Oasis wheats of the South of Algeria: landraces, cultural practices and utilization
Résumé
Wheat populations cultivated in the Saharan oases have been considered as potential parental germplasm for the improvement of drought, heat and salt tolerance. However, risks of genetic erosion have been reported, related to the degradation of the oases cropping systems and the introduction of modern wheat varieties. A better description and characterization of the Saharan wheat landraces is therefore required to make more effective their utilization in breeding. The present study was conducted among fourteen oases distributed in three locations of South Algeria (Adrar, Tamanrasset and Tindouf). In total, 187 samples of wheat landraces were collected from farmers' fields and a survey was carried out to better understand the agronomic practices applied to the crop. Three durum and 38 bread wheat landraces were identified. Most of them appeared to be specific to locations or oases. Forms that differed on spike or grain characteristics were described, and botanical varieties were identified within most landraces. The survey revealed that farmers choose the landraces to be grown according to their ability to face the specific constraints affecting their cultivation in the different oases and the characteristics of their grain end-use. This observation is likely to explain the maintenance of traditional landraces in the oases, despite the different factors threatening these cropping systems. The importance of documenting and collecting the wheat landraces grown in the Saharan oases, evaluating them for their tolerance to abiotic factors and using them in improvement programs, is emphasized.