Combining ability and some genetic parameters for yield and its related traits of rice (Oryza sativa L.) under lysimeter condition

Salinity is a major abiotic constraint faced by farmers in many rice-growing regions of the world and improving grain yield in rice is the most important breeding objective. Thirty-five crosses were generated in a line x tester mating design by crossing seven lines with five testers and were evaluated in a randomized complete block design at the greenhouse lysimeter of Rice Research Department, Sakha, Kafr El-Sheikh, Egypt, during the two rice-growing seasons of May, 2021 and 2022. Analysis of variance revealed a highly significant difference among testers and lines for all the studied traits. Variances of specific combining ability were higher in magnitude than the corresponding general combining ability. The lines Sakha 107, Sakha 104, and Giza 182 including testers SAL 010, and CSR 28 were the best general combiners for grain yield plant -1 under saline conditions. The variety Giza 179 followed by Sakha 107 was the best general combiner for 100-grain weight under both normal and saline conditions. Two crosses Giza 179/MTU 1010 and Sakha 107/SAL 010 exhibited highly significant positive estimates of specific combining effects for grain yield plant -1 , respectively. Estimates of narrow sense heritability for all the traits under study were low which indicated a preponderance of non-additive gene action governing these traits. By selecting the appropriate genotypes and phenotypes, the outcomes will be beneficial in breeding salt-tolerant cultivars at both the seedling and reproductive stages.