An ancient, interdependent relationship that contributes to food systems and ecosystem stability across the globe could be changing.
Many flowering plants can self-pollinate (自花传粉), or transfer pollen between their own blossoms for seed generation and reproduction, but most of these plants have relied on pollinators such as butterflies and bees to reproduce. Now — during declines reported in many pollinator populations — a new study on the evolution of one flower species' mating system has revealed a remarkable change that could worsen the challenges faced by the plants' insect partners.
The flowers reproductive evolution may be linked to environmental changes such as habitat destruction and rapid ongoing decreases in pollinator biodiversity, according to Samson Acoca-Pidolle, who led the study published December 19 in the journal New Phytologist.
Comparing seeds of wild field pansies (三色堇) collected decades ago in France with the plants' modern descendants. Acoca-Pidolle and his colleagues discovered that today's flowers are smaller and produce less nectar (花蜜) as a result of increased self-pollination, which has direct impacts on pollinator behavior.The pansies of the past self-fertilized less and attracted far more pollinators than those of the present, according to the study.
"It seems that it's only traits (特性) that are involved in plant-pollinator interaction that are evolving, " said Acoca-Pidolle. The changes could restrict the plants' ability to adapt to future environmental changes and have implications for "all of floral biodiversity" — potentially decreasing flowering plants' genetic, species and ecosystem variation.
"This may increase the pollinator decline and cause a negative feedback cycle," study coauthor Pierre-Olivier Cheptou told CNN." If plants produce less nectar, there will be less food available to pollinators, which will in turn accelerate the rate at which the animals' numbers decrease", he explained.
"The major message is that we are currently seeing the evolutionary breakdown of plant pollinators in the wild," said Cheptou, an evolutionary ecologist at the French National Centre for Scientific Research and professor at the University of Montpellier.
