近年来,不少群众反映杂交水稻不仅制种难,而且保纯难。特别是V20A和以它为母本配制的杂交稻的混杂退化现象远比常规稻显著。其原因如何?目前众说纷坛,莫衷一是。为此,我们于1982—1983年开展了一些研究,旨在为水稻“三系”良种繁育和提纯复壮提供理论依据和方法。 一、材料和方 In recent years, many people have reported that hybrid rice is not only difficult to seed but also difficult to maintain. In particular, hybrid degeneration of V20A and hybrid rice formulated with it as a female parent was significantly more significant than conventional rice. What are the reasons for this? To this end, we carried out a number of studies in 1982-1983 aimed at providing theoretical evidence and methods for the breeding and rejuvenation of the “three lines” of rice. First, the material and side