A map based on the genome sequence of watermelons could help breeders speed up development of more nutritious, tastier and disease-resistant fruit.

The sequence was published by an international team of more than 60 researchers, including a group from the University of California, Davis, in the online version of the journal Natural Genetics, according to a news release.

The genome of domesticated watermelon contains 23,440 genes, about the same number as in humans.

The team from the United States, Europe and China compared the genomes of 20 different watermelons and developed a first-generation genetic variation map.

The information can be used to identify regions associated with fruit color, taste and size.

William Lucas, UC Davis plant biology chair and one of the genome project leaders, and university colleagues are using the watermelon information as well as the previously published cucumber genome to explore questions about the watermelon vascular system.

They hope to discover what roles proteins and RNA play in carrying water and nutrients throughout the plant.

The knowledge can be used by breeders to increase water use efficiency, enhanced nutritional value and pathogen resistance.

As part of the mapping, the researchers discovered that a large number of disease-resistance genes have been lost when watermelon were domesticated.

Funding for the project came from grants from the Chinese, U.S. and French governments.