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1.
Compared with hexaploid wheat, tetraploid durum is more susceptible to Fusarium crown rot (FCR) infection. The feasibility of enhancing FCR resistance in durum wheat by introgressing chromosome segments of hexaploid wheat was investigated by generating and analysing a backcross population derived from a susceptible durum wheat variety ??Bellaroi?? (recurrent parent) and a resistant hexaploid genotype ??CSCR6?? (donor parent). Together with a few scattered segments on various chromosomes, segments of a large section of the donor chromosome 6B showed a significant effect in enhancing FCR resistance in the durum background. However, a known major locus on the donor 3BL conferring high level of resistance to FCR in hexaploid wheat failed to provide any improvement in resistance than that of the genome average once it was introduced into the durum wheat. A small proportion of the backcross population gave similar resistance to the bread wheat variety ??Kennedy??, a level of FCR resistance acceptable to durum growers. These lines share a 4B segment from the hexaploid donor, although the segment was not among those with the largest individual effect across the whole population. These results show that it is feasible to improve FCR resistance of durum wheat by exploiting hexaploid chromosome segments, although resistance loci of the hexaploid wheat may not function properly in durum backgrounds.  相似文献   

2.
With the aim of examining crossability of durum wheat with maize, two sets of durum wheat genotypes and a set of D-genome chromosome substitution lines of the durum wheat variety ‘Langdon’ were crossed with maize, and followed by 2,4-dichlorophenoxyacetic acid (2,4-D) treatment in detached-tiller culture. In crosses of 25 durum wheat genotypes (breeding lines) with maize, percent frequencies of embryo formation increased from 1.4% to 2.8% by adding silver nitrate to the detached-tiller culture solution. In crosses of 32 durum wheat genotypes (advanced lines and varieties) with maize using the silver nitrate addition, frequencies of embryo formation ranged from 0.0% to 15.8%; seven genotypes showing more than 6.0% embryo formation frequency were related in their pedigrees. In crosses of a set of chromosome substitution lines with maize, higher frequencies of embryo formation were obtained in substitution lines with chromosomes 1D, 3D, 4D and 7D. These results suggest that 1) adding silver nitrate to the 2,4-D treatment increases overall frequency of embryo formation but is not effective enough to induce the development of seeds and embryos from all durum wheat genotypes, and 2) some D-genome chromosomes substituted in a durum wheat genetic background may enhance crossability with maize in combination with homoeologous chromosomes of durum wheat. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

3.
Hessian fly is an important pest of wheat on the North American continent and the temperate Mediterranean drylands. Yield losses caused by this insect in Morocco are the heaviest in the Mediterranean region and are estimated to be 36% on average. Genetic resistance to Mediterranean Hessian fly biotypes has not been found in durum wheat, although large numbers of durum accessions were screened. Genes for resistance were found in common wheat; some of which are transferable to durum. However, there is a need to broaden the genetic base for resistance in durum wheat. The objective of this work was to introgress resistance from selected Triticum araraticum and T. carthlicum accessions using multiple backcross methodology. The experimental recipient durum wheat included numerous adapted and high‐yielding lines. Testing for Hessian fly resistance under controlled conditions and field yield data showed that this programme yields Hessian fly‐resistant durum lines with good yields and adaptation.  相似文献   

4.
Preharvest sprouting that occurs in wheat might affect seed viability and cause genetic erosion during periodical rejuvenation of durum wheat accessions in a gene bank. Two durum wheat landraces (MG 7713 and MG 7805) that had been rejuvenated for several years and did show a high percentage of presprouted seeds in the lot from the fourth rejuvenation cycle were identified. The frequency of durum and bread wheat genotypes and the distribution of the two species in three seed classes (ungerminated seeds, seeds with swollen embryo and germinated seeds) were studied. The modified phenol test was used to identify durum and bread wheat seeds and the genotypic frequencies within each species were assessed on the basis of acid polyacrylamide gel electrophoretic patterns of gliadin storage proteins. In these two landraces, durum wheat was more susceptible to preharvest sprouting than bread wheat and the frequency of bread wheat seeds significantly increased over the three rejuvenation cycles examined. Despite this, preharvest sprouting did not cause significant changes in the genotypic frequencies observed within species or loss of some genotypes that could not be attributed to susceptibility to sprouting.  相似文献   

