Nucleolar number variation in Hordeum species, their haploids and interspecific hybrids

The meiotic pairing behaviour of 39 new interspecific combinations between diploid Hordeum species are reported. On the basis of this data, four "basic genomes" are probably present in the genus. Hordeum bulbosum and H. vulgare have the same genome (I); H. marinum ("X") and H. murinum ("Y") each have one distinct genome. All other diploid taxa have either the same or a somewhat modified form of genome H. In this latter group of diploids, the South American taxa together with H. pusillum and H. intercedens in North America constitue a homogeneous group with respect to genomic structure, which differs somewhat from that found in the other Asiatic and North American species. Hordeum roshevitzii from Central Asia is unique, showing high affinity to both the Asiatic and to the American taxa. Evidence suggesting genetic regulation of chromosome pairing (both pairing promoting and pairing reducing) was obtained from a number of the diploid hybrids.Key words: Hordeum, interspecific hybrids, meiosis, diploids.

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Meiosis in interspecific Hordeum hybrids. IV. Tetraploid (4x × 4x) hybrids

Genome ◽

10.1139/g88-080 ◽

1988 ◽

Vol 30 (4) ◽

pp. 479-485 ◽

Cited By ~ 35

Author(s):

Roland von Bothmer ◽

Jan Flink ◽

Tomas Landström

Keyword(s):

Interspecific Hybrids ◽

Genetic Regulation ◽

The Other ◽

Meiotic Pairing ◽

Genomic Constitution ◽

Hordeum Species ◽

Hordeum Brevisubulatum ◽

Pairing Behaviour

The meiotic pairing behaviour of 31 interspecific combinations of tetraploid Hordeum species are reported. The autoploid H. bulbosum with the II genomic constitution has no homology to the other species. The constitution of tetraploid H. murinum is not clear, but it is not homologous to other tetraploids. Hordeum marinum is a probable autoploid (XX) but with a very strong genetic regulation of pairing. The X genome is possibly found in H. secalinum and H. capense, both of which also possess the H genome in several diploids. Hordeum fuegianum, H. tetraploidum, H. jubatum, H. brachyantherum, and H. roshevitzii are segmental alloploids all with the same two partly homoeologous genomes. Hordeum depressum is probably a segmental alloploid with the H genome and with a very strong pairing regulation. Hordeum brevisubulatum is a pure autoploid with two homologous H genomes.Key words: Hordeum, interspecific hybrids, meiosis, tetraploids.

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Genetic control of meiotic chromosome pairing in polyploids in the genus Hordeum

Canadian Journal of Genetics and Cytology ◽

10.1139/g85-077 ◽

1985 ◽

Vol 27 (5) ◽

pp. 515-530 ◽

Cited By ~ 40

Author(s):

P. K. Gupta ◽

George Fedak

Keyword(s):

Chromosome Pairing ◽

Interspecific Hybrids ◽

Meiotic Chromosome ◽

Intergeneric Hybrid ◽

Meiotic Pairing ◽

Major Locus ◽

In The Wild ◽

Hordeum Species ◽

Homoeologous Chromosomes ◽

Existing Data

Existing data on meiosis in hexaploid and tetraploid species of Hordeum, their respective polyhaploids, and intergeneric – interspecific hybrids indicate that a meiotic pairing control system exists in this genus. The system is probably polygenic and it is therefore unlikely that a major locus such as Ph in Triticum controls chromosome pairing. It is more efficient in the tetraploids than hexaploids, permitting some intergenomic pairing in the latter. In the polyhaploids the pairing control is somewhat hemizygous ineffective. The pairing of homoeologous chromosomes in the wild polyploid Hordeum species is generally inhibited by H. vulgare and variably enhanced by genomes of Secale species.Key words: Hordeum, synapsis regulation, intergeneric hybrid, polyhaploids, hemizygous.

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