Nucleolar organizer competition in Aegilops–rye hybrids

The nucleolar organizer activity in several Aegilops × rye hybrids (A. triuncialis × Secale cereale, A. variabilis × S. cereale, A. biunicialis × S. cereale, A. biuncialis × S. vavilovii, A. juvenalis × S. cereale) is analyzed by using a highly reproducible silver-staining procedure. The 1U and 5U chromosomes show a strong nucleolar activity, suppressing the NOR activity of chromosome 1R from rye in all the hybrid combinations (UCR, USvR, UMbR, UMbRv, and UMjDR). The nucleolus organizer chromosomes from the genomes C, Sv, Mb, and Mj show small activities. Our results confirm previous data of the nucleolar organizer activity predominant status of the 1U and 5U chromosomes from the U genome (A. umbellulata) and the weakest condition of the 1R chromosome from rye. A diagram showing the relationships between the nucleolar organizer activities of chromosomes from different genomes of Triticeae is presented.Key words: nucleolar competition, amphiplasty, Ag-NORs, Triticeae, Aegilops, Secale.

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Nucleolar organizer activity in wheat, rye and derivatives analyzed by a silver-staining procedure

Chromosoma ◽

10.1007/bf00331254 ◽

1984 ◽

Vol 89 (5) ◽

pp. 370-376 ◽

Cited By ~ 37

Author(s):

M. C. Cerme�o ◽

J. Orellana ◽

J. L. Santos ◽

J. R. Lacadena

Keyword(s):

Silver Staining ◽

Nucleolar Organizer ◽

Staining Procedure ◽

Nucleolar Organizer Activity ◽

Organizer Activity

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Nucleolar organizer activity at meiosis in wheat–rye hybrid plants

Canadian Journal of Genetics and Cytology ◽

10.1139/g86-031 ◽

1986 ◽

Vol 28 (2) ◽

pp. 227-234 ◽

Cited By ~ 2

Author(s):

N. Cuñado ◽

M. C. Cermeño ◽

J. Orellana

Keyword(s):

Silver Staining ◽

Staining Method ◽

Nucleolar Organizer ◽

The Other ◽

Nucleolar Organizer Regions ◽

Binucleate Cells ◽

Hybrid Plants ◽

Nucleolar Organizer Activity ◽

Silver Staining Method ◽

Organizer Activity

Nucleoli and nucleolar organizer regions (NORs) have been studied by a silver staining method in all meiotic stages of wheat–rye hybrid plants. The maximum number of nucleoli per cell scored at meiotic prophase and tapetum binucleate cells indicates that only the NORs of 1B, 6B, and 5D wheat chromosomes are active, whereas that of chromosome IR (SAT) of rye is inactive. However, at diakinesis, metaphase and anaphase meiotic stages only chromosomes 1B and 6B show Ag-NOR as was reported previously in somatic metaphase. The absence of Ag-NOR on chromosome 5D has been imputed to its low nucleolar organizer activity, not detectable by silver staining, because of the small number of rDNA clusters it carries. On the other hand, the meiotic behaviour of chromosomes 1B and 6B has been studied at metaphase I and anaphase I, using the Ag-NORs as cytological markers.Key words: nucleolar organizer, Ag-NOR, meiosis, wheat–rye hybrids.

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A simple two-step procedure for silver staining nucleolus organizer regions in plant chromosomes

Canadian Journal of Genetics and Cytology ◽

10.1139/g85-038 ◽

1985 ◽

Vol 27 (2) ◽

pp. 255-257 ◽

Cited By ~ 8

Author(s):

Romesh C. Mehra ◽

Susan Brekrus ◽

Merlin G. Butler

Keyword(s):

Vicia Faba ◽

Allium Cepa ◽

Silver Staining ◽

Lens Culinaris ◽

Nucleolar Organizer ◽

Nucleolus Organizer ◽

Staining Procedure ◽

Nucleolar Organizer Regions ◽

Nucleolus Organizer Regions ◽

Plant Chromosomes

Nucleolus organizer regions (NORs) of Allium cepa, Lens culinaris, and Vicia faba chromosomes were stained by a two-step silver staining procedure which is simple and highly reproducible. Polymorphisms are apparent with respect to the size of NORs in the taxa understudy.Key words: nucleolar organizer regions, silver staining, Allium cepa, Lens culinaris, Vicia faba.

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Nucleolar competition analysis in Aegilops ventricosa and its amphiploids with tetraploid wheats and diploid rye by the silver-staining procedure

Canadian Journal of Genetics and Cytology ◽

10.1139/g84-006 ◽

1984 ◽

Vol 26 (1) ◽

pp. 34-39 ◽

Cited By ~ 13

Author(s):

J. Orellana ◽

J. L. Santos ◽

J. R. Lacadena ◽

M. C. Cermeño

Keyword(s):

Secale Cereale ◽

Silver Staining ◽

Triticum Turgidum ◽

Tetraploid Wheat ◽

Nucleolar Organizer ◽

Triticum Dicoccoides ◽

Staining Procedure ◽

Nucleolar Organizer Regions ◽

Aegilops Ventricosa ◽

Tetraploid Wheats

The nucleolar organizer activity of Aegilops ventricosa and its amphiploids with tetraploid wheats (Triticum turgidum, Triticum dicoccum, and Triticum aethiopicum) and diploid rye (Secale cereale) was analyzed by the silver-staining procedure. Triticum turgidum and Triticum dicoccoides show four Ag-NORs (silver-stained nucleolar organizer regions), in agreement with previous data. Only two Ag-NORs are detected in Ae. ventricosa (genome constitution DDMM) indicating that natural amphiplasty occurs in this allotetraploid species. No amphiplasty was observed in the Ae. ventricosa – tetraploid wheat amphiploids since six Ag-NORs were visible in all of them. On the contrary, only two Ag-NORs were detected in the Ae. ventricosa – Secale cereale amphiploid, the rye NORs being suppressed by the presence of ventricosa chromosomes. The ventricosa NORs therefore are codominant with those of tetraploid wheat (chromosomes 1B and 6B) and dominant to chromosome 1R of rye. Eleven T. aestivum – Ae. ventricosa addition lines have been also analyzed. All of them showed four Ag-NORs. Clear-cut conclusions were not reached since the added ventricosa chromosomes were not identified.

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