A PRELIMINARY STUDY OF IN VIVO INJECTION OF AUXIN AND CYTOKININ INTO Rafflesia patma Blume FLOWER BUDS

Abstract

The controlling mechanisms for the growth and differentiation of Rafflesia from a flower bud into the anthesis stage is currently unknown, particularly if any plant growth regulator (PGR) physiological pathways play some type of roles. In the wild, the number of flower buds available to study are extremely limited. In this study, we grouped six flower buds of Rafflesia patma Blume into three different treatments: two buds injected with auxin (indoleacetic acid, IAA), two buds injected with cytokinin (kinetin), and two buds injected with sterile distilled water as a control. Buds enlarged with both IAA and kinetin treatments compared to the control, but only buds injected with IAA showed a transition stage with the bract revealed (cupule-bract stage from previously cupule stage) within two weeks of five weeks of observation. These results raise further questions whether Rafflesia development is more likely due to auxin exposure when in flower bud as compared to cytokinin. Future studies should include increased sample size for treatments, enhanced PGR administration to allow exposure to the tissue and less tissue damage, injection of other PGRs such as gibberellin (GA) and jasmonic acid (JA), and histological tissue analysis to investigate PGR effects in depth.