This study was conducted with the objective of estimating combining ability and gene action for some economical useful traits in kenaf. This was achieved via evaluating 15 progenies of the line x tester analysis consisting of five females (P1=S,13, P2= S.114, P3= S.119, P4= S.98/205 and P5= S.38) and three males (P6=Giza3, P7=S.105/2, and P8=S.112). In 2010, the eight parents and their 15 F1 ,s progenies were evaluated in a randomized complete block design with four replications at Ismailia Agric. Res. Station Farm, Ismailia Governorate, Egypt. The predominant role of additive gene action was involved in the expression of all studied characters except for each of plant height, technical stem length and fiber length. Therefore, selection can be performed followed in the F2 and subsequent generations for all studied characters, except for the previous three traits. P3 and P7 exhibited significant and positive GCA effects for green weight and most of its components as well as P6 for three important components (green weight/plant, fiber weight/plant and fiber percentage), indicating that the use of these parents in kenaf breeding programs could increase green weight and consequently increasing fiber yield. Concerning, seed weight per plant results indicated that the P7 followed by P3 and P5 exhibited high best combiners for seed weight. The cross P3P7 exhibited significant positive SCA effects for green weight and most components ( plant height, technical stem length, fiber length, fiber weight and seed weight per plant). This cross involved high x high general combiners for these traits. Also, P4P6 (high x high) for fiber percentage. Whereas, P4P6 exhibited significant positive SCA effects as well as high x low general combiner parents for green weight/plant and most important components. Phenotypic (rp) and genotypic (rg) correlation coefficients concluded that the green stalk weight, plant height, technical stem length, fiber percentage and fiber length are the major components contributing to fiber weight/plant in kenaf. Therefore, selection for these traits will improve the fiber yield in kenaf.
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