Genomic and taxonomic relationships of Agropyron vaillantianum and E. arizonicus (Poaceae: Triticeae)

Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 640-645 ◽  
Author(s):  
K. B. Jensen ◽  
C. Hsiao ◽  
K. H. Asay
Keyword(s):  
Interspecific Hybridization ◽  
Chromosome Pairing ◽  
Slight Modification ◽  
Meiotic Behavior ◽  
Genomic Constitution ◽  
Pseudoroegneria Spicata ◽  
New Name ◽  
Taxonomic Relationships ◽  
Genomic Relationships ◽  
Ecological Parameters

Agropyron vaillantianum (Wulf. &Schreber) Trautv. and E. arizonicus (Scribn. &Smith) Gould were studied to describe their (i) reproductive characteristics, (ii) meiotic behavior, (iii) genomic constitution, and (iv) correct taxonomic alignment based on genomic relationships. Both species were found to be self-fertile tetraploids (2n = 28) and behaved as strict allotetraploids averaging 14.00 and 13.77 bivalents per cell, respectively. The hybrids A. vaillantianum × Pseudoroegneria spicata (Pursh) A. Love, 2n = 14, SS, A. vaillantianum × E. trachycaulus (Link) Gould ex Shinners, 2n = 28, SSHH, and E. arizonicus × E. canadensis L., 2n = 28, SSHH, averaged 6.21, 12.56, and 12.60 bivalents per cell, respectively. Chromosome pairing in this series of hybrids demonstrated that A. vaillantianum and E. arizonicus contain the S and H genomes, with each taxon having a slight modification resulting from evolutionary pressures under different ecological parameters. On the basis of chromosome pairing and mode of pollination it is proposed that A. vaillantianum be treated in the genus Elymus rather than in the genus Agropyron, with the following new name combination: Elymus vaillantianus (Wulf. &Schreb.) K. B. Jensen comb.nov., based on Triticum vaillantianum Wulfen &Schreber. Elymus typically encompasses those species that are self-fertile, and contain the SH genomes. Elymus arizonicus has been correctly classified.Key words: genome, meiosis, chromosome pairing, cytology, interspecific hybridization, Elymus, Agropyron, and Triticeae.

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.

Amphidiploids of perennial Triticeae. I. Synthetic Thinopyrum species and their hybrids

Genome ◽  
1992 ◽  
Vol 35 (6) ◽  
pp. 951-956 ◽  
Author(s):  
Richard R.-C. Wang
Keyword(s):  
Gene Flow ◽  
Chromosome Pairing ◽  
Colchicine Treatment ◽  
Meiotic Pairing ◽  
Pseudoroegneria Spicata ◽  
Genomic Relationships ◽  
Thinopyrum Elongatum ◽  
Metaphase I

Amphiploids of the hybrid Thinopyrum elongatum (Host) D.R. Dewey (2n = 2x = 14; JeJe) × Pseudoroegneria spicata (Pursh) A. Löve (2n = 2x = 14; SS) were obtained by the colchicine treatment of regenerants from inflorescence culture. Meiotic pairings in the JJSS amphiploids averaged 2.90 I + 4.44 rod II + 7.50 ring II + 0.14 III + 0.20 IV at metaphase I but had 13.38 ring II + 0.30 IV at diakinesis. This amphidiploid was crossed with that of T. bessarabicum (Savul. &Rayss) A. Löve (2n = 2x = 14; JbJb) × T. elongatum and the latter was also crossed with T. scirpeum (K. Presl) D.R. Dewey (2n = 4x = 28; JeJeJeJe) to obtain JbJeJeS and JeJeJeJb hybrids, respectively. The former hybrid had a metaphase I pairing pattern of 7.82 I + 4.33 rod II + 2.76 ring II + 1.51 III + 0.35 IV. The latter hybrid had 3.04 I + 4.05 rod II + 4.31 ring II + 1.26 III + 1.08 IV. These meiotic pairing data are in agreement with the genomic relationships based on the diploid hybrids involving these genomes. Fertility of the hybrid between T. scirpeum and the amphiploid of T. bessarabicum × T. elongatum suggested that their genomes were similar and balanced and that gene flow could occur between the JJ diploids and the JJJJ tetraploid.Key words: hybrid, amphidiploid, genome, isozyme, chromosome pairing, Triticeae, Thinopyrum.

