Ploidy Levels Affect Phenotype and Cytogenetic Traits in Zea mays ssp. mays (2n=20 or 40) and Zea mays ssp. parviglumis Hybrids.

Molina, Marı́a del Carmen; García, María Dina

doi:10.1508/cytologia.66.189

Cited by 2 publications

(7 citation statements)

References 16 publications

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“…The most frequent meiotic configuration in the tri‐hybrid MDP was 5IV+10II. From this result and previous reports that support the polyploid condition of the genus Zea with the presence of two homoeologous genomes A and B (M olina and N aranjo 1987; N aranjo et al 1990; M olina and G arcía 1999, 2001; G arcía and M olina 1994) it can be suggested that the observed 5IV were the product of homoeologous chromosome pairing of A genomes from the three species.…”

Section: Discussionsupporting

confidence: 79%

“…From the meiotic configurations and genomic formulae of Zea species and their hybrids shown in Table 3 (M olina 1978, 1981, 1982, 1983, 1985, 1986, R osales and M olina 1984, M olina and N aranjo 1987, N aranjo et al 1990, M olina and G arcía 1999, 2001) it can be suggested: i) the 5 chromosomes of the A genome have not been significantly differentiated in the evolution of the different Zea species since they keep the ability of pairing in interspecific hybrids; ii) in interspecific Zea hybrids, B genome homoeologous chromosome pairing take place only if the respective homologous chromosomes are not present. A possible explanation of this observed pairing behavior is that mutations, variations in gene function or both events together occurred during evolution, resulting in a higher differentiation of B Zea genomes compared to A genomes.…”

Section: Discussionmentioning

confidence: 99%

“…The evidences mentioned above support the polyploid condition of the genus Zea with a basic genome number x=5 (M olina and N aranjo 1987) and suggest the existence of two homoeologous genomes A and B (P oggio et al 1990; N aranjo et al 1994), the first one more genetically conserved than the second (M olina and G arcía 1999, 2001; P oggio et al 1999).…”

mentioning

confidence: 86%

“…So far, studies conducted to elucidate the phylogenetic relations among Zea species showed the following evidences: i) the fertility of the hybrids is related to ploidy level. F 1 hybrids with 2n=20 or 40 and the next generations are fertile independently of the phylogenetic distance among parental species (M olina 1982, 1985; M olina and R osales 1983; R osales and M olina 1984; M olina and G arcía 1999, 2001; G arcía and M olina 1994). Conversely, 2n=30 hybrids are sterile (L ongley 1934; M olina 1978, 1985; M olina and G arcía 1999, 2001); ii) interspecific hybrids with 2n=20 chromosomes show a meiotic configuration of 10II (M olina and R osales 1983; R osales and M olina 1984; M olina and G arcía 1999, 2001; P oggio et al 1999, 2000); iii) in hybrids with 2n=30, obtained from crosses of Z. perennis (2n=40) and Z. mays, diploperennis, mexicana, parviglumis or luxurians (all 2n=20), the most frequently observed meiotic configuration is 5III+5II+5I (M azoti and R imieri 1978; M olina 1978, 1981, 1982; M olina and N aranjo 1987; M olina and G arcía 1999, 2001; P oggio et al 1999, 2000); iv) in the 2n=40 hybrid produced from the fusion of an unreduced gamete of Z. diploperennis with a normal gamete of Z. perennis (M olina 1985), as well as in the hybrid Z. mays (2n=40)× Z. perennis (M olina and G arcía 1999, 2000), the most frequent meiotic configuration is 5IV+10II, which is similar to the configuration observed in Z. perennis (M olina 1986); v) Plants treated with diluted colchicine solution (0.5×10 −4 M) during a 12 h period showed cryptic homology in the species Z. mays ssp.…”

mentioning

confidence: 99%

“…parviglumis (M olina and G arcía 1999), Z. mays ssp. mays (2n=20 or 40)× Z. perennis (M olina and G arcía 2001) and Z. diploperennis × Z. perennis (N aranjo et al 1994).…”

mentioning

confidence: 99%

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Meiotic pairing in the hybrid (Zea diploperennis×Zea perennis)×Zea mays and its reciprocal

et al. 2004

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Genomic formulae, fertility, chromosome pairing, and the cryptic intergenomic pairing (induced by using diluted colchicine solution) were analysed in the tri-hybrid (MDP), obtained by crossing DP40 (2n=40, which was inferred in previous studies to have originated from the fusion of an unreduced gamete of Zea diploperennis with a normal gamete of Z. perennis) with the maize inbred line Zm40 (2n=40). MDP (2n=40) showed a higher fertility (90% of the seeds are viable) than Zm40 (60%) and DP40 (80%). A regular migration of 20 chromosomes to each pole occurred in 92% of the cells in anaphase I, while bridges were observed in the other 8% of the cells. When Zm40 was used as female of the crossing (Zm40 x DP40), ears were similar to corn. Conversely, ears resembled those of the wild species when cytoplasm was donoured by Zd. Then, it can be stated the existence of cytoplasmic influence on MDP ear type. MDP had almost no I or III, with an average of 0.04I + 10.90II + 0.01III + 4.50IV. The most frequent meiotic configuration was 10II + 5IV (43.93% of the cells). On average, 33.81 chiasmata/cell were observed (17.34, 0.05 and 16.42 average numbers of chiasmata/cell in bivalents, trivalents and tetravalents, respectively). It can be inferred that the 5IV were the product of homoeologous chromosome pairing of A genomes from the three species. On the other hand, the 10II configuration suggests separate pairing of the 5 homologous B chromosomes from maize and the 5 homoeologous B chromosomes from Zp and Zd.

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Section: Discussionsupporting

confidence: 79%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 86%

mentioning

confidence: 99%

“…parviglumis (M olina and G arcía 1999), Z. mays ssp. mays (2n=20 or 40)× Z. perennis (M olina and G arcía 2001) and Z. diploperennis × Z. perennis (N aranjo et al 1994).…”

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confidence: 99%

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