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1.
Synthetic hexaploid wheat, produced by combining tetraploid wheat (AB genome) with Triticum tauschii (D genome), was crossed to modern hexaploid wheat (Triticum aestivum ABD genome) in an attempt to introduce new cold hardiness genes into the common hexaploid wheat gene pool. The cold hardiness levels of F) hybrids ranged from similar to parental means to equal to the hardy parent, indicating that cold hardiness was controlled by both additive and dominant genes. As expected when dominant gene action is involved, differences between F2 and parental means were smaller than comparable differences in the F., Frequency distributions of F2—derived F3 lines also suggested that dominant genes were involved in the control of cold hardiness in some crosses. Heritability estimates for cold hardiness ranged from 63 to 70 % indicating that selection for cold hardiness should be effective in populations arising from crosses between common and synthetic hexaploid wheat. However, high selection pressure on the progeny of crosses that included the most hardy T. aestivum, T. durum, and T. tauschii accessions as parents did not identify transgressive segregates for improved cold hardiness. These observations indicate that the close wheat relatives, sharing common genomes with T. aestivum, are not promising sources of new genes to increase the maximum cold hardiness potential of common hexaploid wheat. 相似文献
2.
Summary Male-sterile plants of reduced vigor were obtained by substitutingT. aestivum and/orT. durum genomes into the cytoplasm ofT. boeoticum, T. monococcum and amphidiploidT. boeoticum-A. squarrosa. Apparent segregation for plant vigor occurred even in advanced generations of the following backcross progenies:T. boeoticum/12*T. durum, T. monococcum/10*T. durum, T. boeoticum/2*T. durum//7*T. aestivum, amphidiploidT. boeoticum-A. squarrosa/6*T. durum and amphidiploidT. boeoticum-A. squarrosa/8*T. aestivum. Highly fertile F1 hybrids of normal vigor were obtained from crosses of A lines of common wheat in the cytoplasm of amphidiploidT. boeoticum-A. squarrosa orT. timopheevi with R lines having male fertility restoring factors fromT. boeoticum, T. boeoticum-A. squarrosa andT. zhukovskyi. Apparently, vigor-genes complemented the male fertility restoring genes to produce fertile hybrids of normal plant vigor in the crosses amphidiploidT. boeoticum-A. squarrosa/6*T. aestivum, Chris//amphidiploidT. boeoticum-A. squarrosa/T. durum/T. aestivum, Chinese Spring, andT. zhukovskyi/3*T. aestivum, Justin F8 R lines.Published with the approval of the Director, North Dakota State Agricultural Experiment Station, as Journal Article No. 231Associate Professors of Agronomy. 相似文献
3.
W. Sodkiewicz 《Plant Breeding》1992,109(4):287-295
Four hexaploid triticale lines were crossed as females with a T. monococcum×S. cereale amphiploid (AmAmRR), with the aim of introducing the genetic material of diploid wheat. F1-plants (AmABRR)were back-crossed with a parental form of 6×-triticale as male and progenies were subjected to four different types of pollination with the aim of finding the optimal one in respect to gradual stabilization of introgressive hexaploid karyotypes. Beginning with BC1-plants, a strong tendency to decrease the somatic chromosome number was observed. In subsequent generations this was accompanied by the decrease of seed germination and plant fertility. Both of these characters showed statistically significant dependence on somatic chromosome number variation which was analyzed in BC1/F2 and BC2 populations. Based on spike fertility, an effective selection pressure was applied to restitute the hexaploid chromosome number. In the BC1/F4 generation, the first morphologically uniform secondary hexaploid lines were selected. 11.4% of the lines showed a non-waxy spike — a morphological marker transmitted from T. monococcum. 相似文献
4.
