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1.
Summary Reciprocal crosses were carried out between Triticum dicoccoides sel. G-25-highly resistant to Puccinia striiformis race 20A-and Triticum durum cultivar Nursith 163-which served as susceptible parent.F1 hybrids in one of the crosses showed a wide range of infection types to the test isolate, whereas in a repeated cross all F1 plants proved highly resistant. The variable reaction pattern observed in the F1 hybrids of the first cross suggests incomplete penetrance of the resistance factor in certain environmental conditions.The segregation ratio displayed by the F2 progenies indicates that a single dominant factor for resistance to stripe rust race 20A was transferred from wild emmer to cultivated durum wheat.Contribution from the Agricultural Research Organization, Volcani Center, Bet Dagan, Israel. 1973 Series, No. 291-E. 相似文献
2.
Race-specificity of temperature-sensitive genes for resistance to Puccinia striiformis in Triticum dicoccoides 总被引：1，自引：0，他引：1
Summary Twenty-four entries of wild emmer possessing temperature-sensitive genes for resistance to yellow rust were studied in the seedling stage, at two temperature-profiles, with 15 pathogenic races from 11 countries in South America, Africa, Asia and Europe. It was shown that the majority of the resistance genes in these wild emmer entries were race-specific. In most of these entries a more resistant reaction was displayed at the higher temperature-profile; however in three entries a shift in reaction towards resistance was observed with certain races but towards susceptibility with some of the other races, suggesting that two different kinds of temperature-sensitive genes were involved in each of these entries. The similarity of temperature-sensitive genes occurring in wild emmer and in cultivated wheat is discussed. 相似文献
3.
Summary Wild emmer from 73 collection sites, including 107 accessions from Israel, two from Lebanon and one from Turkey, were evaluated for resistance to powdery mildew in field nurseries in Israel and the Netherlands.The wild emmer entries displayed a diversity of responses to powdery mildew infection, ranging from high resistance to complete susceptibility. Most entries were resistant in at least one of the nurseries; several entries proved to be resistant in all the tests.Comparing the reactions of 47 wild emmer accessions tested in six nurseries, 11 markedly different patterns were discerned, indicating the probable presence of several different resistance genes.Genes for resistance to powdery mildew appear to be very common in wild emmer indigenous to Israel. Resistance was found in accessions from most collection sites, in all the geographic regions represented in the collection.The common occurrence of resistance and the apparent diversity of genotypes makes wild emmer a rich gene-pool for resistance to powdery mildew. Since genes for resistance to wheat pathogens can be quite readily transferred to cultivated wheat, wild emmer may be utilized as a valuable source of powdery mildew resistance in wheat breeding. 相似文献
4.
Summary Seedling resistance to wheat stem rust was determined in populations of wild emmer wheat, Triticum dicoccoides, and characterized by means of ecological factors and allozyme genotypes. Reactions to wheat stem rust were studied in 102 single plant accessions of T. dicoccoides from ten populations by inoculation with Puccinia graminis tritici race 14, isolate GSR-739. Six populations displayed different degrees of response polymorphism with reactions ranging from high resistance to complete susceptibility, whereas four populations contained only susceptible plants. In some of the accession, unexplained intrasib variation in resistance and intraplant variation of infection-types were found. Resistance to stem rust was negatively correlated with two ecological factors, altitude and number of Sharav (hot-dry) days which are unfavorable to disease development. Variation in stem rust response was shown to exist in ecogeographic regions where climatic variables enhanced the development of the fungus, conceivably maintained by natural selection. Likewise, allozyme genotypes, single or in multiple loci combinations, appeared to be associated with resistance or susceptibility to rust. Such association need to be verified by genetic studies in order to become established as useful markers. 相似文献
5.
Summary Seedlings of 38 wild emmer derivatives, and a total of 53 advanced wheat varieties/lines introduced from the International Maize and Wheat Improvement Centre (CIMMYT) or other sources, Nepalese breeding lines and local cultivars were inoculated with 18 different yellow rust isolates to postulate yellow rust resistance genes (Yr). Many wild emmer wheat derivatives used were resistant to all isolates indicating the presence of undescribed genes. Some derivatives carried Yr9, Yr6 and/or YrSU. Genes Yr1, Yr2, Yr6, Yr7, Yr8, Yr15, YrSU and YrA+ are no longer effective in Nepal; Yr4, Yr5, Yr9, Yr10, YrSP and YrSD are still effective; the effectiveness of Yr3 remains unclear. This study shows that stripe rust resistance in seedling stage of most Nepalese cultivars and advanced materials is based on Yr9 with combinations of Yr2, Yr6, Yr7, and YrA+, of which only Yr9 is still effective in Nepal. In many countries Yr9 has lost its effectiveness. Therefore the introduction of new Yr-genes from wild emmer wheat in Nepalese cultivars is highly important. 相似文献
6.
