Flax ( Linum usitatissimum L.) is one of the oil seed crop, that its seed, oil and crushed-seed meal is used in different industries, in human diet and for feeding of livestock. This study was conducted to investigate genetic variation for different agronomic traits and the selection indices for yield improvement. In this experiment, 30 isolated lines along with 6 landraces were evaluated in a randomized complete block design with three replications at the Research Farm of Isfahan University of Technology in 2008. The results showed that there were significant differences among the genotypes for all of the studied traits. The traits of branches/plant, capsules/plant and 100-seed weight had high correlation with seed yield/plant and Days to 50% emergence, capsules/plant and seed yield/plant also had high correlation with seed yield/plot. Seed oil content was determined for 10 lines with higher seed yield and this trait had a variation 36.62% to 39.26% and high broad-sense heritability. The result of stepwise regressio showed that capsules/plant, 100-seed weight and seeds/capsules contributed in 98% of phenotypic variation for seed yield/plant. The path analysis revealed that capsules/plant had the most direct effect on seed yield/plant. Cluster analysis dir=rtl Key Words: Genetic variation, Correlation, Agronomic traits, Path analysis, direct and Correlated response, selection.
