title: Chemical and physical defense traits in two sexual forms of Opuntia robusta in Central Eastern Mexico.
abstract: Sexually dimorphic plants provide an excellent opportunity for examining the differences in the extent of their defense against herbivores because they exhibit sex-related differences in reproductive investment. Such differences enable comparison of the sex with high reproduction expenses with the sex that expends less. The more costly sex is usually also better defended against herbivores. Generally, females are considered more valuable than hermaphrodites in terms of fitness; however, hermaphrodites are more valuable if they can produce seed by autonomous selfing, provided that the inbreeding depression is low and pollen is limited. We studied a gynodioecious population of Opuntia robusta from Central-Eastern Mexico, which has been reported to be trioecious, dioecious, or hermaphrodite, and addressed the following questions: 1) Is the hermaphrodite's reproductive output higher than the female's, and are hermaphrodites thus better defended? 2) Are plant tissues differentially defended? 3) Do trade-offs exist among different physical defense traits? and 4) among physical and chemical defense traits? We found that 1) hermaphrodites had a higher seed output and more spines per areola than females and that their spines contained less moisture. Non-reproductive hermaphrodite cladodes contained more total phenolic compounds (TPCs) than female ones. In addition, 2) hermaphrodite reproductive cladodes bore more spines than female cladodes, and 3) and 4) we found a negative relationship between spine number per areola and areola number per cladode and a positive relationship between spine number per areola per plant and TPC concentration per plant. Non-reproductive hermaphrodite cladodes contained a higher concentration of TPCs than female cladodes, and parental cladodes contained fewer TPCs than both reproductive and empty cladodes.
authors.affiliation: Research Group in Behavioral Biology and Conservation, Autonomous University of the State of Mexico, Toluca, State of Mexico, Mexico, Carretera Toluca-Tlachaloya, Toluca, Estado de México, México; Research Group in Life History Evolution, Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland.
authors.forename: Mariusz Krzysztof
authors.initials: MK
authors.lastname: Janczur
authors.affiliation: Research Group in Behavioral Biology and Conservation, Autonomous University of the State of Mexico, Toluca, State of Mexico, Mexico, Carretera Toluca-Tlachaloya, Toluca, Estado de México, México.
authors.forename: Héctor Javier
authors.initials: HJ
authors.lastname: León Solano
authors.affiliation: Research Group in Behavioral Biology and Conservation, Autonomous University of the State of Mexico, Toluca, State of Mexico, Mexico, Carretera Toluca-Tlachaloya, Toluca, Estado de México, México.
authors.forename: Lupita Tzenyatze
authors.initials: LT
authors.lastname: Solache Rámos
authors.affiliation: Research Group in Behavioral Biology and Conservation, Autonomous University of the State of Mexico, Toluca, State of Mexico, Mexico, Carretera Toluca-Tlachaloya, Toluca, Estado de México, México.
authors.forename: Citlalli Hypatia
authors.initials: CH
authors.lastname: Mendoza Reyes
authors.affiliation: Research Group in Behavioral Biology and Conservation, Autonomous University of the State of Mexico, Toluca, State of Mexico, Mexico, Carretera Toluca-Tlachaloya, Toluca, Estado de México, México.
authors.forename: María del Carmen
authors.initials: Mdel C
authors.lastname: Oro Cerro
authors.affiliation: Faculty of Agricultural Sciences, Autonomous University of the State of Mexico, Toluca, State of Mexico, Mexico, Carretera Toluca-Tlachaloya, Toluca, Estado de México, México.
authors.forename: María Dolores
authors.initials: MD
authors.lastname: Mariezcurrena Berasain
authors.affiliation: Research Group in Flora Composition, and Ecology of Tropical and Template Systems, Autonomous University of the State of Mexico, Toluca, State of Mexico, Mexico, Carretera Toluca-Tlachaloya, Toluca, Estado de México, México.
authors.forename: Irma Victoria
authors.initials: IV
authors.lastname: Rivas Manzano
authors.affiliation: Research Group in Behavioral Biology and Conservation, Autonomous University of the State of Mexico, Toluca, State of Mexico, Mexico, Carretera Toluca-Tlachaloya, Toluca, Estado de México, México.
authors.forename: Javier
authors.initials: J
authors.lastname: Manjarrez
authors.affiliation: Division of Computing Service, Information and Communication Technology, National Autonomous University of Mexico, Ciudad Universitaria, Mexico Distrito Federal, Mexico.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Villareal Benitez
authors.affiliation: Research Group in Life History Evolution, Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Czarnoleski
mesh_terms: D000818:Animals; D001947:Breeding; D060434:Herbivory; D008800:Mexico; D029747:Opuntia / Q000033:anatomy & histology / Q000502:physiology*; D010636:Phenols / Q000378:metabolism; D035261:Plant Components, Aerial / Q000033:anatomy & histology / Q000502:physiology*; D012639:Seeds / Q000502:physiology
chemical_list: D010636:Phenols