The study was carried out to analyse gene effects for various yield attributes in wheat at CCS Haryana Agricultural University Hissar during rabi 2008-09 and 2009-10. six basic populations (parents, F1, backcrosses and F2) of the five wheat crosses namely HS 27 × PBW 502(C-I); HS67 × PBW 502 (C-II); HJP 81 × PBW 502 (C-III) and HG 2 × HD 2009M (C-IV) were grown in the compact family block design in three replications and the morpho-phenological characters such as plant height, Number of spikelet/spike, Number of kernel/spike, Kernel weight/spike (g), Number of spikes per plant, Grain yield per plant (g). By scaling tests the dduplicate gene interaction was observed in most of the characters which is difficult to exploit in breeding programs. Some traits shows failure of six parameter model reflected the occurrence of either higher order gene interactions or linkage between the interacting loci or the presence of genotype x environment interaction which may also influence the expression of character(s). Since several important characters are influenced by non-allelic gene interaction.