CYTOGENETICS OF SOME NATURAL INTERGENERIC HYBRIDS BETWEEN ELYMUS AND AGROPYRON SPECIES

1981 ◽  
Vol 23 (1) ◽  
pp. 131-140 ◽  
Author(s):  
R. S. Sadasivaiah ◽  
J. Weijer
Keyword(s):  
Chromosome Pairing ◽  
Vegetative Growth ◽  
Interspecific Hybrids ◽  
Growth Habit ◽  
Intergeneric Hybrids ◽  
Homoeologous Relationships ◽  
Elymus Species

The occurrence of natural interspecific hybrids between Elymus and Agropyron species was detected and verified by cytomorphological studies. The hybrids were highly vigorous and resembled Elymus species in vegetative growth habit, although their spikes were sterile, and intermediate between the putative parents in morphology. Chromosome pairing in the hybrids was highly irregular with 14 to 28 univalents per cell. The formation of up to seven bivalents, with mean frequencies of 2.86 to 3.14 per cell in different hybrids, was attributed to homoeologous relationships existing between the genomes of E. innovatus (JJXX) and those of Agropyron species (SSHH).

Cytology of intergeneric hybrids between Psathyrostachys and Elymus with Agropyron (Poaceae: Triticeae)

Genome ◽  
1992 ◽  
Vol 35 (4) ◽  
pp. 676-680 ◽  
Author(s):  
Kevin B. Jensen ◽  
Ira W. Bickford
Keyword(s):  
Chromosome Number ◽  
Chromosome Pairing ◽  
Intergeneric Hybrids ◽  
Agropyron Cristatum ◽  
Stainable Pollen ◽  
Meiotic Analysis ◽  
C Value ◽  
Elymus Species ◽  
I Cells ◽  
Metaphase I

This paper describes the cytogenetics and fertility of intergeneric hybrids of Psathyrostachys stoloniformis × Agropyron cristatum and two Elymus species, E. dentatus ssp. ugamicus and E. grandiglumis × A. cristatum. Bivalent frequencies of metaphase I cells in the F1 hybrid P. stoloniformis (NN) × Agropyron cristatum (PP) ranged from 0 to 4 per cell, with an average of 0.87 bivalent per cell and a c value of 0.07. The hybrid E. dentatus ssp. ugamicus (SSYY) × A. cristatum (PP) averaged 3.07 bivalents per cell and ranged from 0 to 7 with a c-value of 0.27. Bivalents were predominantly end to end associations. Meiotic analysis in E. grandiglumis (SSYYPP) × A. cristatum (PP) revealed an average of 6.84 bivalents per metaphase I cell with a c value of 0.73. This hybrid had a chromosome number of 2n = 30 rather than the expected 2n = 28. All hybrids had less than 1% stainable pollen and set no seed under open-pollination.Key words: chromosome pairing, meiosis.

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
Keyword(s):  
Triticum Aestivum ◽  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
Meiotic Chromosome ◽  
Plant Morphology ◽  
Intergeneric Hybrids ◽  
Hybrid Vigor ◽  
Brittle Rachis ◽  
Hordeum Jubatum

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.

CHROMOSOME PAIRING IN TWO INTERSPECIFIC HYBRIDS OF TRIFOLIUM

1970 ◽  
Vol 12 (4) ◽  
pp. 790-794 ◽  
Author(s):  
Chi-Chang Chen ◽  
Pryce B. Gibson
Keyword(s):  
Phylogenetic Relationship ◽  
Chromosome Pairing ◽  
Trifolium Repens ◽  
Interspecific Hybrids ◽  
Triploid Hybrid ◽  
Close Phylogenetic Relationship ◽  
Metaphase I

Both Trifolium repens (2n = 32) and T. nigrescens (2n = 16) formed bivalents during meiosis. However, their triploid hybrid showed an average of 4.27 trivalents per microsporocyte at metaphase I. The frequency of trivalents in the hybrid between T. nigrescens and autotetraploid T. occidentale (2n = 32) was 5.69. The data are interpreted to indicate: (1) a possible autotetraploid origin of T. repens; and (2) a close phylogenetic relationship among T. repens, T. nigrescens and T. occidentale.

Intergeneric hybrids of Hordeum vulgare with Agropyron caninum and A. dasystachyum

1985 ◽  
Vol 27 (4) ◽  
pp. 387-392 ◽  
Author(s):  
George Fedak
Keyword(s):  
Hordeum Vulgare ◽  
Chromosome Pairing ◽  
Meiotic Chromosome ◽  
Intergeneric Hybrids ◽  
Spindle Fibre ◽  
Chromosome Behavior ◽  
Paternal Parent ◽  
Agropyron Caninum

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.