5.
A set of bread wheat and durum wheat cultivars adapted to Spanish conditions was tested for resistance against leaf rust caused by different pathotypes of Puccinia triticina in field trials and in growth chamber studies. Lower levels of resistance were found in durum wheat than in bread wheat. The most frequent Lr genes found in bread wheat were Lr1, Lr10, Lr13, Lr20, Lr26 and Lr28. In durum wheat, additional resistance genes that differed from the known Lr genes were identified. The level of partial resistance to leaf rust was in general low, although significant levels were identified in some bread wheat and durum wheat cultivars.  相似文献   

6.
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   

7.
Growing in Central Europe winter instead of spring durum wheat would substantially increase yield potential but is currently hampered by the lack of knowledge of frost tolerance present in elite material. The objectives of our survey were to (i) study the genetic variability and heritability of frost tolerance and its association with other important agronomic and quality traits in durum wheat, (ii) examine the potential to combine frost tolerance with high quality and high grain yield and (iii) investigate the consequences of the heritabilities and associations among traits on the optimum design of a multistage selection programme for winter durum wheat. We investigated 101 elite winter durum wheat lines and four commercial checks in field trials at four locations. Four agronomic as well as nine quality traits were recorded. In addition, frost tolerance was evaluated using a semi‐controlled test resulting in high‐quality phenotypic data. Genotypic variances (σ²G) were significantly larger than zero for all traits, and heritabilities were moderate to high. Several elite durum wheat lines exhibited a frost tolerance comparable to that of two frost‐tolerant Triticum aestivum varieties. Frost tolerance was not negatively associated with other important agronomic and quality traits. The high quality of the phenotypic data for frost tolerance evaluated in a semi‐controlled test suggests that this is a cost‐efficient approach to consider frost tolerance at early stages of a multistage durum wheat breeding programme.  相似文献   

8.
Greenhouse and growth chamber experiments were carried out using seven bread wheat (Triticum aestivum), three durum wheat (T. durum), two rye (Secale cereale), three barley (Hordeum vulgare), two triticale (x Triticosecale Wittmack) and one oat (Avena sativa) cultivars to study response to zinc (Zn) deficiency and Zn fertilisation in nutrient solution and in a severely Zn deficient calcareous soil. Visual Zn deficiency symptoms, such as whitish-brown necrotic patches on leaf blades, developed rapidly and severely in the durum wheat and oat cultivars. Bread wheat showed great genotypic differences in sensitivity to Zn deficiency. In triticale and rye, visual deficiency symptoms were either absent or appeared only slightly, while barley showed a moderate sensitivity. When grown in soil, average decreases in shoot dry matter production due to Zn deficiency were 15% for rye, 25% for triticale, 34% for barley, 42% for bread wheat, 63% for oat and 65% for durum wheat. Differential Zn efficiency among and within cereal species was better related to the total amount of Zn per shoot, but not to the Zn concentration in the shoot dry matter. However, in leaves of Zn efficient rye and bread wheat cultivars, the activity of Zn-containing superoxide dismutase was greater than in Zn inefficient bread and durum wheat cultivars, suggesting higher amounts of physiologically active Zn in leaf tissue of efficient genotypes. When grown in nutrient solution, there was a poor relationship between Zn efficiency and release rate of Zn-chelating phytosiderophores from roots, but uptake of labelled Zn (65Zn) and its translocation to the shoot was higher in the Zn efficient rye and bread wheat cultivars than in inefficient bread and durum wheat cultivars. The results demonstrate that susceptibility of cereals to Zn deficiency decline in the order durum wheat > oat > bread wheat > barley > triticale > rye. The results also show that expression of high Zn efficiency in cereals was causally related to enhanced capability of genotypes to take up Zn from soils and use it efficiently in tissues. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

