Two field experiments were conducted at the experimental Farm of Etay El-Baroud, El-Beheira Governorate, Egypt. These trials included forty lines sown in F6 (in season, 2009/10) and F7 generation (in seasons, 2010/11). The objective of this investigation is to compare these lines through two generations with the two commercial varieties, Sakha 1 and Sakha 2 for straw, seed, oil yields and their related traits. These materials were evaluated in a randomized complete block design with three replications at the two previous seasons. Mean squares due to lines were significant for straw weight, seed weight and their components as well as for technological traits, fiber percentage and oil percentage in both seasons. Phenotypic (PCV) and genotypic (GCV) coefficient of variability and broad sense heritability (H%), the slight discrepancy between PCV and GCV for straw weight components (plant height, technical stem length and fiber percentage) and also for seed weight components (oil percentage and 1000-seed weight) were reflected in the high heritability estimates in both seasons for these traits, indicated the possibility of using these yield component traits in selection index technique to achieve further improvement both straw and seed weights by selection for these components. Concerning mean Performance, out of forty flax lines, five lines, (No. 18, 20, 34, 35, and No. 40) were superior for each seed, oil, straw and fiber yields/fed. Therefore, these five lines may be considered good substitutes for the low yielding ones, Sakha 1 and Sakha 2 in future after evaluation in more locations and years before releasing as a new Egyptian flax cultivar for both straw and seed yields production (as a dual purpose type). Straw weight per plant was significantly positively correlated with each of plant height, technical stem length, number of capsules per plant and 1000-seed weight in both seasons. Also, plant height exhibited positive correlation with technical stem length in both seasons, indicating that maximization of straw weight per plant may be obtained by selection for these component variables specially plant height and technical stem length. Seed weight per plant, exhibited positive association with oil percentage in both seasons. Whereas, number of capsules per plant was highly positive correlation with 1000-seed weight, indicating the possibility of selection for a genotype as dual purpose type which had high seed weight and high straw components (plant height and technical stem length).

Sixteen flax genotypes {13 promising lines and 3 check varieties viz., Giza 8 (oil type), Sakha 1 (dual purpose type) and Sakha 3 (fiber type)} were evaluated for straw, seed, oil yields and their related traits under twelve different environments; four locations (Sakha, Etay El-Baroud, Ismailia and Giza Exp. Stations through three successive seasons (2011/12, 2012/13 and 2013/14). These materials were evaluated in a randomized complete blocks design with three replications at the twelve above-mentioned environments. The analysis of variance revealed highly significant differences among genotypes (G), environments (E) and G x E interaction for all studied traits except straw weight per plant, indicating a wide range of variation among genotypes, environments and these genotypes exhibited differential response to environmental conditions. The significant variance due to residual for all characters except both straw weight per plant and oil yield per fad indicated that genotypes differed with respect to their stability suggesting that prediction would be difficult, which means that mean performance alone would not be appropriate. Interaction component of variance (σ 2 ge) was less than the genotypic variance (σ 2 g) for all characters, indicating that genotypes differ in their genetic potential for these traits. This was reflected in high heritability and low discrepancy between phenotypic (PCV) and genotypic (GCV) coefficients of variability values for these traits indicating the possibility of using each of long fiber percentage, plant height and technical stem length as selection indices for improving straw weight per plant, as well as, using 1000-seed weight and capsules number per plant as selection indices for improving seed weight per plant. Yield stability (YSi) statistic indicated that S.541-C/3 and S.541-D/10 gave high mean performance and stability for straw, fiber, seed and oil yields per fad in addition to oil percentage, capsules number per plant and 1000-seed weight. Therefore, the two genotypes well be released under the name Giza 11 and Giza 12, respectively. These newly released varieties are of dual purpose type for straw, fiber, seed and oil yield. They may replace the low yielding cultivars Giza 8, Sakha 1 and Sakha 3.

Three field experiments were conducted at the experimental Farm of Etay El-Baroud , El-Beheira Governorate, Egypt. These trials included forty eight families sown in F5, F6 and F7 generations at the three successive seasons, 2004/05, 2005/06 and 2006/07, respectively. The objective of this investigation is to compare these families through three generations when with the two commercial varieties, Sakha 1 and Sakha 2 for yield and yield components as well as fiber and oil quality characters.Mean squares due to families were significant for straw, seed weight and their components as well as for technological traits, fiber percentage, fiber fineness and oil percentage in all tested generations. For phenotypic (PCV) and genotypic (GCV) coefficient of variability and broad sense heritability (H%), the slight discrepancy between PCV and GCV for straw weight components (plant height and technical stem length) and also for seed weight components (No. of capsules and 1000-seed weight) with high heritability estimates in each of the three generations under study, indicated the presence of genetic variability among tested families for these characters and that selection in advanced generations would be effective for improving the abovementioned traits.Five families (No. 46 followed by 27. 43, 44 and No. 20) were superior for both seed and straw yields per fed, four of them (No. 46, 44, 43 and No. 20) were also superior for the two fiber technological characters, fiber percentage and fiber fineness. It is notable that the three families (No.43, 44 an No.46) are derived from the hybrid (S.2419/1 x S.148/6/1), whereas family No.20 and No.27 are belonged to the two hybrids (Giza 7 x S.2419/1) and (Giza 8 x S.2419/1), respectively. Therefore, these families (specially family No. 46) are recommended to be released and become as substitute for the commercial varieties Sakha 1 and Sakha 2 after evaluation in more locations before releasing as new commercial varieties for fiber and oil yields (as dual purpose type).Phenotypic (rp) and genotypic (rg) correlation coefficients concluded that, straw weight per plant was significantly positively correlated with both of plant height and technical stem length. Seed weight per plant, exhibited positive association with each of capsules number per plant, 1000-seed weight, plant height and technical stem length, indicating that flax yield improvement could be achieved through selection for seed weight and high straw components (plant height and technical stem length). Fiber percentage showed positive association with both of straw weight per plant and fiber fineness, indicating that selection for a genotype characterized by high yielding ability for fiber yield and high fineness is possible.