关键词: 氮素, 氮素, 矿化, 烤烟, 累积分配, 烟碱

Abstract: There have been six times of severe heat damages happened to the mid-season rice in Yangtze River Valley (YRV), China during the past 50 years, with the latest one occurred in 2003. It was estimated that the involved acreage of rice in 2003 was about 3 million ha, with a loss of about 5.18 million rice grain yields. The serious heat stress situation in YRV might be closely correlated with the characteristic climatic environment of this area, as well as some hybrid rice cultivars commercialized here which showed likely more susceptible to heat stress. From 2003 on, heat stress of rice in YRV has gradually become a highlight issue in Chinese crop science. The current researches focus on,1) identifying on-farm micro-meteorological factors with heat stress; 2) the meteorological pattern for heat stress weather formation and its forecasting; 3) facilities and methods for germplasms and cultivars screening; 4) breeding-related researches; 5) cellular and biochemical processes underlining heat stress injury.