Citrullus lanatus (Thunb.) Matsum. & Nakai - Cucurbit Breeding ...

As a consequence, the already narrow genetic base of the watermelon breeding populations currently
used will become even narrower and the improvement of major traits, such as disease resistance and yield, will
be strongly limited and delayed for many years.
Alternatives to breeding triploid hybrids for seedless production could come from biotechnology.
Genes for parthenocarpy and gynoeciousness are not currently known in watermelon, but homologous genes are
known in cucumber, Comparative studies of the two species may allow watermelon biotechnologists to isolate
the genes involved in sex expression and seed development in watermelon. The knowledge of the genetics of
these mechanisms may allow to produce seedless fruit from diploid plants. It could be possible to repress the
production of seeds, or to overexpress the development of female flowers with parthenogenetic potential.
A strong limitation to the deployment of such a strategy would certainly come from customer
acceptance of transgenic crops, but certainly this is a common issue to all the cultivated transgenic species.
Even though it is difficult to forecast the future of customer preferences, history teaches us that initial response
will be cautious and reluctant towards what is new, but it then becomes accepted and commonplace. It is
possible that each generation somehow is needed to balance the mistakes of the previous and that the
randomness of this scheme be the internal motor of progress. Should an example be needed, we could refer to
the last century. Destruction and loss of lives, resources, and freedom came prior to World War II, then
reconstruction and fast progress followed with a second industrial revolution in Europe, the end of the Cold
War, the defeat of many dictators in Europe, Asia, Latin America, and Africa, and the end of colonialism. In
art, music, and culture, Futurism and Cubism promoted the idea of the humankind projected into the future and
in fast movement towards a better, but yet unknown, society. Yet, now we are folding back on ourselves, trying
to slow down and fix the mistakes that have been unwittingly made during those years of great progress. It is
useful to fix mistakes, but it is necessary to move forward again soon. Some repairs are necessary, but many
may be overreaction to the unknown.
For watermelon breeding, certainly the deployment of biotechnology for the production of seedless
diploid cultivars may be delayed by major ethical and sociological issues in biotechnology. Nevertheless, in
absence of natural mechanisms for parthenocarpy and gynoeciousness in watermelon, and in light of the
limitations that tetraploid breeding is posing to the genetic improvement of this crop, there is not a valid
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