Direct introgression of genes from diploid Aegilops squarrosa L into hexaploid wheat (Tnticum aestivumL.) is an efficient way of developing stable, hexaploid lines with unique, useful genes. 39 such lines derived front direct crosses to determine the effects of Ac. squarrosa germplasm were field-tested on productivity. Whereas some lines were agronomically inferior to the recurrent parent, others periormed at an equall or better level. In addition to the larget traits (Hessian-fly and leaf-rust resistance), other traits, including soilborne-mosaic-virus resistance and protein concentration, were improved. 相似文献
5.
Agronomical performance and breeding value of selected strains of diploid wheat,Triticum monococcum 总被引：1，自引：0，他引：1
Victor Vallega 《Euphytica》1992,61(1):13-23
Summary Twenty-one germplasm accessions and breeding lines of einkorn wheat (Triticum monococcum ssp. monococcum and ssp. sinskajae) were grown at two sites in Italy and evaluated for various field and seed characteristics. Grain yields of germplasm accessions were relatively high (317–3238 kg/ha), but distinctly lower than those of four modern cultivars of tetraploid (T. turgidum ssp. durum) and hexaploid wheat (T. aestivum ssp. Aestivum) included in the experiments as controls. As expected, all Einkorns-including some substantially higher yielding crossbred lines (3415–4362 kg/ha)-were defective for one or more agronomically relevant features. However, a few of the accessions examined were found to contain, as a group, practically all the genes needed to breed monococcums having the main field attributes of a modern wheat cultivar: high yielding capacity, good threshability, large kernel size, earliness, short stature and adequate lodging resistance. Still higher yielding diploid wheats, more responsive to improved growing conditions and of better seed quality, could probably be obtained from crosses with wild monococcums bearing mostly two-seeded florets and with accessions producing less slender-shaped kernels. Some of the Einkorns examined were found to carry minor genes for easy threshing which might enhance the efficacy of the major gene for soft glumes carried by T. monococcum ssp. sinskajae, a partially free-threshing diploid wheat taxon. Seed protein percentage of monococcums was markedly higher than that of durum and bread wheat cultivars even in those cases where their grain yields surpassed those of the polyploid checks. The possibilities offered by diploid wheat in the exploitation of novel endosperm mutants and F1 hybrid vigour, as well as in the fields of celiac disease, crop diversification and resistance to agro-biological stresses are discussed. Breeding priorities and strategies are also proposed. 相似文献
6.
Interspecific hybrids and backcross generations between the wild perennial species Helianthus resinosus, Helianthus paucifiorus, Helianthus laevigatus, Helianthus nuttallii ssp. nuttallii T. & G. and Helianthus giganteus, resistant to broomrape (Orobanche cernua) and susceptible inbred lines were obtained to study crossability to cultivated sunflower and the transmission and expression of resistance to this parasitic weed. Conventional crosses with all the species tested were successful except for the crosses with diploid H. giganteus, for which embryo rescue techniques were needed to overcome hybrid incompatibility. Pollen viability and seed set were highest for F1 hybrids with hexaploid species and lowest for those with the diploid H. giganteus. We evaluated F1, BC1F1, some BC2F1 plants and the wild and cultivated parents. The wild species and interspecific hybrids were resistant to broomrape infection except for H. nuttallii, which showed segregation, indicating that the resistance is dominant. The crossability and resistance of F1, and back-cross generations of species with different ploidy levels indicate that the transfer of broomrape resistance to cultivated sunflower is feasible. 相似文献
7.
