title: Mistletoe Berry Outline Mapping with a Path Curve Function and Recording the Circadian Rhythm of Their Phenotypic Shape Change.
abstract: This paper presents a discovery: the change of the outline shape of mistletoe (Viscum albumssp.album) berriesin vivoandin situduring ripening. It was found that a plant organ that is usually considered to merely increase in size actually changes shape in a specific rhythmic fashion. We introduce a new approach to chronobiological research on a macro-phenotypic scale to trace changes over long periods of time (with a resolution from hours to months) by using a dynamic form-determining parameter called Lambda (λ). λ is known in projective geometry as a measure for pertinent features of the outline shapes of egg-like forms, so called path curves. Ascertained circadian changes of form were analyzed for their correlation with environmental factors such as light, temperature, and other weather influences. Certain weather conditions such as sky cover, i.e., sunshine minutes per hour, have an impact on the amplitude of the daily change in form. The present paper suggests a possible supplement to established methods in chronobiology, as in this case the dynamic of form-change becomes a measurable feature, displaying a convincing accordance between mathematical rule and plant shape.
authors.affiliation: Institute of Integrative Medicine, University of Witten/HerdeckeWitten, Germany; Research Institute at the Goetheanum, Science SectionDornach, Switzerland.
authors.forename: Renatus
authors.initials: R
authors.lastname: Derbidge
authors.affiliation: Institute of Integrative Medicine, University of Witten/HerdeckeWitten, Germany; Hiscia Institute, Society for Cancer ResearchArlesheim, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Baumgartner
authors.affiliation: Institute of Integrative Medicine, University of Witten/Herdecke Witten, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Heusser
keywords: change of shape; circadian rhythm; form and function; mistletoe; phenotypic study; plant movement; shape mapping