Genomic affinities of individual chromosomes based on C- and N-banding analyses of tetraploid Elymus species and their diploid progenitor species

Genome ◽  
1987 ◽  
Vol 29 (2) ◽  
pp. 247-252 ◽  
Author(s):  
K. L. D. Morris ◽  
B. S. Gill
Keyword(s):  
Diploid Progenitor ◽  
Pseudoroegneria Spicata ◽  
Banding Patterns ◽  
Elymus Trachycaulus ◽  
C And N ◽  
Elymus Species ◽  
Agropyron Trachycaulum ◽  
Triticeae Genome ◽  
Donor Species ◽  
Genome Designation

Giemsa C- and N-banding techniques were used to identify individual somatic chromosomes in the tetraploid (2n = 28) species Elymus trachycaulus (= Agropyron trachycaulum) (genome designation SH) and E. ciliaris (= A. ciliare) (SY) and five diploid progenitor species (2n = 14), Pseudoroegneria spicata (= A. spicatum) (S), P. libanotica (= A. libanoticum) (S), P. stipifolia (= A. stipifolium) (S), Critesion bogdanii (= Hordeum bogdanii) (H), and C. californicum (= H. californicum) (H). Comparisons based on banding patterns of E. trachycaulus and E. ciliaris with parental donor species P. spicata indicated a common S genome origin. The heterochromatin composition of several E. trachycaulus chromosomes were similar to chromosomes of both Critesion species. However, the possible origin of characteristic C- and N-banded chromosomes of E. ciliaris remained undetermined. These patterns of evolution among genomes of E. trachycaulus, E. ciliaris, and their progenitor species proved valuable for the allocation of individual chromosomes into specific genomes. This approach may be useful for the genomic allocation of wheat-Elymus addition lines. Key words: C-banding, N-banding, Elymus, Triticeae, genome.

The heterochromatin distribution and genome evolution in diploid species of Elymus and Agropyron

1984 ◽  
Vol 26 (6) ◽  
pp. 669-678 ◽  
Author(s):  
T. Ryu Endo ◽  
Bikram S. Gill
Keyword(s):  
Diploid Species ◽  
Banding Technique ◽  
Agropyron Elongatum ◽  
Pseudoroegneria Spicata ◽  
Banding Patterns ◽  
C Banding ◽  
Psathyrostachys Juncea ◽  
High Level ◽  
Thinopyrum Elongatum ◽  
Genome Designation

The acetocarmine–Giemsa C-banding technique was used to study heterochromatin distribution in somatic chromosomes of diploid Elymus junceus (= Psathyrostachys juncea) (2n = 14) (genome designation Ju = N) and nine diploid Agropyron species (2n = 14): A. cristatum (C = P), A. imbricatum (C = P), A. elongatum (= Elytrigia elongata = Thinopyrum elongatum) (E = J), A. junceum (= E. bessarabicum = T. bessarabicum) (J = E), A. spicatum (= Pseudoroegneria spicata) (S), A. libanoticum (= P. libanotica) (S), A. ferganense (S), A. stipifolium (= P. stipifolia) (S), and A. velutinum (V). With the exception of A. elongatum and A. velutinum, which were self-fertile, all species were cross-pollinating and self-sterile. The cross-pollinating species showed large terminal C-bands and a high level of C-band polymorphism. Agropyron elongatum, moderately self-fertile, showed small terminal and interstitial bands and a minimal C-band polymorphism. Agropyron velutinum, fully self-fertile, almost totally lacked C-bands. The Ju, C, E, and J genomes appeared to be distinctive and the equivalence of the E and J genomes was not supported from their C-banding patterns. Four species sharing the S genome, A. spicatum, A. libanoticum, A. ferganense, and A. stipifolium had C-band patterns similar to one another, although C-bands were less prominent in A. stipifolium than others.Key words: C-banding, karyotype, wheatgrass, cytology.

Genome discrimination by in situ hybridization in Icelandic species of Elymus and Elytrigia (Poaceae: Triticeae)

Genome ◽  
2001 ◽  
Vol 44 (2) ◽  
pp. 275-283 ◽  
Author(s):  
Marian Ørgaard ◽  
Kesara Anamthawat-Jónsson
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Genomic Dna ◽  
Genomic In Situ Hybridization ◽  
Pseudoroegneria Spicata ◽  
Genome Constitution ◽  
Elytrigia Repens ◽  
Elymus Caninus ◽  
Elymus Species

