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1.
×Tritordeum sp. (Ascherson et Graebner) is the amphiploid obtained after chromosome doubling of hybrids between Hordeum chilense (Roem. et Schult.) and diploid, tetraploid or hexaploid wheats. Tritordeums have consistently higher carotenoid pigment contents than durum or bread wheat. Two distinct H. chilense accessions (used for the synthesis of tritordeum) were analysed for this trait. The chromosomal localization of the genes coding the ability of H. chilense to increase the carotene content of wheat were carried out using two sets of wheat- H. chilense addition lines. The a arm of chromosome 7Hch is proposed to be responsible for the high carotene content in tritordeum. The implication of this finding in wheat breeding is discussed.  相似文献   

2.
Hexaploid tritordeum, the amphiploid Hordeum chilense x Triticum turgidum conv. durum has a higher grain carotene content than durum wheat. In order to decide strategies for introgressing this character into durum wheat, the effect on the carotene content of tritordeum synthesized with H. chilense and durum wheat differing in carotene content was analysed. Carotene content was evaluated in 35 primary tritordeum lines and their parents, 27 H. chilense accessions and 19 durum wheat cultivars. Some amphiploids have either one barley or wheat parent in common. In general, the influence of H. chilense is more important than that of wheat in the amphiploid carotene content. Nevertheless, the interactions between both parents on the amphiploid carotene content are also important.  相似文献   

3.
Hexaploid tritordeum is the amphiploid derived from the cross between Hordeum chilense and durum wheat. The storage proteins synthesized in the Hch genome influence the gluten strength of this amphiploid. The D‐prolamins of H. chilense have been analysed by sodium dodecyl sulphate‐polyacrylamide gel electrophoresis with and without urea. A new locus named Glu‐Hch3 has been detected. The effects of allelic variation at this locus on gluten strength, as measured the sodium dodecyl sulphate sedimentation test, were determined using seeds of 92 lines from a cross of two hexaploid tritordeum lines. Two allelic variants have been detected for this locus, which have shown different effects on gluten strength.  相似文献   

4.
×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   

5.
Somatic Embryogenesis and Plant Regeneration from Tritordeum   总被引：2，自引：0，他引：2  
P. Barceló    A. Vazquez  A. Martín 《Plant Breeding》1989,103(3):235-240
Regeneration of plants by somatic embryogenesis from immature embryos of hexaploid tritordeum (AABBHchHch, amphiploid Hordeum chilense×Triticum turgidum conv. durum) and durum wheat (Triticum tergidum) was induced on MS medium supplemented with different 2.4-D concentrations. Well-defined embryoids were formed with a high frequency on the scutellar callus from 1 or 2 weeks onwards and plantlets were developed from them. In the best cases from one single explant more than 100 plants could be obtained. Plants were also regenerated by somatic embryogenesis from inflorescences of Hordeum chilense×Triticum turgiditm conv. durum hybrid and its respective hexa-amphiploid. With regard to callus induction and regenerative ability, evident differences between hexa- and octoploid (H. chilense×T. aestivum) tritordeum were found, the latter showing a very low response.  相似文献   

6.
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   

7.
A hybrid between an induced tetraploid of Hordeum chilense (2n = 28 = HchHchHchHch) and Triticum aestivum var. ‘Chinese Spring’ (2n = 42 = AABBDD) has been produced to test gene effects of this wild barley on homoeologous pairing in wheat. Cytological investigations in metaphase I have shown that the hybrid, which is perennial like H. chilense but morphologically more similar to the wheat parent, possesses the expected genome composition HchHch ABD and a stable euploid chromosome number of 2n = 35. Pairing among the homologous H. chilense chromosomes was almost complete. The level of non-homologous chromosome association proved to be lower than the range of pairing known from euhaploids of ‘Chinese Spring’.  相似文献   

8.
Chromosome 7Hch from Hordeum chilense has potential for improving seed carotenoid content in wheat as it carries a Phytoene synthase 1 (Psy1) gene, which has a major role in this trait. Structural changes in chromosome 7Hch were obtained in common wheat background by crossing the wheat disomic substitution line 7Hch(7D) with a disomic addition line carrying chromosome 2Cc from Aegilops cylindrica in common wheat cv. ‘Chinese Spring’. Rearranged 7Hch chromosomes were cytologically characterized by FISH. A set of 24 molecular markers and the Psy1 gene were used to identify the H. chilense chromosome segments involved in the introgressions. Six structural rearrangements of chromosome 7Hch were identified. They included three homozygous wheat–H. chilense centromeric translocations, one involving the 7HchS arm (T‐7HchS·A/B) and two involving the 7HchL arm (T1‐7HchL·A/B and T2‐7HchL·A/B). In addition, one 7HchS arm deletion, one 7HchL·7HchL isochromosome and one 7HchS telosome were obtained in hemizygous condition. These genetic stocks will be useful for studying the effect of chromosome 7Hch on wheat flour colour.  相似文献   

9.
Hordeum chilense Roem. et Schult. is a diploid wild South American barley that contains genes of interest for cereal breeding, many of them located on chromosome 1Hch. In the current study, two H. chilense-wheat addition lines with deletions in the 1Hch chromosome were used for sub-arm localization of five prolamin (glutenin and gliadin) loci and 33 EST-SSR marker loci on chromosome 1Hch. The two sets of markers were distributed across five sub-arm chromosome regions. Three glutenin loci (Glu-H ch 2, Glu-H ch 3, Glu-H ch 4) together with the gliadin locus Gli-H ch 1 were located on the distal 20% of the 1HchS arm, whereas the glutenin locus Glu-H ch 1 was on the proximal 88% region of 1HchL. Among 33 EST-SSR marker loci, 7 (21.2%) were on the 1HchS arm and, of them, 3 (9.1%) were on the distal 20% end and 4 (12.1%) on the proximal 80% region. The 26 loci (78.8%) on 1HchL were distributed across three different regions: 18 (78.8%) in the proximal 88%, 3 (9.1%) in the distal 12% and 5 (15.2%) in a region less than 12% from the distal end. The deletions in the 1Hch chromosome added to the common wheat background were thus shown to be useful for determining the sub-arm location of EST-SSR and prolamin loci. This could facilitate the identification of molecular markers linked to genes of agronomic interest and the isolation of such genes for use in common wheat improvement.  相似文献   

