EFFECTS OF INSECT DAMAGE ON GLYCOALKALOID CONTENT IN POTATOES (SOLANUM-TUBEROSUM)

Potato plants (Solanum tuberosum), cultivar Superior, were subjected to insect damage by Colorado potato beetles (Leptinotarsa decemlineata) and potato leafhoppers (Empoasca fabae) to assess the influence of pest-related stresses on glycoalkaloid content in tubers. Detection and quantification of the glycoalkaloids, solanine and chaconine, were achieved using a C-18 reversed phase HPLC computer integrated system equipped with a UV photodiode array detector at 208 nm. Field and growth room studies indicated that the tuber glycoalkaloid concentrations of potatoes subjected to defoliation damage by Colorado potato beetles were consistently greater than those concentrations found in tubers from undamaged plants. Damage to plants by potato leafhoppers did not have any apparent effect on tuber glycoalkaloid content. These results indicate that a food crop not protected from common pests may produce elevated levels of natural toxins, possibly affecting the degree of food safety.