Some Comments Concerning the Origin and Taxonomy of Old World Pumpkins

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Cucurbit Genetics Cooperative Report 23:99-100 (article 33) 2000

Harry S. Paris
Department of Vegetable Crops, Agricultural Research Organization, Newe Ya’ar Research Center, P.O. Box 1021, Ramat Yishay 30-095, Israel; [email protected]

Various forms of cucurbita pepo, many of them pumpkins, are recorded in botanical tomes of Europe beginning in the mid-16th century (6). Of the pumpkins, nearly all appear to be similar to one of two very distinct kinds: the orange-fruited, 20-grooved pumpkins of eastern Canada and U.S.A. and the green-striped or plain green-fruited, heavily 10-ribbed pumpkins of Mexico. There is also a large, slightly ribbed, broad dark green and orange striped pumpkin: the “Colocynthis oblonga variegata” of Fuchs (2) is similar phenotypically to the pumpkins of Europe and Asia Minor of today, including the oil pumpkins. A question concerning this last form is: was is derived directly from North America or was it derived through hybridization resulting from the two North American kinds being grown in close proximity with unchecked pollution, in the plots of plant collectors and/or herbalists?

There are other illustrations in that same work by Fuchs of C. pepo plants that appear to me to be the offspring of unchecked pollination among North american forms. Had the striped pumpkin of Fuchs been a relatively true-breeding stock, cold it alone have resulted in the tremendous phenotypic variability observed today among the striped pumpkins of Europe and Asia Minor? I believe that the answer is no, and that these pumpkins are ultimately derived through unchecked cross-pollinations between the two major kinds of North American pumpkins in the Old World. Other striped pumpkins, some quite large and some small, most with an orange background color, had already appeared in 16th century paintings of Europe (11).

Whilst the hull-less or “naked-seed” characteristic of pumpkin is sometimes considered to be a single-gene trait, the inheritance has also been seen as complex and under the control of several genes. I know of no earlier history of the isolation of this trait than the 19th century, as discussed by Teppner (8). A complex mode of inheritance would favor the idea that the hull-less seed trait was derived not so much through mutation as through genetic recombination. A great deal of recombination would be expected to have occurred, of course, if the two major kinds of North American pumpkins had hybridized.

The oil pumpkins are often referred to as Cucurbita pepo var. styriaca or C. pepo var. citrullina. Over the past 15 years or so, there has been a trend to differentiate between botanical taxonomy (10) and taxonomy of cultivated plants (9). Whilst the basic unit of botanical taxonomy is the species, the basic unit of cultivated-plant taxonomy is the cultivar.

Botanical taxonomy employs Latin terms and its lowest level is usually the subspecies, though at times is even lower, to botanical variety. The definition below the species level can be done with greatest confidence if based on genetic evidence. Thus, for Cucurbita pepo, Decker (1) has recognized three subspecies C. pepo spp. pepo, C. pepo spp. ovifera, and C. pepo spp. fraterna.

The highest level of horticultural plant taxonomy is usually the “cultivar group”, which can be referred to simply as “group”, and common terms, rather than Latin epithets, are preferred. The use of the term cultivar-group can be loose and refer to different characteristics. I believe that the greatest usefulness of this term is obtained when the characteristic(s) used for classification are easily recognizable to those who have any dealings with the species while at the same time reflect genetic relationships. Thus I proposed the use of fruit shape, a highly polygenic characteristic familiar to all who have anything to do withCucurbita pepo, to classify the horticultural forms of this species (4,6). The edible-fruited cultivar-groups I named Cocozelle, Pumpkin, Vegetable marrow, Zucchini, Acorn, Crookneck, Scallop, and Straightneck.

The relationship between the botanical classification and the horticultural classification can be observed from genetic evidence (1,3,5,7): the first four groups named above belong to C. pepo spp. pepo whilst the later four groups belong to C. pepo spp. ovifera. C. pepo spp. fraterna contains wild forms only.,

Using the botanical and horticultural classifications described above, the oil pumpkins of Europe and Asia Minor, the grooved pumpkins of Canada and the U.S.A. and the ribbed pumpkins of Mexico, could be considered as three sub-groups or market types within C. pepo spp. pepo Pumpkin Group.

Literature Cited

  1. Decker, D.S. 1988/ Origin(s), evolution, and systematics of Cucurbita pepo (Cucurbitaceae). Econ. Bot. 42: 4-5.
  2. Fuchs, L. 1542. Vienna Codex 11, 120: 479. Austrian National Library.
  3. Katzir, N., Y. Tadmor, G. Tzuri, E. Leshzeshen, N. Mozes-Daube, Y. Danbin-Poleg, and H.S. Paris. 2000. Further ISSR and preliminary SSR analysis of relationships among accessions of Cucurbita pepo. In: N. Katzir and H.S. Paris, eds. Proceedings of Cucurbitaceae 2000, the 7th Eucarpia Meeting on Cucurbit Genetics and Breeding. Acta Hort. 510: 433-439.
  4. Paris, H.S. 1986. A proposed subspecific classification for Cucurbita pepo. Phytologia 62: 133-138.
  5. Paris, H.S. 1996. Summer squash: history, diversity, and distribution. HortTechnology 6:6-13.
  6. Paris, H.S. History of the cultivar-groups of Cucurbita pepo. Hort. Revs. 25: (in press).
  7. Robinson, R.W. and D.S. Decker-Walters. 1997. Cucurbita. CAB International, New York.
  8. Teppner, H. 1999. Notizen zur Geschichte des Kurbisses. Obst, We in, Garten (Graz) 68(10): 36
  9. Trehane, P.,. C.D. Brickell, B.R. Baum, W.L.A. Hetterscheid, A.C. Leslie, J. McNeill, S.A. Spongberg, and F. Vrugtman. 1995. International code of nomenclature for cultivated plants. Quaterjack, Wimborne, U.K.
  10. Voss, E.G., H.M. Burdet, W.G. Chaloner, V. Demoulin, P.Hiepko, J. McNeill, R.D. Meikle, D.H. Nicolson, R.C. Rolina, P.C. Silva, and W. Greuter. 1983. International code of botanical nomenclature, in: F.A. Stafleu, ed. Regnum vegetabile 111. Utrecht.
  11. Zeven, A.C. and W.A. Bradenburg. 1986. Use of paintings from the 16th to the 19th centuries to study the history of domesticated plants. Econ. Bot. 40: 397-408.

Contribution No. 118/00 from the Institute of Field & Garden Crops, Agricultural Research Organization, Bet Dagan, Israel.