The effects of antiviral chemicals on potato virus X-I

Summary

The antiviral properties of Malachite green and thiouracil with regard to potato virus X were studied using tissue culture technique. Stem nodal tissues of Russet Burbank potatoes were grown in culture using modified White's medium enriched with gibberellin and containing Malachite green at the rate of 2, 4, 6, 10 and 15 ppm or thiouracil at the rate of 5 and 10 ppm. Stem tissues grew well with no evidence of phytotoxicity due to the presence of antiviral chemicals. Antiviral properties of these chemicals were evaluated by inoculating the leaves ofG. globosa with the extract of the apical portion of the newly developed shoots. As the concentration of Malachite green was increased, the detectible amounts of virus activity was generally reduced, and the number of apparently virus-free tips was increased. Thiouracil treatment at 5 ppm reduced the detectible virus activity present in the new shoots, but there were no antiviral effects at a concentration of 10 ppm.

The effects of soaking stem nodal segments in thiouracil solution on virus X was studied using Red McClure potatoes. Stem segments were immersed in thiouracil solution at the rate of 50 and 100 ppm for periods of 1,2 and 3 hours and then maintained on modified White's solid medium. The detectible virus activity of the new young shoot tissues was reduced following the soaking treatment of stem segments in solution at the rate of 50 ppm. Concentration of 100 ppm exhibited antiviral properties only with 1 hour treatment.