Abstract: Seed morphophysiological dormancy (MPD) is a combination of physiological dormancy (PD) and morphological dormancy (MD), which occurs in seeds with undifferentiated or underdeveloped embryos that are linear, spatulate, or globular in shape. Based on cold and/or warm stratification requirements for germination, temperature requirements for embryo growth, and response to GA³, MPD can be classified into nine types, i.e. non-deep simple, intermediate simple, deep simple, deep simple epicotyl, non-deep simple epicotyl, deep simple double, non-deep complex, intermediate complex and deep complex MPD. The embryo growth and dormancy break are promoted by the same environmental conditions for species, whereas in others they require different conditions. The species that have been reported with MPD are about 34 orders and 72 families. We summarized the morphology of MPD seeds, the environmental conditions required to break MPD, the origin and evolution of MPD, and the species with MPD. Last, we summarized the shortcomings of the previous studies and prospected future researches.

Key words: rice, agroclimatic resource, three provinces of Northeast China, sterile-type chilling injury