TISSUE DIFFERENTIATION OF THE EARLY AND THE LATE FLOWER BUDS OF RAFFLESIA PATMA BLUME

Abstract

The flower bud of Rafflesia patma Blume following the protocorm stage of the flower will undergo rapid cell growth followed by the differentiation stage which lead to the later stage of the flower bud morphogenesis into the floral organs. During this transitional period of the flower bud, we revisited our R. patma flower bud microscope slide samples and some images from the previous study in [MURSIDAWATI & SUNARYO, 2012] to examine how the R. patma tissue behave prior to the late differentiation stage. We discovered that there are several types of meristematic cells in the R. patma early flower bud tissue: The elongated cells in the basal/proximal region of the bud where it in proximity with host xylem, then a column of non-elongated cells where ovary will develop in the later stage (in female flower), and in the apical/distal region of the flower bud, we found a densely packed meristematic cells where in the later flower bud this area will be developed into the protective bracts, perigone lobes, and central disc as later seen in the late flower bud tissue. During the late stage of the flower bud growth, the flower bud also inhibits growth of 1-2 vascular bundles, altering few others host vascular bundles surrounding the flower bud, while on the other side the root vascular bundle growth is just normal. This growth mechanism can minimize the host vasculature damage if multiple buds are growing the same growth direction.