An international group of scientists, including those from the University of California, Davis, and Korea, have sequenced the genome of a hot pepper.

The reference genome, akin to a genetic roadmap, provides information crucial to improving the agronomic, nutritional and medicinal qualities of hot peppers, according to a news release.

Global production of hot peppers, the most widely used spice, has grown 40-fold during the past two decades and now exceeds $14.4 billion annually.

The genetic map sheds light on the biology of the pepper's pungency, or spiciness, as well as fruit-ripening and disease-resistance mechanisms.

The researchers chose a domesticated variety, Criolo de Morelos 334, for their work.

The variety from the Mexican state of Morelos, has consistently show high levels of disease resistance and has been used extensively in research and breeding.

The project revealed that blocks of genes appear in much the same chromosomal position in hot pepper as they do in its closest relative, the tomato. But the pepper genome was 3.5 times larger than the tomato genome.

Researchers already knew that pepper pungency was caused by the accumulation of naturally occurring chemicals called capsaicinoids. More than 22 of these compounds already have been isolated from peppers, and many have shown health benefits, such as inhibiting tumor growth, arthritis pain relief, appetite suppression and weight-loss promotion.

“The whole genome assembly of pepper and comparative genomics to the closely-related tomato species, with its nearly four-fold smaller genome, provides new insights into evolutionary aspects of genome expansion in acquiring newly developed genetic function,” Ryan W. Kim, research co-author with the UC Davis Genome Center, said in the release.