Cucurbit Genetics Cooperative Report 3:4 (article 2) 1980
A.C. de Ruiter and B.J. van der Knap
DeRuiterzonen Seed Co., Bleiswijk, The Netherlands
R.W. Robinson
New York State Agricultural Experiment Station, Station, Geneva, NY 14456
An interesting variant, given the acronym “megurk” from the combined Dutch words for cucumber and muskmelon, was obtained when cucumber plants were pollinated with a mixture of cucumber and muskmelon pollen (2). The plants had shorter internodes, more obtuse leaf lobing, and smaller length-diameter fruit ratio that the cucumber parent, and in some respects, were intermediate to normal cucumber and muskmelon plants. The possibility of interspecific origin, however, was refuted by electrophoretic evidence (1).
Crosses between the “megurk” and normal cucumber plants were fully fertile and normal in appearance. The F2 segregated 483 normal to 162 mutant plants, in close agreement to 3:1 ratio (p= .95). Seven of 11 normal F2 plants that were self pollinated produced segregating progeny and the four other F3 lines were homozygous normal, agreeing with the 2:1 ratio. It is concluded that a single recessive gene is involved.
The non-Mendelian ratio in the original cross (2) is attributed to mixed pollination involving several homozygous normal cucumber plants and a single cucumber plant heterozygous for a spontaneous mutation. The Mendelian ratio expected for the selfed progeny of the heterozygote was distorted by the mixture of self- and cross-pollination, the selfed progeny would be expected to segregate but those from crosses would all by phenotypically normal.
The mutant is named rosette after its short internodes and closely spaced upper leaves, with the symbol ro.
Literature Cited
- Robinson, R.W., J.T. Puchalski, ad A.C. de Ruiter. 1979. Isozyme Analysis of the megurk. Cucurbit Genetics Coop. Rpt. 2:17-18
- van der Knap, B.J. and A.C. de Ruiter. 1978. An Interspecific Cross Between Cucumber (Cucumis sativus) and Muskmelon (Cucumis melo). Cucurbit Genetics Coop. Rpt. 1:6-8.