Accelerating rice breeding can be accomplished through various approaches, including molecular or conventional techniques. In this regard, some rice breeding programs around the world have changed to use rapid generation advancement (RGA) as a new breeding method. The objectives of this investigation are to establish and implement RGA techniques at the Rice Research & Training Center (RRTC) to develop new, improved, blast disease-resistant, and high-yielding varieties more quickly and at a low cost. Three F2 populations, (Giza177 x Sakha Super300), (IR75589-31 x Giza178), and (Giza179 x IR59673-93-2-3-3-2), were advanced to F2 and evaluated in Lines Stage Trials (LST) and preliminary yield trials (PYT). RGA facilities were installed at the greenhouse of the RRTC, and the F2 plants of each population were harvested individually. One seed from each panicle was used to cultivate the next generation (F3) according to the single seed descent (SSD) method. The RGA technique was successfully implemented at RRTC with simple multipot trays and the maintenance of the greenhouse and screen house. The early generations (F2, F3, F4, and F5) showed good performance in the greenhouse; the narrow space and low fertilizer led to early flowering. promising RGA lines, SK-RGA2-5, SK-RGA2-9, and SK-RGA3-6, revealed grain yields of more than 11.0 t/ha compared with the check varieties, Giza177, Giza178, and Sakha super300, which gave 9.57, 10.17, and 10.50 t/ha, respectively. For grain quality traits, most of the test RGA lines and check varieties have low to medium amylose content, ranging between 17.83 and 23.13%. RGA lines and check varieties gave desirable values for hulling and milling. In general, hulling% ranged between 80.0 and 85.0%, and milling% ranged between 69.43 and 73.0%.

Salinity is one of the major factors responsible for crop yield losses in the world. Genetic improvement for salt tolerance becomes an urgent task to cope with the salinity rice problem. In order to evaluate the presence of variability for desirable traits and correlations under both normal and salinity stress conditions, thirty genotypes of rice were evaluated in the two successive rice seasons of 2020 and 2021. The results showed highly significant for all studied traits for the genotype (G), and L x G. The heaviest panicle and highest number of spikelets per panicle were recorded for the promising lines, RGA-2, RGA-3, RGA-4 and RGA-14. Under normal location, RGA-2, RGA-3, RGA-6, RGA-9 and RGA-14 revealed the high yielding, while under saline location, RGA-13 and RGA-14 showed the highest yields compared with the salinity tolerance check Giza178. The salinity yield indices, SSI and TOL gave the same trend approximately for thirty genotypes, whereas, the salinity susceptible genotypes resulted in the highest values, while the salinity tolerance genotypes recorded the lowest values. Using mean performances and salinity tolerance indices for the screening of salinity tolerant genotypes exhibited that Giza178, Giza179, RGA-2, RGA-3, RGA-4, RGA-11, RGA-13, RGA-14 and RGA-15 were tolerant to salinity stress.