Studies on heterosis for grain yield and its component traits for developing new plant type hybrids in rice (Oryza sativa L.).

The heterosis and heterobeltiosis were estimated for 15 grain yield, and its component traits in 27 cross combinations to develop heterotic hybrids. The result revealed that grain yield and its component showed highly significant differences for all the traits. Among the 27 hybrids, five hybrids viz., IR58025A/IRFAN-115, IR58025A/SR-6-SW-8, IR58025A/ET 1–13, APMS 6A/ET 1–12, and APMS 6A/NPTR-2 showed significant heterosis for grain yield and seven hybrids showed significant negative heterosis for earliness and three hybrids for plant height. These hybrids may be exploited for heterosis breeding and should be screened for yield stability.