The genome constitution of Icelandic Elymus caninus, E. alaskanus, and Elytrigia repens was examined by fluorescence in situ hybridization using genomic DNA and selected cloned sequences as probes. Genomic in situ hybridization (GISH) of Hordeum brachyantherum ssp. californicum (diploid, H genome) probe confirmed the presence of an H genome in the two tetraploid Elymus species and identified its presence in the hexaploid Elytrigia repens. The H chromosomes were painted uniformly except for some chromosomes of Elytrigia repens which showed extended unlabelled pericentromeric and subterminal regions. A mixture of genomic DNA from H. marinum ssp. marinum (diploid,Xa genome) and H. murinum ssp. leporinum (tetraploid,Xu genome) did not hybridize to chromosomes of the Elymus species or Elytrigia repens, confirming that these genomes were different from the H genome. The St genomic probe from Pseudoroegneria spicata (diploid) did not discriminate between the genomes of the Elymus species, whereas it produced dispersed and spotty hybridization signals most likely on the two St genomes of Elytrigia repens. Chromosomes of the two genera Elymus and Elytrigia showed different patterns of hybridization with clones pTa71 and pAes41, while clones pTa1 and pSc119.2 hybridized only to Elytrigia chromosomes. Based on FISH with these genomic and cloned probes, the two Elymus species are genomically similar, but they are evidently different from Elytrigia repens. Therefore the genomes of Icelandic Elymus caninus and E. alaskanus remain as StH, whereas the genomes of Elytrigia repens are proposed as XXH.Key words: Elymus, Elytrigia, H genome, St genome, in situ hybridization.

Cytology of triploid and pentaploid hybrids of Elymus trachycaulus × Pseudoroegneria spicata and P. spicata ssp. inermis

Genome ◽  
1987 ◽  
Vol 29 (3) ◽  
pp. 470-480 ◽  
Author(s):  
Taing Aung ◽  
P. D. Walton
Keyword(s):  
Low Frequency ◽  
Plant Size ◽  
Double Dose ◽  
Homoeologous Pairing ◽  
Pseudoroegneria Spicata ◽  
Elymus Trachycaulus ◽  
Chromosome Associations ◽  
Size Variability ◽  
High Degree ◽  
Very High

Emasculated clones of tetraploid and octaploid Elymus trachycaulus crossed with Pseudoroegneria spicata yielded 69 triploids and 13 pentaploid hybrids. The triploid hybrids were morphologically intermediate between the parental species but the pentaploid hybrids resembled E. trachycaulus more closely than P. spicata. A very high degree of plant size variability (very weak to very vigorous) was observed among the 50 triploids that survived to maturity. The variability among the pentaploids, though apparent, was not high. Mean chromosome associations among the selected eight triploids varied from low multivalent formation at meiosis (7.60 I + 6.18 II + 0.24 III + 0.08 IV) to high multivalent-forming meiosis (7.28 I + 5.66 II + 0.32 III + 0.36 IV). The bivalent configurations in these triploids were attributed to homoeologous pairing between the S1 genome of P. spicata and S genomes of E. trachycaulus and the multivalents indicated intergenomal and intragenomal pairings. Mean chromosome associations of 5.22 I + 11.94 II + 1.97 III in 78.7% and 7 I + 14 II in 21.3% of the 150 cells were distributed among the three pentaploid hybrids. The low frequency of trivalents and the absence of multivalents higher than trivalent configurations suggest that homoeologous pairing was substantially reduced and there was no intergenomal and intragenomal pairing in these 2n = 35 x hybrids. Fourteen triploids and three pentaploid hybrids were produced from 4x and 8x forms of E. trachycaulus and P. spicata spp. inermis crosses. The triploids were intermediate between the parents but the pentaploids were more similar to E. trachycaulus. Mean chromosome associations in the triploids (6.020 I + 5.315 II + 0.554 III + 0.235 IV + 0.250 V + 0.048 VI + 0.03 VII) and in the pentaploids (3.50 I + 10.18 II + 3.54 III + 0.13 IV) indicated a very high degree of intergenomal and intragenomal pairing in the triploids; nevertheless, it was greatly reduced in the pentaploids. The Pseudoroegneria spicata ssp. inermis genome may have gene(s) that affect a high degree of intergenomal and intragenomal pairing in triploid hybrids with E. trachycaulus. However, in pentaploid hybrids (SS HH S2) the S and H genomes of E. trachycaulus in double dose seem to have restored its regular meiotic bahaviour, at least partially, and reduced homoeologous pairing as well as intergenomal and intragenomal pairing. Key words: Elymus trachycaulus, Pseudoroegneria spicata, regular meiotic behaviour, double dose, intergenomal pairing, intragenomal pairing.