THE MEIOTIC BEHAVIOR OF ANEUPOLYHAPLOIDS OF THE CULTIVATED OAT AVENA SATIVA (2n = 6x = 42)

1977 ◽  
Vol 19 (4) ◽  
pp. 651-656 ◽  
Author(s):  
J. M. Leggett
Keyword(s):  
Genetic Control ◽  
Chromosome Pairing ◽  
Avena Sativa ◽  
Meiotic Behavior ◽  
Homoeologous Chromosomes

Chromosome pairing and the frequency of secondary associations in two aneupolyhaploid plants of A. sativa are described. There was little evidence of pairing between homoeologous chromosomes in either plant. The results are discussed in relation to the genetic control of bivalent pairing in A. sativa and the possible divergence between the constituent genomes.

scholarly journals Oligo-painting and GISH reveal meiotic chromosome biases and increased meiotic stability in synthetic allotetraploid Cucumis ×hytivus with dysploid parental karyotypes

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Qinzheng Zhao ◽  
Yunzhu Wang ◽  
Yunfei Bi ◽  
Yufei Zhai ◽  
Xiaqing Yu ◽  
...  
Keyword(s):  
Interspecific Hybridization ◽  
Interspecific Hybrids ◽  
Chromosome Doubling ◽  
Meiotic Chromosome ◽  
Genomic In Situ Hybridization ◽  
Meiotic Behavior ◽  
Cytological Evidence ◽  
Meiotic Stability ◽  
Inbred Family

Abstract Background Meiosis of newly formed allopolyploids frequently encounter perturbations induced by the merging of divergent and hybridizable genomes. However, to date, the meiotic properties of allopolyploids with dysploid parental karyotypes have not been studied in detail. The allotetraploid Cucumis ×hytivus (HHCC, 2n = 38) was obtained from interspecific hybridization between C. sativus (CC, 2n = 14) and C. hystrix (HH, 2n = 24) followed by chromosome doubling. The results of this study thus offer an excellent opportunity to explore the meiotic properties of allopolyploids with dysploid parental karyotypes. Results In this report, we describe the meiotic properties of five chromosomes (C5, C7, H1, H9 and H10) and two genomes in interspecific hybrids and C. ×hytivus (the 4th and 14th inbred family) through oligo-painting and genomic in situ hybridization (GISH). We show that 1) only two translocations carrying C5-oligo signals were detected on the chromosomes C2 and C4 of one 14th individual by the karyotyping of eight 4th and 36 14th plants based on C5- and C7-oligo painting, and possible cytological evidence was observed in meiosis of the 4th generation; 2) individual chromosome have biases for homoeologous pairing and univalent formation in F1 hybrids and allotetraploids; 3) extensive H-chromosome autosyndetic pairings (e.g., H-H, 25.5% PMCs) were observed in interspecific F1 hybrid, whereas no C-chromosome autosyndetic pairings were observed (e.g. C-C); 4) the meiotic properties of two subgenomes have significant biases in allotetraploids: H-subgenome exhibits higher univalent and chromosome lagging frequencies than C-subgenome; and 5) increased meiotic stability in the S14 generation compared with the S4 generation, including synchronous meiosis behavior, reduced incidents of univalent and chromosome lagging. Conclusions These results suggest that the meiotic behavior of two subgenomes has dramatic biases in response to interspecific hybridization and allopolyploidization, and the meiotic behavior harmony of subgenomes is a key subject of meiosis evolution in C. ×hytivus. This study helps to elucidate the meiotic properties and evolution of nascent allopolyploids with the dysploid parental karyotypes.

A study on genomic relationships of Agropyron trachycaulum with Elymus scabriglumis, E. innovatus, and Hordeum procerum

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 525-528 ◽  
Author(s):  
P. K. Gupta ◽  
H. S. Balyan ◽  
George Fedak
Keyword(s):  
Chiasma Frequency ◽  
Embryo Rescue ◽  
Intergeneric Hybrids ◽  
Genomic Constitution ◽  
Rescue Technique ◽  
Genomic Relationships ◽  
Chromosome Associations ◽  
Synthetic Hybrids ◽  
The Mean ◽  
Agropyron Trachycaulum

