前言为了不断提高水稻的生产水平,达到高产、稳产的目的,当前,各级科研机关及广大科研人员对水稻的感光性、基本营养生长性以及防御低温冷害等方面进行了大量的研究工作,取得了较大的成绩。但要真正解决好水稻的高产、稳产根本问题,除进行以上的研究工作外,我认为必须尽快解决好水稻品种的定向问题。因为在不同年份的情况下,水稻抽穗期的变化对水稻生产的影响是很大的,但水稻品种定向仍然没有引起我们足够的重视 Preface In order to continuously improve the level of rice production and achieve the purpose of high yield and stable yield, a large amount of research work has been done on scientific aspects of rice sensitivity, basic vegetative growth and defense against chilling damage. A larger result. However, in order to truly solve the fundamental problem of high yield and stable production of rice, in addition to carrying out the above research work, I think it is imperative to solve the orientation problem of rice varieties as soon as possible. Because in different years, the change of heading date of rice has a great impact on rice production, but the orientation of rice varieties still does not pay enough attention to us