Are cytological parameters of maize landraces (Zea mays ssp. mays) adapted along an altitudinal cline?
The Northwestern Argentina (NWA) highland region is one of the southernmost areas of native maize cultivation. We studied variations of different cytological parameters, such as DNA contents, presence/absence of B chromosomes (Bs), and number and sequence composition of heterochromatic knobs in ten...
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2018
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09189440_v131_n2_p285_Fourastie http://hdl.handle.net/20.500.12110/paper_09189440_v131_n2_p285_Fourastie |
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paper:paper_09189440_v131_n2_p285_Fourastie2023-06-08T15:50:02Z Are cytological parameters of maize landraces (Zea mays ssp. mays) adapted along an altitudinal cline? B chromosomes DNA content FISH Knobs Maize landraces plant DNA altitude Argentina chemistry environment fluorescence in situ hybridization genetic variation genetics genotype heterochromatin maize plant chromosome Altitude Argentina Chromosomes, Plant DNA, Plant Environment Genetic Variation Genotype Heterochromatin In Situ Hybridization, Fluorescence Zea mays The Northwestern Argentina (NWA) highland region is one of the southernmost areas of native maize cultivation. We studied variations of different cytological parameters, such as DNA contents, presence/absence of B chromosomes (Bs), and number and sequence composition of heterochromatic knobs in ten accessions of four maize landraces growing along a broad altitudinal cline in NWA. The aim of this work was to assess variations in cytological parameters and their relationship with the crop altitude of cultivation, in an adaptive context. The A-DNA content of the A chromosome complements showed 40% of difference between the lowest (4.5 pg) and the highest (6.3 pg) 2C value. This variation could be attributed to differences in number and size of heterochromatic knobs. Fluorescent in situ hybridization studies revealed the sequence composition of each knob, with a higher proportion of knobs composed of 180-bp repeats rather than TR-1 repeats, in all accessions. We also found numerical polymorphisms and the highest frequency of Bs reported in maize to this date. These results lead us to propose that the frequencies and doses of Bs are influenced by the landrace genotypical make-up. The Bs might be maintained in higher frequencies in those accessions having lower heterochromatin content, so as to preserve an optimal nucleotype. Furthermore, selective forces acting along the altitudinal gradient might be modulating the cytological parameters studied, as suggested by the significant correlations found among them. © 2017, The Botanical Society of Japan and Springer Japan KK, part of Springer Nature. 2018 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09189440_v131_n2_p285_Fourastie http://hdl.handle.net/20.500.12110/paper_09189440_v131_n2_p285_Fourastie |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
B chromosomes DNA content FISH Knobs Maize landraces plant DNA altitude Argentina chemistry environment fluorescence in situ hybridization genetic variation genetics genotype heterochromatin maize plant chromosome Altitude Argentina Chromosomes, Plant DNA, Plant Environment Genetic Variation Genotype Heterochromatin In Situ Hybridization, Fluorescence Zea mays |
| spellingShingle |
B chromosomes DNA content FISH Knobs Maize landraces plant DNA altitude Argentina chemistry environment fluorescence in situ hybridization genetic variation genetics genotype heterochromatin maize plant chromosome Altitude Argentina Chromosomes, Plant DNA, Plant Environment Genetic Variation Genotype Heterochromatin In Situ Hybridization, Fluorescence Zea mays Are cytological parameters of maize landraces (Zea mays ssp. mays) adapted along an altitudinal cline? |
| topic_facet |
B chromosomes DNA content FISH Knobs Maize landraces plant DNA altitude Argentina chemistry environment fluorescence in situ hybridization genetic variation genetics genotype heterochromatin maize plant chromosome Altitude Argentina Chromosomes, Plant DNA, Plant Environment Genetic Variation Genotype Heterochromatin In Situ Hybridization, Fluorescence Zea mays |
| description |
The Northwestern Argentina (NWA) highland region is one of the southernmost areas of native maize cultivation. We studied variations of different cytological parameters, such as DNA contents, presence/absence of B chromosomes (Bs), and number and sequence composition of heterochromatic knobs in ten accessions of four maize landraces growing along a broad altitudinal cline in NWA. The aim of this work was to assess variations in cytological parameters and their relationship with the crop altitude of cultivation, in an adaptive context. The A-DNA content of the A chromosome complements showed 40% of difference between the lowest (4.5 pg) and the highest (6.3 pg) 2C value. This variation could be attributed to differences in number and size of heterochromatic knobs. Fluorescent in situ hybridization studies revealed the sequence composition of each knob, with a higher proportion of knobs composed of 180-bp repeats rather than TR-1 repeats, in all accessions. We also found numerical polymorphisms and the highest frequency of Bs reported in maize to this date. These results lead us to propose that the frequencies and doses of Bs are influenced by the landrace genotypical make-up. The Bs might be maintained in higher frequencies in those accessions having lower heterochromatin content, so as to preserve an optimal nucleotype. Furthermore, selective forces acting along the altitudinal gradient might be modulating the cytological parameters studied, as suggested by the significant correlations found among them. © 2017, The Botanical Society of Japan and Springer Japan KK, part of Springer Nature. |
| title |
Are cytological parameters of maize landraces (Zea mays ssp. mays) adapted along an altitudinal cline? |
| title_short |
Are cytological parameters of maize landraces (Zea mays ssp. mays) adapted along an altitudinal cline? |
| title_full |
Are cytological parameters of maize landraces (Zea mays ssp. mays) adapted along an altitudinal cline? |
| title_fullStr |
Are cytological parameters of maize landraces (Zea mays ssp. mays) adapted along an altitudinal cline? |
| title_full_unstemmed |
Are cytological parameters of maize landraces (Zea mays ssp. mays) adapted along an altitudinal cline? |
| title_sort |
are cytological parameters of maize landraces (zea mays ssp. mays) adapted along an altitudinal cline? |
| publishDate |
2018 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09189440_v131_n2_p285_Fourastie http://hdl.handle.net/20.500.12110/paper_09189440_v131_n2_p285_Fourastie |
| _version_ |
1768542846677155840 |