Summary Seedling responses to one Australian isolate of each of the stripe rust, stem rust and leaf rust pathogens were determined for 541 accessions of T. dicoccoides collected from 23 locations in Israel. Resistance to stripe rust was more frequent than resistance to stem rust. Stripe rust responses showed a wide range of variability indicative of a number of genes for resistance. Comparison of the present stem rust data and that reported for the same accessions tested in Israel indicated that different genes were operating in each country. Only moderately resistant responses to stem rust were obtained. This level of resistance is probably inadequate for transfer to commercial wheat cultivars. We found no potentially useful seedling resistance to leaf rust. 相似文献
7.
Genetic Resources for Salt Tolerance in the Wild Progenitors of Wheat (Triticum dicoccoides) and Barley (Hordeum spontaneum) in Israel 总被引：2，自引：0，他引：2
Salt tolerance was tested in the progenitors of cultivated cereals, wild barley (Hordeum spontaneum) and wild emmer wheat (Triticum dicoccoides) from Israel. Plants from five selected populations of H. spontaneum from the Mediterranean Coastal Plain and northern Negev desert, were grown on 250 and 350 mM of NaCl. Likewise, five populations of T. dicoccoides from the eastern Samaria steppes, Mt. Hermon and Mt. Carmel, were grown on 175 and 250 mM of NaCl. Here we report on superior genotypes of H. spontaneum, ripening at 350 mM NaCl (= 60 % sea water), and of T. dicoccoides ripening at 250 mM (— 40 % sea water). We are proceeding now with both genetical and physiological studies aimed at chromosomally-locating salt tolerant genes and unravelling the mechanism(s) of salt resistance in these wild cereals. 相似文献
8.
Summary The reactions of 233 Triticum dicoccoides acessions, collected at 10 sites in Israel and elsewhere, to infection with cultures of Erysiphe graminis tritici, were determined. The reactions indicated that the number of sources of resistance to E. graminis tritici which can be obtained from T. dicoccoides plants growing wild in Israel and elsewhere is almost unlimited. One hundred and fourteen or 49% of the accessions were resistant, and 137 or 59% of the accessions were resistant or moderately resistant to infection with four cultures of E. graminis tritici which possess the virulence genes corresponding to most of the identified resistance genes in wheat. Accessions collected at sites with marginal habitats where T. dicoccoides grows poorly and has lower grain weight, were more susceptible than were accessions collected at sites with an optimal habitat for growth of T. dicoccoides. The results agreed with those in a previous study with Hordeum spontaneum, and indicate that to obtain H. spontaneum or T. dicoccoides accessions with the highest level of resistance to the powdery mildew pathogens, plants should be collected at sites in ecological and geographic regions where those two species occupy optimum habitats and are exposed to the powdery mildew pathogens. 相似文献
9.
Wild emmer, Triticum dicoccoides, the progenitor of cultivated wheat, harbors rich genetic resources for wheat improvement. They include many agronomic traits
such as abiotic stress tolerances (salt, drought and heat), biotic stress tolerances (powdery mildew, rusts, and Fusarium
head blight), grain protein quality and quantity, and micronutrient concentrations (Zn, Fe, and Mn). In this review, we summarize
(1) traits and controlling genes identified and mapped in T. dicoccoides; and (2) the genes transferred to cultivated wheat from T. dicoccoides. These genes, controlling important agronomic traits such as disease resistance, high protein and micronutrient content,
should contribute to wheat production and food nutrition. However, most of the rich genetic reservoir in wild emmer remains
untapped, highlighting the need for further exploration and utilization for long-term wheat breeding programs. 相似文献
10.
Doubled haploid lines derived from anther culture of two Iranian spring wheat genotypes‘Ghods’susceptible and‘9106’resistant to yellow rust in Iranian field conditions, and their F1 hybrids were used in this study. Seedlings of 36 doubled haploid lines, selected out of 96 according to their agronomic traits and the two parental genotypes were inoculated with eight races of yellow rust. The parental genotypes (‘Ghods’and‘9106’) were segregating for some of the races but their doubled haploid lines were either resistant or susceptible to them.‘Ghods’was susceptible to three of the races studied but three doubled haploid lines derived from it were resistant to them. Five selected doubled haploids from the‘9106’genotype and six from F1 hybrid plants were resistant to all eight races tested. After further investigations in Iranian field conditions it was found that some of these lines can be used as donor genotypes for resistance to yellow rust in wheat breeding programmes. Use of these genotypes should be possible if the French yellow rust races used for selection also represent the dominant races in Iran. It can be concluded that anther culture provides an efficient method for fixing genes of resistance to yellow rust and desirable doubled haploids from F1 plants can be derived. 相似文献
11.
