Flax is an oil seed crop that its seed, oil and crushed-seed meal is used in different industries and in human diet and feeding of livestock. Genetic variation for agronomic traits of flax can be used in breeding programs to select the desirable genotypes for seed yield and other agronomic traits. This study was conducted at the research farm of Isfahan University of Technology in 2006 to investigate genetic variability for different agronomic traits in isolated lines from 6 landraces of flax. In this study, 73 isolated lines by single plant selection along with the landraces and "Flanders" cultivar from Canada (as the control genotypes) were evaluated in a randomized complete block design with two replications. There were significant differences among the genotypes for all of the studied traits such as capsules/plant, seeds/capsule, 100-seed weight, seed yield/plant and seed yield/plot. High phenotype and genetic coefficients of variation was observed for number of seedlings/m 2 , rate of infection by powder mildew, branches/plant, capsules/plant, seeds/capsule, seed yield/plant and seed yield/plot. Also, high broad-sense heritability was observed for all the traits, except for days to 50% emergence. Branches/plant, capsules/plant, seeds/capsule and 100-seed weight had high correlation coefficient with seed yield/plant. Number of seedlings/m 2 , capsules/plant, seeds/capsule and seed yield/plant also had a high correlation with seed yield/plot. The result of stepwise regression showed that capsules/plant, seeds/capsule and 100-seed weight contributed in 56% of observed variation for seed yield/plant; however, seeds/capsule, capsules/plant, seedlings/m 2 and 100-seed weight explained 47% of the variation for seed yield/plot. The result of path analysis indicated that capsules/plant had the most direct and positive effect on seed yield/plant and traits of number of seedlings/m 2 , capsules/plant and seeds/capsule had positive direct effects on seed yield/plot. Estimation of narrow-sense heritabilities for of all traits was low and the highest estimation was observed for plant height. Cluster analysis ltr"
