The investigation was conducted at the experimental farm of the Rice Research and Training Centre, Kafr el Sheikh, Egypt, during the summer seasons from 2017 to 2019 using the experimental material consisting two populations with their two parents (P₁, P₂, F₁ and F₂) to study the variability in the F₂ population of four crosses: IR 78,936-B-B-B-B (water deficit tolerant) x Giza 177 (water deficit sensitive), FL-496 (moderately water deficit tolerant) x Giza 177, IR 78,936-B-B-B-B (water deficit tolerant) x Giza 178 (moderately water deficit tolerant), FL-496 × Giza 178 under normal (NWS) and deficit water supply (DWS). The experiment was conducted in a randomized complete block design with three replications. The results indicated that the phenotypic values of the measured characters were significantly different between the two parents of all the studied crosses under the two water supply conditions. The means of all the studied characters under DWS were lower than the means under NWS, but the yields and the yield components under DWS varied greatly among the parents due to stress. The averages of the measured traits of the F₁ plants and the F₂ populations in all crosses were near the averages of those of the parents. The results showed no consistent reduction in heritability under DWS compared to NWS. High heritability in a broad sense coupled with high genetic advance (GA) was observed for grain yield in Cross 1 under the two studied conditions offering good scope for selection.

调查于 2017 年至 2019 年夏季在埃及 Kafr el Sheikh 水稻研究和培训中心的实验农场进行，使用的实验材料包括两个种群及其两个亲本（P ₁、P ₂、F ₁和F ₂）研究的F变异₂四个杂交种群：IR 78,936-BBBB（耐缺水）x Giza 177（缺水敏感），FL-496（中等缺水耐受）x Giza 177，IR 78,936-BBBB（耐缺水）x Giza 178（中等缺水）缺水耐受)，FL-496 × Giza 178 在正常 (NWS) 和缺水供应 (DWS) 下。实验以随机完整区组设计进行，重复三次。结果表明，在两种供水条件下，所有研究杂交的两个亲本的实测性状表型值存在显着差异。DWS下所有研究性状的均值均低于NWS下的均值，但DWS下的产量和产量成分因胁迫而在亲本之间差异很大。F 的测量性状的平均值₁株和F ₂种群在所有杂交中均接近亲本的平均值。结果表明，与 NWS 相比，DWS 下的遗传力没有持续降低。在提供良好选择范围的两种研究条件下，在杂交 1 中观察到谷物产量的广义上的高遗传力和高遗传进步 (GA)。