the hematoxylin-Al medium in the vicinity of the root
tips began to change immediately after starting the
treatment. This change in color of the medium around
the roots then gradually spread and the purple color of
hematoxylin-Al agar completely disappeared after 6 days
of treatment. During the treatment period, no microbial
activity was detected in any of the test tubes containing
treatment media (data not shown).
To examine the discoloring capacity of tea seedling
roots more clearly, the change of color around the main
root was observed after 5, 20 and 40 h of treatment
(Fig. 2). The purple color of hematoxyline-Al around the
main root was slightly discolored at 5 h and formed a
thin discoloring layer at 20 h that gradually became more
clear and broadened in area at 40 h of treatment.