<p>Twenty hybrids were developed from crossing four environmental genic male sterile (EGMS) lines with five testers in line × tester mating design to magnitude of heterosis over better parent for grain yield and contributing traits in rice (<em>Oryza sativa </em>L.). Five hybrids ‘WTSC9059’ × ‘Sakha101’, ‘WTSC9039’ × ‘Sakha102’, ‘WTSC9059’ × ‘Sakha108’, ‘WTSC9039’ × ‘Sakha108’ and ‘WTSC9039’ × ‘Sakha101’ express superior value for number of panicles, fertility percentage, 100-grain mass, grain yield, ...