Chengdao Li

Many plant species have acquired seed dormancy during evolution to maximise their fitness and survival. This adaptive trait has many evolutionary benefits such as allowing seed dispersal, preventing germination in unfavourable conditions, and improving survival rate across multiple conditions (Koornneef et al., 2002; Venable, 2007). However, seed dormancy has generally been lost or weakened during crop domestication due to artificial selection for rapid and uniform germination (Hammer, 1984). And this loss of seed dormancy makes modern cultivated crops particularly susceptible to a grain defect called pre-harvest sprouting (PHS).

Seed germination is the first critical step of the plant life cycle and the foundation of agricultural production. In contrast, seed dormancy prevents seedling emergence in a wrong season or place in wild species. In cereal crops, the lack of dormancy results in pre-harvest sprouting (PHS) under particular conditions of humidity and temperature, which triggers reserve mobilization, mainly starch degradation by α-amylase (Bewley et al., 2013), and reduces grain quality. Annual losses from PHS are likely to approach $1 billion U.S. dollars worldwide (Black et al., 2006).