作物的发育需要一定的温度和光照条件。凡低温促进作物发育的作用称作“春化作用”。冬性油菜通过春化时对低温的要求比较严格,如果环境不能满足它对低温的要求,其发育就受到阻碍,从而不能进行花芽分化和现蕾开花。在冬油菜生长的上海地区,油菜在田间冬季自然低温条件下通过春化,一年只能生长一季。在油菜育种工作中,为了缩短 Crop development requires a certain temperature and light conditions. Where the role of low temperature to promote crop development is called “vernalization.” Winter rape through the vernalization of the relatively stringent requirements of low temperature, if the environment can not meet the requirements of its low temperature, its development has been hindered, which can not flower bud differentiation and budding flowering. In Shanghai, where winter rape grows, rape can only grow one season a year when it passes through vernalization at natural low temperatures in the field in winter. In rapeseed breeding work, in order to shorten