Heterosis for yield and yield component traits in rice (Oryza sativa L.)

Heterosis in rice was studied for yield and its component traits in 20 F 1 s involving 9 parents comprises of 4 lines and 5 testers. The high magnitude of heterosis for grain yield per plant is evident by significant superiority of crosses over mid parent and better parents in several crosses. The crosses viz. Sudu Hondarawala × PLA 1100, Sudu Hondarawala × IR 64 and Sudu Hondarawala × MTU 7029 showed high relative heterosis and heterobeltiosis for grain yield per plant. The crosses exhibiting good heterotic expression in F 1 may be further studied to isolate superior transgressive segregants in later generations. The development of pure lines from segregating population is very important for evolving high yielding varieties.