Expression of heterosis in rice hybrids over three environments

Sixty rice hybrids developed through a line x tester fashion involving jive cytoplasmic male sterile lines and 12 restorer lines were evaluated in a randomized complete block design over three locations for yield and its components. In most of the heterotic crosses, significant positive standard heterosis for single plant yield achieved due to positive and significant standard heterosis for component characters like panicle length, panicle weight, number of productive tillers per plant, number of filled grains per panicle, 1000-grain weight. The top most heterotic combinations identified for single plant yield were APMA6A x IR-54742R, APMS6A x IR24R, APMS6A x BR-827-35R, IR-80555A x IR-54742R, IR-80559A x IR-54742R and IR-80559A x KMR-3R over three locations.