Further hybrids involving the perennial autotetraploid oat Avena macrostachya

Genome ◽  
1992 ◽  
Vol 35 (2) ◽  
pp. 273-275 ◽  
Author(s):  
J. M. Leggett
Keyword(s):  
Chromosome Pairing ◽  
Triploid Hybrid ◽  
Genome Species ◽  
A Genome ◽  
C Genome

Chromosome pairing in the triploid hybrid Avena damascena × A. macrostachya is very similar to the chromosome pairing observed in previously reported triploid hybrids involving the A genome diploid taxa A. atlantica and A. prostrata, indicating that little more than residual homology remains between these A genome diploids and either of the genomes of A. macrostachya. The chromosome pairing in the hybrid between A. macrostachya and the C genome diploid A. ventricosa is similar to that observed in the previously reported hybrid A. eriantha × A. macrostachya. In both these hybrids, the frequency of trivalents is greater than that observed in hybrids involving the A genome species and A. macrostachya, which is indicative of closer homology of A. macrostachya to the C genome diploids than the A genome diploids.Key words: Avena, hybrids, interspecific chromosome pairing, phylogeny.

Chromosome pairing in triploid and tetraploid hybrids in Elytrigia (Triticeae; Poaceae)

1984 ◽  
Vol 26 (5) ◽  
pp. 519-522 ◽  
Author(s):  
Patrick E. McGuire
Keyword(s):  
Chromosome Pairing ◽  
Genome Analysis ◽  
Triploid Hybrid ◽  
Pollen Mother Cells ◽  
Tetraploid Hybrid ◽  
A Genome ◽  
Mother Cells ◽  
Metaphase I

Mean chromosome pairing of 5.14I + 1.28II (rod) + 3.86II (ring) + 1.47III + 0.11IV (open) + 0.11V was observed in pollen mother cells at metaphase I in the triploid hybrid Elytrigia scirpea (K. Presl) Holub, 2n = 4x = 28 × E. bessarabica (Savul. et Rayss) Dubrovik, 2n = 4x = 14. Mean chromosome pairing of 3.71I + 2.29II (rod) + 1.82II (ring) + 2.64III + 0.29IV (open) was observed in the triploid hybrid E. curvifolia (Lange) Holub, 2n = 4x = 28 × E. bessarabica. Mean chromosome pairing of 3.00I + 0.93II (rod) + 1.57II (ring) + 1.36III + 1.79IV (open) + 1.I4IV (closed) + 0.79V was observed in the tetraploid hybrid E. junceiformis Löve et Löve, 2n = 4x = 28 × E. curvifolia. The first hybrid provides the first evidence by genome analysis that E. bessarabica possesses a genome (designated Eb) which is closely related to the genomes of E. scirpea (ES and ESC) and hence to the E genome of E. elongata (Host) Nevski, 2n = 2x = 14. The second and third hybrids provide the first evidence that the two genomes of E. curvifolia (designated EC and ECU) are related to the Eb genome of E. bessarabica and thus to the E genome of E. elongata.Key words: Elytrigia, homoeology, Triticum, phylogeny, triploid, tetraploid.

Giemsa C-banded karyotypes of Avena species

Genome ◽  
1988 ◽  
Vol 30 (5) ◽  
pp. 627-632 ◽  
Author(s):  
A. Fominaya ◽  
C. Vega ◽  
E. Ferrer
Keyword(s):  
Interspecific Hybrids ◽  
Chromatin Condensation ◽  
Diploid Species ◽  
Divergent Evolution ◽  
Intercalary Heterochromatin ◽  
Banding Patterns ◽  
Genome Species ◽  
C Banding ◽  
A Genome ◽  
C Genome

Giemsa C-banding was used to identify individual somatic chromosomes in eight diploid species of Avena. Two patterns of heterochromatin distribution were found. The chromosomes of five A genome species (A. strigosa, A. hirtula, A. longiglumis, A. damascena, and A. canariensis) possessed mainly telomeric bands, whereas those from three C genome species (A. clauda, A. pilosa, and A. ventricosa) were characterized by higher chromatin condensation and several intercalary heterochromatin bands. The divergent evolution between the two groups is confirmed after C-banding. The unique C-banding patterns of several chromosomes in each species will be a useful tool for the study of meiotic behaviour in interspecific hybrids among Avena spp.Key words: C-banding, Avena, heterochromatin.

