Cucurbit Genetics Cooperative Report 1:39 (article 36) 1978
J. T. Puchalski, R. W. Robinson, and J. W. Shail
New York Agricultural Experiment Station, Geneva, NY 14456
Electrophoretic patterns of esterase, peroxidase, and leucine aminopeptidase of 24 different Cucumis species were compared. Large differences between several species were found for all these enzyme systems, but some other species showed a large degree of isozymic pattern similarity. For example, the zymograms of C. myriocarpus and C. leptodermis were identical, and similar to those of C. africanus, C. zeyheri, C meeusii, and C. anguria.
Cucumis longipes, which has been classified as a subspecies of C. anguria, differed from C. anguria in specific esterase bands. The isozyme evidence does not support the theory that C. longipes is the direct progenitor of C. anguria.
According to isozyme analysis, C. angolensis, C. dinteri, C. sagittatus, and C. asper appear to be taxonomically closely related. Isozyme patterns distinctly different from all other species were found for C. dipsaceusand for C. heptadactylus.
Cucumis trigonus was enzymatically very similar to muskmelon, and appears to be a subspecies of C. melo. Two other species, C hirsutus and C. humifructus, are distinctive in enzyme patterns, yet possess some common bands of esterase and peroxidase with C. melo.
Cucumis sativus and C. hardwickii, the only species with 14 chromosomes, were very distinctly different in isozymes from all species with 24 or 48 chromosomes. The zymogram of C. hardwickii was very similar to that of some cucumber varieties. According to these results, it should be classified as a subspecies of C. sativus rather than as a distinct species.