Effects of nitrogen rates on carbon and nitrogen assimilate translocation in two different wheat varieties under soil drought and waterlogging from anthesis to maturity were investigated in a cement pool culture experiment. Three water treatments were established from anthesis to maturity

i.e. waterlogging

drought and moderate water supply (CK)

and under each water treatment

two nitrogen levels of 120 and 240 kg/hm~2 were implemented. Compared with CK

drought and waterlogging reduced the amounts and remobilization rate of pre-anthesis stored assimilates

total amount of pre-anthesis stored assimilate and grain weight. Under drought and waterlogging

nitrogen increased amounts and remobilization rate of pre-anthesis stored assimilates in leaves

hull and rachis

stem and sheathes. Under CK and drought nitrogen increased total amounts and remobilization rate of pre-anthesis stored assimilates

grain weight and the amounts of pre-anthesis assimilates transferred into grains

while nitrogen reduced them under waterlogging. Both drought and waterlogging reduced the amounts and remobilization rate of pre-anthesis stored nitrogen and nitrogen accumulation in grains. Under drought and waterlogging nitrogen increased amounts and remobilization rate of pre-anthesis stored nitrogen in leaves

amounts of pre-anthesis stored nitrogen in stem and sheathes

total amount and remobilization rate of pre-anthesis stored nitrogen

nitrogen accumulation in grains and the translocation of pre-anthesis accumulated nitrogen into grains

while under waterlogging nitrogen reduced them. Both drought and waterlogging reduced grain yield

starch and protein yield. Nitrogen favored grain yield

starch yield and protein content under drought

but reduced grain yield under waterlogging. The results indicated that nitrogen regulated translocation of carbon and nitrogen assimilate and sequentially regulated accumulation of grain starch and protein in wheat grown under stress conditions of soil drought or waterlogging from anthesis to maturity.