ISHS Acta Horticulturae 167: II Symposium on Growth Regulators in Floriculture
THE USE OF CYTOKININS FOR PROMOTION OF FLOWER PRODUCTION IN ROSES |
| Authors: | N. Zieslin, Y. Mor, E. Khayat, M. Levy |
| Abstract:
Following decapitation the remained uppermost bud of the rose shoot became preferential to the other buds. This preference is demonstrated by a higher rate of translocation of labelled carbon to the shoot developing from the uppermost bud. The uppermost shoots also have a higher content of various hormones including cytokinins, auxins and gibberellins. On the other hand the content of inhibitors including ABA is lower in the upper part of a rose shoot in comparison with the lower part. As a concenquence of this situation the upper-most buds have a complete sprouting ability with almost all sprouted shoots forming flowers. The sprouting of the second buds from the top is minimal and if it does the flowers are aborted. These aborted shoots are known in practice as "blind shoots". Therefore, the buds located on the second node from the top after decapitation are the potential sites for the improvement in flower production of rose flowers. One of the compounds promoting bud breaking in rose plants is benzyladenine. However, when applied as a spray of the whole plant, the promotion of bud breaking is accompanied with an increase in flower bud abortion and other disturbances in plant growth. One of the possible ways of cytokinin application in a direct application to the second bud by means of paste, spray or dropping. This treatment will result in a promotion of bud breaking and promotion in flower formation in shoots of the second position. The results of this treatment presented in Table 1 show that the lower concentration of CK had a promotive effect on the bud sprouting in the second bud but there was no effect on flower formation. With the higher concentration of CK both, bud breaking and flowering were stimulated. This two different effects of 2 concentrations examined may indicate a separation between two possible roles of cytokinins, the effect on bud breaking and the effect on the translocation of metabolites toward the second shoot. However, it is also possible that this phenomenon is only a quantitative expression of the effect of translocation. From the data presented it can be seen that application of cytokinin to individual buds may be a practical tool in promotion of the flower production in roses. | |
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