GROWTH OF HEALTHY AND VIROID-INFECTED TOMATO CELLS IN-VITRO

Cell cultures of a tomato hybrid infected with the citrus exocortis vi roid (CEVd) display no adverse effects when compared with viroid-free cultures. The growth patterns of the viroid-containing cultures are no t only similar to controls but more efficient as judged by longevity a nd biomass accumulation. Differences in growth characteristics can be accentuated by modification of the incubation temperature and the carb on sources present in the culture media. Supplementing the culture med ia with arabinose and xylose induced marked differences in growth and revealed the enhanced tolerance of viroid-containing cells to these su gars, Differences in carbohydrate metabolism and turnover are suggeste d to be responsible for the previously reported differences in the com position and properties of the cell wall.