Estimation of Hybrid Vigor and some Genetic Parameters in some growth traits of rice (Oryza sativa L.) and the hybrids derived from it using the factorial hybridization method

Abstract

The research was conducted at the rice research station in Al-Mishkhab / Al-Najaf Al-Ashraf for the years 2021 and 2022, which is 20 km south of the center of Al-Najaf Al-Ashraf province and located at latitude 31.48 north and longitude 44.29 east, at an altitude of 70 m above sea level, using eight genotypes of rice, which are four. Local cultivars (Amber 33, Yasmine, Al-Furat, and Degla), which were obtained from the rice research station in Al-Mishkhab, and four Egyptian cultivars (Giza 201, Giza 178, Giza 179, and Basmati 1), with the aim of evaluating the performance of the cultivars used in the research and the hybrids derived from them using the factorial hybridization method, numbering (16). Hybrid and estimating the proportions of hybrid vigor and the combining ability in public and private  GCA (General combining ability) SCA(Specific combining ability ) with some other genetic parameters. In autumn fall season of 2021, hybridization was conducted according to the factorial hybridization method. Comparative experiments were carried out for hybrid and their parents for the year 2022 using a randomized complete block design (RCBD) with three replicates. The results showed the following:

Significant differences were found between the genotypes (cultivars and their hybrids) in all the studied traits. The results showed that the Hybrid Vigor values were significant for most of the studied traits and for the two seasons, indicating the effects of complete dominance and superdominance of the genes that control the inheritance of these traits. The genetic analysis of the study showed that the general (GCA) and specific (SCA) and the male parent (3) and female parent   (8) showed high combination ability and in the desired direction in most of the traits. The values of the specific combination ability of the hybrids were significant in most of the traits. The hybrid (3×5) was distinguished by giving the best effect of the specific combination ability in most of traits, and the average degree of dominance was higher than one true in all traits. It was found that the percentage of heritability in the broad sense was high in all traits. The narrow sense heritability peracentage was low to moderate for all traits. The results indicate that the hybridization method is the most appropriate for improving these traits. The hybrid (3×5) (Giza 201  × Al-Furat) is one of the most promising hybrids