Institute of Genetics, Bulgarian Academy
In vitro colchicine - mediated doubling
of corn maternal haploids
--Nedev, T, Gadeva, P, Krapchev, B,
Experiments have been made with colchicine,
dimethyl sulfoxide (DMSO), and Tween 80‚
(Fluka AG, Buchs SG) to optimize dose treatment combination for double
halpoidization (DH) plants. Maternal haploids were derived from dry seeds.
Corn genotype, Ig1IRL - 93 - 18/8 - 6 x A 654, was used in this investigation.
Seeds were surface sterilized with 70% ethanol, followed by sodium hypochloride
solution, washed a few times with autoclaved tap water and transferred
onto three variants of artificial medium: colchicine; colchicine plus DMSO;
colchicine plus DMSO plus Tween 80‚.
Different concentrations and different durations for components of variants
were examined. Regarding procedures for colchicine preparation, concentration,
and treatment duration, please see our publication in Maize Genetics Cooperation
Newsletter No 73. After treatment, seeds were rinsed with sterile water
and transferred onto medium free of colchicine to promote germination.
The ploidy status of the plants obtained was determined by chromosome counting
of germinated root tip cells. Experiments performed have shown that variations
of chromosome number, including aneuploidy, diploidy and polyploidy were
observed. Depending on combination used, different percentages of DH plants
were obtained. Considering the total number of cells counted, the colchicine
(for the best concentration and treatment duration, please see our publication
in Maize Genetics Cooperation Newsletter No 73), DMSO and Tween 80‚
medium was very effective. The greater frequency of DH plants on the colchicine
plus DMSO plus Tween 80‚ medium
is probably due to slow penetration of these substances, which maybe favors
and allows more doubling. From our point of view, these results clearly
demonstrate the high potential of such treatment in acting as a chromosome
In summary, the results of this study
suggest that the combination of colchicine plus DMSO plus Tween 80‚
optimized chromosome doubling of corn dry seeds of genotype Ig1IRL - 93
- 18/8 - 6 x A 654.
This work was supported by grant B-602
from the National Fund of Scientific Investigations of the Bulgarian Ministry
of Education and Science.
Please Note: Notes submitted to the Maize Genetics Cooperation Newsletter may be cited only with consent of the authors.
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