Flanking sequences of the puroindoline a(pinA) and puroindoline b (pinB) genes from Triticum monococcum, T. urartu, Aegilops speltoides and A. tauschii were obtained by inverse PCR. Two accessions from each of these related diploid taxa were sequenced, and the sequences compared
to those of the soft hexaploid wheat cultivar `Penawawa'. As expected from the origin of the D-genome in hexaploid wheat,
the highest sequence identity was observed for the A. tauschii sequences, whereas the sequences for A.speltoides were the most divergent. The promoter sequences were further analyzed for putative regulatory elements, and the possible
significance of several highly conserved sequence motifs is discussed. Western blots of Triton X-114 extracted proteins separated
by SDS-PAGE confirmed the accumulation of pinA and pinB gene products in the endosperm of all the germplasm lines studied. The deduced amino acid sequences for the related diploid
taxa do not imply any major structural changes as compared to the wild-type T. aestivum puroindolines, and is therefore in agreement with the soft endosperm texture of these species.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
Summary Ten varieties of Triticum aestivum and three synthetic T. durum + Aegilops squarrosa
hexaploids were crossed with an Ae. bicornis + Ae. squarrosa amphiploid. 55 hybrid plants involving 9 different combinations developed necrosis and died before maturity. The two plants which survived were both from the F1 with a synthetic hexaploid, T. durum var. Carleton + Ae. squarrosa.The genetic necrosis developing in these hybrids differed from hybrid necrosis and red hybrid chlorosis both in symptoms and in the genetic basis. The symptoms were similar to those reported for a number of Triticum x Aegilops hybrids in which Ae. bicornis and Ae. squarrosa were involved but the genetic basis was not determined. The survival of 2 of the 13 progenies from one cross is discussed.
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9.
Summary Wheat pentaploids were produced by hybridizing a high kernel weight (1000 grain wt=56 g), high protein (25.4%) line of wild tetraploid wheat (Triticum turgidum dicoccoides) as male parent, with the three hexaploids (T. aestivum) — normal Chinese Spring and its two homoeologous pairing mutants, ph
1b and ph
2. The pentaploids were crossed as female parents to the two commercial hexaploid cultivars Warigal and Barkaee and 42-chromosome stable plants selected from the F1 of the pentaploid x hexaploid crosses.Mean protein content of certain F3 lines from all six pentaploid x hexaploid crosses was significantly higher than Chinese Spring and the respective commercial hexaploid parent (p<0.005) indicating high protein had been transferred from the tetraploid to the hexaploid level.Kernel weight amongst certain F3 lines of the three pentaploids x Barkaee was significantly (p<0.0005) higher than either Chinese Spring or Barkaee, indicating the transfer also of high kernel weight from the tetraploid to the hexaploid level. However kernel weight was not significantly increased over Warigal in any F3 lines of its crosses with the three pentaploids.High levels of homoeologous chromosome pairing in the ph-mutant pentaploids, plus evidence for significant modification of the composition of high-molecular weight (HMW) glutenin subunits of grain protein in certain F3 derivatives of the ph-mutant pentaploid x hexaploid, crosses indicates that the ph-mutant-derived lines may possess novel (intergenome) genetic recombination, at least for high protein, and possibly kernel weight. 相似文献
10.
The multiploid mutant of durum wheat is a genotype that produces unreduced gametes. Our objective was to test the recovery of pentaploid hybrids in crosses of the mutant with rye and Triticum monococcum L. Compared with check crosses, the mutant had a two‐third reduction in percent seed set for rye crosses, but had only a slight decrease in crossability with T. monococcum. Pentaploid hybrids were associated with plump seeds of the mutant/rye cross, and with shrivelled seeds of the mutant/T. monococcum cross. We suggest that the endosperm balance number hypothesis explains the association of pentaploid hybrids with endosperm type. This association made for easy recovery of pentaploid hybrids from crosses to both species. Mature, plump seeds from the mutant/rye cross were germinated and pentaploid hybrids were recovered. One pentaploid hybrid was recovered for every 50.5 and 15.1 florets pollinated with rye and T. monococcum, respectively. Unreduced gametes in the multiploid mutant will facilitate interspecific hybridization by reducing the time to produce pentaploid plants. 相似文献
11.
