Wheat and barley seed system in Syria: How diverse are wheat and barley varieties and landraces from farmer's fields?

The present study described the diversity of wheat and barley varieties and landraces available in farmer's fields in Syria using different indicators. Analysis of spatial and temporal diversity and coefficient of parentage along with measurements of agronomic and morphological traits were employed to explain the diversity of wheat and barley varieties or landraces grown by farmers in Syria. Farm level surveys showed low spatial diversity of wheat and barley where only a few dominant varieties occupied a large proportion of wheat and barley areas. The five top wheat varieties (ACSAD 65, Cham 1, Cham3, Lahan and Cham 6) occupied 81% of the wheat area and were grown by 78% of the sample farmers. In case of barley one single landrace was grown in almost the entire survey area in north eastern Syria. The weighted average age of wheat varieties was highest with an average of 10.8 years showing low temporal diversity by farmers. In Syria bread wheat showed lower average diversity and weighted diversity than durum wheat. Variance component analysis showed significant variations for desirable agronomic characters such as plant height, grain yield and yield components (kernels per spike(-1), seed weight) among wheat and barley varieties and landraces. The principal component analysis explained the variations that existed among modern varieties and landraces. Cluster analysis based on agronomic and morphological traits grouped the modern varieties and landraces into separate clusters. The variation that existed among the landraces showed broad opportunities for using in plant breeding programs to develop varieties suitable for different agro-ecological zones. To date large areas previously grown to traditional varieties and landraces are now increasingly replaced by contiguous expanse of land planted to uniform modern bread and durum wheat varieties and are grown by large number of farmers. Apart from the landraces, the wild relatives and progenitors of both wheat and barley are being threatened by extinction in the center of origin.