Genetic Analysis of Some Agronomic Traits in Flax (Linum Usitatissimum L.) (Report‪)‬

Introduction Flax (Linum usitatissimum L.) is one of the important species cultivated as an oil seed crop in some area of the world. Flaxseed is used for oil production and also in food industries because of its nutritional merits, essential poly unsaturated fatty acids such as alpha-linolenic acid and rich supply of soluble dietary fiber. Flaxseed oil is used as an industrial drying oil due to its high linolenic acid content (Green, 1986; Muir and Westcott, 2003). However, some flax genotypes have been developed which contain very low levels of linolenic acid in their oil, making them suitable for use as edible-oil (Green, 1986; Rowland, 1991). Knowledge of genetic behavior and type of gene action controlling target traits is a basic principle to design an appropriate breeding procedure for genetic improvement purposes. Hence, the success of any selection or hybridization breeding program depends on precise estimates of genetic variation components for the interested traits consisting of additive, dominance and non-allelic interaction effects (Jinks, 1983). The genetic improvement of seed yield and its components is one of the main objectives of flax breeding programs (Lay and Dybing, 1989). A number of genetic studies on quantitative traits of flax including yield components have been reported (Bhateria et al., 2006; Kurt and Evans, 1996; Murty et al., 1967; Patil and Chopde, 1981; Popescu et al., 1999; Singh et al., 2009; Sood et al., 2007). The findings of Popescu et al. (1999) indicated the importance of general combining ability, underlining the additive gene effects in governing plant height, capsules per plant, seed weight and seed yield in flax. Other workers also found the significant additive gene action for most of the traits with the exception of nonadditive genetic effects being significant for number of seeds per capsule, 1000-seed weight and biological yield (Sood et al., 2007). However, Bhateria et al. (2006) found that both additive and non-additive (with predominance) gene actions significantly affected inheritance of seed yield and its related traits. Tyson (1989) observed that dominance gene action and maternal effects were contributed in genetic variation of seed weight in flax. Griffing's methods of diallel analysis have been widely used to provide reliable information on the nature and magnitude of gene effects that contribute to the expression of quantitative traits and to help plant breeders select appropriate parents for hybridization and producing desirable transgressive segregants (Griffing, 1956; Shattuck et al., 1993). Realizing that a better understanding of the mode of inheritance of the traits leads to improve breeding strategies, the present study was conducted: 1) to estimate the genetic parameters and the mode of inheritance for yield components and some morpho physiological traits of flax in a set of complete diallel crosses, and 2) to identify superior parents for producing favorable progenies in the breeding program.