9.
Screening for low grain cadmium phenotypes in sunflower, durum wheat and flax   总被引：10，自引：0，他引：10  
Cadmium (Cd) level in nonoilseed sunflower (Helianthus annuus L.), flax (Linum usitatissimum L.), and durum wheat (Triticum turgidum L. var. durum) grown on uncontaminated, alkaline soils has exceeded limits established in Northern Europe. Separate field experiments were conducted to investigate variability of grain Cd levels among sunflower, durum wheat and flax germplasm, and to seek an efficient screening method for future breeding. There were large variations in leaf Cd concentration among 200 sunflower lines. These lines performed more consistently for Cd uptake at the R5 stage than at the V8 stage across 4 locations with markedly differing soils. Cd concentration in V8 leaves was not related to Cd in grain. The positive correlation between R5 leaf Cd and kernel Cd level was obtained from nonoilseed hybrid (Sigco 954) (R2; = 0.74**), and 200 lines (R2 = 0.44**) tested over 4 locations in 2 field trials, respectively. This indicates that an efficient and low cost screening method can be developed for genotype selection, but plants must be grown to the R5 stage. A preliminary evaluation of 30 durum wheat and 74 flax lines indicated large variations in grain Cd level of durum wheat and flax. Grain Cd concentration ranged from 0.11 to 0.34 mg Cd kg-1 DW for durum wheat, and 0.14 to 1.37 mg Cd kg-1 DW for flax, respectively. This variability indicates that breeding for low grain Cd in durum wheat and flax should be feasible. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

10.
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   

11.
Triticum turgidum ssp. durum (tetraploid durum) germplasm is very susceptible to crown rot, caused by the fungus Fusarium pseudograminearum. Screening activities to date have failed to identify even moderately susceptible lines. In contrast partial resistance to this disease has been identified in a number of Triticum aestivum (hexaploid wheat) lines, including 2-49 and Sunco. This study describes the successful introgression of partial crown rot resistance from each of these two hexaploid wheat lines into a durum wheat background. Durum backcross populations were produced from two 2-49/durum F6 lines which did not contain any D-genome chromosomes and which had crown rot scores similar to 2-49. F2 progeny of these backcross populations included lines with field based resistance to crown rot superior to that of the parent hexaploid wheat.  相似文献   

12.
The high molecular weight glutenin subunit (HMW-GS) composition of 42 Ethiopian-grown bread wheat and 31 durum wheat cultivars and lines were examined using SDS-PAGE. Low variability in HMW-GS composition was present in both classes of wheat. A total of 10 variants with 14 different HMW patterns and seven variants with six different patterns were identified in bread and durum wheat, respectively, reflecting the limited ability of HMW-GS for cultivar identification. The most predominant alleles were 2*, 7 + 9 and 5 + 10 in bread wheat and nul and 7 + 8 in durum wheat. The Glu-1 quality scores for bread wheat ranged from 6 to 10, with an average value of 8.7. The variation in HMW-GS significantly correlated with and accounted for 44 % of the total variation in gluten quality, measured by the sodium dodecyl sulphate sedimentation test. In durum wheat, HMW-GS variation at Glu-B1 explained about 25 % of the variation in gluten quality. The high frequency of the 7 + 8 alleles among the landraces and the significant contribution of Glu-B1 alleles to the total variation in gluten quality indicate the potential benefit of Ethiopian tetraploid landraces in the development of lines suitable for both bread and pasta production.  相似文献   

