Rafflesia
produces the largest single flowers in the world, at the expense of its host vine,
Tetrastigma,
yet it begins as an inconspicuous endophyte. It is unknown how the
Rafflesia
seed gets into ...the host and germinates. Multiple locals claim to have successfully grown the holoparasitic flower from seeds resulting in blooms. Using available morpho-histological studies, combined with descriptions from local
Rafflesia
seed growers, as well as unpublished details of our own work, we filled in the missing details of
Rafflesia’s
life cycle from seed germination to endophyte inside the host before it transitions to its flowering stage. Post-germination, the
Rafflesia
endophyte forms a clonal network of vegetative meristematic cells, separated by the dividing host tissue, each meristematic cell cluster eventually developing into the primordial floral bud or protocorm. We propose future work involving mass spectrometry imaging to characterize the metabolites that allow communication between distant endophytic clusters and floral bud induction without destroying the histology of the sample.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Main conclusion
A histological study of Rafflesia patma revealed the simplicity of a flower’s vascular tissue and epidermal features of flower organs, including their structures and pigmentation.
...Rafflesia
is an endophytic holoparasitic plant that infects
Tetrastigma
. In a previous study, we characterized the shape of the strands of an endophyte (
Rafflesia patma
Blume) and hypothesized their distribution. In this study, we deepened our analysis by assessing parts of flower tissue sampled during anthesis, performed surface casting of the abaxial and adaxial sides of the perigone lobe to profile their surface features, and histologically characterized the perigone lobe, perigone tube, and central column base, including the anther and cupula region. The objective of these observations was to compare tissues from different organs and the distribution of cells staining positive for tannin, suberin, and lignin. Observable features in this study were vascular and epidermal tissue. We also observed reduced vascular tissue with xylem and vascular parenchyma in multiple organs. The adaxial epidermis found in the perigone lobes and tube had papillate cells, and their function might be to assist with the emission of odor through chemical evaporation. The abaxial epidermis, also found in perigone lobes and tube, had flattened cells. These, combined with the nearby flattened parenchyma cells, especially in the outermost, early perigone lobe, might provide a tougher (stiffer) outer protective barrier for the flower. The accumulation of tannin in perigone lobes might offer protection to the flower from herbivores prior to anthesis. Although a previous observation indicated the possibility of stomata on the surface of
Rafflesia
flowers, no stomata were found in this study.
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.
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Rhizanthes
is a holoparasitic plant of the Rafflesiaceae, and, just like
Rafflesia
, its host is
Tetrastigma
(Vitaceae). Unlike
Rafflesia
, very little research has been conducted on
Rhizanthes
other ...than a few studies focusing on its taxonomy and anatomy, and limited studies on its propagation, despite some ethnomedicinal uses in several regions of Indonesia. Wild populations of
Rhizanthes
are declining due to deforestation and overharvesting by locals. Artificial pollination and possible seed spread, which are similar to
Rafflesia
, may be useful for future propagation-based studies, which are generally very difficult and challenging for members of the Rafflesiaceae. This paper emphasizes the cultural and ethnomedicinal importance of
Rhizanthes
and seeks to define a conservation road-map that incorporates a scientifically-based approach to research while also seeking a four-pronged approach to the conservation of
Rhizanthes
: 1) conventional and biotechnology-based conservation; 2) germplasm multiplication and preservation; 3) reintroduction into the wild and conservation of wild populations; 4) policy-based protective measures.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This report presents some methods of cultivation and the inducing of flowering of Rafflesia patma in Bogor Botanical Garden (Indonesia). Many natural habitats of Rafflesia have disappeared through ...time. Therefore, gardening may contribute to the survival of these species. The grafting method has proven to be successful for the ex situ cultivation of R. patma. However, many biological and ecological aspects of this endangered plant are still unknown, while its habitat is disappearing rapidly. This needs a better understanding of the Rafflesia biology to establish appropriate conservation efforts.
