Watermelon
Crop Information
History, Important Varieties
- by Todd C. Wehner
- Department of Horticultural Science
- North Carolina State University
- Raleigh, NC 27695-7609
Watermelon varieties have been described in the vegetable
variety lists maintained by the American Society for Horticultural
Science. Also, a complete set of descriptions for all vegetable
crops from lists 1 through 25 has been collected into a
book to be produced by ASHS Press. Seeds are available for
many of the open pollinated and inbred varieties on the
list, but there are a significant number of varieties that
are no longer available. Watermelon breeders should obtain
and evaluate a sample of the varieties available to become
familiar with the diversity of germplasm. It is also useful
to observe the improvement in horticultural traits that
has been made in varieties developed over time.
A breeding program usually is started by intercrossing
the best varieties currently available, or by crossing the
best varieties with accessions having one or more useful
traits missing from the elite varieties. Thus, in the beginning
a watermelon breeder will need to obtain seeds of the best
varieties, a set of varieties developed at different times
in the past, a set of accessions from germplasm repositories,
and lines with useful or interesting gene mutants.
A survey of popular varieties in the ten major watermelon-producing
states in the United States by D.N. Maynard in 2000 indicated
that popular varieties for commercial production were almost
all hybrids, with few open-pollinated varieties being used
commercially. Popular diploid (seeded) open-pollinated varieties
('Allsweet', 'Black Diamond', 'Calsweet', 'Crimson Sweet',
'Jubilee II', and 'Legacy') were grown mostly in one state
each, suggesting regional adaptation or local demand. Hybrids
generally were grown in several states, suggesting they
have wider adaptation. The 'Allsweet' type, generally considered
to be of high quality, was represented by more than half
of the listed varieties (three of the open-pollinated and
11 of the hybrids). The most popular diploid (seeded) varieties
were 'Sangria' and 'Royal Sweet' (seven states), 'Fiesta'
(six states), and 'Mardi Gras' and 'Regency' (five states).
For triploid (seedless) varieties, almost half of the varieties
were 'Tri-X-313' type. The most popular triploid varieties
were 'Tri-X-313' (ten states), 'Summer Sweet 5244' (nine
states), 'Millionaire' (eight states), 'Genesis' (five states),
and 'Tri-X-Shadow' (four states).
In order to develop improved varieties for an industry
in a particular region of the world, the watermelon breeder
will need to have seeds of varieties, breeding lines, populations,
plant introduction accessions, and gene mutants that express
the traits of interest at a high level. The breeder should
identify a source that has the highest level of expression.
That would be true whether the trait is quantitatively inherited
(fruit yield, earliness, size, sweetness) or qualitatively
inherited (dwarfness, anthracnose resistance, flesh color).
If there is a choice of accession for a particular trait
(for example, white flesh), it is better to use an adapted
accession with the best genetic background. Thus, 'Cream
of Saskatchewan' would be a better choice to use in the
development of white flesh varieties for use in the United
States, than a wild-type, white-fleshed citron having large
vines, late maturity, hard flesh, bitter flavor, large green
seeds, and seed dormancy.
