Resumen:
Virus are an important problem in plants, since they can generate important economic lost in many crops. Production of virus-free plants is a requirement in seed production schemes. This chapter demonstrates the potential effect of salicylic acid on getting virus-free plants. Thermotherapy followed by meristem isolation and culture is the usual method for eradication of virus. Thermotherapy can be done in vitro or in pots. The thermotherapy treatment depends on the virus present in the plants and the sensitivity of the cultivar to heat. Often plants do not tolerate the high temperatures for periods long enough to inactivate the virus. Enhanced thermotholerance effect of salicylic acid is demonstrated for getting PVX-free plants in Solanum tuberosum and TSWV, TAVfree plants in Dendranthema grandiflora Tzvelev. Short and long terms effects of SA were tested in microplants infected. Survival after thermotherapy, recovery period and virus-free microplants were assessed. Both short and long term SA treatments showed a significant survival during thermotherapy. The number of virus-free microplants was also increased by SA treatments in contrast with control. SA was able to improve the survival and the virus-free microplantas. The induction of thermotolerance by salicylic acid is associated with active oxygen species.