Cucurbit Genetics Cooperative Report 23:101-104 (article340) 2000
Joanna Winkler
Saatzucht Gleisdorf, Am Tieberhof 33, A-8200 Gleisdorf, Austria; [email protected]
Abstract: The cultivation of pumpkins (C. pepo L.) for the combined use of fruits and seeds in Styria is confirmed by records going back 200 years. This was the first and, at the beginning, the largest region in Europe that cultivated pumpkins for making seed oil.
Originally the hard seedcoat had to be removed to make good oil. A mutation having hull-less seeds seems to have appeared around 1880, but reports of cultivation first appeared around 1925. The quality of oil in the seeds and the vining form of growth did not change. For a long time farmers had selected for larger fruits, larger seeds and higher oil content and exchanged seed between regions. Based on local plant material systematic breeding activities and genetic studies were started in the 1930s.
Besides disease resistance and improvement of seed yield, reduction in the length of vines, an increase of the oil content in the seeds and – recently – an increase of tocopherols are the main goals in breeding work today.
History: Cultivation of vining Styrian-type oil pumpkins in Austria has been documented over the past 200 years. Because of the favourable climatatic conditions Styria was the main oil pumpkin producing and consuming area in Austria from the very beginning. Other countries that traditionally produced oil from pumpkin seeds are Hungary, Northern Yugoslavia, Romania nd the Ukraine.
Originally the same types of pumpkin were used for producing fruit flesh and seeds for pressing oil. Selection practised by farmers was influenced by both of these uses.
In the Styrian cultivation area, which was the oldest and largest in central Europe, farmers had ben practicing selection for at least 100 years (1). Usually farmers exchanged seeds or used seeds from the best production areas. Some of these selections could not adapt to other regions, but others proved suitable for various conditions and were sufficiently stable. For seed production the first fruits set, the largest fruits, and those containing the most and largest seeds were chosen. Attention was also paid to uniformity of shape and colouring of the fruit. fields for growing pumpkins were usually fertilised with manure. This practise favoured types for intensive cultivation. The experience gained from pressing oil from seed dehulled by hand enabled farmers to select seed for higher oil content as well. Thus landraces were continually being improved in the traditional oil pumpkin regions.
A mutation to pumpkins with hull-less seeds seems to have occurred in Styria around 1880. Reports of the cultivation of such hull-less-seeded pumpkins in Austria began to appear after the first World War. Cultivation of the hull-less-seeded pumpkins increased rapidly because it was now possible to produce more oil (Fig. 1 and 2) with less work and less expense. The oil from hull-less seeds was equal in quality to that of the hulled seeds (3).
To optimise cultivation techniques Professor Tschermak from the University of AGriculture in Vienna developed a bush-type hull-less seeded pumpkin, the so-called Tschermak’s oil-pumpkin, by crossing the Styrian vining hull-less oil-seed pumpkin with the hulled-seeded bush-type squash ‘Mark Marrow’ (4). This variety, ‘Tschermaks oil pumpkin’ was registered at the Federal Institute in Vienna in 1955. Tschermak chose the bush form so that the fruits could mature more rapidly and uniformly and facilitated mechanical weed control. But his type produced smaller fruits and smaller seeds so the farmers still preferred the Styrian hullless vining pumpkin which they themselves had selected.
Breeding to increase the oil content of hull-less seeds of the Styrian vining oil pumpkin was begun in 1940 at the Lamberg Breeding station (2) near Ilz in the eastern part of Styria. In 1948 Prof. Gorbach of the Technical University in Graz initiated analyses of oil and protein content of seeds originating from elite plants.
Saatzucht Gleisdorf started its oil pumpkin breeding program on a small scale already in the first year after its foundation in 1947. Collections of landraces were made from different parts of Austria, mainly in the south-eastern Styria and in Slovenia. In 1960 the breeding program was enlarged. A number of lines were evaluated with respect to seed yields, excellent performance, and high oil content in the seeds. From this plant material the first vining hull-less oil-seed pumpkin variety of Austria based on local material was selected and registered under the name “Gleisdorfer Olkurbis” in 1970. Even today this is the most widespread oil-seed pumpkin variety in Austria and in 1995 the “Glei8sdorfer Olkurbis” was also registered in Hungary.
The typical “Gleisdorfer Olkurbis” has very long vines of 8-10 m in length, globular yellow fruits with green streaks weighing 3 to 7 kg. at maturity, and the oil content of its seeds is about 50%. Fig. 3 shows fruits at maturity.