ELECTROPHORETIC PATTERNS OF OAT PROLAMINES AND SPECIES RELATIONSHIPS IN AVENA

1979 ◽  
Vol 21 (3) ◽  
pp. 309-318 ◽  
Author(s):  
S. I. Kim ◽  
J. Mossé
Keyword(s):  
Intraspecific Variation ◽  
Evolutionary Process ◽  
Species Relationships ◽  
D Genome ◽  
Genome Species ◽  
Electrophoretic Patterns ◽  
A Genome ◽  
C Genome ◽  
Starch Gel

Starch gel electrophoretic studies on seed prolamines of 17 different di-, tetra-, and hexaploid Avena species were undertaken to determine species relationships and the evolutionary process of the polyploids. Significant intraspecific variation was observed. Electrophoregrams of each species were obtained by superposing all the bands found in the same species and in total, 17 bands were observed. Clear differences were found between species in their patterns, which allowed determination of the bands specific to three genomes (A, C and D). Like the diploids, the tetraploids can be divided into two groups on the basis of electrophoretic patterns: A. barbata and A. magna-A. murphyi. It is evident that A. magna-murphyi group is derived from both the A and C genome species of diploids while A. barbata is derived from the A genome species only. The similarity between A. magna and A. murphyi was also confirmed. The hexaploids were derived from A. magna-murphyi group and a D genome ancestor although the last one is not discovered yet.

Isolation and identification of Triticeae chromosome 1 receptor-like kinase genes (Lrk10) from diploid, tetraploid, and hexaploid species of the genus Avena

Genome ◽  
2003 ◽  
Vol 46 (1) ◽  
pp. 119-127 ◽  
Author(s):  
D W Cheng ◽  
K C Armstrong ◽  
G Drouin ◽  
A McElroy ◽  
G Fedak ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Analyses ◽  
Chromosome 1 ◽  
Isolation And Identification ◽  
Genome Species ◽  
A Genome ◽  
Receptor Like Kinase ◽  
C Genome ◽  
Multiple Copies ◽  
Genome Group

The DNA sequence of an extracellular (EXC) domain of an oat (Avena sativa L.) receptor-like kinase (ALrk10) gene was amplified from 23 accessions of 15 Avena species (6 diploid, 6 tetraploid, and 3 hexaploid). Primers were designed from one partial oat ALrk10 clone that had been used to map the gene in hexaploid oat to linkage groups syntenic to Triticeae chromosome 1 and 3. Cluster (phylogenetic) analyses showed that all of the oat DNA sequences amplified with these primers are orthologous to the wheat and barley sequences that are located on chromosome 1 of the Triticeae species. Triticeae chromosome 3 Lrk10 sequences were not amplified using these primers. Cluster analyses provided evidence for multiple copies at a locus. The analysis divided the ALrk EXC sequences into two groups, one of which included AA and AABB genome species and the other CC, AACC, and CCCC genome species. Both groups of sequences were found in hexaploid AACCDD genome species, but not in all accessions. The C genome group was divided into 3 subgroups: (i) the CC diploids and the perennial autotetraploid, Avena macrostachya (this supports other evidence for the presence of the C in this autotetraploid species); (ii) a sequence from Avena maroccana andAvena murphyi and several sequences from different accessions of A.sativa; and (iii) A. murphyi and sequences from A. sativa andAvena sterilis. This suggests a possible polyphyletic origin for A. sativa from the AACC progenitor tetraploids or an origin from a progenitor of the AACC tetraploids. The sequences of the A genome group were not as clearly divided into subgroups. Although a group of sequences from the accession 'SunII' and a sequence from line Pg3, are clearly different from the others, the A genome diploid sequences were interspersed with tetraploid and hexaploid sequences.Key words: phylogeny, genome evolution, speciation, oat.