Parasitic plants contain some of the most bizarre and fascinating organisms in the plant kingdom. Yet they are notable for their absence from botanic gardens’ plant collections and conservation ...strategies. Besides a handful of species, few are widespread in cultivation; indeed we estimate at least 76 per cent of species are entirely missing from collections today, and most of these have never been grown at all. Here, we place focus on the holoparasites, a group of plants long neglected due to their difficulty in cultivation. We review propagation breakthroughs in temperate and tropical botanic gardens to identify guiding principles for the cultivation of these neglected plants. We document the life cycle of a range of parasitic plants, and assess successful and failed attempts to propagate Rafflesia specifically, which has been the focus of decades of research. By uniting isolated case studies from around the world, we identify future directions for the cultivation and possible ex situ conservation of these botanical enigmas at a time when this is needed urgently. Finally, we recommend a dedicated global community of purpose as an intentional step forward: this could take the form of a Global Consortium for Conservation for parasitic plants, or a Parasitic Plant Specialist Group under the International Union for Conservation of Nature.
Rafflesia are obligate endo-holoparasitic plants with the genus Tetrastigma playing an important role as their host plants. Rafflesia arnoldii is one of Indonesian endemic plants that grows in ...Sumatra island. This island is also known to have eleven species of Tetrastigma. Three of them are known as host plants of R. arnoldii, namely Tetrastigma curtisii, T. pedunculare and T. leucostaphylum. Unfortunately, it is not possible to survey the entire native distribution range of R. arnoldii and its host plants due to practical constraints. Species Distribution Modeling using Maximum Entropy (MaxEnt) is considered to be an alternative way to understand the potential regions that are suitable for a species. Predicting habitat suitability of a parasitic plant through predicting its host plant distribution may be a useful approach. The model prediction from MaxEnt for all host species has an AUC value more than 0.70, indicating the model adequately classified the occurrence records of R. arnoldii and its host plants. Suitable habitats for R. arnoldii were predicted to occur along the Bukit Barisan Mountain range from Lampung to Aceh, mostly in Lampung, Bengkulu, West Sumatra and Aceh. However, the suitable habitats of R. arnoldii estimated from host plants were predicted to occur predominately in Lampung, Bengkulu, West Sumatra, North Sumatra and Aceh. The important environmental variables affecting the occurrence of R. arnoldii and its host plants are mean temperature, slope, elevation, soil organic carbon and soil type. Rafflesia species can be found in various soil types, but mostly in Humic Andosols, Humic Acrisols, Orthic Acrosols, Dystric Fluvisols, Dystric Cambisols and Eutric Fluvisols based on the actual data points and predicted habitats. The suitable habitats of R. arnoldii based on its host plants were predicted to be mostly outside conservation areas, but suitable habitats were predicted inside approximately 46 conservation areas. The findings of this study may be used by the Government of Republic Indonesia, c.q. Ministry of Environment and Foresty for establishing protected areas and conservation-based management improvement and could also help inform the R. arnoldii listing status in IUCN red list category in the future.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study provides a hypothetical discussion about the growth of Rafflesia patma Blume (syn. R. horsfieldii R. Br. (1821); Rafflesiaceae), an endophytic parasite, within a grafted host, a woody vine ...(Tetrastigma leucostaphylum (Dennst.) Alston). Based on the observation of a 10-year old (2007 to 2017) R. patma - T. leucostaphylum graft, we hypothesize that R. patma moves away from its host rather than remaining in an anchored position from which it flowers, although flower knobs that emerge later may vary in range from the grafting point, i.e., flower knobs may develop close to or far away from the grafting point. Our provisional macroscopic observations point towards a gradual creeping motion of the endophyte towards new host tissues, flowering opportunistically when sufficient nutrients have been found. Much has yet to be discovered about the growth and flowering behavior of R. patma and about the dynamics of the R. patma - T. leucostaphylum interaction.
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