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Increasing yield is the most important aim in any breeding program. Since yield is a complex trait and involves several quantitative components with low inheritance, its direct study is not usually sufficient and therefore it is suggested that its components be investigated instead. In order to study the genetics of yield and its components, a cross was made between Ghafghaz variety* and line 14. F1, F2, BC1 and BC2 progenies were produced, planted, and evaluated under field conditions using a Randomized Complete Block Design with three replications. Mean squares in spike weight, plant height, number of seeds per spike, seed weight per spike, 1000 seed weight, awn length, spike length, condition of awn, spikelet compactness, seed color, seed coverage by glume as well as the number of tillers were significant. The minimum number of genes controlling these traits were estimated as 2, 2, 2, 2, 1, 3, 1, 3, 2, 2, 6 and 2 respectively. Generation mean analysis (GMA) was performed by scaling test which essays all generations simultaneously. This analysis indicated that gene effects including mean effect, additive, dominance, epistasis effects of additive × additive, additive × dominance and dominance × dominance were effective in inheritance of these traits. For spike length and awn condition the additive and dominance effects and for other traits the epistasis effects (Specially additive × dominance and dominance × dominance) were important in controlling the traits. For seed weight per spike and spiklet compactness, additive effect was more important than dominant effect and for number of seed per spike and 1000 seed weight dominant effect was more important than the additive effect.