METHOD: Glycoalkaloid Assay CONDITIONS: Field METHOD NARR: Glycoalk content was determined using the column and HPLC analytical method of Sinden et al 1986. Additionally, high-performance thin-layer chromatography was used on thLTS NARR: The only glycoalkaloids detected by both HPLC and TLC in chc were a-Solanine and a-Chaconine. F2 and F4 populations had similar sol, chac and TGA mean contents. Both populations had signifcantly lower mean contehigher contents than tbr. Chc produced 7 times more TGA than tbr, while the F2 mean TGA content was only 2.4 times higher than tbr and 3-fold lower than chc. The chac:sol ratios in F2 were closer to the tbr parent. AUTHOR EXPprogeny between the chc x tbr cross indicates a dominance effect of the tbr gene for lower glycoalkaloid synthesis in the hybrid population. Even after 2 backcrosses to tbr, there were still some effects of the chc genes on foliage GA