In Iran, rice is an important source of carbohydrate, next to wheat. In recent years, rice production in Iran increased from 2.4 million t (2000) to 3.3 million (2003). This came from an area of 615,000 ha. This sudden increase in rice production and productivity is attributed to the wide-scale adoption of improved varieties. Furthermore, with Iran's economic boom, consumer preference has been toward premium-quality rice. Therefore, rice breeders needed to develop varieties with superior cooking quality features that match those of traditional landraces such as Hashemi, Musa Tarom, and Hassani, while keeping the yield level close to that of improved semidwarf varieties. Through this strategy, it is possible to partially replace traditional landraces (60% of the country's total area) with improved rice varieties having the same cooking quality.