13.
G. Galterio    L. Grita  A. Brunori 《Plant Breeding》1993,110(4):290-296
Densitometric analysis of the gluten subunits as resolved by SDS-PAGE electrophoresis of 23 samples from seven varieties of durum wheat has provided further evidence for the positive effect on the quality of pasta made from durum wheat of low-molecular-weight glutenins (LMWG) and high-molecular-weight-glutenins (HMWG) and the negative influence of the intermediate-molecular-weight group (IMWG) (albumins, globulins, some glutenins, and omega gliadins). Differences in the expression of pasta quality were expected among the varieties investigated. However, high quality was invariably the result of a preferential accumulation of (LMWG) and (HMWG) in respect to IMWG. It appeared that such a biochemical feature could represent a general mechanism on which the pasta-making quality of durum wheat relies. The high correlation observed between the ratio (LMWG)/IMWG or (LMWG + HMWG)/IMWG and quality (r = 0.85*** and 0.88***, respectively) suggested that SDS-PAGE with densitometry of the gluten subunits could provide new quality indices useful in breeding durum wheats with improved pasta-making quality and for the grading of durum produce for industrial purposes.  相似文献   

14.
Pearl millet is an efficient alternative to maize as a pollen source for haploid production in bread wheat. To compare haploid production frequencies in other Triticeae species, the crossabilities of two genotypes each of bread wheat, durum wheat and hexaploid triticale with four pearl millet genotypes and a maize control were examined. Embryos were obtained from crosses of all three species with both pearl millet and maize. However, significant differences in crossability were found among the three species (10.5–79.8% seed development and 1.4–15.8% embryo formation), as well as among genotypes of durum wheat (7.2–23.7% and 2.1–6.4%) and hexaploid triticale (0.3–20.6% and 0.1–2.7%). Crossability of bread wheat with pearl millet was relatively high. Haploid plants were regenerated from crosses of all three species with pearl millet. As in the case of maize crosses, low crossabilities of durum wheat and hexaploid triticale with pearl millet can be attributed to the absence of D-genome chromosomes.  相似文献   

15.
Durum or macaroni wheat (Triticum turgidum L., 2n = 4x = 28; AABB) is an allotetraploid with two related genomes, AA and BB, each with seven pairs of homologous chromosomes. Although the corresponding chromosomes of the two genomes are potentially capable of pairing with one another, the Ph1 (Pairing homoeologous) gene in the long arm of chromosome 5B permits pairing only between homologous partners. As a result of this Ph1-exercised disciplinary control, durum wheat and its successor, bread wheat (Triticum aestivum L., 2n = 6x = 42; AABBDD) show diploid-like chromosome pairing and hence disomic inheritance. The Ph mutants in the form of deletions are available in bread wheat (ph1b) and durum wheat (ph1c). Thus, ph1b-haploids of bread wheat and ph1c-haploids of durum wheat show extensive homoeologous pairing that has been shown by us and several others. Here we study the effect of ph1b allele of bread wheat on chromosome pairing in durum haploids, whereas we studied earlier the effect of ph1c allele in durum haploids that we synthesized. In durum wheat, the ph1b-haploids show much higher (49.4% of complement) pairing than the ph1c-haploids (38.6% of complement). Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the USDA or imply approval to the exclusion of other products that also may be suitable.  相似文献   

16.
The aim of this study was to evaluate the performance of three species of unhulled-wheat (Triticum monococcum L., Triticum dicoccum Schubler and Triticum spelta L.) with respect to durum wheat (Triticum durum Desf. cv. Trinakria) in southern Italy's flat environment.
As far as yield is concerned, the mean yield was significantly different among species. Durum wheat yielded 16.1 %, 37.6% and 69.5 % more than dicoccum, spelta and monococcum species, respectively.
Among unhulled-wheat species, only Triticum dicoccum showed some similarity with durum wheat, such as one-thousand kernels weight, plant height and number of spikes per m2.
Among the factors studied, the days to reach heading represented the factor that mostly influenced yield  相似文献   

