2-hidroxyethyl disulfide effect on spindle and chromosomes

MOLINA, MC Y BERNATENÉ, EA.

Maize Genetics Coorporation Newsletter

University of Illinois

Lugar: Illinois; Año: 1993 vol. 67 p. 69 - 70

1090-4573

Cytological evidence of the basic number x=5 in the genus Zea were obtained by Molina and Naranjo (TAG 73:542-550, 1987) and Naranjo and Molina (MNL 61:62-63, 1987). One observation was the formation of a double spindle with 5 II each. From the (C-banding) analysis of the chromosome distribution in each spindle it was concluded that they do not distributed at randon. The formation of quadrivalents up to a maximun number of 5 IV was also observed when treating Zea mays with a diluted solution of colchicine. Similarly an increase in the number of quadrivalents up to a maximum of 10 IV was detected when treating Z. perennis and hybrids between Z. perennis x Z. diploperennis (2n=40) with the same solution (Poggio et al., TAG 79; 461-464, 1990; Naranjo et al., Res. XXI Cong. Arg. de Genet., C. del Uruguay: 62, 1990). With the purpose of studying in further detail the spindle and the chromosome distribution in the genus Zea, the cultivar "Ever Green" was treated with two different 2-hidroxyethyl disulfide diluted solutions during 1991, whilst immature tassels og "Ever Green" and "Colorado Klein" were treated with three diluted solutions during 1992. When comparing the treated and untreated tassels, it was seen that 2-hydroxyethyl disulfide concentrations at 1x10-4M and 2x10-4M did not affect any cells. Higher concentrations (3x10-4M and 4x10-4M) showed significant differences at diplotene, diakinesis and metaphase I. 65% of the cells in metaphase I showed a clear differentiation in two spindles with 5 chromosomes each. In the remaining 35% of the cells this configuration was not clear. A remarkable difference never observed before in the untreated material is the appearance of a high number of quadrivalents, up to a maximum of five. This effect is similar to that produced when treating "Colorado Klein" with colchicine diluted solutions (0.5x10-4M).