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
Cacao necrosis virus virus is not infective in sap after heating to 65 °C for 10 minutes, dilution to 0.0001 virions, or storage for 7 days at room temperature. Cacao necrosis virus "Cacao necrosis virus" (CNV) is a plant pathogenic virus of the genus "nepovirus" that infects "Theobroma cacao" en natura causing cacao necrosis disease. CNV is considered synonymous with Strain S of cacao swollen shoot virus. Unlike cacao swollen-shoot virus, it is not transmitted by mealybugs nor vectored by aphids, beetles or leafhoppers that also commonly infest cacao. It is serologically, distantly related to Tomato black ring virus and very distantly related