Slippery flowers as a mechanism of defence against nectar-thieving ants

Background and AimsThe great diversity of floral characters among animal-pollinated plants is commonly understood as the result of coevolutionary interactions between plants and pollinators. Floral antagonists, such as nectar thieves, also have the potential to exert selection on floral characters, but adaptation against floral antagonists has attracted comparatively little attention. We found that the corollas of hornet-pollinated Codonopsis lanceolata (Campanulaceae) and the tepals of bee-pollinated Fritillaria koidzumiana (Liliaceae) are slippery to nectar-thieving ants living in the plant’s habitat; because the flowers of both species have exposed nectaries, slippery perianths may function as a defence against nectar-thieving ants.MethodsWe conducted a behavioural experiment and observed perianth surface microstructure by scanning electron microscopy to investigate the mechanism of slipperiness. Field experiments were conducted to test whether slippery perianths prevent floral entry by ants, and whether ant presence inside flowers affects pollination.Key ResultsScanning electron microscopy observations indicated that the slippery surfaces were coated with epicuticular wax crystals. The perianths lost their slipperiness when wiped with hexane. Artificial bridging of the slippery surfaces using non-slippery materials allowed ants to enter flowers more frequently. Experimental introduction of live ants to the Codonopsis flowers evicted hornet pollinators and shortened the duration of pollinator visits. However, no differences were found in the fruit or seed sets of flowers with and without ants.ConclusionsSlippery perianths, most likely based on epicuticular wax crystals, prevent floral entry by ants that negatively affect pollinator behaviour. Experimental evidence of floral defence based on slippery surfaces is rare, but such a mode of defence may be widespread amongst flowering plants.

ВМІСТ ФОСФОЛІПІДІВ У ТКАНИНАХ КОРОПА ЛУCКАТОГО (CYPRINUS CARPIO L.) ЗА ДІЇ НАТРІЙ ЛАУРИЛСУЛЬФАТВМІСНОГО ТА БЕЗФОСФАТНОГО СИНТЕТИЧНИХ МИЮЧИХ ЗАСОБІВ

The biological laws of adaptation of fish to the action of surfactants are studied. Changes in the content of phospholipids in the gills, brain, liver and skeletal muscle of the scaly carp (Cyprinus carpio L.) under the influence of sodium lauryl sulfate and nonphosphate synthetic detergent have been studied. Ambiguous mediated changes in indicators were identified under the action of toxicants. Such changes can be caused by both the direct action of surfactants on the body of hydrobionts and the peculiar restructuring of the lipid bichar in the direction of counteracting the influence of toxicants. With the experimental introduction of sodium lauryl sulfate-containing synthetic detergent and non-phosphate synthetic detergent into aquarium water, changes in the activity of phospholipids occur in all test tissues of the carp. When applying lauryl sulfate, we observe almost uniform effect on all investigated fabrics. With the tendency to increase, we observe indicators in the brain and white muscles, but with a tendency to decrease in the liver and gills. As for the effect of lauryl sulfate on the tissue, we observe the greatest importance in the liver tissues and uniform effect on the white muscle, brain and gills of the carp.

МОДЕЛЬ ПІДГОТОВКИ МАЙБУТНЬОГО ВЧИТЕЛЯ ПОЧАТКОВОЇ ШКОЛИ ДО ПРОЕКТУВАННЯ ДИДАКТИЧНИХ ЕЛЕКТРОННИХ РЕСУРСІВ

Improving the information technology opens up new possibilities for productivity of the learning process. The emergence of pedagogical tools for creating e-learning resources, allows the teacher to plan not only the course of the lesson, but also educational and cognitive pupils’ activity taking into account their individual characteristics. In the article it is presented the structural-functional model of future elementary school teachers training to design e-learning resources, criteria and indicators of formation of future teachers readiness for such activities, as well as description and the results of the developed model experimental introduction into the educational process.