Synthetic hybrids of Agropyron trachycaulum (2n = 4x = 28) with Elymus scabriglumis (2n = 6x = 42), E. innovatus (2n = 4x = 28), and Hordeum procerum (2n = 6x = 42) were produced through the embryo rescue technique, at relative frequencies of 7.1, 4.2, and 1.8%, respectively, of pollinated florets. The mean chromosome associations in two hybrids with E. scabriglumis was 11.71II + 1.47III + 0.15IV (mean chiasma frequency = 22.75), in one hybrid with H. procerum was 7.27II + 0.63III + 0.09IV (mean chiasma frequency = 10.20) and in a hybrid with E. innovatus was 2.8II (2.19 chiasma frequency). The data suggested two common genomes (S and H) with E. scabriglumis, one common genome (H) with H. procerum, and no common genome with E. innovatus. The evidence obtained suggested a SSHHYY genomic constitution for E. scabriglumis and two genomes different from SH for E. innovatus. The evidence also suggested that in H. procerum there may not be two related genomes present (derived from H. jubatum) as speculated in some earlier studies.Key words: intergeneric hybrids, Agropyron, Elymus, Hordeum, chromosome pairing.

Genomic in situ hybridization (GISH) reveals high chromosome pairing affinity between Lolium perenne and Festuca mairei

Genome ◽  
2000 ◽  
Vol 43 (2) ◽  
pp. 398-403 ◽  
Author(s):  
Mingshu Cao ◽  
David A Sleper ◽  
Fenggao Dong ◽  
Jiming Jiang
Keyword(s):  
In Situ Hybridization ◽  
Lolium Perenne ◽  
Chromosome Pairing ◽  
Cytogenetic Analysis ◽  
Direct Evidence ◽  
Genomic In Situ Hybridization ◽  
Genomic Constitution ◽  
Conventional Cytogenetic Analysis ◽  
Festuca Mairei

Intergeneric hybridizations have been made between species of Lolium and Festuca. It has been demonstrated, largely through conventional cytogenetic analysis, that the genomes of the two genera are related, however, much information is lacking on exactly how closely related the genomes are between the two species. We applied genomic in situ hybridization (GISH) techniques to the F1 hybrids of tetraploid Festuca mairei with a genomic constitution of M1M1M2M2 and diploid Lolium perenne with a genomic constitution of LL. It was shown in the triploid hybrids (LM1M2) that the chromosomes of M1 and M2 from F. mairei could pair with each other, and it was further discovered that L chromosomes of L. perenne paired with M1 and M2 chromosomes. Our results showed that meiocytes of Lolium-Festuca are amenable to GISH analysis, and provided direct evidence for the hypothesis that the chromosomes of Lolium and Festuca may be genetically equivalent and that reciprocal mixing of the genomes may be possible. Key words: Lolium, Festuca, in situ hybridization, meiosis.

Genomic constitution of the allo-octoploid Elymus tenuis (Poaceae: Triticeae) of New Zealand

2010 ◽  
Vol 23 (5) ◽  
pp. 381 ◽  
Author(s):  
Hai-Qin Zhang ◽  
Xue Bai ◽  
Bao-Rong Lu ◽  
Henry E. Connor ◽  
Yong-Hong Zhou
Keyword(s):  
New Zealand ◽  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
Genomic Constitution ◽  
Pollen Mother Cells ◽  
Mother Cells

Elymus tenuis (Buch.) Á.Löve et Connor is a perennial octoploid (2n = 56) wheatgrass endemic to New Zealand. To investigate its genomic constitution, four artificial interspecific hybrids between E. tenuis and E. enysii (2n = 4x = 28, HW), and E. solandri (2n = 6x = 42, StYW) and E. multiflorus (2n = 6x = 42, StYW) were studied cytologically. Meioses in pollen mother cells (PMCs) of the hybrids showed relatively high chromosome pairing, with an average of 13.50 in E. enysii × E. tenuis, 20.22 in E. solandri × E. tenuis, 19.62 in E. multiflorus × E. tenuis, and 20.00 in E. tenuis × E. multiflorus bivalents per cell, respectively. The results indicate that E. tenuis is an allo-octoploid species, with the new and unique genomic constitution StYHW. An autochthonous origin is proposed for it.

