Cucurbit Genetics Cooperative Report 4:11 (article 5) 1981
A Second Source of Non-bitterness in Cucumber
H. Inggamer and O. M. B. de Ponti
Institute for Horticultural
Plant Breeding, Wageningen, The Netherlands
The non-bitter character is commercially of vital importance
in The Netherlands, bitter cucumbers being unwanted and
In the 1950s, a continuous search went on at the IVT for
non-bitter plants. In the gene bank then available, among
15,000 individuals one plant of the United States variety
Improved Long Green (ILG) was found which was completely
non-bitter in all vegetative and generative parts. Probably
it was a spontaneous mutant. According to Andeweg and De
Bruyn, the non-bitter character depends on one recessive
gene (1). In the 1960s, this character was incorporated
into the Dutch varieties with the result that at present
almost all varieties are completely plant non-bitter.
In 1969, the IVT received from a missionary the pickling
cucumber variety Jiwika, originating from the village of
Jiwika in the Balliem valley in the central highlands of
New Guinea. It was said to be plant-bitterfree.
Crosses were made both with the non-bitter ILG mutant and
a bitter line. All 48 F1 plants from the cross between Jiwika
and the non-bitter ILG mutant were found to be completely
free from bitter principles. Of the F2 progeny from the
cross of Jiwika and the bitter line, 192 plants were
tested for the presence of bitter principles. Of those, 47 plants
were found to be completely non-bitter. From this it may
be concluded that in Jiwika too, the non-bitterness is governed
by one recessive gene and that this gene is identical with
the ILG gene, designated bi.
Recently, it was found that the gene Bi is not
inherited in dominant fashion but intermediary (2). This
could be demonstrated via the development of a method for
the quantitative determination of cucurbitacin.
- Andeweg, J. M. and J. W. de Bruyn. 1959. Breeding of
non-bitter cucumbers. Euphytica 8:13-20.
- Ponti, O. M. B. de and F. Garretson. 1980. Resistance
in Cucumis sativus L. to Tetranychus urticae
Koch. 7. The inheritance of resistance and bitterness
and the relation between these character. Euphytica 29: 513-523.