Genetic Analysis of Yield Attributes in Rice for Water Deficit Under Egyptian Conditions التحليل الوراثى لصفات المحصول فى الارز للاجهاد المائى تحت الظروف المصرية

Rice parental genotypes with good combining abilities provide an efficient tool to enhance rice yield under water deficit conditions. Using 15 F1 hybrids derived from a half diallel mating involving six parental genotypes, two experiments were carried out during 2019 and 2020 growing seasons to investigate the genetic analysis and combining ability for yield and its components under irrigated (E I) and water stress (E II) environments. Eight agronomic traits were studied over a period of two seasons, and cluster analysis based on 16 SSR primers found that the genotypes under study differed greatly in terms of variation. Overall, all yield attributes have been significantly affected by water deficit and was governed by both additive and non-additive gene actions. Based on the mean values and GCA effects, Gaori and IET1444 are suitable for incorporation of earliness and drought tolerance traits. Obviously that Gaori, IET1444, IRAT 170 and WAB 450 would serve as good general combiners for grain yield attributes under (E II) conditions. Due importance should be given for six combinations viz, Giza 177 x IRAT 170, Giza 177x Gaori, Sakha 101x IRAT 170, Sakha 101x IET 1444, Gaori x WAB 450 and IET 1444x WAB 450 to identify as new genotypes with high grain yield under water deficit condition. There might be a great possibility to get the best new combinations through crossing genotypes with highest genetic distance. Therefore, these findings should be considered when selecting elite genotypes for developing superior new rice crosses under water-stress conditions.