Summary Resistance to septoria nodorum blotch in Triticum monococcum, T. tauschii, T. timopheevii, T. dicoccum and T. durum was evaluated on plants at the three-leaf stage in greenhouse tests. A high frequency of resistant genotypes was found in T. monococcum, T. tauschii and T. timopheevii, but not in T. dicoccum and T. durum. The resistance of F1 plants of crosses of resistant T. monococcum (PI 289599) and T. timopheevii (PI 290518) accessions with susceptible common wheat cv. Park and durum wheat cv. Wakooma, respectively, was evaluated on the basis of percentage leaf necrosis, lesion number, lesion size and incubation period. No dominance was found for long incubation period, but various dominance relationships occurred for low percentage leaf necrosis, low lesion number and small lesion size, depending on the cross. Multiple regression analysis showed that lesion number contributed more to percentage leaf necrosis than lesion size or incubation period. Resistance to septoria nodorum blotch was transferred successfully from T. timopheevii to cultivated durum wheat. Resistant BC1F7 lines, recovered from the T. timopheevii (PI 290518) × Wakooma cross, showed normal chromosome behaviour at meiosis (14 bivalents) and were self-fertile. However, an effective level of resistance was not recovered in lines derived from the other interspecific crosses. 相似文献
12.
Diploid wheat, Triticum monococcum s.l., is a host for the wheat leaf rust fungus, Puccinia triticina. Some accessions have been reported to show a high degree of prehaustorial resistance. This is non-hypersensitivity resistance,
which acts before the formation of haustoria by the pathogen. To assess the frequency of prehaustorial resistance 598 accessions
of diploid wheat were inoculated with the wheat leaf rust isolate Felix. Most T. monococcum s.s. accessions (84%) were resistant whereas all T. urartu and all but three T. boeoticumaccessions were susceptible. Histological components analysis revealed that a high percentage of prehaustorial resistance
to P. triticina was found in only three T. monococcum accessions. No haustoria were observed in such infection units confirming the prehaustorial nature of the resistance. Prehaustorial
abortion of certain infection units in an accession always coincided with posthaustorial abortion of the other infection units.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
13.
The inheritance of resistance to root‐lesion nematode was investigated in five synthetic hexaploid wheat lines and two bread wheat lines using a half‐diallel design of F1 and F2 crosses. The combining ability of resistance genes in the synthetic hexaploid wheat lines was compared with the performance of the bread wheat line ‘GS50a’, the source of resistance to Pratylenchus thornei used in Australian wheat breeding programmes. Replicated glasshouse trials identified P. thornei resistance as polygenic and additive in gene action. General combining ability (GCA) of the parents was more important than specific combining ability (SCA) effects in the inheritance of P. thornei resistance in both F1 and F2 populations. The synthetic hexaploid wheat line ‘CPI133872’ was identified as the best general combiner, however, all five synthetic hexaploid wheat lines possessed better GCA than ‘GS50a’ The synthetic hexaploid wheat lines contain novel sources of P. thornei resistance that will provide alternative and more effective sources of resistance to be utilized in wheat breeding programmes. 相似文献
14.
Kesara Anamthawat-Jónsson Sigrídur K. Bödvarsdóttir Birkir Th. Bragason Jón Gudmundsson P.K. Martin R.M.D. Koebner 《Euphytica》1997,93(3):293-300
A total of 240 F1 hybrids was made beween wheat (Triticum aestivum L. em. Thell. (2n = 6x = 42) and T. carthlicum Nevski (2n = 4x = 28)) and
perennial lymegrass (North European Leymus arenarius (L.) Hochst. (2n = 8x = 56) and North American L. mollis (Trin.) Pilger
(2n = 4x = 28)). The wide crosses yielded embryos in 20% of caryopses and 96% of the embryos developed into normal hybrid
plants. The hybrids were vegetatively vigorous, with evidence of the Leymus rhizomatous habit. Those deriving from L. arenarius
survived overwintering in Iceland, but the hybrids L. mollis did not, whereas in a milder environment, both showed perenniality.
