Cucurbit Genetics Cooperative Report 5:59-60 (article 28) 1982
H.Q. Varekamp, D.L. Visser and A.P.M. den Nijs
Institute for Horticultural Plant Breeding (IVT), P.O. Box 16, Wageningen, The Netherlands
During last summer we were fortunate enough to have the assistance of the Royal Botanic Gardens at Kew to check the taxonomic determinations of our Cucumis species collection. We found this necessary because doubts existed about the correct name for certain accessions used in breeding experiments. It concerns our conception of C. africanus L.f., which has led to confusion with certain forms of C. zeyheri Sond., owing to the variable fruit indumentum of the latter. Accession numbers that were determined by us as C. africanus invariably appeared to be the diploid form of C. zeyheri. All the other accessions of our collection that had in the past been determined as C. zeyheri, were found to be tetraploid forms of this species. It has, therefore, been necessary to rename all the former C. africanus accessions as C. zeyheriSond. 2X (2n = 24), while the tetraploidC. zeyheri accessions will be designated as C. zeyheri Sond. 4X (2n – 48). These two levels of ploidy were also distinguished by Dane, et. al. (1). The two forms show consistent morphological differences in the size and the indumentum of the fruits. The corrections for the accessions involved are given in Table 1. It follows that it will be necessary to change in previous reports of the IVT-Cucumis working group the name C. africanus L.f. into C. zeyheri Sond. These reports are listed in Table 2.
Meanwhile, further studies of our collection have turned up at least three accessions that correspond in the morphology of their fruits with the holotype of C. africanus L.f. cited by Jeffrey (3), which was examined in the Paris herbarium and also with specimens of this species in the Kew Herbarium that were annotated by Jeffrey. Unfortunately, we have been unable to procure seeds of PI 282 440, the C. africanus for which Deakin, et. al. (2), gave a description and a figure of the fruit.
We are indebted to the Royal Botanic Gardens at Kew for the loan of reference material of Cucumis specimens and to C. Jeffrey for generously putting his profound knowledge of the genus at our disposal.
Table 1. Accessions of C. zeyheri Sond. in the IVT Cucumis Species Collection
IVT Genebank nr. |
Chrom. nr. |
Origin |
| 0162 | 24 | Glasshouse Crops Research Institute, LIttlehampton, U.K. |
| 0181 | 24 | H.B.z, Montpellier or Nancy, France |
| 0330 | 24 | H.B., Coimbra, Portugal |
| 1750 | 24 | ZGK, Gatersleben, D.D.R. |
| 1773 | 24 | H.B., Izmir, Turkey |
| 1780 | 24 | H.B., Basel, Switzerland |
| 1785 | 24 | PI 203 974 |
| 1786 | 24 | PI 274 036 |
| 1787 | 24 | PI 299 569 |
| 1835 | 24 | H.B., Salisbury, Zimbabwe |
| 1969 | 24 | H.B., Izmir, Turkey. |
| 2064 | 24 | H.B., Salisbury, Zimbabwe |
| 2065 | 24 | Vavilov Institute, Leningrad, U.S.S.R. |
| 2074 | 24 | Vavilov Institute, Leningrad, U.S.S.R. |
| 2148 | 24 | H.B., Kosice, U.S.S.R. |
| 1053 | 48 | PI 299 572 |
| 1807 | 48 | PI 299 570 |
| 1809 | 48 | PI 409 732 |
zH.B. – Hortus Botanicas
Table 2. List of reports with accessions of C. africanus L.f. which must be considered C. zeyheri Sond. 2x.
Reference citation |
| Custers, J.B.M. 1980. Proc. Eucarpia Meeting, Wageningen 50-55. |
| Custers, J.B.M. 1981. Cucurbit Genetics Coop. Rpt. 4:48-49. |
| Custers, J.B.M. and G. J. van Ee. 1981. Cucurbit Genetics Coop. Rpt. 3:50-51 |
| Custers, J.B.M., A.P.M. den Nijs and A.W. Riepma. 1981. Cucurbit Genetics Coop. Rpt. 4:50-53. |
| Kho, Y.O., A.P.M. den Nijs and J. Franken. 1980. Cucurbit Genetics Coop. Rpt. 3:52-54. |
| Kho, Y.O., A.P.M. den Nijs and J. Franken. 1980. Euphytica 29:661-672. |
| Leeuwen, L. van and A.P.M. den Nijs. 1980. Cucurbit Genetics Coop. Rpt. 3:55-59. |
| Nijs, A.P.M. den, J.B.M. Custers and A.J. Kooistra. 1980. Cucurbit Genetics Coop. Rpt. 3:60-62. |
| Nijs, A.P.M. den and E. Oost. 1980. Euphytica 29:267-271. |
| Nijs, A.P.M. den, D.L. Visser and J.B.M. Custers. 1981. Cucurbit Genetics Coop. Rpt. 4:58-60. |
| Oost, E. and A.P.M. den Nijs. 1979. Cucurbit Genetics Coop Rpt. 2:43-44. |
| Visser, D.L., L. van Leeuwen and Y.O. Kho. 1980. Proc. Eucarpia Meeting, Wageningen : 44-49 |
| Visser, D.L. and A.P.M. den Nijs. 1980. Cucurbit Genetics Coop. Rpt. 3:68-74. |
Literature Cited
- Dane, F., D.W. Denna and T. Tsiuchiya. 1980. Evolutionary studies of wild species in the genus Cucumis. Zeitchr. Pfl. Zucht. Journ. Pl.
- Deakin, J.R., G.W. Bohn and T.W. Whitaker. 1971. Interspecific hybridization in Cucumis. Econ. Bot. 25:195-211.
- Jeffrey, C. 1962. Notes on Cucurbitaceae, including a proposed new classification of the family. Key Bull. 15:337-371.