Seed oil is the primary energy source needed for germination and establishment of plants. Studying the biogeographic distribution of seed oil content is therefore fundamental to understanding mechanisms of adaptive evolution in plants.
In this study, researchers combined details of oil content of more than 2,500 species of angiosperm plants with species distributions data from GBIF and other sources. On a broad scale, they show that tropical species have higher oil content than temperate species. This pattern is also evident at the family level.
When examining the effect of latitude, however, the correlation is only significant in three families. In two families, Sapindaceae and Sapotaceae, oil content increases with latitude, while it decreases in Papaveraceae. They also find that proportions of unsaturated fatty acids increase with latitude.
Shedding light on the role of oil seed content in plant adaptation, this study may also provide useful data for breeding of oilseed crops for human consumption.