Breeding of non-bitter cucumbers

Abstract

A large number of seedlings of various cucumber varieties have been tested for bitterness . In the American variety Improved Long Green one plant was encountered that was non-bitter . This form of non-bitterness is highly valuable for breeding purposes, because of the possibility to select for non-bitterness at the seedling stage . Nonbitter varieties, as occur in other Cucurbitaceae, were not encountered in the many varieties investigated . Bitterness of cucumber and melon plants seems to be controlled by one dominant gene .Plants can be judged for non-bitterness simply by tasting them, provided that the tasters have previously been tested for sufficient discriminatory power .Non-bitterness of the young seedlings can also be shown by a chemical reaction . To this end a simple method has been developed .

Resistance in Cucumis sativus L. to Tetranychus urticae Koch. 7. The inheritance of resistance and bitterness and the relation between these characters

“…In all tests the frequency distributions of acceptance and oviposition show a continuous variation in the non-segregating as well as in the segregating generations, so that individual genes cannot be identified and quantitative analyses are necessary to elucidate the inheritance of these resistance factors. The discontinuity in the frequency distributions of cucurbitacin content is due to the segregation of the major gene Bi, whose recessive allele causes non-bitterness (ANDEWEG & DE BRUYN, 1959). As observed in the seedling stage the segregations in B, r and F, corroborated the expected 1: 1 and 3: 1 ratios.…”

“…This enabled us to check earlier findings that bitterness is not causally related to resistance to T. urticae (DE PONTI, 1979, 1980. The occurrence of bitterness is regulated by one major gene Bi (ANDEWEG & DE BRUYN, 1959), but the genetic basis of the degree of bitterness is still unknown. Therefore the bitter principle cucurbitacin-C was determined quantitatively in part of the material.…”

Cytogenetical Studies in the Genus <i>Citrullus</i>, III. Bitter Substances in Fruits of <i>C. colocynthis</i> Schrad. and <i>C. vulgaris</i> Schrad

“…The inheritance of bitterness of Cucurbitaceae has been reported for Cucumis sativus (Barham 1953;Andeweg & De Bruyn 1959), Lagenaria leucantha (Pathak and Singh 1950), Cucumis melo (Andeweg & De Bruyn 1959) and Cucurbita pepo (Grebenscikov 1954(Grebenscikov , 1955. All of them indicate the same monohybrid inheritance with dominance of bitterness.…”

Cucurbitacins in plant food

“…Due to the original selection of non-bitter plants for food use by our ancestors and later on by plant breeders, all parts of cucurbitaceous plants intended for food use are nowadays generally free of cucurbitacins. After searching around 15 000 cucumber plants for non-bitterness of seedlings, Andeweg and De Bruyn (1959) found one American variety of cucumber, Improved Long Green, which did not show any sign of containing bitter compounds and had no bitter taste. F 1 plants from a cross between non-bitter Improved Long Green and a bitter Dutch variety were all bitter, whereas selfing of the non-bitter Improved Long Green plant only produced seeds giving nonbitter seedlings.…”

“…Cucumis sativus, the cucumber, occurs in three different forms -varieties which have vegetative parts that always are bitter and produce fruits that may be bitter, varieties which always have bitter vegetative parts but fruits that even under unfavourable conditions do not turn bitter, and varieties which completely lack bitter principles both in the fruits and in the vegetative parts of the plant (Andeweg and De Bruyn, 1959). found seedlings of bitter (Hanzil) and non-bitter strains to contain similar amounts of cucurbitacin B in radicles and cotyledons.…”