Comparison of crossover frequencies in barley (Hordeum vulgare) and H. vulgare × H. bulbosum hybrids using a paracentric inversion

Genome ◽  
1991 ◽  
Vol 34 (4) ◽  
pp. 666-673 ◽  
Author(s):  
R. A. Pickering
Keyword(s):  
Hordeum Vulgare ◽  
Paracentric Inversion ◽  
Chromosome 3 ◽  
Crossing Over ◽  
Gene Introgression ◽  
Hordeum Bulbosum ◽  
Hordeum Vulgare L ◽  
Meiotic Analyses ◽  
Mother Cells ◽  
Homoeologous Chromosomes

Crosses between different parental ploidy combinations of barley (Hordeum vulgare L.) and H. bulbosum L. have been carried out principally to obtain hybrids with high allosyndetic chromosome pairing. Fertility has been observed in tetraploid and triploid hybrids, but there has been little evidence of gene introgression from H. bulbosum into H. vulgare in their progeny. To investigate whether crossing-over takes place between homoeologous chromosomes of H. vulgare and H. bulbosum, diploid hybrids were obtained from crosses between a barley mutant (wst3) homozygous for a paracentric inversion on chromosome 3 and one H. bulbosum genotype. Meiotic analyses at metaphase I and anaphase I and II were carried out on several viable hybrids and compared with control diploid hybrids without the inversion and H. vulgare plants heterozygous for the inversion. Aberrations (bridges and (or) fragments) in H. vulgare × H. bulbosum pollen mother cells at anaphase I were significantly less frequent than in the barley hétérozygote. It is concluded that reduced crossing-over between the parental chromosomes in hybrids contributes to the lack of success in obtaining genetic recombinations between the two species.Key words: Hordeum vulgare, Hordeum bulbosum, interspecific hybrid, paracentric inversion, crossing-over.

scholarly journals Importance of the Secondary Genepool in Barley Genetics and Breeding. I. Cytogenetics and Molecular Analysis

2011 ◽  
Vol 40 (No. 3) ◽  
pp. 73-78 ◽  
Author(s):  
R. Pickering ◽  
A. Johnston P ◽  
B. Ruge
Keyword(s):  
Hordeum Vulgare ◽  
Plant Breeding ◽  
Molecular Analysis ◽  
Hordeum Bulbosum ◽  
Hordeum Vulgare L ◽  
Cultivated Barley

There have been no plant breeding developments using species from the tertiary genepool of cultivated barley for breeding or genetics since the VIII<sup>th</sup> International Barley Genetics Symposium in 2000. Hence, the first part of this review describes progress since 2000 in developing and characterising recombinant lines derived from hybridisations between the sole species in the secondary genepool, Hordeum bulbosum L., and cultivated barley, Hordeum vulgare L. The topics discussed in part I are cytogenetics and molecular analysis of recombinant lines. &nbsp;

Characterization by RFLP analysis and genomic in situ hybridization of a recombinant and a monosomic substitution plant derived from Hordeum vulgare L. × Hordeum bulbosum L. crosses

Genome ◽  
1997 ◽  
Vol 40 (2) ◽  
pp. 195-200 ◽  
Author(s):  
R. A. Pickering ◽  
A. M. Hill ◽  
R. G. Kynast
Keyword(s):  
In Situ Hybridization ◽  
Hordeum Vulgare ◽  
Rflp Analysis ◽  
Leaf Sheath ◽  
Genomic In Situ Hybridization ◽  
Barley Chromosome ◽  
Interspecific Crosses ◽  
Hordeum Bulbosum ◽  
Hordeum Vulgare L

Interspecific crosses in Hordeum have been made with the aim of transferring desirable traits, such as disease resistance, from a wild species, Hordeum bulbosum, into cultivated barley (Hordeum vulgare). Interspecific recombinants have previously been identified using several methods, but there are limitations with all the techniques. We improved our ability to characterize progeny from H. vulgare × H. bulbosum crosses by using genomic in situ hybridization (GISH). The plant material comprised a recombinant and a monosomic alien substitution plant derived from H. vulgare × H. bulbosum crosses. The recombinant possesses a pubescent leaf sheath conferred by a gene transferred from H. bulbosum into barley cultivar Golden Promise. The use of GISH on a plant homozygous for the pubescence gene confirmed the presence of H. bulbosum DNA located distally on two barley chromosomes and we mapped the introgression to barley chromosome 4HL using RFLP analysis. Furthermore, by means of an allelism test we found that the transferred gene for pubescence is allelic or closely linked to a gene for pubescence (Hs) located on barley chromosome 4HL. The presence of a single H. bulbosum chromosome in the monosomic substitution plant was confirmed by GISH. A distal introgression of H. bulbosum DNA was also observed on one barley chromosome, which was located on chromosome 3HL by RFLP analysis.Key words: Hordeum vulgare, Hordeum bulbosum, interspecific hybrid, gene introgression, genomic in situ hybridization.

