Abstract Detail



Ecophysiology

Gujral, Anjum [1], Rosengreen, Lars [2], Lambrecht, Susan [3].

Evolution and plasticity of flowering time in response to historic California drought.

Plants are evolving due to drought. The frequency and severity of drought in California is expected to increase as climate change progresses, which will have consequences for native plants. It is predicted that annual wildflowers will begin flowering earlier in the season as a strategy for drought avoidance. We studied the implications of a prolonged, historic California drought (2012-2017) on flowering time in the annual wildflower, Leptosiphon bicolor Nutt. (true babystars, Polemoniaceae). The objective of the study was to examine evidence for evolution in this species in response to the drought. We collected seeds from three field populations with dissimilar levels of moisture availability, both before and after the drought. These seeds were grown together in a greenhouse to control for maternal and environmental effects. Seeds collected from this first generation were used to grow our second experimental generation, to which we administered two different watering regimes. To test for evolution in drought coping traits, we measured the number of days to first flower, flower size, and water-use efficiency, as indicated by stable carbon isotope analyses (δ). Plants flowered significantly earlier after the drought, as compared with before, indicating evolution toward drought avoidance. The amount of evolution varied across the populations, with the driest population exhibiting the greatest response. The watering experiment also revealed that plants from all populations, regardless of year, showed significant plasticity in response to watering, by flowering earlier in the low water treatment. Our results provide insight into the evolution and plasticity of flowering time as a result of drought, which is biologically relevant for understanding the effects of climate change on native flora.


1 - San Jose State University, Department of Biological Sciences, San Jose, CA, 95112, USA
2 -
3 - Department Of Biological Sciences, 1 Washington Square, San Jose, CA, 95192, United States

Keywords:
drought
Flowering time
evolution
Plasticity .

Presentation Type: Poster This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PPE004
Abstract ID:445
Candidate for Awards:Physiological Section Best poster presentation,Physiological Section Physiological Section Li-COR Prize


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