Most centers of crop diversity where relatives and ancestors of the crops are still being found in the tropical regions of the world namely Asia, eastern Mediterranean, Northeast Africa, Central and South America. One of the important areas is Peruvian Andes. It is a rugged terrain, harsh unforgiving climate, and have isolated communities. Because of the harsh environment, the plants in this area tend to store energy in the tubers. When the Indians arrived in this area 10,000 or more years ago their main staple food was the tubers.
Potatoes are still their staple diet.
There are thousands of varieties of potatoes grown in Peru, Thousands of varieties of rice grown in India and Southeast Asia, and thousands of varieties of wheat grown in Greece. Each variety has special characteristics. Each grows in different season of the year and each is resistant to different plant disease. Recall the potato controversy in Europe and potato famine in Ireland. To preserve the diversity of potato plants, there has been established an International Potato Center in Lima, Peru.