This proposal examines why some common fruits, such as deadly nightshade, are poisonous to consumers. These fruits may be selectively toxic to those consumers that would normally damage the fruits or seeds. By isolating toxins (glycoalkaloids) form fruits in the Solanaceae and offering them in small quantities to different animals, this research will test this hypothesis and several alternatives. The work will help explain patterns and maintenance of biodiversity through an integrative approach to plant-animal interactions. The applied significance of the research is two-fold: (1) Since many species of Solanaceae are important food crops (e.g., potatoes, tomatoes), an understanding of what makes other Solanaceae poisonous will aid in reducing their toxicity and may lead to the development of new food crops; (2) several Solanaceae are troublesome agricultural weeds whose toxic fruits often contaminate crops, and this research is a first step in finding ways of countering this toxicity. By discovering more about the ecology of these weeds, we can better control their spread.
