GENERATION MEANS ANALYSIS FOR SOME QUANTITATIVE TRAITS IN SESAME (SESAMUM INDICUM L.) CROSSES FROM ETHIOPIA

Abstract

The nature of gene action governing the expression of various traits is very helpful in formulating an effective and sound breeding program. The objective of the present study was to determine the type and magnitude of gene action in sesame using generation means analysis to provide a basis for an evaluation of selection methods for the improvement of sesame. The six basic generations parent 1(P₁), parent 2 (P₂),  hybrid (F₁), F₂, back cross 1(BC₁) and  back cross (BC₂) of five crosses such as cross-1 (EW002 x BG006), cross-2 (Dicho x EW006), cross-3 (EW002 x Dicho), cross-4 (Obsa x Dicho) and cross-5 (EW002 x Obsa) were planted in 2012 and 2013 at Uke trial site of Bako Agricultural Research Center in a randomized complete block design, with three replications. The combined analysis of variance indicated highly significant differences among generations for all the traits in all crosses. Simple additive-dominance model exhibited lack of good fit for all the characters studied in all the crosses, except days to maturity in cross 2. The result of the generation means analysis showed that days to flowering, plant height, branches per plant, and capsules per plant and yield per plant were found to be under the control of additive and non-additive gene effects, coupled with duplicate type of epitasis. Biparental mating followed by selection of desired recombinants from the segregating population is the most applicable breeding methodology for traits under the influence of duplicate type of epitasis. Complementary type of epitasis was only observed for plant height in cross 1 and capsules per plant in cross 3, which appeared to be desirable and would be helpful in further improvement of these traits.