Evaluation of Combining Ability and Heterosis for Yield and Its Components Traits of Rice under Normal Irrigation and Drought Stress Conditions تقییم القدرة على التآلف وقوة الهجین للمحصول ومکوناته فی الأرز تحت ظروف الری الطبیعی والجفاف

Abstract

During 2010 and 2011seasons, two field experiments of rice experimental farm of Sakha, Kafr El-Sheïkh, Egypt, were performed through a 6 x 6 diallel system analysis to investigation the combining ability and heterosis and their component features of rice under normal irrigation and drought stress conditions.A broad range of genetic variation among research genotypes was indicated by the routine analysis of variance. As for all the features of normal irrigation and drought stress conditionsThe significance of non-additive genetic variation in the heritage of grain yield / plant has been established by GCA / SCA ratios. While the selection based on the accumulation of the additive effect will boost yield and assign it successfully. According to drought susceptibility index (DSI), four parents and six crosses were the lowest genotypes affected by drought.GCA shows all parental lines are intrinsically performing with a strong index of their overall ability to blend. The combinations of IR7887-176-B-2-B X IR80508-B-194-1-B to boost the output of grain per plant was the best possible cross, as reported by SCA.Under drought, the highest values significant for heterosis from better parent, five crosses for panicle length and seven crosses for number of branches / panicles and grain yield characters. In the general sense, higher heritability levels emerged in normal irrigation; genotypic variances played a major part in phonotypical yield variances and their components.Lower and moderate heritage tests for all yields and their components showed that selection for these characteristics would be successful in late generations.

Diallel Analysis of Different Rice Genotypes under Water Deficiency Conditions and Assessing Genetic Diversity Using SSR Markers

“…Consequently, one or more of these crosses could be used in rice breeding programs for producing hybrid rice under normal and stress conditions. Positive and significant heterosis for grain and some of its components in rice under normal and water deficit conditions have been reported by Sultan et al (2014), Ushakumari et al (2014), El-Sayed et al (2018 and Abd El-Hadi et al (2020).…”

“…The GCA and SCA provide a simple approach to predict additive and no-additive effects, respectively. Both additive and non-additive gene actions were reported to be important in the inheritance of rice grain yield under normal and water deficit conditions by El-Hity et al (2016), Farid et al (2016), El-Adl et al (2019) and Abd El-Hadi et al (2020). However, the grain yield and other assessed traits under water deficit condition were mostly controlled by non-additive gene action as reported by Hasan et al (2015), Sathya and Jebaraj (2015), Malemba et al (2017), Elgamal et al (2018) and El-Sayed et al (2018).…”