Cytogenetics of Elymus caucasicus and Elymus longearistatus (Poaceae: Triticeae)

Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 860-867 ◽  
Author(s):  
Kevin B. Jensen ◽  
Richard R.-C. Wang
Keyword(s):  
Chromosome Pairing ◽  
Interspecific Hybrid ◽  
Intergeneric Hybrids ◽  
Cytological Analysis ◽  
Meiotic Behavior ◽  
Pseudoroegneria Spicata ◽  
Central Asian ◽  
Elymus Lanceolatus

Two accessions of Elymus caucasicus (Koch) Tzvelev and three accessions of Elymus longearistatus (Boiss.) Tzvelev were studied to determine the meiotic behavior and chromosome pairing in the two taxa, their interspecific hybrid, and their hybrids with various "analyzer" parents. Interspecific and intergeneric hybrids of the target taxa were obtained with the following analyzer species: Pseudoroegneria spicata (Pursh) A. Löve (2n = 14, SS), Pseudoroegneria libanotica (Hackel) D. R. Dewey (2n = 14, SS), Hordeum violaceum Boiss. &Hohenacker (2n = 14, HH) (= Critesion violaceum (Boiss. &Hohenacker) A. Löve), Elymus lanceolatus (Scribn. &Smith) Gould (2n = 28, SSHH), Elymus abolinii (Drob.) Tzvelev (2n = 28, SSYY), Elymus pendulinus (Nevski) Tzvelev (2n = 28, SSYY), Elymus fedtschenkoi Tzvelev (2n = 28, SSYY), Elymus panormitanus (Parl.) Tzvelev (2n = 28, SSYY), and Elymus drobovii (Nevski) Tzvelev (2n = 42, SSHHYY). Cytological analysis of their F1 hybrids showed that E. caucasicus and E. longearistatus were allotetraploids comprising the same basic genomes. Chromosome pairing in the E. caucasicus × P. libanotica hybrid demonstrated that the target taxa contained the S genome, based on 6.1 bivalents per cell. The lack of chromosome pairing, less than one bivalent per cell, in the E. longearistatus × H. violaceum hybrid showed that the H genome was absent. Increased pairing in the tetraploid and pentaploid hybrids when the Y genome was introduced indicated that the second genome in the two taxa was a segmental homolog of the Y genome. The S and Y genomes in E. caucasicus and E. longearistatus have diverged from each other and from those in many of the eastern and central Asian SY tetraploids.Key words: genome, meiosis, chromosome pairing, morphology, hybrid, Triticeae.

Suppression of homologous pairing between chromosomes of A and B genomes of 4x and 6x wheats by Hordeum californicum Covas and Stebbins

Genome ◽  
1988 ◽  
Vol 30 (1) ◽  
pp. 8-11
Author(s):  
H. S. Balyan ◽  
G. Fedak
Keyword(s):  
Chromosome Pairing ◽  
Chinese Spring ◽  
Chiasma Frequency ◽  
Mother Cell ◽  
Triticum Turgidum ◽  
Regulatory Gene ◽  
Intergeneric Hybrids ◽  
Homologous Pairing ◽  
Meiotic Analysis ◽  
Hybrid Plants

Three hybrids of Triticum turgidum cv. Ma with Hordeum californicum × T. aestivum cv. Chinese Spring amphiploid were obtained at a frequency of 1.6% of the pollinated florets. Meiotic analysis of the hybrid plants revealed an average chiasma frequency per pollen mother cell ranging from 15.27 to 17.60. The lower than expected chromosome pairing in the hybrid plants was attributed to the suppression of pairing between homologous wheat chromosomes by pairing regulatory gene(s) in H. californicum.Key words: intergeneric hybrids, Hordeum californicum, Triticum turgidum, meiosis, chromosome pairing.

Evidence for genetic suppression of heterogenetic chromosome pairing in polyploidy species of Solanum, sect. Petota

1983 ◽  
Vol 25 (5) ◽  
pp. 530-539 ◽  
Author(s):  
Jan Dvořák
Keyword(s):  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
Diploid Species ◽  
Diploid Hybrid ◽  
Polyploid Species ◽  
Chromosome Differentiation ◽  
Genetic Suppression ◽  
Solanum Sect ◽  
Paradoxical Results

Data on chromosome pairing in haploids and interspecific hybrids of Solanum, sect. Petota reported in the literature were used to determine whether the diploidlike chromosome pairing that occurs in some of the polyploid species of the section is regulated by the genotype or brought about by some other mechanism. The following trends emerged from these data. Most of the polyploid × polyploid hybrids had high numbers of univalents, which seemed to indicate that the polyploid species were constructed from diverse genomes. Haploids, except for those derived from S. tuberosum, had incomplete chromosome pairing. All hybrids from diploid × diploid crosses had more or less regular chromosome pairing, which suggested that all investigated diploid species have the same genome. Likewise, hybrids from polyploid × diploid crosses had high levels of chromosome pairing. These paradoxical results are best explained if it is assumed that (i) the genotypes of most polyploid species, but not those of the diploid species, suppress heterogenetic pairing, (ii) that nonstructural chromosome differentiation is present among the genomes of both diploid and polyploid species, and (iii) the presence of the genome of a diploid species in a polyploid × diploid hybrid results in promotion of heterogenetic pairing. It is, therefore, concluded that heterogenetic pairing in most of the polyploid species is genetically suppressed.