10.
Hexaploid tritordeum, the amphiploid Hordeum chilense×Triticum turgidum, has potential for bread making. In order to estimate the potential of bread wheat chromosome 1D for improving the bread‐making quality of tritordeum, and the processing properties and agronomic performance of euploid tritordeum, (1Hch)1D and (1A)1D substitution lines have been evaluated in field trials. No significant differences for agronomical traits were observed between the two substitution lines and the sister euploid tritordeum, except for the kernel weight of the (1Hch)1D tritordeum substitution, which was lower than that of euploid tritordeum. Gluten strength, estimated by alveograph deformation energy (W), and loaf volume were substantially higher in both substitution lines than in the euploid tritordeum.  相似文献   

11.
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   

12.
Hordeum chilense is a wild barley species that has a high degree of genetic variability and significant potential for use in plant breeding. To establish a series of trisomics in H. chilense (2n = 14), plants with 2n + 1 chromosome numbers were isolated from the progenies of selfed triploid plants. Based on both fluorescent in situ hybridization with pAs1 and pTa71 repetitive DNA probes and C-banding patterns, seven different trisomics were tentatively identified. Primary trisomic plants were for chromosomes 1Hch, 4Hch, 5Hch, 6Hch and 7Hch. A secondary trisomic carrying a 5HchS-5HchS isochromosome as the extra chromosome and a trisomic for chromosome 3Hch heterozygous for the 3HchS-4HchL and 4HchS–3HchL interchange were identified. The trisomic for chromosome 1Hch cannot be phenotypically distinguished from the diploid. The rest of the trisomic types were distinguishable from the diploid by their morphological characteristics (relatively poor vigour, decreased size and shorter spikes) but they were morphologically indistinguishable from each other. The frequencies of trisomics among the progenies derived from self-fertilization of these aneuploids ranged from 10.7% to 37.5%, with an average frequency of 26.1%. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

13.
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   

14.
The genome of Tritordeum, AABBHchHch, was substituted into the cytoplasms of Triticum aestivum, T. turgidum and Hordeum chilense by repeated back-crossing to produce alloplasmic lines. This substitution did not greatly affect the characters studied, except yield per plot and fertile ears per plant, which were lower on T. turgidum cytoplasm. Cytoplasm from either H. chilense or T. aestivum could be used for breeding tritordeum.  相似文献   

15.
The reaction of tritordeum and its Hordeum chilense and Triticum spp. parents to Septoria tritici was studied in field and seedling experiments. All H. chilense lines were highly resistant to all the isolates and did not allow pycnidia development. The ‘durum wheat isolate’ developed pycnidia only on durum wheats. The ‘breed wheat isolate’ was very virulent on bread wheat but also on the wild tetra-ploid wheats. The other two isolates were compatible with durum and bread wheat. All hexaploid tritordeums were highly resistant both in the field and the seedling experiments. Some octoploid tritordeums allowed pycnidial development, but at much lower levels than their wheat parent. Resistance in tritordeum was not associated with plant stature and only in octoploid tritordeum was association of resistance with late maturity detected.  相似文献   

16.
Hordeum chilense, a South-American wild barley, is being used in cereal breeding because of its good crossability with both wild and cultivated Triticeae species. Amphiploids and chromosome addition lines of H. chilense in common and durum wheats have been obtained as a means to transfer desirable agronomic characters from wild barley to wheat. No allosyndetic pairing has been detected in diverse hybrids involving H. chilense. Several biochemical markers have been associated with the seven chilense chromosome pairs. New approaches are necessary to transfer genes from H. chilense to cereals.  相似文献   

17.
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   

18.
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   

19.
The reaction of tritordeum and its Hordeum chilense and Triticum spp. parents to common bunt incited by Tilletia tritici were determined in field experiments. H. chilense accessions were very resistant, and durum wheats exhibited high to moderate levels of resistance. Conversely, bread wheats were highly susceptible. Resistance from H. chilense was expressed in the amphiploids, although the level of resistance was partially diluted at higher ploidy levels. Hexaploid tritordeums were immune to the disease; some infection was observed among the octo-ploids but at much lower levels than in their respective wheat parents.  相似文献   

20.
Hexaploid tritordeum is an amphiploid derived from the cross between Hordeum chilense and durum wheat. This amphiploid has shown potential for bread making, which has been associated to the prolamins from H. chilense. The role of each prolamin subunit on the gluten strength in tritordeum has been evaluated. Advanced progenies from two hexaploid tritordeum crosses were analysed for prolamins composition and gluten strength. Six loci were found for the prolamins synthesised at the Hch genome, which showed significant effects on gluten strength. Although these tritordeum lines represent only a small proportion of the genetic variability available in the development programme for this new crop, a certain degree of variation for prolamins composition was detected. In fact, up to three allelic variants have been detected for some loci, which have shown different effect on gluten strength in tritordeum. Each of these six loci appeared on the same linkage group that corresponded to chromosome 1Hch. The search of new variants for these loci could be useful for tritordeum quality breeding and, using tritordeum as a bridge species, this genetic variability could be introgressed into bread wheat. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

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