CHROMOSOME RELATIONSHIPS BETWEEN THE CULTIVATED OAT AVENA SATIVA (6x) AND A. VENTRICOSA (2x)

1970 ◽  
Vol 12 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Hugh Thomas
Keyword(s):  
Chromosome Pairing ◽  
Avena Sativa ◽  
Diploid Species ◽  
Meiotic Behaviour ◽  
Hexaploid Species ◽  
C Genome

Chromosome pairing in the F1 hybrid between the cultivated oat Avena sativa and a diploid species A. ventricosa, and in the derived amphiploid, shows that the diploid species is related to one of the genomes of the hexaploid species. The amount of chromosome pairing observed in complex interamphiploid hybrids demonstrates further that A. ventricosa is related to the C. genome of A. sativa. However, the chromosomes of the diploid species have become differentiated from that of the C genome of A. sativa and this is readily apparent in the meiotic behaviour of both the F1 hybrid and the amphiploid.

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.

Patterns of genome duplication within the Brassica napus genome

Genome ◽  
2003 ◽  
Vol 46 (2) ◽  
pp. 291-303 ◽  
Author(s):  
I A.P Parkin ◽  
A G Sharpe ◽  
D J Lydiate
Keyword(s):  
Brassica Napus ◽  
Genome Duplication ◽  
Chromosomal Rearrangements ◽  
Centric Fusion ◽  
Linkage Groups ◽  
Gross Chromosomal Rearrangements ◽  
A Genome ◽  
C Genome ◽  
Homologous Locus ◽  
Duplicate Loci

The progenitor diploid genomes (A and C) of the amphidiploid Brassica napus are extensively duplicated with 73% of genomic clones detecting two or more duplicate sequences within each of the diploid genomes. This comprehensive duplication of loci is to be expected in a species that has evolved through a polyploid ancestor. The majority of the duplicate loci within each of the diploid genomes were found in distinct linkage groups as collinear blocks of linked loci, some of which had undergone a variety of rearrangements subsequent to duplication, including inversions and translocations. A number of identical rearrangements were observed in the two diploid genomes, suggesting they had occurred before the divergence of the two species. A number of linkage groups displayed an organization consistent with centric fusion and (or) fission, suggesting this mechanism may have played a role in the evolution of Brassica genomes. For almost every genetically mapped locus detected in the A genome a homologous locus was found in the C genome; the collinear arrangement of these homologous markers allowed the primary regions of homoeology between the two genomes to be identified. At least 16 gross chromosomal rearrangements differentiated the two diploid genomes during their divergence from a common ancestor.Key words: genome evolution, Brassicaeae, polyploidy, homoeologous linkage groups.

EVOLUTION OF AVENA SATIVA: ORIGIN OF THE CYTOPLASMIC GENOME

1976 ◽  
Vol 18 (4) ◽  
pp. 769-771 ◽  
Author(s):  
Martin W. Steer ◽  
Hugh Thomas
Keyword(s):  
Avena Sativa ◽  
Conclusive Evidence ◽  
Cytoplasmic Genome ◽  
A Genome ◽  
Isoelectric Points ◽  
C Genome

Comparisons of the isoelectric points of the large subunits from the enzyme ribulose biphosphate carboxylase, extracted from species and hybrids of Avena, provide conclusive evidence for the origin of the cytoplasmic genome of the hexapioid A. sativa L. from the A. genome diploids rather than the C genome diploids.

