Abstract
Among stock calli successively transferred for 70 generations at 30 days intervals, the green colored compact calli containing high concentration of tobacco mosaic virus (TMV) vigorously differentiated shoots when they were transferred to a differentiation medium. However, TMV-eliminated translucent calli derived from TMV-containing green calli by successive transfers of the translucent part of the tissue showed no sign of differentiation.
TMV-eliminated translucent callus became greenish and compact when the selected greenish and compact peripheral tissue was successively transferred on the medium containing higher concentration (2mg/l) of kinetin. Transfers with longer intervals (50 days) and incubation under higher intensity of light (3, 000-12, 000lux) promoted the change. TMV-eliminated green and compact callus thus obtained acquired the ability of differentiation.
All the plantlets differentiated from the 6 year-old callus were aneuploid. However, virus-free plantlets obtained from newly established virus-eliminated callus were diploid (2n=48).
