Filip Vandelook1, Rosemary J Newton2, Angelino Carta3. 1. Botanic Garden Meise, Nieuwelaan, Meise, Belgium. 2. Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex, UK. 3. Department of Biology, Unit of Botany, University of Pisa, Via Derna, Pisa, Italy.
Abstract
Background and Aims: Photoinhibition of seed germination, known to occur notably in species growing in dry and hot habitats, is considered an adaptation to avoid germination at the soil surface after unpredictable rainfall events during the dry season. Hence, the association of this ecophysiological response with plant life histories and the natural environment was investigated in Lilioid monocots, a group of plants where photoinhibition has been pre-eminently observed. Methods: A data set including germination in light and darkness of about 150 monocots was compiled. Habitat preference, local climate conditions, seed traits and temperature conditions used during germination experiments were retrieved. Factors driving the evolution of photoinhibition were analysed within a phylogenetic framework. Key Results: Significant phylogenetic signal was found in germination response (λ between 0.76 and 0.80) and photoinhibition (D = 0.406). Photoinhibition was mainly related to plant traits, namely seed coat colour, seed mass and plant height. A relationship with habitat light and moisture was also evident, but the association with climate as well as temperature conditions during incubation was rather poor. Conclusions: Whilst photoinhibition is prevalent in open habitats, the relationship with habitat moisture conditions and hot and dry climate is weak. Indeed, photoinhibition is also commonly observed in temperate and alpine climate geophytes growing in habitats that are much less susceptible to drought. Hence, phylogenetic inertia, probably mediated by seed morphological traits such as seed coat colour, may explain why temperate climate species have retained photoinhibition inherited from their Mediterranean ancestors.
Background and Aims: Photoinhibition of seed germination, known to occur notably in species growing in dry and hot habitats, is considered an adaptation to avoid germination at the soil surface after unpredictable rainfall events during the dry season. Hence, the association of this ecophysiological response with plant life histories and the natural environment was investigated in Lilioid monocots, a group of plants where photoinhibition has been pre-eminently observed. Methods: A data set including germination in light and darkness of about 150 monocots was compiled. Habitat preference, local climate conditions, seed traits and temperature conditions used during germination experiments were retrieved. Factors driving the evolution of photoinhibition were analysed within a phylogenetic framework. Key Results: Significant phylogenetic signal was found in germination response (λ between 0.76 and 0.80) and photoinhibition (D = 0.406). Photoinhibition was mainly related to plant traits, namely seed coat colour, seed mass and plant height. A relationship with habitat light and moisture was also evident, but the association with climate as well as temperature conditions during incubation was rather poor. Conclusions: Whilst photoinhibition is prevalent in open habitats, the relationship with habitat moisture conditions and hot and dry climate is weak. Indeed, photoinhibition is also commonly observed in temperate and alpine climate geophytes growing in habitats that are much less susceptible to drought. Hence, phylogenetic inertia, probably mediated by seed morphological traits such as seed coat colour, may explain why temperate climate species have retained photoinhibition inherited from their Mediterranean ancestors.
Authors: Angela T Moles; David D Ackerly; Campbell O Webb; John C Tweddle; John B Dickie; Andy J Pitman; Mark Westoby Journal: Proc Natl Acad Sci U S A Date: 2005-07-19 Impact factor: 11.205
Authors: Zsuzsanna Mérai; Kai Graeber; Per Wilhelmsson; Kristian K Ullrich; Waheed Arshad; Christopher Grosche; Danuše Tarkowská; Veronika Turečková; Miroslav Strnad; Stefan A Rensing; Gerhard Leubner-Metzger; Ortrun Mittelsten Scheid Journal: J Exp Bot Date: 2019-06-28 Impact factor: 6.992