ESTIMATES OF GENETIC COMPONENTS, PREDICTION AND GENETIC CORRELATION IN WHEAT (TRITICUM AESTIVUM,L.) USING NORTH CAROLINA DESIGN III

North Carolina Design III was used to estimate gene effects in bread wheat crosses. Twelve Egyptian bread wheat genotypes i.e. Sakha 69, Sakha 8, Gemmeiza 1, Gemmeiza 3, Gemmeiza 7, Giza 160, , Giza 162, Giza 164, Giza 165, Sids 1, Sids 3 and Sids  4, each was crossed back to testers, high performing (Gemmeiza 9) and low performing parent (Sakha 92) during three winter successive seasons i.e. 2002/2003, 2003/2004 and 2004/2005, to study; heading date (days) plant height (cm), flag leaf length (cm) flag leaf width (cm), flag leaf area (cm)2, extrusion length (cm), number of spikelets/spike, spike grain weight (g.), number of spikes/plant, number of grains/spike, 1000-grain weight (g.) and grain yield/plant (g.) characters. Results indicated that epistasis played great role in the inheritance of all studied characters except number of spikes/plant. Additive(D)and dominance(H) genetic variances were significant in all studied characters except number of spikes/plant and number of grains/spike. The additive genetic variance was more than dominance for heading date, plant height, flag leaf length, flag leaf width, extrusion length, spike length and 1000- grain weight. The ratio of (H./D) 0.5 was less than one for these characters but for the remaining characters the dominance genetic variance was more than additive. The values of(F) indicated that dominance was unidirectional for flag leaf length and flag leaf area, whereas it was ambidirectional for the remaining characters Prediction results revealed that it could be possible to derive reasonable proportion of new recombinants which are falling out side parental range for heading date, flag leaf length, flag leaf width, spike length, number of spikelets/spike, number of spikes/plant, 1000- grain weight and grain yield/plant. Genetic correlation indicated that additive, dominance and epistasis gene effects controlling grain yield/plant and spike grain weight, number of spikes/plant, number of grains/spike, 1000- grain weight, were signifant, suggesting common genetic pool or pleiotropy. Thus, selection based on additive genetic correlation indicated that indirect selection via, spike grain weight, number of spikes/plant, number of grains/spike and 1000- grain weight would be effective and enhance its importance as selection criteria .