0021) and 7HL (significant linkage with EBmac0755). Our prospective aim is identification of further linked DNA markers and the exact location of the resistance genes on the barley chromosomes.  相似文献   

12.
RAPD markers were developed for octoploid X Tritordeum (amphiploid Hordeum chilense × Triticum aestivum) and its parents. Two bread wheats, two H. chilense accessions and the two tritordeums synthesized with them were used. A total of 41 arbitrary decamer primers were tested, yielding 190 products that could be assigned to wheat, 185 to H. chilense and 108 that were nonspecific (present in wheat and barley). A total of 44 products were specific to one H. chilense line and 33 to the other 16 of the former were located on the chromosomes using a set of H. chilense in T. aestivum addition lines. The potential of RAPDs for developing addition lines or the detection of introgressions of H. chilense in bread wheat is discussed.  相似文献   

13.
A population of 103 recombinant inbred lines (RILs, F9-derived lines) developed from the two-row spring barley cross L94 × ‘Vada’ was evaluated under field conditions for resistance against powdery mildew (Blumeria graminis f.sp. hordei) and scald (Rhynchosporium secalis). Apart from the major resistance gene mlo on chromosome 4 (4H), three QTLs (Rbgq1, Rbgq2 and Rbgq3) for resistance against powdery mildew were detected on chromosomes 2 (2H), 3 (3H), and 7 (5H), respectively. Rbgq1 and Rbgq2 have not been reported before, and did not map to a chromosome region where a major gene for powdery mildew had been reported. Four QTLs (Rrsq1, Rrsq2, Rrsq3 and Rrsq4) for resistance against scald were detected on chromosomes 3 (3H), 4 (4H) and 6 (6H). All four mapped to places where QTLs for scald resistance had been reported before in different populations.  相似文献   

14.
Molecular mapping of powdery mildew resistance genes in wheat: A review   总被引：40，自引：3，他引：40  
Powdery mildew, caused by Blumeria graminis f. sp. tritici (syn. Erysiphe graminis f. sp. tritici), is one of the most important diseases of common wheat (Triticum aestivum L.) worldwide. Molecular mapping and cloning of genes for resistance to powdery mildew in hexaploid wheat will facilitate the study of molecular mechanisms underlying resistance to powdery mildew diseases and help understand the structure and function of powdery mildew resistance genes, and permit marker-assisted selection in breeding programs. So far, 48 genes/alleles for resistance to powdery mildew at 32 loci have been identified and located on 16 different chromosomes, of which 21 resistance genes/alleles have been tagged by restriction fragment length polymorphisms (RFLPs), random-amplified polymorphic DNAs (RAPDs), amplified fragment length polymorphisms (AFLPs), sequence characterized amplified regions (SCARs), sequence-tagged sites (STS) or simple sequence repeats (SSRs). Several quantitative trait loci (QTLs) for adult plant resistance (APR) to powdery mildew have been associated with molecular markers. The detailed information on chromosomal location and molecular mapping of these genes has been reviewed. Isolation of powdery mildew resistance genes and development of valid molecular markers for pyramiding resistance genes in breeding programs is also discussed.  相似文献   

15.
Summary Biochemical, karyological and morphological characterization of Triticum turgidum conv. durum/Hordeum chilense addition forms was carried out. Nine H. chilense isozyme markers, belonging to ACPH, CPX, EST, PGM, 6-PGD, GOT and MDH enzymatic systems, were used to identify the chilense chromosomes in 50 monosonic or polysomic addition forms. Several morphological traits were associated with the presence of chilense chromosome in the complement. The transmission frequencies of addition chilense chromosomes were also investigated in the offspring of various crosses.  相似文献   

