Flower closure in the feld bindweed ( Convolvulus arvensis): a feld test of the pollination hypothesis

Abstract

Although the behavioral plasticity of fower traits has received considerable attention, its adaptive value is not thoroughlyunderstood. We experimentally examined fower opening/closure in feld bindweed (Convolvulus arvensis), a species with short fowerpersistence (1 day) in which adaptive responses to pollination were not previously expected. In line with the pollination hypothesis wesuggested that fower exposure in this species should respond to pollination. More specifcally, we predicted that fower closure in thepollinated fowers would be quicker than that in unpollinated fowers. As predicted, the unpollinated fowers were open for a longertime than the pollinated fowers. Tere was no diference, however, between the self- and cross-pollinated fowers in terms of fowerlongevity. Tere was an inverse relationship between fower longevity and fertility, which also suggests that pollination leads to reducedfower longevity. Collectively, our results suggest that feld bindweed fowers respond to pollination adaptively, because prolonged fowerlongevity may increase the likelihood of successful pollination and fower closure reduces energy spent on fower maintenance and/orintraspecifc competition with genetically familiar fowers. Te behavioral plasticity of fower closure does not seem to be restricted onlyto plants with high fower longevity.