Flower Colour Polymorphism, Pollination Modes, Breeding System and Gene Flow in Anemone coronaria

Abstract

The flower colour of Anemone coronaria (Ranunculaceae) is a genetically inherited trait. Such intra-specific flower colour polymorphism might be driven by pollinators, other non-pollinating agents, or by abiotic factors. We investigated the genetic relations among red, white and purple-blue flower colour morphs growing in 10 populations of A. coronaria in Israel, in relation to their breeding system, pollination modes, differential perception by bees and visitors’ behaviour. Flowers of these three morphs differed in their reflectance that could be perceived by bees. Honeybees, solitary bees and flies demonstrated only partial preferences for the different colour morphs. No spontaneous self-pollination was found; however, fruit set under nets, excluding insects but allowing wind pollination, was not significantly lower than that of natural free pollinated flowers, indicating a potential role of wind pollination. Anemone coronaria flowers were visited by various insects, honeybees and Andrena sp. preferred the white and purple-blue morphs, while the syrphid flies preferred the white flowers. Thus, visitor behaviour can only partially explain the evolution or maintenance of the colour polymorphism. No significant genetic differences were found among the populations or colour morphs. Wind pollination, causing random gene flow, may explain why no significant genetic divergence was found among all studied populations and their colour morphs. The existence of monomorphic red populations, along other polymorphic populations, might be explained by linked resistance to aridity and/or grazing.

Unravelling the mystery of red flowers in the Mediterranean Basin: How to be conspicuous in a place dominated by hymenopteran pollinators

“…The strategy of patterned flowers does not show phylogenetic signal, and a nonnegligible number of species showed both strategies, suggesting that this floral feature is a colour signal widespread among angiosperms (Lunau et al, 2017). Although flower colour is often considered an evolutionarily labile floral trait (Dafni et al, 2020; Ortiz et al, 2021; Reverté et al, 2016), we have found that UV‐red colour presented a significant phylogenetic signal. Taking together, our results suggest that the prevalence of hymenopterans pollination in red‐flowered species of the Mediterranean Basin is not the product of a single coevolutionary interaction between species, but rather the result of diverse evolutionary and ecological processes acting at the species and community level (Dalrymple et al, 2020; Kemp et al, 2019; Narbona et al, 2018; Strauss & Whitall, 2006).…”

“…The strategy of patterned flowers does not show phylogenetic signal, and a nonnegligible number of species showed both strategies, suggesting that this floral feature is a colour signal widespread among angiosperms (Lunau et al, 2017). Although flower colour is often considered an evolutionarily labile floral trait (Dafni et al, 2020;Ortiz et al, 2021;Reverté et al, 2016), we have found that UV-red colour presented a significant phylogenetic signal.…”

Intrafloral Color Modularity in a Bee-Pollinated Orchid

“…Plants were cultivated in clay pots (20 cm in diameter and 15 cm in depth) using tree barks as substrate. To reduce the possible effects of environment on color differences ( Schemske and Bierzychudek, 2001 ; Dafni et al, 2020 ), individuals were cultivated in the same natural light and temperature conditions and were watered at least twice a day.…”

Conservation issues and infraspecific polymorphism of Cypripedium guttatum on selected locations in Russia

“…Flower colouration polymorphism refers to the variation in flower colours within or between natural populations of the same species (Dafni et al, 2020). Although the flower colour is diverse throughout flowering plants, variation within a species is uncommon.…”