Peru researchers uncover genetic diversity in cocoa

Researchers from Toribio Rodríguez de Mendoza National University have conducted an important study on fine aroma cocoa from northern Peru. This research focused on the genetic makeup and evolutionary history of the cacao plant, known scientifically as Theobroma cacao. Cacao is a vital crop worldwide, but understanding its genetic relationships has been challenging due to limited data. Traditionally, cacao is classified into three main types: Forastero, Criollo, and Trinitario. However, recent genetic studies show that these groups do not fully represent the diversity of cacao in South America. The study used chloroplast DNA to provide new insights into the genetic structure of fine aroma cocoa. This type of cocoa is prized for its unique flavor, but its lineage has not been fully understood before. The researchers analyzed samples from Bagua and Utcubamba provinces in northern Peru. They found that the genome sizes of the samples varied slightly, and all contained a specific gene not seen in other cacao genomes studied. The researchers identified three distinct genetic groups among the fine aroma cocoa samples. One group was linked to Criollo and Trinitario varieties, while another was connected to Forastero. The third group aligned with other genetic types known as National and Curaray. Notably, a specific gene called ycf1 showed significant variation, which could help differentiate between fine aroma cocoa lineages. The study estimated that Theobroma cacao and its relative, Theobroma grandiflorum, shared a common ancestor about 10 million years ago. The cacao species itself began to diverge around 7.55 million years ago. Fine aroma cocoa populations are thought to have diversified during the Pleistocene era, between 0.31 and 1.82 million years ago. These findings shed light on the genetic diversity and evolution of fine aroma cocoa. The identification of specific genetic markers could support efforts in breeding, conservation, and better categorization of Theobroma cacao.