Heritability and genetic gain to a selectiveof maize under sufficient and insufficientwater, nitrogen and potassium


The objective of experiment was to estimate the heritability and genetic gain of phenotypic superior plants of the synthetic cultivar IBA 5012, by S1–progeny selection to improve growth and grain yield. Seeds planted in field station of Field Crop Sci. Dept.-College of Agriculture–Univ. of Baghdad for four season during 2010-2011.seeds planted under three types of a biotic stress :water 5 and 10 days. Two levels of nitrogen 250 and 500 kg ha-1 and two levels of potassium 100 and 200 kg ha-1. The plants were selected from each group of combinations according to phenotypic superiority. Plants were self pollinated for three cycles under sufficient and non sufficient water. The manual random mating was used between selected plants in each group in fourth season. Random sample of 50 plants were took from each selective population of combination treatments of fertilizer under each treatment of irrigation to estimate the mean y ̅, standard deviation σp and coefficient of variation C.V for three cycles of selection.Results showed that the yield for selective increase by 39.9, 29.4, 28.5 for SN1K1 and 35.46, 24.91, 47.26 for SN1K2, 34.31, 17.69, 14.67 for SN2K1, and 39.59, 21.01, 24,05 for SN2K2 for three cycles sufficient water, and 31.97, 51.47, 20.94 for SDN1K1, 41.36, 24.97, 23.56 for SDN1K2, 31.61, 18.26, 34.29 for SDN2K1,and 40.07,19.51,21.66 for SDN2K2 ,for three cycles under un sufficient water .In other hand the values of σp and C.V% was decreased. Heritability narrow sense and genetic gain under insufficient water were higher than sufficient for three combination, only SN2K1 was differ, its lower. These results confirm the efficiency of selection for high yield. Selection under sufficiency and in sufficiency of water resulted in improving the performance of selected plants for most phenotypic and genetic traits. So we recommend the S1-progeny selection for high yield and tolerant water stress.In order to improve growth and yield in maize (Zea mays L.) to select a superior.