Adventitious root induction is one of the basic steps in micropropagation of apple
rootstocks. Light quality play key role on new adventitious roots initiation. We
explored the efficacy of jelly food coloring (red, blue and purple) on rooting
percentage, the numbers of roots and root length in MM.111 rootstock as a model
plant, at the first time. We established that colored medium improves adventitious
root formation, and found that this results can recommend for other rootstocks in
rooting phase. In general, red culture medium had the highest percentage of root
induction and also the number of roots. On the other hand, the results showed that it
is necessary to combine both red and blue color (purple) for maximum increase in
the root length of shoot explants.