Identification of the somatic chromosomes of Psathyrostachys fragilis (Poaceae)

1984 ◽  
Vol 26 (4) ◽  
pp. 430-435 ◽  
Author(s):  
I. Linde-Laursen ◽  
R. von Bothmer
Keyword(s):  
Silver Nitrate ◽  
Banding Pattern ◽  
Constitutive Heterochromatin ◽  
Differential Staining ◽  
Feulgen Staining ◽  
Banding Patterns ◽  
C Banding ◽  
Nucleolar Organizers ◽  
Silver Nitrate Staining ◽  
C And N

The karyotype of the outbreeding P. fragilis (2n = 2x = 14) was investigated by Feulgen staining and by C-, N-, and Ag-banding techniques. The complement consisted of 14 large chromosomes, 8 metacentrics and 6 satellite (SAT) chromosomes, probably among the longest within the Poaceae. Two SAT-chromosome pairs carried small, and one pair carried minute, polymorphic, completely heterochromatic satellites. Each chromosome could be referred to one of the seven chromosome pairs by its C-banding pattern. The patterns comprised from zero to three conspicuous, but not large bands per chromosome resulting in an overall low content of constitutive heterochromatin (<4%). The C-banded karyotype of P. fragilis differed from any previously reported in the Triticeae. Six of seven chromosome pairs were polymorphic either for C-banding patterns or satellite size (or for both). N-banding gave no differential staining of chromosomes. Silver nitrate staining established that the nucleolar organizers had different nucleolus-forming capacities. The presence of the small and minute satellites was more consistently demonstrated after C- and N-banding than after Feulgen staining.Key words: Triticeae, Poaceae, karyotype, C-, N-, and Ag-banding.

Repetitive DNA sequences from polyploid Elymus trachycaulus and the diploid progenitor species: detection and genomic affinity of Elymus chromatin added to wheat

Genome ◽  
1991 ◽  
Vol 34 (5) ◽  
pp. 782-789 ◽  
Author(s):  
H. Tsujimoto ◽  
B. S. Gill
Keyword(s):  
Repetitive Dna ◽  
Dna Sequences ◽  
Tandem Repeats ◽  
Fragment Length Polymorphism ◽  
Telomeric Sequence ◽  
Repetitive Dna Sequences ◽  
Diploid Progenitor ◽  
Specific Detection ◽  
Genome Species ◽  
Elymus Trachycaulus

A set of four repetitive DNA clones, pEt1, pEt2, pCb1, and pCb3, were isolated from SH-genome polyploid Elymus trachycaulus and H-genome diploid Critesion bogdanii. The clone Et1 represents a tandemly arranged telomeric sequence. Et2 represents tandem repeats interspersed along the entire length of individual chromosomes. The Cb1 sequence was more evenly dispersed. The Et1 clone shared homology with a 350 base pair family of rye sequences. The Cb3 sequence was evenly distributed in S- and H-genome species. All the repetitive DNA sequences were excellent markers for the specific detection and genomic affinity of Elymus chromatin added to wheat. All clones showed intragenomic variation in copy number and chromosomal location. Based on the analysis of this variation, we conclude that E. trachycaulus most probably originated from putative diploid H- and S-genome species resembling Critesion californicum and Pseudoroegneria spicata, respectively.Key words: wheatgrass, wheat–Elymus hybrid, addition lines, polyploidy, restriction fragment length polymorphism.

Chromosome pairing at five ploidy levels in Elymus trachycaulus

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 136-143 ◽  
Author(s):  
Taing Aung ◽  
P. D. Walton
Keyword(s):  
Key Words ◽  
Chromosome Pairing ◽  
Dry Matter ◽  
Dry Matter Yield ◽  
Ploidy Levels ◽  
Elymus Trachycaulus ◽  
Ring Bivalents ◽  
Almost All ◽  
Agropyron Trachycaulum ◽  
Metaphase I

