EVALUATION OF SOME FLAX GENOTYPES FOR YIELD AND YIELD COMPONENTS UNDER DIFFERENT ENVIRONMENTAL CONDITIONS

Abstract

Ten flax genotypes (G) were evaluated over six environments combination of three years (Y) [2003/04, 2004/05 and 2005/06] and two locations (L) [Gemmiza Exp. Sta., Gharbia Govemorate and Ismaelia Exp. Sta., Ismaelia Governorate ] in Egypt. The objectives were to determine the genotype x environment interactions and estimates the potential of a genotype to stabilize its performance over various environments. Genotypes mean squares were highly significant for all studied characters, indicating that the genotypes differ in their genetic potential. GxY interaction was Insignificant for most characters, except straw weight per plant and plant height. On the other hand, GxL interaction was highly significant for all studied characters, indicating that location had the major effect on the relative genotypic potential for these traits. Therefore, it would certainly be necessary to test genotypes in more than two locations with few number from years. Estimates of variance components, phenotypic (PCV) and genotypic (GCV) coefficients of variability and broad sense heritability (H) indicated the possibility of using plant height as selection index for improving straw weight per plant and each of 1000-seed weight, No. of capsules per plant and No. of seeds per capsule in selection index for improving seed weight per plant. Based on estimates of mean performance ( ), regression coefficient (b), deviation from regression (Ski), coefficient of determination (r2) and the ecovalence stability index (w), it could be concluded that the most stable genotype in straw yield, Sakha 3, in seed and oil yield, S.2419/1/3, in fiber yield, Sakha 1 followed by each of Escalina, Elona and Marleen, and in both fiber percentage and oil percentage, Sakha 4. Thus, they are recommended to be released as stable high-yielding cultivars and/or to be incorporated in the breeding stocks in any breeding program aiming to produce stable genotypes for the above-mentioned characters. Phenotypic (rp) and genotypic (rp) correlation coefficients among straw weight and other components indicated the possibility of selecting genotypes characterized by high straw yielding ability and in the same time high seed yield potentialities. However, seed yield per plant was significant positively correlated with both No. of capsules per plant and 1000-seed weight. Also, No. of capsules per plant exhibited highly significant positive correlation with 1000-seed weight, indicated that both No. of capsules per plant and 1000-seed weight are the main components for seed weight per plant.