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

Potato plants (Solanum tuberosum), cultivar Superior, were subjected t o insect damage by Colorado potato beetles (Leptinotarsa decemlineata) and potato leafhoppers (Empoasca fabae) to assess the influence of pe st-related stresses on glycoalkaloid content in tubers. Detection and quantification of the glycoalkaloids, solanine and chaconine, were ach ieved using a C-18 reversed phase HPLC computer integrated system equi pped with a UV photodiode array detector at 208 nm. Field and growth r oom studies indicated that the tuber glycoalkaloid concentrations of p otatoes subjected to defoliation damage by Colorado potato beetles wer e 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 indi cate that a food crop not protected from common pests may produce elev ated levels of natural toxins, possibly affecting the degree of food s afety.