This work follows on from the 1995 publication on European orchids. The atlas is now completed with a second part, containing data on the pollination of orchids of the continents of America, Asia, Africa (including Madagascar) and Australia (including New Zealand). The first part of the book is adapted from the general account of the previous publication and is extended with chapters on taxonomy and pollinators. The general account deals with such things as the history, evolution, morphology, chemistry and genetics of orchid pollination. The second part gives a systematic account for each continent of all well known details. The text is designed to have relevance for orchid lovers whether professional or amateur.

An Atlas of Orchid Pollination: European Orchids

Attractive but Toxic: Emerging Roles of Glycosidically Bound Volatiles and Glycosyltransferases Involved in Their Formation.

Flower colour polymorphism (FCP) is the occurrence of at least two discrete flower colour variants in the same population. Despite a vast body of research concerning the maintenance and evolutionary consequences of FCP, only recently has the spatial variation in morph frequencies among populations been explored. Here we summarise the biochemical and genetic basis of FCP, the factors that have been proposed to explain their maintenance, and the importance of FCP and its geographic variation in the speciation process. We also review the incidence of FCP in the environmentally heterogeneous Mediterranean Basin. Nearly 88% of Mediterranean FCP species showed anthocyanin-based polymorphisms. Concerning the evolutionary mechanisms that contribute to maintain FCP, selection by pollinators is suggested in some species, but in others, selection by non-pollinator agents, genetic drift or gene flow are also found; in some cases different processes interact in the maintenance of FCP. We emphasise the role of both autonomous selfing and clonal reproduction in FCP maintenance. Mediterranean polymorphic species show mainly monomorphic populations with only a few polymorphic ones, which generate clinal or mosaic patterns of variation in FCP. No cases of species with only polymorphic populations were found. We posit that different evolutionary processes maintaining polymorphism the Mediterranean Basin will result in a continuum of geographic patterns in morph compositions and relative frequencies of FCP species.

Flower colour polymorphism in the Mediterranean Basin: occurrence, maintenance and implications for speciation.

Phenotypic plasticity of floral volatiles in response to increasing drought stress.

Floral scent emitted by white and coloured morphs in orchids.

https://hal.archives-ouvertes.fr/hal-01597859/document

Understanding intraspecific variation of floral scent in light of evolutionary ecology

How floral polymorphism of flowering plants can be maintained in evolutionary time has long intrigued ecologists and is still debated. In particular, how floral colour polymorphism influences reproductive success is still poorly understood. Here, we investigated the case of Orchis mascula, a deceptive orchid species in which the presence of rare white-flowered individuals is known to increase the percentage pollination of co-occurring coloured morphs. In a brief review, we report all the orchid species for which rare colour morphs are recorded and show that colour polymorphism occurs in most orchid genera occurring in France. In this study, more than 20,000 individuals of O. mascula were surveyed and some rare clear pink morphs were recorded. The frequencies of white-flowered and clear pink-flowered individuals were 0.59% and 0.28%, respectively. These two rare-colour flowered individuals were not randomly distributed and restricted to a few populations. In addition, the presence of pink-flowered individuals and the use of experimental pink lures resulted in an increase in the percentage pollination of surrounding purple-flowered individuals, as previously shown for white-flowered individuals and white lures. These new observations favour kin selection as the means by which floral colour polymorphism is maintained in this species. We suggest conducting comparative studies of other species in order to evaluate the importance of this mechanism in orchid pollination and that of other plant families.

/pdf/presence-distribution-and-effect-of-white-pink-and-purple-1voomzv7l2.pdf

Roxane Delle-Vedove

Papers

Understanding intraspecific variation of floral scent in light of evolutionary ecology

Presence, distribution and effect of white, pink and purple morphs on pollination in the orchid Orchis mascula