A Review on the Composition and Biosynthesis of Alkaloids and on the Taxonomy, Domestication, and Cultivation of Medicinal Fritillaria Species

Fritillaria is a perennial herb with medicinal properties. There are 158 Fritillaria species worldwide, 33 of which have reported therapeutic efficacy. Alkaloids are the principal constituents in Fritillaria. Fritillaria species growing at 2700-4000 m are the sources of extract namely Chuan Beimu (the Pharmacopoeia of the People's Republic of China, 2020 Edition), with low biomass, mainly containing more 5a-cevanine isosteroidal alkaloids with cis-configuration. In contrast, species growing below 1500 m are usually taller than 50 cm, and they mainly contain more trans-configuration isosteroidal alkaloids. There are two schemes of the biosynthetic pathways of steroidal alkaloids with different frameworks and catalytic reactions and combined high-throughput omics data. Based on the distributed elevations, Fritillaria species were divided into three major categories, which met classification features based on phylogenetic analysis or morphological features. Artificial or in vitro cultivations are effective strategies for balancing economical requirements and ecological protection. Fritillaria species growing at lower altitudes can be cultivated by bulb reproduction, but species growing at higher altitudes still rely mainly on gathering a large number of wild resources. Integration of asexual tissue culture and bulb reproduction with sexual artificial or imitated wild cultivation may create a very promising and effective way to maintain sustainable industrial development of Fritillaria.