CYTOLOGICAL STUDIES IN BROMUS SPECIES, SECTION BROMOPSIS

1961 ◽  
Vol 39 (4) ◽  
pp. 757-773 ◽  
Author(s):  
M. R. Hanna
Keyword(s):  
Interspecific Hybridization ◽  
Seed Set ◽  
Significant Negative Correlation ◽  
B Chromosome ◽  
Meiotic Behavior ◽  
Stainable Pollen ◽  
Meiotic Irregularities ◽  
Wide Range ◽  
Positive Correlations ◽  
Bromus Erectus

Chromosome numbers and meiotic behavior were determined in clones of Bromus inermis, Bromus pumpellianus, and the Bromus erectus complex. Clones of B. inermis were octoploid (2n = 56) or near-octoploid, one aneuploid having 2n = 54 chromosomes. B. pumpellianus clones were octoploid, with one bearing a B chromosome. B. erectus-type clones had 56, 59, 65, or 70 chromosomes. Meioses varied widely among plants in extent of irregularity. Meiotic behavior was studied in detail and the sequential interrelationships of irregularities at meiotic stages analyzed. Significant or highly significant positive correlations were obtained for the B. pumpellianus clones between percentages of non-stainable pollen and frequencies of metaphase I univalents, anaphase II laggards, and quartet micronuclei. These relationships were non-significant for the B. inermis and B. erectus-type clones. A significant negative correlation was determined between percentage of non-stainable pollen and percentage of seed set following open pollination, but other relationships between meiotic irregularities or pollen stainability and seed-setting characteristics were non-significant. The wide range in chromosome number and meiotic behavior encountered in material commonly distributed on this continent as "B. erectus” may be due to interspecific hybridization in nurseries in which Bromus introductions are grown. Interspecific hybridization may be partially responsible also for aneuploidy and meiotic irregularity in B. inermis.

THE ANALYSIS OF MEIOSIS IN HYBRIDS. I. ANEUPLOID HYBRIDS

1981 ◽  
Vol 23 (2) ◽  
pp. 209-219 ◽  
Author(s):  
G. Kimber ◽  
L. C. Alonso ◽  
P. J. Sallee
Keyword(s):  
Triticum Aestivum ◽  
Mathematical Models ◽  
Chromosome Pairing ◽  
Meiotic Chromosome ◽  
Triticum Aestivum L ◽  
Equal Frequency ◽  
Chromosome Behavior ◽  
Telocentric Chromosomes ◽  
Genomic Relationships ◽  
Meiotic Analyses

The use of telocentric chromosomes in the analysis of the genomic relationships of wheat Triticum aestivum L. em Thell. and its relatives is described and 20 examples are given. The connection between this method of analysis and other mathematical theories of chromosome pairing in hybrids is established. A demonstration of the validity of the assumption that all chromosome arms pair at an equal frequency in calculating expected meiotic analyses is presented. This establishes a practical basis for the development of further mathematical models for predicting meiotic chromosome behavior. Numerical values of the genomic relationships of wheat and its immediate relatives are given.

Biosystematic study of hexaploids Elymus tschimganicus and E. glaucissimus. II. Interspecific hybridization and genomic relationship

Genome ◽  
1993 ◽  
Vol 36 (6) ◽  
pp. 1157-1168 ◽  
Author(s):  
Bao-Rong Lu ◽  
Kevin B. Jensen ◽  
Björn Salomon
Keyword(s):  
Interspecific Hybridization ◽  
General Pattern ◽  
The Other ◽  
South American ◽  
Genomic Relationship ◽  
Target Species ◽  
Species Relationship ◽  
Genomic Relationships ◽  
Pairing Behavior ◽  
Elymus Species

To investigate genomic relationships of Elymus tschimganicus (Drobov) Tzvelev (2n = 6x = 42, S1S2Y genomes) and E. glaucissimus (M. Pop.) Tzvelev (2n = 6x = 42, S1S2Y genomes), interspecific hybridizations of the two target species were carried out with 27 other Elymus species containing the SH, SY, SYH, SYP, SYW, and SH1H2 genomes, respectively, collected from different geographic regions. Chromosome pairing behavior was analyzed at metaphase I in 27 hybrids representing 23 hybrid combinations, and overall genomic relationships of the two target species with the other Elymus taxa were estimated. The study concluded that (i) interspecific hybridization was principally easy to perform between the Elymus species, but no general pattern of crossability was obtained, and all hybrids were completely sterile, (ii) the two species have a similar meiotic pattern in their hybrids with the other Elymus species, and (iii) species containing the SY, SYP, and SYH genomes have a generally higher level of genomic homology to the target species than those possessing the SH genomes, and the South American hexaploid with the SH1H2 genomes has the lowest level of genomic homology to the two target taxa.Key words: Elymus, interspecific hybridization, meiosis, genome, species relationship.

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