Summary Lines of spelt were found to be either resistant to all races of yellow rust used or susceptible to these races. Resistant lines could possibly be used as a source of yellow rust resistance of bread wheat. 相似文献
12.
Amino acid contents were measured in 109 genotypes from 22 populations of wild emmer wheat, Triticum dicoccoides, across its ecological range in Israel. Plants were grown outdoors on mesic Mr. Carmel, in a standardized environment, without irrigation and fertilization. T. dicoccoides was high in lysine and isoleucine contents as compared to six other species of wild wheats, but low in threonine and proline. Significant correlations were found among lysine and the other essential amino acids. Significant differences between Israeli populations of T. dicoccoides were found for isoleucine, methionine, leucine and threonine, but not for lysine, arginine, proline and glutamic acid. Significant differences between regions were only found in methionine. Ecological factors and allozyme markers appear to be good guidelines for predicting the ecogeographical location and allozymic constitution of specific elite amino acid genotypes, either singly or in combination. T. dicoccoides may be used in the future as a promising genetic resource for genetically improving the nutritional value of cultivated wheats. 相似文献
13.
Z. K. Gerechter-Amitai C. H. van Silfhout Adriana Grama Frida Kleitman 《Euphytica》1989,43(1-2):187-190
Summary In a comparative study of reaction patterns and by analysis of segregation ratios in cross progenies, Triticum dicoccoides Koern. sel. G-25 was shown to possess a yet unknown gene for resistance to yellow rust. It is suggested to assign provisionally the symbol Yr15 to this gene. 相似文献
14.
Seedling resistance to stem rust race Ug99 and marker analysis for Sr2, Sr24 and Sr31 in South African wheat cultivars and lines 总被引：1，自引：0，他引：1
The appearance and spread of races of Puccinia graminis f. sp. tritici with virulence for the Sr31 resistance gene has renewed interest in breeding for durable resistance to stem rust of wheat. Since the occurrence of stem
rust has been low in South Africa until the detection of race TTKSF in 2000, breeding for resistance to this disease has not
been a primary objective. The aim of this study was to test bread wheat cultivars and lines at the seedling stage for their
infection response to stem rust, thus determining their level of resistance or vulnerability. A collection of 65 bread wheat
entries was tested with one USA race, two Eastern African races, and three South African races of P. graminis f. sp. tritici. The Eastern African and South African races all belong to the Ug99 lineage. The cultivars Duzi, Caledon, Elands, PAN 3364,
PAN 3191, SST 047, SST 399, and Steenbras produced resistant infection types (IT < 3) to all races. The molecular marker Sr24#50
indicated the presence of Sr24 in 12 entries. In cultivars resistant to TTTTF, TTKSF, and TTKSP but susceptible to TTKSK and PTKST, the iag95 DNA marker
indicated the presence of Sr31 in five wheat lines. Using the cleaved amplified polymorphic sequence marker csSr2, Sr2 was detected in PAN 3377, Inia, and Steenbras. Few South African wheat cultivars appear to have a broad-based resistance
to stem rust, as 88% of the entries were susceptible as seedlings to at least one of the races tested. Diversification of
resistance sources and more directed breeding for stem rust resistance are needed in South Africa. 相似文献
15.
A new powdery mildew resistance gene: Introgression from wild emmer into common wheat and RFLP-based mapping 总被引：28，自引：0，他引：28
An Israeli accession (TTD140) of wild emmer, Triticum turgidum var. dicoccoides, was found resistant to several races of powdery mildew. Inoculation of the chromosome-arm substitution lines (CASLs) of
TTD140, in the background of the Israeli common wheat cultivar ‘Bethlehem’ (BL), with five isolates of powdery mildew revealed
that only the line carrying the short arm of chromosome 2B of wild emmer (CASL 2BS) exhibited complete resistance to four
of the five isolates. To map and tag the powdery mildew resistance gene, 41 recombinant substitution lines, derived from a
cross between BL and CASL 2BS, were used to construct a linkage map at the gene region. The map, which encompasses 69.5 cM
of the distal region of chromosome arm 2BS, contains six RFLP markers, a morphological marker (glaucousness inhibitor, W1
I), and the powdery mildew resistance gene. Segregation ratios for resistance in F2 of BL × CASL 2BS and in the recombinant lines, combined with the susceptability of F1 progeny to all tested isolates, indicate that resistance is controlled by a single recessive allele. This alleleco-segregated
with a polymorphic locus detected by the DNA marker Xwg516, 49.4 cM from the terminal marker Xcdo456. The new powdery mildew resistance gene was designated Pm26.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
16.