Cytogenetic analysis of root tip cells before the plants were treated with colchicine showed that 21 out of 28 hybrids investigated
had chromosome mosaics, with a population of both amphihaploid and amphidiploid cells. This spontaneous doubling of somatic
chromosomes occurred in all cross combinations, with the highest average frequency of diploid cells (28%) in T. carthlicum
× L. arenarius crosses. A few selfed seeds have been obtained from a T. aestivum × L. arenarius hybrid. All the hybrids were
treated twice with colchicine, but the treatment appeared to have little or no effect on the frequency of chromosome doubling
in the hybrids deriving from T. aestivum. The frequency of diploid cells, however, increased significantly (e.g. to 80%) in
the hybrids deriving from the T. carthlicum parent. Genomic in situ hybridization confirmed the hybridity of the plants and
showed that the hybrids were amphiploids containing genomes of both wheat and lymegrass. In situ hybridization using ribosomal
DNA probe differentiated chromosomes of L. mollis, L. arenarius from those of wheat. The hybrids are being backcrossed with
lymegrass pollen, aiming to domesticate the wild, perennial species.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
The wheat progenitors and other wild relatives continue to be important sources of genes for agronomically desirable traits, which can be transferred into durum wheat (Triticum turgidum; 2n = 4x = 28; AABB genomes) cultivars via hybridization. Chromosome pairing in durum × alien species hybrids provides an understanding of genomic relationships, which is useful in planning alien gene introgression strategies. Two durum cultivars, ‘Lloyd’ and ‘Langdon’, were crossed with diploid wheatgrass, Thinopyrum bessarabicum (2n = 2x = 14; JJ), to synthesize F1 hybrids (2n = 3x = 21; ABJ) with Ph1. ‘Langdon’ disomic substitution 5D(5B) was used as a female parent to produce F1 hybrids without Ph1, which resulted in elevation of pairing between durum and grass chromosomes – an important feature from the breeding standpoint. The F1 hybrids were backcrossed to respective parental cultivars and BC1 progenies were raised. ‘Langdon’ 5D(5B) substitution × Th. bessarabicum F1 hybrids were crossed with normal ‘Langdon’ to obtain BC1 progeny. Chromosome pairing relationships were studied in F1 hybrids and BC1 progenies using both conventional staining and fluorescent genomic in situ hybridization (fl‐GISH) techniques. Multicolour fl‐GISH was standardized for characterizing the nature and specificity of chromosome pairing: A–B, A–J and B–J pairing. The A–J and B–J pairing will facilitate gene introgression in durum wheat. Multicolour fl‐GISH will help in characterizing alien chromosome segments captured in the durum complement and in their location in the A and/or B genome, thereby accelerating chromosome engineering research. 相似文献
16.
Triticum tauschii provides breeders with a valuable source of resistance and tolerance genes. Elucidation of the inheritance of traits in this species that hinder its use in breeding programmes is therefore of interest to wheat breeders. Inheritance of threshability was investigated in the crosses of four non-free-threshing (NFT) synthetic hexaploids (Triticum turgidum×T. tauschii) and two free-threshing (FT) T. aestivum cultivars during four crop seasons over 3 years at E1 Batan and Ciudad Obregon, Mexico. The parents, their F1 Hybrids and individual F2 plant-derived F3 progenies of the crosses revealed that ‘Altar 84’/T. tauschii (219), ‘Chen’/T. tauschii (205), ‘Chen’/T. tauschii (224), and ‘Duergand’/T. tauschii (214) have independently segregating loci with two dominant alleles controlling threshability. Intercrosses among the synthetics, except ‘Altar 84’/T. tauschii (219), showed the genes to be allelic to each other. The cross between the FT cultivars showed no segregation in the F3 generation, indicating common recessive genes. Based on these findings, population sizes of the synthetic-derived breeding materials should be increased to improve the chances of selecting FT desirable plants in the programme. 相似文献
17.
