Cucurbit Genetics Cooperative Report 10:78-79 (article 40) 1987
Early Vegetative Development of Spaghetti Squash
is Unaffected by Seed Size
Menahem Edelstein, Haim Nerson, Harry S. Paris, Zvi Karchi and Yosef
Burger
Department of Vegetable Crops, Agricultural Research Organization, Newe
Ya'ar Experiment Station, P. 0. Haifa, Israel
Spaghetti squash (Cucurbita pepo) has experienced a surge
of popularity during the past few years. Since its introduction into North
America from Japan in 1936 (2), the sole cultivar has been 'Vegetable Spaghetti',
a vine- type, open-pollinated, pale-fruited cultivar. We introduced for
1986 the first hybrid spaghetti squash cultivars, 'Orangetti' and 'Go-Getti'
(1). Both hybrids are improved over 'Vegetable Spaghetti' by having semi-bush
habit and attractive, intense fruit color.
As with many other commercial C. pepo hybrids, 'Orangetti'
and 'Go-Getti' are produced by treatment of the female parent with ethephon
and use of honeybees for transferring pollen from the male parent to the
female. It was readily noticeable that ethephon treatment of squash resulted
in smaller plants which in turn produced smaller fruits with seeds about
one-third smaller than normal. Although germinability was excellent, no
comparison had been made between plants developing from small seeds with
plants developing from large seeds. The aim of the present work was to compare
the vegetative development of plants developing from large and from small
seeds.
Two experiments were conducted for this comparison, each with 2 treatments,
"large" seeds (average seed weight 161 mg) and "small"
seeds (average seed weight 108 mg). Seeds of both treatments were derived
from a commercial stock of 'Vegetable Spaghetti' obtained from Sakata Seeds.
The largest and smallest seeds from this commercial stock were selected
for the treatments.
The first experiment was sown in a heated greenhouse on 16 October 1985
at Newe Ya'ar (Yizre'el Valley, northern Israel) in 5-liter plastic pots.
The medium was grumusol-peat-vermiculite (1:1:1, v:v:v). There were 4 plants
per treatment. The plants were taken 3 weeks after emergence for measurement
of leaf blade fresh weight, stem and petiole fresh weight, and stem length.
The second experiment was sown in the field on raised beds, 2 m between
bed centers and 2 plants every 50 cm in the row, on 3 April 1986 at Newe
Ya'ar. There were 6 plants per treatment, which were taken from the center
of a 24 m2 plot 40 days after emergence for measurement of the
same variables as above and for counting the number of internodes.
The results, presented in Tables 1 and 2, show that in spaghetti squash
early vegetative development is unaffected by seed size. Seeds produced
following ethephon treatment can be expected to develop into plants of the
same vegetative vigor as seeds produced without ethephon treatment.
Table 1. Influence of seed size on early vegetative development of spaghetti
squash. Greenhouse, Autumn 1985.
Table 2. Influence of seed size on early vegetative development of spaghetti
squash. Field, Spring 1986.
Literature Cited
- Paris, H.S., M. Edelstein, H. Nerson, Y. Burger, Z. Karchi, and D.
Lozner. 1985. 'Orangetti' and 'Go-Getti', two new spaghetti squash hybrids.
Hassadeh 66: 254-256 (Hebrew, English abstract).
- Torrey, T.C. 1986. Written communication (to HSP). June 18.
Contribution No. 1902-E, 1986 series, from the Agricultural Research
Organization, Bet Dagan, Israel.
