Host preference and physiological performance of the invasive hemiparasite of coastal communities Cassytha filiformis L. (Lauraceae)

Abstract

Background: Invasive parasitic species have barely been studied despite their impact on the communities they invade. Questions: What is the host range used by the invasive parasite Cassytha filiformis in the coastal scrubland of northern Yucatan? Does C. filiformis show host preference? Does the physiological performance of C. fliformis (water deficit and chlorophyll content) vary among hosts on which it establishes and reproduces? Study species: Cassytha filiformis, an invasive hemiparasitic vine of coastal communities. Study sites and dates: Telchac, Yucatán, México. The study lasted from October 2022 to June 2023. Methods: The incidence of C. filiformis parasitism was recorded. Histological analysis confirmed parasitism, and the water potential and chlorophyll concentration of C. filiformis in its main hosts were determined. Results: C. filiformis parasitized 10 species, showing a preference for shrubs. Its main hosts were Scaevola plumieri, Phitecellobium keyense and Croton punctatus. Differences between hosts were observed in water potential variation and total chlorophyll concentration. Differences between stem types (young and mature) in chlorophyll concentration were also observed. Conclusions: C. filiformis prefers shrub species to establish. The physiological performance of C. filiformis varied depending on host identity. Differences in chlorophyll concentration between stem types of C. filiformis suggest functional physiological differences between them.

Keywords

• chlorophyll a and b
• total chlorophyll
• water deficit
• hemiparasitic plants
• host preference
• host range