Learn / Ask The Landscape Professional
I recently ate a seedless watermelon and I got wondering. How do seedless fruits like watermelon and grapes reproduce if they don't have seeds?
Answer
That is a great question. Plants can reproduce by several
ways other than by seeds. Surprisingly, most fruit that we eat today (except
citrus) don't come from seeds. One way strawberries reproduce is by
sending out "stolens" or runners which are long roots that spread out from
an existing main strawberry plant. These runners are capable of becoming
new plants. In the case of seedless grapes, most commonly, they are
grown from cuttings from existing grape vines that are dipped in a rooting
hormone and planted. These cuttings are clones of the original plant. Using cuttings to grow seedless grapes
has been around since Roman times!
Seedless watermelons are a bit different. The seedless watermelon was first "invented" over 50 years ago
and commercial production started about 25 years ago. Early versions of seedless watermelons lacked the
sweetness and color of their seeded counterparts, but watermelon breeders have been steadily improving
them so today they are of high quality. A seedless watermelon is a
man-made hybrid that has 33 chromosomes. Since normal seeded
watermelons have 22 chromosomes, creating a watermelon with 33
chromosomes took some doing.
Scientists discovered that if they applied a chemical compound,
Colchicine, which comes from the seeds and bulbs of Autumn
Crocus, Colchicum autumnale L., to the early growth stages of
normal 22 chromosome watermelons, they could create a seeded
watermelon with 44 chromosomes. They also discovered that if
they took the male pollen from a 22 chromosome watermelon and
fertilized a female flower of a 44 chromosome watermelon plant, the
result was a seeded watermelon that had 33 chromosomes. When the 33 chromosome seeds grow, they
produce the sterile seedless watermelon that we know today. Ironically, even though a seedless watermelon
is grown from seed, it doesn't produce any of its own! It's easy to see why seedless watermelons are more
expensive in the store!
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About Linda Lillie
Linda K. Lillie is the President of Sprigs & Twigs, Inc, the premier
landscape design and maintenance, tree care, lawn care, stonework, and carpentry
service provider in southeastern Connecticut since 1997. She is a graduate of
Connecticut College in Botany, a Connecticut Master Gardener and a national
award winning landscape designer for her landscape design and landscape installation work.
