Microchemical Studies of Rooting and Non-Rooting Rose Cuttings

Adventitious roots are produced in humid air on the new shoots from cuttings of Dorothy Perkins rose and not from like portions of American pillar rose. 2. Microchemical examination showed that Dorothy Perkins cuttings contained more reserve starch than American pillar cuttings. At the time of rooting, Dorothy Perkins had considerable reserve starch remaining, while during a similar period the reserve starch of American pillar was depleted. 3. The changes in the reserves were the same in both roses. As the starch in the canes was hydrolyzed, the content of reducing sugars increased, especially in the new branches. Asparagin was abundant in the branches after 8-11 days. 4. Only slight differences in the anatomy of the overwintered canes were noted. A swelling at the base of new branches of Dorothy Perkins was produced by an unusual development of secondary phloem. Adventitious roots were initiated in this region. These changes did not occur in American pillar branches. 5. Rooting from the bases of young shoots of Dorothy Perkins rose seemed to be related to the high content of reserve starch.