干旱区生态环境知识资源中心

Evaluation of the genetic diversity within a crop is important for its effective utilization by a breeding program, Local varieties (landrace, old cultivars) can be an important gene pool for breeding more highly adapted varieties, particularly in harsh environments. A serious limitation to increasing yields under the harsh environment of the semi-arid regions (SAR) is the narrow genetic base of many high yielding varieties which has been a common trend in many plant breeding programs. National, as well as, international breeding programs have developed varieties that perform well under optimal growing conditions, But the genetic potential of the newly developed germplasm cannot be realized in the SAR due to the lack of appropriate management practices. The landraces will consistently produce a harvestable yield, despite the inherent stress factors. They have an excellent general fitness for local conditions and a wide spectrum of resistance to diseases.