Annual crops, cultivated on 60%–80% of global cropland, form a critical cropping system that supports the majority of food production but requires significant inputs, whose deficiency can lead to soil and nutrient loss. In contrast, perennial cultivation systems, which are planted once and harvested repeatedly, have shown the potential to reduce inputs and help retain soil carbon. Therefore, the primary breeding method for developing perennial major crops has been interspecific hybridization between conventional annual varieties and their relative species. Research has focused on minor crops, such as buckwheat, because their perennial species exhibit waterlogging tolerance. However, developed perennial varieties and breeding lines face more challenges than annual crops, including hybrid sterility, low productivity, susceptibility to plant pests and diseases, and weed potential. Additionally, frost or soil freezing tolerance traits are essential for wintering, especially at high altitudes and in high-latitude regions. In this review, we highlight the differences between annual and perennial species, summarize studies that advance perennial traits and hybrid development, and introduce the latest domesticated perennial hybrids. To maintain stable food production, the development of new breeding technologies for perennial crops are a promising option.
KATSUTA et al. (Thu,) studied this question.