FIELD-RESISTANCE OF TRANSGENIC RUSSET BURBANK POTATO TO EFFECTS OF INFECTION BY POTATO VIRUS-X AND POTATO VIRUS-Y

Transgenic Russet Burbank potato plants expressing the coat protein genes of potato virus X (PVX) and potato virus Y (PVY) were transplanted into the field after propagation in tissue culture. Virus resistance, plant growth and tuber yield were determined. Our results show that expression of PVX and PVY CP genes confer a very high level of resistance to PVX and PVY infection in clone 303, one of the four different transgenic potato clones tested. After inoculation with PVX and PVY, tuber yield of control Russet Bur-bank plants decreased, while the yield of clone 303 was unaffected. Four different uninoculated transgenic clones had tuber yields as high as control Russet Burbank. These results confirm that resistance to PVX and PVY is effective in the field and can prevent yield losses due to dual infection by these viruses. © 1990 Nature Publishing Group.