Exploration of the role of flavonoids on pest resistance in Cannabis sativa

Abstract

Hemp (Cannabis sativa) is a growing crop industry in the United States with a wide variety of uses from fiber to CBD extraction; as more is grown there is a higher importance placed on pest management, particularly of the cannabis aphid (Phorodon cannabis). Flavonoids are a category of secondary metabolite found in all plants that show a wide variety of structures and functions, including some levels of negative impacts on insect pests. We explored how varying flavonoid levels in 7 hemp cultivars affect the ability of cannabis aphids to colonize the plant, and focused on the effect of a specific flavonoid, orientin, through artificial feeding assays. Population screening showed a significant difference in aphid populations when comparing varying flavonoid profiles to a cultivar with none. Artificial feeding showed no significance of orientin on cannabis aphids, suggesting potentially a higher concentration is necessary to see negative effects. Knowing that overall flavonoid levels may aid in plant defenses paves the way for future research to focus on specific flavonoids and narrow down which are responsible, and could be potentially targeted for crop improvement and breeding.