The variety ‘Weis 371’ was developed at the Research Station for Special Crops in Wies, Styria and registered in 1976. This variety ripens a few days later than the Gleisdorfer Olkurbis and has a different shape of leaf. In 1998 the maintenance breeding was taken over by Saatzucht Gleisdorf.
Over the last 20 years breeding efforts have been concentrated on increasing the size, thickness and harvestibility of the seeds as well as improving the ratio of seed to fruit weight. In some selections an increase of dry seeds compared to fresh fruit weight from 1.5% to approximately 3.0% could be achieved.
In order to reduce the variable maturing time of fruits we started to develop bush-type strains with short vines, smaller fruits and more fruits per plant. Until now two oil pumpkin varieties of this type have been registered, the first is ‘Sepp’ (1994) with dark green seeds and marbled fruits and ‘Markant’ (1996) with light green seeds and striped fruits.
In a national research project financially supported by the Funds for Promotion of Research (FFF) with the title “Breeding of early maturing oil-seed pumpkin varieties of high quality” we started in 1995, to analyse, in addition to oil content, the fatty acids and tocopherol content in our breeding material (5, 6_. Table 1 shows the level of oil, linoleic acid and tocopherols content of 2 varieties at the location Gleisdorf over a period of 5 years. ‘Sepp’ is the variety with the higher oil and linoleic acid content. Due to the first serious virus outbreak in 1997 and also in 1998 the oil seed pumpkins showed strongly reduced seed size and as a consequence a reduced oil content in the seeds.
The years 19195 and 1996 with low temperatures in September affected linoleic acid contents for both varieties positively. The first 3 years showed a constant level of tocopherols in both varieties. Since 1997 and 1998 were years with high virus infections in the trials, a substantial increase in tocopherol content was observed (Table 1), however, we did not find the negative correlation between tocopherol content and content of linoleic acid as described previously (7).
High virus infections 9ZYMV,WMV-2) occurred for the first time in Austria in 1997. We at Saatzucht Gleisdorf started a resistance breeding program, financially supported by the FFF and in cooperation with the Research Project for ZYMV-Resistant Oil-Seed Pumpkins for Austria co-ordinated by T. Lelley at IFA-Tulin.
Table 1. The level of oil, linoleic acid and tocopherols content of two varieties, Sepp and Gleisdorfer Olkurbis at the location Gleisdorf over a period of 5 years.
|
|
Oil content (%)
|
Linoleic acid (%)r |
α + γ Tocopherol (mg/kg) |
|||
|---|---|---|---|---|---|---|
|
Year
|
Sepp | Gleisd. | Sepp | Gleisd. | Sepp | Gleisd |
|
1994
|
50,5
|
46,5
|
43,4
|
42,3
|
136
|
149
|
|
1995
|
49,7
|
47,8
|
55,3
|
54,4
|
134
|
147
|
|
1996
|
43,0
|
41,1
|
55,4
|
50,2
|
119
|
144
|
|
1997
|
45,7
|
46,9
|
51,9
|
46,5
|
96
|
339
|
|
1998
|
42,6
|
46,9
|
47,6
|
44,8
|
202
|
327
|
Acknowledgements: We would like to thank the FFF (Funds for Promotion of Research) in austria for funding the research project of breeding for higher quantity and quality of pumpkin seed-oil.
Literature Cited
- Buchinger, A. 1948. Kurbiszuchtung. Die Bodenkultur, 2:10-27.
- Buchinger, A. 1950. Der Steirische, schalenlose, langtriebige Olkurbis. Die Bodenkultur, 4:217-226.
- Grebenscikov, I. 1954. Zur Vererbung der Dunnschaligkeit bei Cucurbita pepo L. Zuchter 24:162-166.
- Schoninger, G. 1950. Genetische Untersuchungen an Cucurbita pepo L. Der Zuchter 20:321-336.
- Murkovic, M., A. Hilebrand, J. Winkler, W. Pfannhauser, 1996. Variability of vitamin E content in pumpkin seeds. (Cucurbita pepo L.) Z. Lebensm. Unters. Forsch., 202:275-278,
- Murkovic, M., A. Hillebrand, J. Winkler, E. Leitner, W. Pfannhauser, 1996. Variability of fatty acid content in pumpkin seeds (Cucurbita pepo L.) Z. L Kebensm. Unters. Forsch. 203:216-219.
- Schuster, W., W. Zipse, R. Marquard, 1983. Der Einfluβ von Genotyp und Anbauort auf verschiedene Inhaltsstoffe von Samen des Olkurbis (Cucurbita pepo L.) Fette, Seifen, Anstrichmittel 85:56-64.