Using path analysis to study the relationship between yield and other morphological characters in four lines of barley

To determine the correlation between important traits with yield in barley through path analysis for selecting high yielding lines، three new lines of barley resistant to cold (C-81-13، C-81-11، C-81 -15)، compared with Valfajr (as control) were studied. This experiment was conducted in a randomized complete block design with three replications، during 2008 to 2010 in Boyer Ahmad city. A number of، 450 seeds of barley lines (per square meter) were cultured. During the growing season and after harvest، 10 plants were randomly harvested and several important agronomic traits such as total number of tillers، fertile tillers، plant height، days to spike، days to maturity، number of grains per spike، spike length، awn length and 1000 seed weight were recorded. Using analysis of variance and covariance، the correlation coefficients between the traits was estimated. Path analysis was used to divide the correlation coefficient to the direct and indirect effects. Results showed that there were significant differences (5%) between grain yields of lines، indicating genetic variation among the studied genotypes. The highest heritability (58/14%)، was recorded on the total number of tillers and the highest genotypic and phenotypic variation (58/28 and 29/47 respectively)، was observed on the number of fertile tillers. Statistical analysis showed that the highest yield with an average yield of 6. 52 and 6. 49 ton/ha belonged to C-81-13 and Valfajr cultivars، respectively.