Chemical and nutritional differences between two bird-dispersed fruits:Ilex opaca andIlex verticillata

Ilex opaca andIlex verticillata are woody species bearing lowquality, bird-dispersed fall fruits that persist for several months. Tests of secondary chemistry show that fruits of both species contain phenolics and saponins as major classes of secondary metabolites. Soluble carbohydrates are the major nutrients in both species. Ripe fruits from ten trees in both wild and cultivated populations of each species were collected during 1986, 1987, and 1988 and analyzed for phenolic and carbohydrate content using Folin-Denis and anthrone methods, respectively. Fruits from 1987 and 1988 were analyzed for saponin content using hemanalysis. Significant differences were found in the average content of the above chemical classes between the two species and among individuals within each species. The fruits ofIlex opaca are more persistent, higher in phenolics, and lower in saponins and carbohydrates thanJ. verticillata fruits. Generally, there are greater differences in fruit chemistry among plants within a year than within one individual between years. Mechanical defenses were tested by puncturing fruits in situ. No differences in decay were found between punctured and unpunctured fruits.