Genetic variation in winter barley and selection of high yielding lines

Barley (Hordeum vulgare L.) is an important crop with excellent nutritious feed and food grain. Winter barley, in particular,
is predominantly grown in highland under rainfed systems due to its ability to tolerate cold. However, it has low productivity
due to complex genetic mechanisms and limitations in determining an optimal environment for its selection and evaluation.
This study evaluated the genetic variability, heritability and genetic gain for yield in barley, using preliminary un-replicated
yield trials in 2011 at two locations and followed by replicated sets of yield trials in 2012, all in Syria. Significant genotypic
variability was found at both stages of the evaluation/selection. During 2011, the best linear unbiased predictor means of
test genotypes adjusted for spatial variability were found in the range of 1.75–3.75 t/ha at Tel Hadya and 0.03–1.58 t/ha at
Breda. A set of 22 advanced yield trials comprising a total of 601 lines at Tel Hadya in 2012 yielded in the range of 1.85–
3.13 t/ha. Based on the mean over these set of trials, the highest heritable trait was days to heading (broad-sense heritability
on mean-basis= 0.64) followed by yield (the heritability = 0.30). The yield gain due to selection, at 20% intensity of
selection, was 5.66% at Tel Hadya and 27.1% at Breda in 2011 using un-replicated genetic material, while it was 7.01 %
for the replicated trials at Tel Hadya in 2012. We recommend use of the best lines selected in 2012 at Tel Hadya for further
exploitation in genotype × environment interaction studies for high yield and specific and broad adaptation.