Plant viruses and viroids in an aqueous environment - survival, water mediated transmission and detection

Hydroponic systems and intensive irrigation in horticulture, are widely used, and hold the potential for rapid and efficient spread of water- transmissible plant pathogens throughout the whole crop. Although numerous plant viruses have been detected in aqueous environment, for many of them, the survival in water and the potential for direct transmission through irrigation water are still unknown. Therefore we decided to explore whether the water can be a source of infection with PepMV, PVY and PSTVd, that are relatively stable and contagious viruses/viroid, and a serious threat to tomato and/or potato production. In irrigation waters, the viruses are usually present in concentrations lower than the detection limit of classical methods, but that may be sufficient to infect plants ; therefore the development of highly sensitive diagnostic methods is necessary. Small sample volumes may lead to non-representative testing, therefore, a concentration step allowing the handling of larger water volumes may improve water monitoring diagnostic scheme. A fast and efficient way to concentrate highly diluted viruses consists on using CIM monolithic chromatographic supports. The application of such strategy to the above mentioned plant viruses/viroid and the results of survival in water at room temperature and transmition efficiency through nutrient solutions in hydroponic cultivation of tomatoes and potatoes will be presented.