Peanut or groundnut (Arachis hypogaea L.) is a very important oilseed and food crop, cultivated on more than 24 million hectares in tropical and subtropical regions and with a global annual production of approximately 38 million tons (FAOSTAT 2012). It originated in a region encompassing the south of Bolivia and the northwest of Argentina by hybridization of two wild species and spontaneous chromosome duplication to form an allotetraploid.