Articles
STOCK PLANT CONDITIONS AND ROOT INITIATION ON CUTTINGS
That this relation at least partly seemed to be due to carbohydrate production was demonstrated by feeding sucrose to carbohydrate-deprived stock plants grown under different irradiances.
We suggest that there is an optimum concentration of soluble carbohydrates for root initiation in cuttings and that the effect of growth hormones in root formation is influenced by the carbohydrate level of the cuttings.
We have also investigated the role of the shoot tip and the lateral buds in the rooting process.
We removed all the meristems at different times after excision of the cuttings and found that one can divide the period of root formation into two phases: 1) The root initiation phase which requires the presence of shoot meristems for root formation, and 2) the root growth and developmental phase which is independent of the presence of shoot meristems.
When we applied growth substances to the cuttings at the same time as decapitation and disbudding of them took place we found that auxin, applied in the first part of the initiation phase, was able to substitute for the meristems in the rooting process.
With cytokinin the results were just the opposite.
Cytokinin depressed root formation at the stage where auxin promoted.
When the promotive effect of auxin disappeared, the inhibitory effect of cytokinin did the same.