PSHS main page    Folia Horticulturae

Current issue content   Search      

Obtaining and characterization of tetraploid forms in cucumber - Cucumis sativus L. var. sativus and var. hardwickii Alef.

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.