Obtaining and characterization of tetraploid forms in cucumber - Cucumis sativus L. var. sativus and var.
Henryk O. Mackiewicz, Stefan Malepszy
Department of Plant Genetics, Breeding and Biotechnology
Faculty of Horticulture, Warsaw Agricultural University
Nowoursynowska 166, 02-787 Warszawa, Poland
Six diploid cucumber lines differing in origin and sex were subjected to
colchicine treatment by the Swalöf method using a 0.5% colchicine
solution. The ploidy level of examined plants was determined with
acetocarmin staining by light microscope. The obtained 4x plants of the C0
generation constituted 2.3% to 12.2% of the plants from which fruit with
seeds were harvested. In 1994 a comparative analysis was performed of
selected morphological characters of the C1
generation and the effectiveness of triploid formation was estimated in
crosses between 2x and 4x.
The investigations showed that monoecious cucumber lines became polyploid most easily as a result of
colchicine treatment, whereas strongly female lines were much more
resistant to colchicine action. Tetraploid plants of the C1
generation differed very distinctly from diploid ones. They had larger and
more denatate leaf blades, a greater corolla of male and female flowers,
larger pollen grains with 3, 4 or 5 pollen tube openings, and were to a
large extent sterile and unequilibrated. Tetraploid plants were smaller
and mature fruit shorter. In comparison with diploid plants the
tetraploids of the C1 generation had a considerable
decrease in fertility and a tendency to form hermaphroditic
flowers. A cosiderable differentiation of characters was demonstrated,
depending on the line. The effectiveness of obtaining seeds, after
crossing diploid and tetraploid forms, was found to be much higher when
the female parent is tetraploid. The number of obtained seeds depended on
the line, and the greatest amount of triploid and tetraploid seeds being
obtained in lines WI-5551/603, MI-805 and GYGV.
Mackiewicz H.O., Malepszy S., 1996. Obtaining and characterization of tetraploid
forms in cucumber - Cucumis sativus L. var. sativus and
var. hardwickii Alef. Folia Horticulturae 8/1: 3-10.