Archivio Journal of Plant Pathology

Abstract:

Chrysanthemum stunt viroid (CSVd) has been detected or isolated from chrysanthemums or other host species in 26 countries. While strains (biological variants) have been described for many viroids, strains have not been described as such specifically for CSVd, despite the determination of 117 sequence variants of CSVd in 16 countries. Tomato has been described as an experimental host, either symptomless, or showing mild, or even severe symptoms, depending on the report; however, most of these studies were done with single isolates of CSVd and one cultivar of tomato plants. Thus, here we re-examined these issues by directly comparing the biological activity of three isolates of CSVd, one each from the USA, China and Australia, varying in their nucleotide sequence. We found that these isolates showed no differences in symptoms induced on either chrysanthemum or tomato plants, suggesting that much of the biological variation reported previously may have been due to cultivar differences and/or environmental effects.