Silique burst of Cardamine scutata (Cruciferae) as a physical inducible defense against seed predatory caterpillars.

摘要

Matured seeds of bitter cress (Cardamine scutata) are scattered by the bursting of siliques. They also burst in response to chewing by seed predatory caterpillars, even when seeds are immature. In this case, the caterpillars are frequently expelledor killed when their bodies become enswathed by the released pericarps. Consequently, many seeds survive. The plant trait is explained as an immediate induction of a physical defence against seed predators. The seed predation process was modelled, usingdata from a laboratory experiment with 8 insects attacking C. scutata seeds. The germination rate of scattered immature seeds was significantly lower than that of mature ones, which is a direct demonstration of trade-off between anti-herbivore defence and reproduction of the plant.