An autoallooctaploid (2n = 56) form of Elymus trachycaulus (Link) Gould ex Shinners (previously Agropyron trachycaulum (Link) Malte ex H. F. Lewis) was induced by treating allotetraploid shoots with 0.2% colchicine. Successive backcrossing to tetraploid pollen parents was successful and yielded five hexaploid (2n = 42), one pentaploid (2n = 35), and three hyperploid (2n = 31, 32, 33) plants. Metaphase I of the tetraploids was normal and 14 II chromosomes were observed, almost all of which were ring bivalents. Chromosome pairing in one octaploid, four hexploids, and one pentaploid were 4.38 IV + 0.65 III + 17.84 II + 0.85 I, 13.16 III + 0.84 II + 0.84 I, and 5.82 III + 8.18 II + 1.18 I, respectively. Efficiency of chromsome pairing (chiasmata per chromsome) was highest in tetraploids (1.29), lowest in hexaploids (0.75), and intermediate in both octaploid (0.95) and pentaploid (0.93) plants. The octaploid produced longer and broader leaves than the tetraploid, although the total dry matter produced was 14.3% lower. Total dry matter yield of the hexaploid was on an average 30.04% higher than the tetraploid and the leaves were significantly larger. The hexaploid plants were taller than both the tetraploid and the octaploid plants. Metaphase I pairing in hyperploid 1 (2n = 33) was 4.34 III + 9.66 II + 0.66 I, hyperploid 2 (2n = 32) was 2.98 III 11.03 II + 1.00 I; hyperploid 3 (2n = 30 + 1 t) was 1.97 III + 12.05 II + 0.66 I + 0.33 t. The pattern of chromosome pairing in these hyperploids suggest that they are a quintupal trisomic, a quadrupal trisomic, and a triple trisomic respectively. Backcrossing these hyperploids to euploid pollen parents was successful. Backosses and their progeny should result in a series of primary trisomiclines and some monosomic plants, which would be useful for gene mapping. Key words: octaploid, hexaploid (double triploid), pentaploid, tetraploid, hyperploid, trisomic monosomic, Agropyron.

Assignment of the genomic affinities of chromosomes from polyploid Elymus species added to wheat

Genome ◽  
1988 ◽  
Vol 30 (1) ◽  
pp. 70-82 ◽  
Author(s):  
Bikram S. Gill ◽  
Kay L. D. Morris ◽  
Rudi Appels
Keyword(s):  
Repetitive Dna ◽  
Dna Sequences ◽  
Single Gene ◽  
Dna Probes ◽  
Addition Lines ◽  
Cross Hybridization ◽  
Elymus Trachycaulus ◽  
Chinese Spring Wheat ◽  
5S Dna ◽  
Elymus Species

Genomic DNAs from 10 disomic addition, substitution, or translocation chromosomes from tetraploid Elymus trachycaulus (SSHH) and 13 tetraploid Elymus ciliaris (SSYY) in Chinese Spring wheat were assayed with 18S–28S rDNA (Nor), 5S DNA, Adh, α-amylase, β-glucanase gene clones, and S-genome and H-genome repetitive DNA sequences. The rDNA from the S genome and 5S DNA from the S and H genomes, under high stringency Southern blot analysis, distinguished S-genome and H-genome loci on individual Elymus chromosomes. The single gene, or low copy gene probes (Adh and others), allowed identification of different addition lines and provided information on the gene synteny relationships of Elymus chromosomes with wheat chromosomes. The S-genome specific and H-genome repetitive DNA probes were not useful in assigning genomic affinities, due to some cross-hybridization between these genomes using these probes and (or) the occurrence of large numbers of translocations in polyploid genomes of Elymus species. However, the repetitive DNA probes provided diagnostic phenotypic markers for identification of individual Elymus addition lines. Moreover, since S- and H-genome DNA sequences were virtually absent from wheat, they were excellent markers for the detection of Elymus chromatin in wheat. The array of DNA probes should prove useful in chromosome manipulation in resistance transfer from Elymus into wheat.Key words: Triticeae, Elymus, aneuploid, DNA probe.

Forage Fibre Analyses: a Comparison of Two Techniques.

1992 ◽  
Vol 19 (3) ◽  
pp. 289 ◽  
Author(s):  
NC Larter
Keyword(s):  
Forage Quality ◽  
Fibre Content ◽  
Poor Correlation ◽  
Strong Negative Correlation ◽  
Elymus Trachycaulus ◽  
Forage Digestibility ◽  
High Fibre ◽  
High Fibre Content ◽  
Hordeum Jubatum ◽  
Agropyron Trachycaulum

Forage fibre content is frequently used as index of forage quality where high fibre content indicates low forage quality. Fibre content is usually estimated by the familiar ADF technique. An alternative method, the acid-pepsin digestibility (AP) technique, provides an estimate of forage digestibility where low digestibility indicates a high fibre content. Fibre content estimates in herbaceous forage (Carex atherodes, C. aquatilis, Phalaris arundinacea, Calamagrostis spp., Agropyron trachycaulum [Elymus trachycaulus] and Hordeum jubatum) were compared by the ADF and AP techniques. There was a strong negative correlation between the fibre content, as determined by ADF, and the digestibility, as determined by AP, in a wide variety of herbaceous forages. This suggests that both techniques provide a very similar estimate of forage quality in herbaceous forages. Contrastingly, a similar analysis on Salix spp. and lichen showed a poor correlation between techniques, suggesting dissimilar estimates of fibre content of these forages.

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