16.
Summary A set of 21 monosomics of Novosadska Rana-1 was used to locate the rust resistance genes of Lüqiyu, a stripe rust resistant line developed by BAU and Yantar, a leaf rust resistant wheat introduced from Bulgaria. The resistance of the former to p. striiformis race C25 was conditioned by a dominant gene located on chromosome 2B, whereas that of the latter to P. recondita race CL3 was controlled by two complementary dominant genes located on chromosomes 5A and 1D, respectively. The relationship of the stripe rust resistance gene in Lüqiyu to Yr5, Yr7 or Yr Suwon' all located on chromosome 2B is unknown. The two complementary leaf rust resistance factors in Yantar appear to be new.  相似文献   

17.
Summary Hexaploid and octoploid tritordeum and their Triticum spp. parents were studied in the seedling stage to compare their components of partial resistance to Puccinia recondita f.sp. tritici. The components studied were infection frequency, latency period and size of uredia. The non-host Hordeum chilense parent does not confer any increase of partial resistance to wheat brown rust to its amphiploids with wheat.  相似文献   

18.
Summary Alien dominant genes of spring habit were introgressed into bread wheat. The introgression was undertaken by simple crossing of winter bread wheat to related spring species or genera, followed by backcrossing to winter bread wheat, and did not involve the use of the ph mutants or embryo culture. The introgressed genes were located mostly on chromosomes of homoeologous group 5, and were allelic to the known Vrn genes in bread wheat. Nevertheless three groups of lines were discovered with the genes possibly located on other chromosomes. These genes were non-allelic to each other and to known Vrn genes and were designated Vrn6 Sc , Vrn7 Sc (introgressed from Secale cereale) and Vrn8 Ts (from Triticum sphaerococcum).  相似文献   

19.
Over the past 20 years, several expeditions were made to northern Chile to collect populations of wild tomatoes (Solanum chilense, S. peruvianum) and allied nightshades (S. lycopersicoides, S. sitiens), and obtain information about their geographic distribution, ecology and reproductive biology. Restricted mainly to drainages of the Andean and the coastal cordillera, populations are geographically fragmented. The two nightshade species are rare and threatened by human activities. Adaptation to extreme aridity and soil salinity are evident in S. chilense and S. sitiens (the latter exhibits several xerophytic traits not seen in the tomatoes) and to low temperatures in S. lycopersicoides and S. chilense. All tested accessions are self-incompatible, with the exception of one S. peruvianum population collected at the southern limit of its distribution. Several distinguishing reproductive traits—anther color, attachment, and dehiscence, pollen size, and flower scent—suggest S. sitiens and S. lycopersicoides attract different pollinators than S. chilense and S. peruvianum. The four Solanum spp. native or endemic to Chile provide a variety of novel traits which, through hybridization and introgression with cultivated tomato, could facilitate development of improved varieties, as well as research on a variety of basic topics, including plant-pollinator interactions, abiotic stress responses, and evolution of reproductive barriers.  相似文献   

20.
Summary Accessions of Hordeum vulgare ssp. spontaneum, the wild progenitor of barley, collected in Israel (70), Iran (15) and Turkey (6) were screened for seedling response to four isolates of Rhynchosporium secalis, the pathogen causing leaf scald in barley. Resistance was very common in the collection (77%) particularly among accessions from the more mesic sites (90%). The genetics of this resistance were investigated in fifteen backcross (BC3) lines that contained an isozyme variant from H.v. ssp. spontaneum in a H.v. ssp. vulgare (cv. Clipper) background and were resistant to scald. Segregation in the BC3F2 families conformed with a single dominant resistance gene in 9 of the 15 lines. Scald resistance and the isozyme marker were closely linked in three of the BC3-lines, loosely linked in four and unlinked in the remaining eight. Scald resistance genes were identified on barley chromosomes 1, 3, 4 and 6. Crosses between several of the scald resistant BC-lines together with the linkage data indicated that at least five genetically independent resistances are available for combining together for deployment in barley. The linkage of scald resistance in several BC3-lines to the isozyme locus Acp2 is of special interest as this locus is highly polymorphic in wild barley.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号