17.
A PCR assay has been developed for selecting low molecular weight (LMW) glutenin genes, located on chromosome 1B, and related to durum wheat quality characteristics. Most durum wheat lines possessing good technological properties can be identified on the basis of the presence of specific 1B LMW glutenin components that have been designated LMW-2 glutenin subunits. On the basis of nucleotide sequences corresponding to LMW glutenin genes, a series of specific oligonucleotide primers were prepared and used in PCR analysis. A pair of these primers gave a single amplification product which can distinguish between durum wheat lines possessing LMW-2 glutenin subunits and lines possessing other 1B-LMW allelic variants. Because the proposed PCR analysis can be carried out using part of the endosperm of a single seed, it represents a helpful approach for speeding up the selection of genotypes possessing LMW-2 glutenin subunits. This part of primers could also be very useful in genome mapping analysis and for testing the purity of wheat flour stock.  相似文献   

18.
The determination of the gluten index is a widely used method for analysing the gluten strength of bread wheat and spring durum wheat genotypes. The present work was carried out to study the effect of the genotype, meteorological factors (temperature, precipitation and number of days with Tmax ≥ 30 °C) and agronomic treatments (N fertilisation and plant protection) on the gluten index of winter durum wheat varieties and breeding lines. The results indicated that the gluten index had little dependence on the environment, being determined to the greatest extent by the genotype. Compared with varieties having weak gluten, those with a strong gluten matrix responded less sensitively to changes in environmental conditions. Among the meteorological factors, high temperature at the end of the grain-filling period caused the greatest reduction in the mean gluten index of three varieties (R 2 = 0.462), while the fertiliser was found to be a significant factor affecting the gluten strength of winter durum wheat varieties. Using selection based on the gluten index, the gluten strength of winter durum wheat lines can be improved sufficiently to make them competitive with high quality spring varieties.  相似文献   

19.
为了提高千粒重,连续8年对普通小麦(T.aestivum)和硬粒小麦(T.durum)的正反交后代进行种质创新研究。结果表明:利用普通小麦、硬粒小麦种间杂种优势,是实现种质创新,培育高千粒重新种质的一条有效途径,在入选的319个子粒饱满度一级的株系中,260个株系千粒重超全国小麦黄淮区域试验对照品种石4185(亲本),占入选株系的81.5%,其中,最高千粒重为61.22 g,超亲优势为46.28%;正交、反交后代在该性状上无差异,表明子粒千粒重与细胞质无关;目前已选育出抗旱、抗病、农艺性状优良,千粒重40.1~61.22 g的株系263个,可直接用于小麦遗传育种研究及新品种选育。  相似文献   

20.
Pre-harvest sprouting (PHS) causes significant yield loss and degrade the end-use quality of wheat, especially in regions with prolonged wet weather during the harvesting season. Unfortunately, the gene pool of Triticum durum (tetraploid durum wheat) has narrow genetic base for PHS resistance. Therefore, finding out new genetic resources from other wheat species to develop PHS resistance in durum wheat is of importance. A major PHS resistance QTL, Qphs.sicau-3B.1, was mapped on chromosome 3BL in a recombinant inbred line population derived from ‘CSCR6’ (Triticum spelta), a PHS resistant hexaploid wheat and ‘Lang’, a PHS susceptible Australian hexaploid wheat cultivar. This QTL, Qphs.sicau-3B.1, is positioned between DArT marker wPt-3107 and wPt-6785. Two SCAR markers (Ph3B.1 and Ph3B.2) were developed to track this major QTL and were used to assay a BC2F8 tetraploid population derived from a cross between the durum wheat ‘Bellaroi’ (PHS susceptible) and ‘CSCR6’ (PHS resistant). Phenotypic assay and marker-assisted selection revealed five stable tetraploid lines were highly PHS resistant. This study has successfully established that PHS-resistance QTL from hexaploid wheat could be efficiently introgressed into tetraploid durum wheat. This tetraploid wheat germplasm could be useful in developing PHS resistant durum cultivars with higher yield and good end-use quality.  相似文献   

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