Compared with three-line hybrid rice, two-line intersubspecieshybrid rice (TLIHR) has more grains per ear and a higher proportion of empty-unfilled grains (EUG). Degrees of grain plumpness vary with the TLIHRcombinations. Combinations with stronger carborn assimilation ability, slowersenscence speed and smaller sink capacity have lower proportion of EUG. It issuggested that big capacity with source shortage was one of the main physiologi-cal factors for the higher EUG proportion of TLIHR. Measures o...
