College Station, Texas
June 26, 2009
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Colored melon flesh are full of nutrients. Plant
breeders may develop even better varieties now that
melon genome with hundreds of DNA markers has been
mapped.
Credit: Texas AgriLife Photo by Kathleen Phillips |
People smell them, thump them and
eyeball their shape. But ultimately, it's sweetness and a sense
of healthy eating that lands a melon in a shopper's cart.
Plant breeders now have a better chance to pinpoint such traits
for new varieties, because the melon genome with hundreds of DNA
markers has been mapped by scientists with
Texas AgriLife
Research. That means tastier and healthier melons are likely
for future summer picnics.
"This will help us anchor down some of the desirable genes to
develop better melon varieties," said Dr. Kevin Crosby, who
completed the study with Drs. Soon O. Park and Hye Hwang. "We
can identify specific genes for higher sugar content, disease
resistance and even drought tolerance."
The results are reported in the
Journal of the
American Society of Horticultural Sciences.
Melons are fleshy, edible cucurbits grown worldwide in a
multitude of varieties. Not only are they economically
important, the scientists noted, but they are a favorite among
consumers internationally.
The average person in the U.S. eats about 25 pounds of melon
every year, according to the Agricultural Marketing Resource
Center at Iowa State University.
Scientists from France and Spain already had completed partial
maps of segments of the melon DNA sequence. The Texas
researchers connected those segments with new findings in their
study to complete the entire melon genome map.
For the study, the Deltex ananas melon was crossed with a wild
melon called TGR 1551. More than 100 of the offspring from that
cross were grown in the AgriLife Research greenhouses at
Weslaco, Crosby noted.
DNA was extracted from leaf tissue collected 21 days after
planting. Results from these tests were integrated into partial
maps created by other researchers.
Previous knowledge of melon DNA was like two sets of directions
- one from Miami to Houston and the other from El Paso to Los
Angeles. That would make one wonder how to get from Houston to
El Paso. The study by Crosby's group, in essence, devised the
path from Miami to LA and all points between.
In addition to the complete map, the researchers located genetic
markers linked to fruit sugars, ascorbic acid (vitamin C) and
male sterility, which is useful for developing hybrid varieties.
The trio said the genetic map will be helpful for future studies
in identifying fruit sweetness, quality, size, shape and
resistance to disease. |
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