Pairing competition between identical and homologous chromosomes in diploid and tetraploid cells of rye telotrisomic plants

Abstract

BENAVENTE, E., and J. ORELLANA. 1986. Pairing competition between identical and homologous chromosomes in diploid and tetraploid cells of rye telotrisomic plants. Can. J. Genet. Cytol. 28: 568-573. Pairing competition between identical and homologous chromosomes 1R has been directly analyzed in diploid-tetraploid chimeras of telotrisomic plants of rye Secale cereale by using C-bands as cytological markers. The results have shown pairing preferences either in diploid cells, with three doses of IR', and in tetraploid cells, with six doses. In both cases, the preferences found could be explained by differential pairing affinities between chromosomes.BENAVENTE, E., et J. ORELLANA. 1986. Pairing competition between identical and homologous chromosomes in diploid and tetraploid cells of rye telotrisomic plants. Can. J. Genet. Cytol. 28: 568-573. La compktition d'appariement entre des chromosomes homologues et identiques 1R a kt6 analyske directement dans des chimkes diploi'des-tktraploi'des de plantes tklotrisomiques du seigle, Secale cereale, a l'aide des bands C cornrne marqueurs cytologiques. Les rksultats rkv2lent des prkfkrences d'appariement tant chez les diploi'des, avec trois doses de IR', que chez les tktraploi'des, avec six doses. Dans les deux cas, les diffkrences observkes pourraient Ctre expliqukes par des affinitks d'appariement diffkrentielles entre les chromosomes.

Connection between rod bivalents and incomplete meiotic association at NORs in Hordeum marinum Huds.

“…The lower frequency of rod bivalents with rDNA sites among rods in self‐pollinating ssp. gussoneanum (2x) compared to the frequencies in the intraspecific hybrids may be due to a higher pairing level among the identical chromosomes of the taxon than among the, although homologous, non‐identical chromosomes of the hybrids in agreement with results of observations on meiotic cells of diploid/tetraploid chimeras of S. cereale, Secale hybrids, chromosome‐ doubled rye‐wheat derivatives and the grasshoppers Euchorthippus pulvinatus gallicus and Eyprepocnemis plorans (Giraldez and Santos 1981, Santos et al 1983, Benavente and Orellana 1986, 1991, 1992, Orellana and Santos 1985). However, association of identical partners was not always preferred indicating an influence of other factors (Santos et al 1983, Benavente and Orellana 1991).…”

Pairing competition between metacentric and telocentric chromosomes in autotetraploid rye

“…Recently, the use of C-bands as cytological markers has allowed direct analyses of pairing preferences for specific chromosome arms in tetraploid meiocytes of rye and grasshoppers (Giraldez and Santos 1981;Santos eta!., 1983;Naranjo and Orellana, 1984;Orellana and Santos, 1985;Benavente and Orellana, 1986). Orellana and Santos (1985) pointed out that mutual influences between both arms should be taken into account when metacentric or submetacentric chromosomes are considered because pairing preferences at a given arm might influence those of the other arm.…”