Archiv der Kategorie: Papers

Plastic and genetic responses to shifts in snowmelt time

Our new article on plastic and genetic responses to shifts in snowmelt time in Ranunculus acris has just been accepted in PPEES. I will present the study at the ESA in Portland in August.

Changes in both temperature and precipitation will affect snowmelt time at high elevation, thereby influencing plant reproduction and growth. Species can respond to changed climate with phenotypic plasticity or genetic adaptation, and these responses might vary at different levels of advanced and delayed snowmelt time. Here we mimicked future climate change projections for western Norway by transplanting individuals of Ranunculus acris towards warmer, wetter and warmer & wetter climates. And we replicated the experiment along regional-scale temperature and precipitation gradients. This setup resulted in both advanced (warmer and warmer & wetter transplants) and delayed (wetter transplants) snowmelt in the experimental sites. We recorded phenological development and growth over one growing season.

The reproductive phenology of the transplanted R. acris individuals was affected by both phenotypic plasticity and genetic differences between populations of different origins, while growth showed only plastic responses. Plants expressed high plasticity to both advanced and delayed snowmelt time by acceleration of the onset of buds, flowers and fruits. Only the plants from wet and high-elevation sites showed a small response to advanced SMT. The late snowmelt time these populations experience could potentially cause high selection pressure leading to more constrains in plasticity. When grown under common conditions, plants from late snowmelt sites responded with earlier onset of phenological development, suggesting that the timing of snowmelt exerts strong selection on reproduction. To project species fates under future climate we need to consider the interplay between genetic adaptation and plastic responses under different climate contexts, especially towards the species range limits.

Plasticity and genetic difference in growth (top) as the difference in leaf size +/- 2SE in cm (top) and first flowering in days after snowmelt timing (SMT; bottom) between treatment and origin-control (left) or destination-control (right) plants. The x-axis represents the difference in SMT between origin and destination site. The colours indicate the transplant treatments to: warmer (red), wetter (blue) and warmer & wetter (purple) climate. Points above/below the dashed grey line indicate larger/smaller leaf size or earlier/later days since SMT for first flowering in the transplanted plants compared to the origin-control (left) or destination-control (right) plants. Closed circles indicate a significant difference between treatment and destination-control plants and open circles no significant difference. Dashed error bars indicate a sample size lower than 6 individuals.

Delnevo, N., Petraglia, A., Carbognani, M., Vandvik, V. and Halbritter, A.H. (accepted). Plastic and genetic responses to shifts in snowmelt time affects the reproductive phenology and growth of Ranunculus acris. PPEES.




New article on mushroom-mimickring Dracula orchids and 3D printed flowers

Tobias Policha and collegues published an interestig article how they used 3D printed flowers to disentangle visual and olfactory signals in an orichid. You can get to the article here. The picture shows a Dracula lafleurii.

Dracula lafleuriicropped

Flowers use olfactory and visual signals to communicate with pollinators. Disentangling the relative contributions and potential synergies between signals remains a challenge. Under- standing the perceptual biases exploited by floral mimicry illuminates the evolution of these signals. Here, we disentangle the olfactory and visual components of Dracula lafleurii, which mimics mushrooms in size, shape, color and scent, and is pollinated by mushroom-associated flies.

 To decouple signals, we used three-dimensional printing to produce realistic artificial flower molds that were color matched and cast using scent-free surgical silicone, to which we could add scent. We used GC-MS to measure scents in co-occurring mushrooms, and related orchids, and used these scents in field experiments.

 By combining silicone flower parts with real floral organs, we created chimeras that identi- fied the mushroom-like labellum as a source of volatile attraction. In addition, we showed remarkable overlap in the volatile chemistry between D. lafleurii and co-occurring mush- rooms.

 The characters defining the genus Dracula – a mushroom-like, ‘gilled’ labellum and a showy, patterned calyx – enhance pollinator attraction by exploiting the visual and chemosen- sory perceptual biases of drosophilid flies. Our techniques for the manipulation of complex traits in a nonmodel system not conducive to gene silencing or selective breeding are useful for other systems.

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