Doubled Haploid Production in Watermelon

Doubled haploid (DH) technology is very advantageous in plant breeding. This technique is beneficial for reducing the time required to obtain pure lines and contributes to the selection efficiency. Using this technique, 100% homozygosity can be achieved in a single generation, while the development of stable lines using the traditional self-pollination method takes from 6 to 8 years. It has long been used in diverse crops including cucurbits. DHs can be obtained via parthenogenesis (pollination mostly with irradiated pollen), gynogenesis (in vitro culture of ovules and ovaries), and androgenesis (in vitro culture of microspores and anthers). All these methods have been used for over 30 years to develop haploid and DH lines in cucurbit crops. Nowadays, many researchers benefit from these techniques routinely. However, there are still many limits for using DH technology in watermelon breeding programmes. The number of developed DH lines is still very low.In this chapter, we present a protocol based on the different studies on haploids and DHs induced in watermelon through irradiated pollen technique, unfertilized ovule/ovary culture and anther/microspore culture. According to the results of all these studies, it is crucial to develop an efficient protocol for haploid embryo induction to enhance the frequency of obtaining haploid embryos in watermelon.