Genetic diversity
Two species are important cereals for human nutrition:
- Oryza sativa, grown worldwide, and
- Oryza glaberrima, grown in parts of West Africa.
Ecological diversification in Oryza sativa: two major ecographic races were differentiated as a result of isolation and selection:
- Indica, adapted to the tropics, and
- Japonica, adapted to the temperate regions and tropical uplands
A tremendous ecological diversity can be found in Asian cultivars evolved by natural and human selection (diverse climates, seasons and soils, varied cultural practices e.g. seeding vs. transplanting, cultural preferences and socioreligious traditions) (Rice almanac, 2002).
