PPDL Picture of the Week
April 17, 2017
Seedless fruit production
Wenjing Guan, Assistant Professor, Department of Horticulture and Landscape Architecture, Purdue University, Southwest Purdude Agricutural Center
A plant is considered to be seedless if it is able to
produce a fruit either without seed or a much-reduced number of seeds. In some
cases, seedless fruit may possess traces of aborted seeds. Seedlessness is a
desirable fruit character because seeds are often hard, have a bad taste and
produce hormones that lead to fruit deterioration. As a result, seedless fruit
often has better quality and longer shelf lives.
Seedless watermelons that were introduced in the 1990s have
become the main type of watermelons grown in the U.S. Besides seedless watermelons, breeders have
developed seedless varieties for other fruiting vegetables. This article
briefly introduces the different types of seedless fruit and discusses potential
opportunities for growing theses varieties.
Seedlessness exists in two forms. In the case of seedless
watermelons, the fruit contains partially formed seeds that are aborted after
fertilization. Seedless watermelon plants are self-infertile. They must be
pollinated by a seeded watermelon plant (diploid) in order to produce a
seedless fruit. Another form of seedlessness is called parthenocarpy, for which
fruit are seedless because the ovary is able to develop without fertilization,
therefore they do not need pollination. The parthenocarpic character can be
found in most of the common cucumber types, i.e. picking, slicer, long and mini
cucumbers. It also exists in summer squashes. Green zucchinis are more likely
to carry the parthenocarpic character; varieties include Partenon, Dunja etc. A
yellow summer squash Golden Glory has also been found can set fruit without
Without the need for pollination, parthenocarpic cucumbers
and summer squashes are ideal for high tunnel and greenhouse production. In
addition, these varieties work well with insect netting, as the nettings do not
need to be removed at flowering stage as required by varieties that need
pollination. Parthenocarpic tomato and
eggplant varieties are also available. One of the advantages of growing
parthenocarpic tomatoes is that they can set fruit when environmental
conditions are undesirable. This is particularly true in the early season that
low temperature prevents fertilization.
Producing summer squash without pollination – ranking
Less is better: new approaches for seedless fruit production
These varieties are ideally to grow in high tunnels are
where keeping bees in the tunnel is always a challenge. We have seen more
growers, especially organic growers start to use row covers to exclude pests.
However, these row covers must be removed once female flowers are produced in
order to allow for pollination. Parthenocarpic cucumbers and summer squashes
Some varieties of cucumbers and summer squashes are
parthenocarpic. They can set fruit without pollination.
Parthenocarpic characters are present in pickling, long and
slicer cucumbers, are available in and summer squashes are becoming popular.
However, fertilization is required to produce seedless
watermelon. As a matter of fact, grow seedless watermelons require planting
pollienier plants nearly. This is because the plants producing seedless
watermelons are tetraploid. Because of the imbalance of chromosome number, tetraploid
plants are self-infertile. They must be pollinated by a diploid plant in order
to produce a seedless watermelon.
One is called parthenocarpic, for which fruit are seedless
because the ovary is able to develop without fertilization.
We understand the way
to grow seedless watermelons require planting pollinizer plants nearby. This is
because the plants producing seedless watermelons are tetraploid. Because of
the imbalance of chromosome number, tetraploid plants are self-infertile. They
must be pollinated by a diploid plant in order to produce a seedless
watermelon. Seedless watermelons have white seed traces, seeds in the seedless
watermelon are aborted after fertilization.
Developing tetraploid is a typical way of producing seedless
fruit. In these cases, pollination is required, although development of the
seeds disrupted after fertilization. Another form of developing seedless fruit
is called parthenocarpy, in which the ovary is able to develop without