Intergeneric hybrids between Hordeum jubatum (4x) and Triticum aestivum (6x)

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 245-249 ◽  
Author(s):  
A. Comeau ◽  
G. Fedak ◽  
C. A. St-Pierre ◽  
R. Cazeault

Twelve embryos of interspecific hybrids between Hordeum jubatum (4x) and Triticum aestivum (6x) cv. Fukuho were produced out of 280 pollinated florets. Embryos were minute and globular and only one of them was successfully grown in vitro. Plant morphology of the hybrid was intermediate between the two parents and hybrid vigor was observed. Several traits of the hybrid were characteristic of the Hordeum parent such as brittle rachis, long awn, outerglume characteristics, and foliage waxiness being the most prominent. Average meiotic chromosome pairing in the hybrid was 28.6 univalents + 3.2 bivalents + 0.007 trivalents, which is not above what would be expected in a common wheat haploid.Key words: intergeneric hybrids, Critesion, Hordeum, Triticum, meiosis.

Genome ◽  
1992 ◽  
Vol 35 (1) ◽  
pp. 98-102 ◽  
Author(s):  
Qin Chen ◽  
Joseph Jahier ◽  
Yvonne Cauderon

Triticum aestivum cv. Chinese Spring (2n = 6x = 42, ABD genomes) was crossed with diploid Inner Mongolian Agropyron Gaertn. species A. cristatum and A. mongolicum and reciprocal hybrids between them (2n = 2x = 14, P genome, with or without B chromosomes). Intergeneric hybrids with 2n = 27, 28, 32, and 33 chromosomes were produced by the aid of embryo rescue. The extra chromosomes in two hybrids were assumed to be B chromosomes transmitted by the male Agropyron parent. Average meiotic pairing in the euploid hybrid with 28 chromosomes was 14.38 univalents + 4.92 bivalents + 1.26 trivalents. This level of pairing higher than expected was likely due to homeologous associations between wheat chromosomes. This data indicates that the P genome of diploid as well as tetraploid Agropyron originating from Inner Mongolia possess a genetic system interfering with 5B homoeologous restricting system of wheat.Key words: intergeneric hybrids, Triticum aestivum, diploid Agropyron species, chromosome pairing.


Genome ◽  
1990 ◽  
Vol 33 (5) ◽  
pp. 663-667 ◽  
Author(s):  
Qin Chen ◽  
Joseph Jahier ◽  
Yvonne Cauderon

Three hybridizations of Triticum aestivum cv. Chinese Spring (CS) (2n = 42) with Agropyron mongolicum (2n = 14), A. michnoi (2n = 28), and A. desertorum (2n = 28) are reported for the first time. Hybrid embryos were obtained at frequencies of 0.24, 1.13, and 2.05%, respectively. The hybrid plants obtained from pollinating CS by A. mongolicum had the expected chromosome number of 2n = 4x = 28, but as a result of hybrid necrosis, none could be raised to the adult stage. Hybrids CS × A. michnoi and CS × A. desertorum both had 2n = 5x = 35 chromosomes. The average meiotic chromosome pairing per cell was 7.04 I + 12.14 II + 1.06 III + 0.07 IV + 0.02 V + 0.02 VI and 9.29 I + 11.05 II + 1.14 III + 0.05 IV, respectively. Their analysis leads to the conclusions that (i) the two Agropyron genomes in the hybrids share a high degree of homology, thus revealing that tetraploid Agropyron species are true autoploids (genome constitution PPPP) and (ii) gene(s) in the Agropyron species suppress the activity of the homoeologous pairing control system of wheat. The possibility of gene transfer from Agropyron to wheat is discussed.Key words: intergeneric hybrids, Triticum aestivum, Agropyron species, hybrid necrosis, chromosome pairing.


1985 ◽  
Vol 27 (4) ◽  
pp. 387-392 ◽  
Author(s):  
George Fedak

Hybrids were obtained by pollinating Hordeum vulgare cv. Betzes with Agropyron caninum (4x) and A. dasystachyum (4x) at frequencies of 1.4 and 6.1% of pollinated florets, respectively. The hybrids were sterile and phenotypically resembled the paternal parent, except for floret structure which was intermediate between the parental types. Chromosome pairing at meiosis was very low and thus provided no indication of homoeology between parental genomes. Abnormal meiotic chromosome behavior in meiocytes that occurred in sectors on the 'Betzes' × A. dasystachyum hybrid was attributed to abnormal spindle fibre function.Key words: intergeneric hybrids, Hordeum vulgare, Agropyron caninum, Agropyron dasystachyum.


Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 622-628 ◽  
Author(s):  
Sawsan S. Youssef ◽  
R. Morris ◽  
P. S. Baenziger ◽  
C. M. Papa

Karyotype stability, which is essential when using wheat (Triticum aestivum L.) doubled haploids in a breeding program, was evaluated in 14 anther-derived doubled-haploid lines after at least three generations of selfing, by crossing them as females with the parent cultivar 'Centurk' and doing cytological studies on the progenies. There were no deviations from the hexaploid chromosome number (2n = 42) in root tips. Meiotic chromosome pairing was as stable as that in the control ('Centurk' × 'Centurk') in most progenies. Chromosomal structural changes and (or) behavioral deviations were detected at the metaphase I, anaphase I, telophase I, and quartet stages of meiosis in a minor proportion of the cells. The frequencies of multivalents, lagging bivalents and univalents, bridges, and micronuclei were higher in some progenies than in the control. Chromosomal fragments were infrequent. The ranges in percentages of normal cells were 72.4–90.0 at anaphase I, 76.4–92.6 at telophase I, and 82.6–93.2 at quartet stages in the doubled-haploid progenies, compared with 95–100, 92–100, and 94–96, respectively, in the control. On the basis of these results, the doubled-haploid lines should produce enough normal gametes to provide adequate seed supplies when they are used as parents in wheat cultivar and population improvement.Key words: Triticum aestivum, chromosome pairing, chromosome aberrations, gametoclonal variation.