Preferential intragenomic chromosome pairing in two new diploid intergeneric hybrids between Hordeum and Secale

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 594-597 ◽  
Author(s):  
P. K. Gupta ◽  
George Fedak
Keyword(s):  
Key Words ◽  
Chromosome Pairing ◽  
Secale Cereale ◽  
Binomial Distribution ◽  
Homologous Chromosome ◽  
Intergeneric Hybrids ◽  
Hybrid Combination ◽  
Close Relationship ◽  
Chromosome Segments

Intergeneric hybrids involving Hordeum californicum with Secale anatolicum and Hordeum bogdanii with Secale cereale ssp. segetale were produced at a frequency of 1.3% of pollinated florets. Chiasmata frequencies of plants ranged from 0.13 to 0.21 per cell in the first hybrid combination and from 0.30 to 0.68 per cell in the second. The paucity of heteromorphic bivalents indicated absence of a close relationship between parental genomes. The associations in bivalents could be classified into Secale–Secale (R–R), Hordeum–Hordeum (H–H), and Secale–Hordeum (R–H) on the basis of difference in size of the chromosomes of Secale and Hordeum. Using a binomial distribution, it is shown that there was preferential intragenomic (R–R, H–H) chromosome pairing, which was attributed to the presence of homologous chromosome segments on nonhomologous chromosomes of the same genome. The distribution of Hordeum and Secale chromosomes to the poles at anaphase occurred at random. Key words: Hordeum, Secale, hybrids (intergeneric), chromosome pairing.

CYTOTAXONOMY OF THE SPECIES AND INTERSPECIFIC HYBRIDS OF THE GENUS ELYMUS IN CANADA AND NEIGHBORING AREAS

1964 ◽  
Vol 42 (5) ◽  
pp. 547-601 ◽  
Author(s):  
Wray M. Bowden
Keyword(s):  
United States ◽  
Chromosome Number ◽  
Introduced Species ◽  
Interspecific Hybrid ◽  
Native Species ◽  
Interspecific Hybrids ◽  
Voucher Specimens ◽  
Elymus Canadensis ◽  
Elymus Species

A cytotaxonomic treatment is given for 12 native species, 2 introduced species, and 3 natural interspecific hybrids of the genus Elymus L. that occur in Canada. Five of the native Elymus species and an additional natural interspecific hybrid are found in Alaska. Eleven of the native species, one introduced species, and two of the natural interspecific hybrids are present in the mainland United States. Some additional native species and natural interspecific hybrids of Elymus from the mainland United States are treated briefly.Nomenclatural proposals include: Elymusglaucus Buckl. var. virescens (Piper) Bowden; E. ×uclueletensis Bowden (E. mollis Trin. f. mollis × E. glaucus Buckl. var. glaucus); E. × aleuticus Hultén (pro sp.) (E. mollis Trin. f. mollis × E. hirsutus Presl); E. canadensis L. var. wiegandii (Fern.) Bowden f. wiegandii and f. calvescens (Fern.) Bowden; E. ×maltei Bowden nm. maltei, nm. simulans Bowden, nm. churchii Bowden, and nm. brownii Bowden (E. virginicus L. × E. canadensis L.); E. virginicus L. var. jenkinsii Bowden; E. hystrix L. var. bigelovianus (Fern.) Bowden; E.piperi Bowden; E. innovatus Beal subsp. innovatus var. glabratus Bowden; and E. triticoides Buckl. var. pacificus (Gould) Bowden. Hystrixpatula Moench is here treated as Elymushystrix L.Voucher specimens are cited for the following chromosome number determinations:(1) diploid, 2n = 14: Elymusjunceus.(2) tetraploid, 2n = 28: Elymus canadensis var. canadensis, E. canadensis var. wiegandii f. wiegandii, E. diversiglumis, E. glaucus var. glaucus, E. glaucus var. virescens, E. hirsutus, E, hystrix var. hystrix, E. hystrix var. bigelovianus, E. innovatus subsp. innovatus var. innovatus, E. × maltei nm. maltei, E. riparius, E. sibiricus, E. villosus f. villosus, E. virginicus var. virginicus f. virginicus, and E. virginicus var. submuticus.Earlier literature reports (based on voucher specimens) are given for the following:(1) tetraploid, 2n = 28: Elymus mollis (two subsp. and three forms), E. piperi, and E. × vancouverensis nm. crescentianus.(2) hexaploid, 2n = 42: Elymus × vancouverensis nm. vancouverensis, and E. × vancouverensis nm. californicus.(3) octoploid, 2n = 56: Elymus arenarius, E. innovatus subsp. velutinus, and E. piperi.

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