Stripe rust and leaf rust caused by Puccinia striiformis (Ps) Westend. and P. triticina (Pt) Eriks., respectively, are important foliar diseases of wheat worldwide. Breeding resistant wheat cultivars is the preferred strategy to control these diseases. Genes for resistance when introgressed from alien species or wheats of lower ploidy are frequently diluted effectiveness in the hexaploid wheat background or are completely suppressed. The objective of this study was to examine the expression of wheat stripe rust and leaf rust resistances derived from wild emmer wheat and Aegilops tauschii when combined in synthetic hexaploid lines. Eight amphidiploid wheat lines, synthesized by crossing five tetraploid wheats (AABB), viz. Triticum carthlicum var. darginicum, T. carthlicum var. fuligioscum, T. dicoccoides var. fuligioscum, T. durum with five lines of Ae. tauschii (DD), were evaluated in the seedling stage for resistance to five pathotypes of stripe rust caused by Ps and four pathotypes of leaf rust caused by Pt. Resistance in one or both parents was frequently suppressed in synthetic hexaploid lines, indicating the presence of suppressor genes in both Ae. tauschii and T. carthlicum var. darginicum. Specific suppression of resistance genes in the parental genotypes and to pathotypes of Ps and Pt were also observed. The presence and specificity of the suppressors for rust resistance obtained in this study provides useful knowledge for developing cultivars resistant to both rusts utilizing such genetic stocks in wheat breeding programs. 相似文献
17.
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
18.
The purpose of this study was to identify the species of local landraces of wheat (Triticum spp.), held in the Israel Gene
Bank, to evaluate them for basic characters and to assess their response to infection by two rust fungi under artificial inoculation
conditions. One-hundred-thirty one seed samples were collected from local or Beduin farmers during 1978–1981 throughout the
Galilee, Mt. Gilboa. Judean Desert and the south Negev. The samples were collected and stored in the Israel Gene Bank without
any characterization or evaluation. Each accession was planted in a 1 m row at Bet Dagan and grown under favorable conditions
for plant growth and rust development. Determination of the species, data of plant height, days to heading and reaction of
the landraces to artificial inoculation with a composite inoculum of Puccinia recondita and P. striiformis were collected
from each row. A small part of the landraces collection consisted of mixed populations of T. durum and T. aestivum plants,
where one of the two species was predominant. One-hundred-fourteen and 17 accessions from this collection represented, respectively,
Triticum durum and T. aestivum Israel landraces. Large variations were found for all the characters examined. Of the total
accessions, 6.5% (8 accessions) and 32% (42 accessions) were resistant, respectively, to yellow- and leaf-rust. It was concluded
that the diversified populations of the local landraces of wheat can be used as a source not only for genes affecting basic
characters such as plant height and heading date, but also for resistance to leaf rust and yellow rust.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
Summary Common and durum wheat populations obtained from Sweden and originally collected in Ethiopia were screened for resistance to steum rust and leaf rust. Resistant selections of common wheat were crossed and backcrossed with either stem rust susceptible RL6071, or leaf rust susceptible Thatcher. Genetic studies, based largely on tests of backcross F2 families, showed that four of the selections had in common a recessive gene SrA. Plants with this gene were resistant (1+ infection type) to all stem rust races tested. This gene was neither Sr26 nor Sr29. The resistance of other selections, based on tests with an array of rust isolates, was due to various combinations of Sr6, 8a, 9a, 9d, 9c, 11, 13, 30, and 36. One of the selections had linked genes, Lr19/Sr25. Another selection had a dominant gene for resistance (;1 infection type) to all the races of leaf rust. With the possible exception of this gene for leaf rust resistance and SrA, no obviously new resistance was found. 相似文献
20.
Wheat pre-breeding using wild progenitors 总被引：6，自引：1，他引：6
J. J. Valkoun 《Euphytica》2001,119(1-2):17-23
To facilitate the use of wheat wild relatives in conventional breedingprograms, a wheat pre-breeding activity started at ICARDA in 1994/1995season. Preliminary results of gene introgression from wild diploidprogenitors, Triticum urartu, T. baeoticum, Aegilops speltoides andAe. tauschii and tetraploid T. dicoccoides are described. Crosseswith wild diploid Triticum spp. yielded high variation in plant andspike morphology. Synthetic hexaploids were produced from crosses of alocal durum wheat landrace `Haurani' with two Ae. tauschiiaccessions. Both Ae. tauschii accessions carry hybrid necrosis allelesthat gave necrotic plant phenotypes in crosses with some bread wheats.Backcross progenies with agronomical desirable traits, i.e. high spikeproductivity, short plant stature, earliness, drought tolerance and highproductive tillering, were identified in crosses of durum wheat with wild Triticum spp. and in a cross of one of the hexaploid synthetics with alocally adapted bread wheat cv. `Cham 6'. Resistance to yellow rust wasfound in durum wheat crosses with the three wild Triticum spp. andAe. speltoides and leaf rust resistance was identified in crosses withT. baeoticum and Ae. speltoides. The results show that wheatimmediate progenitors may be a valuable and readily accessible source ofnew genetic diversity for wheat improvement. 相似文献