DURUM-WHEAT LANDRACES FROM SYRIA .1. AGROECOLOGICAL AND MORPHOLOGICAL CHARACTERIZATION

A total of 185 durum wheat (Triticum turgidum var. durum Desf.) landraces was collected from 166 sites in the Syrian Arab Republic. With K-means clustering the collecting sites are grouped based on four climatological variables to create relatively homogeneous regions of origin with respect to agro-ecological characteristics. Stepwise Discriminant Analysis confirmed the minimization of variation within regions. Regional description with respect to agro-ecological characteristics is given. According to farmers' estimations, average grain yield is lowest in western mountainous regions, and highest in southern parts of the country, which illustrates the tendency of landraces to produce more straw rather than grain dry matter under high rainfall conditions. Other data, however, show that farmers in southern regions supposedly have overestimated yield levels. Landrace groups as distinguished by farmers are morphologically identified, to provide a systematical description of visible variation. Distribution patterns of the various landrace groups are indicated. Only few landrace groups are widely distributed, whereas most others are regionally concentrated. Genetic diversification is found in the heterogeneous nature of landraces and in the cultivation of different landraces per region or village. Large proportions of T. aestivum were found in T. durum populations in the mountainous regions in the west of the country, where farmers apparently desire a species mixture.