Identification of all chromosome arms and their involvement in meiotic homoeologous associations at metaphase I in 2 Hordeum vulgare L. × Hordeum bulbosum L. hybrids

Genome ◽  
2006 ◽  
Vol 49 (1) ◽  
pp. 73-78 ◽  
Author(s):  
R Pickering ◽  
S Klatte ◽  
R C Butler
Keyword(s):  
In Situ Hybridization ◽  
Hordeum Vulgare ◽  
Fluorescence In Situ Hybridization ◽  
Interspecific Hybrids ◽  
Association Studies ◽  
Hordeum Bulbosum ◽  
Hordeum Vulgare L ◽  
Chromosome Addition ◽  
Chromosome Associations

We have identified all Hordeum bulbosum chromosomes in 2 diploid Hordeum vulgare × Hordeum bulbosum hybrids using suitable probes and fluorescence in situ hybridization. Using the parental idiograms allowed us to carry out a full analysis of chromosome associations among all chromosome arms in the hybrids. Association frequencies were generally lower for the short arms than for the long arms. There were also significant differences among the chromosome arms in association frequencies, partly correlated with the absolute length of the chromosome arm, as well as with the frequency of recombinant lines, which were recovered from partially fertile interspecific hybrids. The H. bulbosum idiogram will be useful for further chromosome association studies and will enable the identification of H. bulbosum chromosomes involved in chromosome addition or substitution lines.Key words: Hordeum vulgare, Hordeum bulbosum, interspecific hybrids, chromosome associations, meiosis, fluorescence in situ hybridization.

The Relationship Between Chromosome Volume and Dna Content in Unsquashed Metaphase Cells of Barley, Hordeum Vulgare Cv. Tuleen 346

1982 ◽  
Vol 56 (1) ◽  
pp. 101-111
Author(s):  
M. D. BENNETT ◽  
J. B. SMITH ◽  
J. P. WARD ◽  
R. A. FINCH
Keyword(s):  
Hordeum Vulgare ◽  
Dna Content ◽  
Root Tip ◽  
Hordeum Vulgare L ◽  
Reciprocal Translocations ◽  
Morphological Criteria ◽  
Relative Dna Content ◽  
Sole Criterion ◽  
Mother Cells ◽  
Diploid Cells

The present work used haploid and diploid cells of barley, Hordeum vulgare L. cv. Tuleen 346 (2n = 2x = 14), which has three reciprocal translocations. All seven chromosomes of the haploid set are distinguishable using morphological criteria in Feulgen-stained root-tip squashes seen in the light microscope, as are five of the bivalents at diakinesis. The relative DNA content per bivalent was estimated in pollen mother cells at diakinesis. The results showed that all seven chromosomes or bivalents of Tuleen 346 can be identified using relative DNA content as sole criterion. The absolute and relative volumes of the seven chromosomes were estimated from electron micrographs of serial sections of unsquashed root-tip cells of a haploid. The results show that, using relative chromosome volume as sole criterion, it is highly probable that all seven chromosomes in single unsquashed cells of Tuleen 346 can be correctly identified. Consequently, teats for various non-random spatial arrangements of chromosomes in unsquashed cells of Tuleen 346 using this character to identify the chromosomes should be feasible. There was a very highly significant positive relationship (r&gt;0.99) between relative chromosome volume and mean relative DNA content per chromosome for each cell examined at metaphase of mitosis or meiosis. Thus, some mechanism ensures that the degree of condensation of all seven chromosomes within a cell is usually very similar in Tuleen 346, despite its grossly abnormal karyotype.

Meiotic crossing-over between sites on opposite sides of the centromeres of homoeologues is frequent in hybrid Aloeaceae

Genome ◽  
1990 ◽  
Vol 33 (2) ◽  
pp. 170-176 ◽  
Author(s):  
P. E. Brandham
Keyword(s):  
Pollen Mother Cell ◽  
Mother Cell ◽  
Crossing Over ◽  
Centromere Region ◽  
Short Chromosome ◽  
Pollen Mother Cells ◽  
Mother Cells ◽  
Homoeologous Chromosomes

During meiosis, long and short arms of acrocentric homoeologues pair and cross over in the centromere region in 95 (66.9%) of 142 hybrids of differing parentage in the monocotyledon family Aloeaceae. A characteristic configuration, the L–S bridge, is produced at anaphase I with frequencies ranging from <1 to 48% of pollen mother cells and in up to three bivalents per pollen mother cell. Too frequent to be due to inversion hybridity, L–S crossing-over most probably results from straight, noninverted pairing between nonhomologous proximal segments of the long and short chromosome arms following centromere mismatching in the heteromorphic bivalents. It is suggested that there are several lengths of DNA in different regions of homoeologous chromosomes, but perhaps concentrated around the centromere, that are sufficiently similar to recognize each other, pair, and cross over when brought together in a heteromorphic bivalent with mismatching of centromeres.Key words: Aloeaceae, hybrid, meiosis, nonhomologous pairing, crossing-over.

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