Durum wheat landraces from syria. II. patterns of variation

Summary Phenotypic variation components were estimated with respect to days to heading, flag leaf length and width, plant height, awn and spike length, awn and spike colour, spikelets per spike and seed shrivelling of 84 Syrian durum wheat landrace populations. Multivariate patterns of variation were established through principal component analysis to describe relationships between landrace groups and regions of collection. Agroecological site characteristics and plant traits were compared with respect to patterns of geographical variation. Grouping on the basis of landrace groups proved more discriminative than on the basis of regions of origin. Landraces originating from sites characterized by favourable growth conditions tended to be later in heading and to have longer spikes with longer awns but with less spikelets. The observed relation between favourable growth conditions in the regions of origin and smaller flag leaves may be caused by genotype × environment interaction.Among populations variation was high, and amounted to 96% of the total variation, whereas the remnant 4% was contributed to differences within populations and among lines. Variation among landrace groups and among regions was calculated as 79% and 75% of total variation, respectively.