Outcrossing rates of barley landraces from Syria

Diversity levels in populations of barley landraces may be influenced by varying levels of natural outcrossing caused by environmental conditions, Outcrossing was studied in 10 accessions of the barley landrace Arabi Aswad from different environments in Syria. Electrophoretic variation at two codominant isoenzymes (Est1 and Est2) in six seeds of 50 families per population were analysed and multilocus outcrossing rates calculated. Results were correlated with interpolated environmental conditions. Outcrossing was, on average, 1.7% and not significantly different from the outcrossing rate of wild barley. A significant increase of outcrossing was observed with increasing inter-annual variation in rainfall and decreasing minimum temperatures of the coldest month.