INHERITANCE AND GENE ACTION FOR YIELD AND ITS ATTRIBUTES IN THREE BREAD WHEAT CROSSES (Triticum aestivum L.).

Abstract

The present investigation was carried out at El-Gemmeiza Agricultural Research station, Agricultural Research Center (ARC), Egypt during four successive seasons from 2007/2008 through 2010/2011. Three crosses were used among five parental varieties, namely P1xP2 (1), P3xP4 (2) and P4xP5 (3) five populations (P1, P2, F1, F2 and F3) for each cross were used in this investigation. Highly significant heterotic values in positive direction were found for all charcters except for plant height and 1000-grain yield in the first cross, spike length in the second cross, and plant height, No. of grains/spike and No. of spikes/plant in the third cross. Over domenance for all characters except plant height and 1000-grain weight in the first cross, spike length in the second cross and No.of grains /spike in the third cross was detected. Inbreeding depression was obtained in two out of three crosses for spike length, No.of grains/spike, No.of spikes/plant, 1000-grain weight and grain yield/plant and in one out of the three crosses for plant height. The important roles of both additive and non-additive gene actionwere found in certain studied traits. Significant positive F2 deviation (E1) were indicated for plant height in the third cross, No.of spikes/pant and grain yield/plant in the second and third crosses and 1000-grain weight in the first and third crosses. High to medium values of heritability estimates were found to be associated with high and moderate expected and actual gain in most traits. These obtained results indicated that, these traits could be used in the early generations, but would be more effective if postponed to late generations.