Genome ◽  
1994 ◽  
Vol 37 (5) ◽  
pp. 876-881 ◽  
Author(s):  
Gan-Yuan Zhong ◽  
Patrick E. Mcguire ◽  
Calvin O. Qualset ◽  
Jan Dvořák

Barley yellow dwarf is the most damaging virus-caused disease in bread wheat (Triticum aestivum L.). A resistant line, SW335.1.2-13-11-1-5 (2n = 47), derived from a cross of T. aestivum × Lophopyrum ponticum was characterized by meiotic chromosome pairing, by in situ DNA hybridization and by expression of molecular markers to determine its chromosome constitution. All progeny of this line had three pairs of L. ponticum chromosomes from homoeologous chromosome groups 3, 5, and 6 and the 2n = 47 progeny had an additional L. ponticum monosome. The pairs from groups 3 and 6 were in the added state, while the group 5 pair was substituted for wheat chromosome 5D. Several wheat–wheat translocations with respect to the parental wheat genotype occurred in this line, presumably owing to the promotion of homoeologous chromosome pairing by L. ponticum chromosomes. It was hypothesized that homoeologous recombination results in homoeologous duplication–deletions in wheat chromosomes. An aberrant 3:1 disjunction creates the potential at each meiosis for replacement of these wheat chromosomes by homoeologous L. ponticum chromosomes. Wheat chromosomes 3A and 6A appeared to be in intermediate stages of this substitution process.Key words: wheat, wheatgrass, Lophopyrum, barley yellow dwarf virus, disease resistance, homoeologous chromosome recombination, homoeologous pairing, alien chromosome substitution.


Euphytica ◽  
2014 ◽  
Vol 200 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Tomonari Kishimoto ◽  
Miki Yamakawa ◽  
Daisuke Nakazawa ◽  
Junji Amano ◽  
Sachiko Kuwayama ◽  
...  

1971 ◽  
Vol 18 (3) ◽  
pp. 311-328 ◽  
Author(s):  
A. M. Wall ◽  
Ralph Riley ◽  
Victor Chapman

SUMMARYPlants of Triticum aestivum (2n = 6x = 42) ditelocentric 5BL were treated with EMS in order to produce mutations in the 5B system by which meiotic pairing between homoeologous chromosomes is normally prevented. To check for the occurrence of mutation T. aestivum ditelo-5BL plants were pollinated with rye (Secale cereale 2n = 14) and meiosis was examined in the resulting hybrids.Wheat-rye hybrids were scored for the presence of mutants when the wheat parents were either the EMS-treated wheat plants, or their selfed derivatives, or their progenies obtained after pollination with untreated euploid individuals.Mutants were detected by each of these procedures and mutant gametes were produced by the treated ditelocentric plants with frequencies between 1·5 and 2·5%, but there were differences between the mutants in the extent to which homoeologous pairing occurred in the derived wheat-rye hybrids. The differences may have resulted from the occurrence of mutation at different loci or to different extents at the same locus.Two mutants, Mutant 10/13 and Mutant 61, were fixed in the homozygous condition. Mutant 10/13 was made homozygous both in the 5BL ditelocentric and in the euploid conditions but these genotypes regularly formed 21 bivalents at meiosis, and there was no indication of homoeologous pairing although the mutant 10/13 gave rise to homoeologous pairing in wheat-rye hybrids.


1970 ◽  
Vol 12 (2) ◽  
pp. 278-282 ◽  
Author(s):  
C. J. Driscoll ◽  
C. J. Quinn

Genetic differences which affect the extent of homoeologous chromosome pairing in intergeneric hybrids have been demonstrated between varieties of Triticum aestivum. Each of seven varieties of Triticum was crossed with the same strain of Aegilops variabilis. Significant differences in chiasma frequencies between varieties were found. Varieties Eureka, Gamut and Chinese Spring constitute one group with a relatively low chiasma frequency and varieties A. R. Falcon, Federation and Poso constitute a distinct second group with a relatively high chiasma frequency. The variety Bearded Yalta is intermediate to the two groups. Thus, this genetic variation appears to be common among varieties of Triticum. Presumably this variation does not become subject to natural selection as long as chromosome pairing in the parental varieties remains strictly homologous.


1986 ◽  
Vol 28 (6) ◽  
pp. 947-953 ◽  
Author(s):  
Richard R. -C. Wang ◽  
C. Hsiao

Hybrids of Elymus canadensis (2n = 28; SSHH) × Critesion californicum (2n = 14) and E. canadensis × C. bulbosum (2n = 14) were synthesized at relative frequencies of 11.8 and 0.3%, respectively, by the aid of embryo rescue techniques. A natural hybrid was identified as C. violaceum × C. bogdanii (2n = 14) by a combination of karytotype analysis and plant morphology. Gross spike morphology of the hybrids was intermediate to that of the parents. Meiotic chromosome pairings in these hybrids suggested that the genome of C. californicum and C. bogdanii is more or less homologous with one of the two genomes of E. canadensis. Genomes of C. violaceum and C. bulbosum appeared to be different from each other and from those in C. bogdanii and C. californicum. Based on the data in this study and others, the degree of genome differentiation among some Critesion and some Elymus species containing the H genome was examined and discussed. The symbol H is proposed for the genome in C. bogdanii and C. californicum, Hv for C. violaceum, Hb for C. bulbosum, and Hc for C. chilense.Key words: interspecific hybrids, synapsis, phylogeny, Hordeum, Elymus, Critesion.


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