Taing Aung Pamela Zwer Robert Park Philip Davies Parminder Sidhu Ian Dundas 《Euphytica》2010,174(2):189-198
Two diploid accessions of wild oat, CIav6956 and CIav7233, were identified as carrying seedling resistance to oat crown rust
(caused by Puccinia coronata f. sp. avenae; Pca). Two vigorous interploidy F1 hybrids were generated from crosses involving the hexaploid oat cultivar Wintaroo and the diploid oat Avena strigosa Schreb. accession CIav6956. An additional interploidy F1 hybrid, designated “F1-Aa1”, was produced from a cross of Wintaroo and the diploid oat accession CIav7233. All three hybrids
were more vigorous and taller than the cultivated parent Wintaroo. The three F1 hybrids contained full chromosome complements from both parents (2n = 4x = 28), but no seeds were obtained when the three F1 hybrids were selfed. Meiotic analyses of the hybrids indicated that they exhibited a high degree of inter-genome and intra-genome
pairing. Trivalent configurations were detected in 95–96% of meiotic cells and a minimum of three bivalents was present in
all cells. An average chiasma frequency of 7.2–7.9 per cell was observed for the three F1 hybrids. A fourth F1 hybrid was subsequently generated from a cross between the diploid oat accession CIav7233 and Wintaroo. One octaploid (2n = 8x = 56) was generated from this hybrid and progeny were resistant to two Pca races. The chromosome number of the octaploid progeny varied between 51 and 54 chromosomes. Development of a chromosome addition
line(s) with the crown rust resistance should be possible from these partial-octaploids. 相似文献
18.
Interspecific hybrid plants and backcross 1 (BC1) progeny were produced through sexual crosses and embryo rescue between Brassica carinata accession PI 360883 and B. oleracea cvs Titleist’and‘Cecile’to transfer resistance to powdery mildew to B. oleracea. Four interspecific hybrids were obtained through application of embryo rescue from crosses with B. carinata as the maternal parent, and their interspecific nature confirmed through plant morphology and random amplified polymorphic DNA (RAPD) analysis. Twenty‐one BC1 plants were obtained through sexual crosses and embryo rescue although embryo rescue was not necessary to produce first backcross generation plants between interspecific hybrids and B. oleracea. All interspecific hybrids and eight of the BC1 plants were resistant to powdery mildew. 相似文献
19.
Inheritance of resistance to Karnal bunt was investigated in the crosses of four resistant synthetic hexaploid wheats (SH; Triticum turgidum×T. tauschii) and two susceptible T. aestivum cultivars. The resistance was dominant or partly dominant over susceptibility. The SH cultivars Chen/T. tauschii (205) and Chen/T. tauschii (224) have single dominant resistance genes which could be allelic to each other. ‘Altar 84’/T. tauschii (219) appeared to have two dominant genes for resistance. ‘Duergand’T. tauschii (214) possessed two complementary dominant genes for resistance. The work is being extended to involve diverse Karnal bunt-resistant SH and bread wheat cultivars. 相似文献
20.
Rapid screening of selected European winter wheat varieties and segregating populations for the Glu-D1d allele using PCR 总被引：2，自引：0，他引：2
Forty-two winter wheat varieties and 193 F2 and BC1F2 seeds were screened for Glu-D1d allele encoding the HMW glutenin subunits 5 + 10 using polymerase chain reaction (PCR). The segregating populations originated from crosses involving wheat parents with good and poor bread-making quality. A clear PCR product of 450 bp, representing 1Dx5 of the Glu-D1d allele was identified in 24 varieties and 111 hybrid seeds. Four different Glu-D1 alleles: a (2 + 12), b (3 + 12), c (4 + 12) and d (5 + 10) were detected using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Only genotypes possessing Glu-D1d gave a positive PCR signal, hexaploid triticale and 4 × wheat lacking Glu-D1 locus gave a negative signal. The efficiency of PCR selection for bread-making quality in early generations using half seed is discussed. 相似文献