Hot stuff: embracing the diversity of capsicums

A comprehensive article about the Capsicum species has been published with academic and scientific input from across the globe. It is hoped the article will inspire increased interest and collaboration among scientists to address the many questions regarding the botany, physiology, genetics, genomics, etc of this horticulturally important crop plant.

Capsicum (pepper/chilis) is a major vegetable and spice crop. Global production of both fresh and dried fruit continues to increase steadily in terms of area harvested and total yield. Today, Asia currently contributes approximately 65% of the global production of pepper, whereas the Americas, Europe and Africa each contribute 13.3%, 11.9% and 10.1%, respectively.

Robert Jarret of the USDA’s Agricultural Research Service, Plant Genetic Resources Unit, coordinated the efforts of the 18-member team as they delved into the breadth and diversity of the Capsicum species. Their findings are illustrated in the article entitled Capsicum – An Abbreviated Compendium published in the current issue of The Journal of the American Society for Horticultural Science.

Various topics are addressed, including recent additions to and clarification of Capsicum taxonomy, Capsicum genetic resources, cytogenetic studies, the use of gene mutations to elucidate carotenoid biosynthetic pathways and their regulation, capsaicinoid biosynthesis, and recent advances in whole-genome sequencing and assembly.

Archaeological data allude to the use of Capsicum species as a spice as early as 5500 BCE. The crop was first introduced into Europe by Christopher Columbus during his travels in the 15th century. It later spread to countries in Africa and Asia by way of the flourishing trade routes of Spain and Portugal operating at that time. As it spread around the world, it was quickly adopted and served as a spice and gave rise to many regional varieties.

The increasing value of the pepper crop coincides with its role in international trade. Fresh pepper is cultivated in approximately 126 countries and dried pepper in approximately 70 countries.

Although developed countries continue to be the main producers of pepper crops, their cultivation provides an important source of income for small producers in many developing countries. The estimated global value of the fresh and dried pepper crops is approximately $30 billion and $3.8 billion, respectively.

Capsaicinoids are compounds unique to the genus Capsicum and are responsible for the pungency (heat) of pepper fruit. Aside from their value as a spice, capsaicinoids have well-established medicinal and antimicrobial properties and can affect seed dispersal and survival. Advances in the understanding of the molecular biology of the capsaicinoid biosynthetic pathway often have focused on the identification of new candidate genes, the characteristic of key previously identified genes and the exploration of possible mechanisms of regulation.

The potential of the information presented in this review, to augment crop improvement activities, is substantial given adequate resources to employ this information and to improve and expand upon it.

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