The use of double fluorescence in situ hybridization to physically map the positions of 5S rDNA genes in relation to the chromosomal location of 18S–5.8S–26S rDNA and a C genome specific DNA sequence in the genus Avena

Genome ◽  
1996 ◽  
Vol 39 (3) ◽  
pp. 535-542 ◽  
Author(s):  
Concha Linares ◽  
Juan González ◽  
Esther Ferrer ◽  
Araceli Fominaya
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequence ◽  
Diploid Species ◽  
5S Rdna ◽  
Rdna Genes ◽  
26S Rdna ◽  
A Genome ◽  
Rdna Loci ◽  
C Genome

A physical map of the locations of the 5S rDNA genes and their relative positions with respect to 18S–5.8S–26S rDNA genes and a C genome specific repetitive DNA sequence was produced for the chromosomes of diploid, tetraploid, and hexaploid oat species using in situ hybridization. The A genome diploid species showed two pairs of rDNA loci and two pairs of 5S loci located on both arms of one pair of satellited chromosomes. The C genome diploid species showed two major pairs and one minor pair of rDNA loci. One pair of subtelocentric chromosomes carried rDNA and 5S loci physically separated on the long arm. The tetraploid species (AACC genomes) arising from these diploid ancestors showed two pairs of rDNA loci and three pairs of 5S loci. Two pairs of rDNA loci and 2 pairs of 5S loci were arranged as in the A genome diploid species. The third pair of 5S loci was located on one pair of A–C translocated chromosomes using simultaneous in situ hybridization with 5S rDNA genes and a C genome specific repetitive DNA sequence. The hexaploid species (AACCDD genomes) showed three pairs of rDNA loci and six pairs of 5S loci. One pair of 5S loci was located on each of two pairs of C–A/D translocated chromosomes. Comparative studies of the physical arrangement of rDNA and 5S loci in polyploid oats and the putative A and C genome progenitor species suggests that A genome diploid species could be the donor of both A and D genomes of polyploid oats. Key words : oats, 5S rDNA genes, 18S–5.8S–26S rDNA genes, C genome specific repetitive DNA sequence, in situ hybridization, genome evolution.

Nuclear- and chloroplast-microsatellite variation in A-genome species of rice

Genome ◽  
2001 ◽  
Vol 44 (4) ◽  
pp. 658-666 ◽  
Author(s):  
T Ishii ◽  
Y Xu ◽  
S R McCouch
Keyword(s):  
Oryza Sativa ◽  
Length Polymorphism ◽  
Allelic Diversity ◽  
Sequence Length ◽  
Chloroplast Microsatellites ◽  
Microsatellite Variation ◽  
Chloroplast Microsatellite ◽  
Genome Species ◽  
A Genome ◽  
Simple Sequence

Simple sequence length polymorphism analysis was carried out to reveal microsatellite variation and to clarify the phylogenetic relationships among A-genome species of rice. Total DNA from 29 cultivars (23 Oryza sativa and 6 O. glaberrima) and 30 accessions of wild A-genome species (12 O. rufipogon, 5 O. glumaepatula, 2 O. longistaminata, 6 O. meridionalis, and 5 O. barthii) was used as a template for PCR to detect 24 nuclear and 10 chloroplast microsatellite loci. Microsatellite allelic diversity was examined based on amplified banding patterns. Microsatellites amplified clearly in all 59 accessions, with an average of 18.4 alleles per locus. The polymorphism information content (PIC) value ranged from 0.85 to 0.94, with an average of 0.89. At the species level, high average PIC values were observed in O. sativa (0.79) and O. rufipogon (0.80). For chloroplast microsatellites, the average number of alleles per locus and the average PIC value were 2.9 and 0.38, respectively. While the magnitude of diversity was much greater for nuclear microsatellites than for chloroplast microsatellites, they showed parallel patterns of differentiation for each taxonomic group. Using the ratio of common alleles (estimated as size of amplified fragments) as a similarity index, the average percentages of common microsatellite alleles were calculated between taxa. For both nuclear and chloroplast microsatellites, O. sativa showed the highest similarity values to O. rufipogon, and O. glaberrima was most similar to O. barthii. These data support previous evidence that these cultivars originated from the corresponding wild ancestral species.Key words: simple sequence length polymorphism, SSLP, microsatellite marker, rice, Oryza sativa, allelic diversity, phylogenetics.

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