Performance of transgenic plants of potato (Solanum tuberosum cv. Laila) grown in vitro, in greenhouse and in a field trial

Effects of transformation, regeneration, and integration of marker genes, on the performance of transgenic potato (Solanum tuberosum) plants were analysed by examination of the regenerated clones at different cultivation stages. Twenty out of 55 clones resistant to kanamycin in vitro were further analysed under greenhouse conditions and, finally, the performance of 4 clones was examined in the field. An enzyme-linked immunosorbent assay (ELISA) was developed to quantify the expression of the marker gene encoded beta-galactosidase. In the field trial, a significant correlation was found between the expression of beta-galactosidase and percent of dry matter of the tubers (r = -0.908, P = 0.033). Furthermore, the variation in infection of haulm by Phytophthora infestans was significant among clones (P = 0.001) and accounted for the variation in tuber weight seen among clones (R-2 = 0.95). A good correlation of the relative tuber yields of r = 0.997 (P = 0.00025) between the greenhouse and the held suggests that greenhouse experiments can be designed which enable the prediction of field performance of transgenic clones.