Chocolate lowland climate in the narrow band of latitudes where cacao is grown (20 degrees north and south of the equator), the commercial company Mars, Incorporated and the University of California, Berkeley are conducting genomic research in 2017–18 to improve the survivability of cacao plants in hot climates. Chocolate is made from cocoa beans, the dried and fermented seeds of the cacao tree ("Theobroma cacao"), a small, 4–8 m tall (15–26 ft tall) evergreen tree native to the deep tropical region of the Americas. Recent genetic studies suggest the most common genotype of the plant originated in the Amazon basin and
Moniliophthora perniciosa Moniliophthora perniciosa Moniliophthora perniciosa (previously "Crinipellis perniciosa") is a fungus that causes "witches' broom disease" (WBD) of the cocoa tree ("Theobroma cacao" L.). "T. cacao" a tropical tree with seeds that are processed into cocoa (=cacao) products. This pathogen is currently limited to South America, Panama and the Caribbean, and is perhaps one of the best-known cocoa diseases, thought to have co-evolved with cocoa in its centre of origin (first recorded in the Brazilian Amazon in 1785). This fungus is hemibiotroph, with two characteristic phases: biotrophic (expanding and infecting, on living tissue) and saprotrophic (producing basidiospores, on necrotic tissue). The