Yield Formation Characteristics of Transgenic Rice Strains with Different Protein Contents in Grains

Abstract

Relationship between protein content(PC) in grains and grain yield in rice has not been clearly understood.Nipponbare and its five transgenic strains with different PCs in grains were used in the study to investigate their yield formation characteristics under the condition of field cultivation.There were two main results:(1) Under the same nitrogen amount,grain yields were lower in strains with higher PC in grains.Filled grain rate was very significantly and negatively correlated with PC in grains.With an increase in N fertilizer,PC in grains and grain yield significantly increased and the increase in yield was mainly dependent on the increase in panicle number and grains per panicle.(2) Under the same nitrogen amount,the strains with higher PC had less dry matter accumulation before heading stage,shorter functional period and lower photosynthetic rate of flag leaves after heading stage and lower apparent translocation amounts of dry matter and non-structure carbohydrates(NSC) from stems to grains during grain filling stage,leading to lower filled grain rate,which is the possible physiological reason for lower yield in those strains.