Kumquat (Fortunella spp.), a common fruit crop and ornamental tree, is characterized by small, flavorful, and brilliant orange-like fruit. The cultivated Fortunella species (F. margarita, F. crassifolia, and F. japonica) is known to be originated from China, and was introduced to Europe for the first time by English botanist Robert Fortune during the Daoguang period of China's Qing Dynasty. The wild Hong Kong kumquat (F. hindsii) is widely distributed in southern China, and it has been developed as a model material for citrus gene function research due to its dwarfness, short juvenility, and monoembryony characteristics.