Viability of having the gigantic Rafflesia flowers in our park

doi:10.15406/oajs.2018.02.00053

Open Access Journal of

eISSN: 2575-9086

Science

Short Communication Volume 2 Issue 2

Viability of having the gigantic Rafflesia flowers in our park

Latiff A

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Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Malaysia

Correspondence: Latiff A, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia

Received: February 13, 2018 | Published: March 8, 2018

Citation: Latiff A. Viability of having the gigantic Rafflesia flowers in our park. Open Access J Sci. 2018;2(2):109-110. DOI: 10.15406/oajs.2018.02.00053

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Abstract

The genus Rafflesia which consists of ca. 24 species is confined to South-east Asia, mostly found in the Philippines, Borneo and Sumatera. It is a holoparasite on the stems of the vine genus Tetrastigma (Vitaceae). The iconic and gigantic flowers range from ca. 9 cm to more than a meter across and have been the envy of observers and tourists. The biology of the flowers has not been fully understood and poses conservation issues. Most enthusiasts and biologists dreamt of having the flowers either in the botanic garden, park or even in their vicinity. The viability of having the flowers in such localities is briefly discussed.

Introduction

Rafflesia is said to be vulnerable to extinction because of its biological peculiarities.¹ Being unisexual and dioeciously, the male and female flowers need to bloom synchroniously in the same area for effective pollination by carrion flies to succeed. Without new seeds formed to be deposited onto the mature hosts, no one can guarantee that they will be there in the ecosystem forever. It is true that the parasite continues to multiple inside the host’s tissue and later emerge in new colony but without out-crossing, inbreeding will ultimately genetically disastrous. With this innocent biological hick-up, and a specific host requirement, namely the Tetrastigma species (Vitaceae), made Rafflesia even more prone to extinction in the near future (Figure 1). Its parasitic mode of life and specialized biological requirement also decrease Rafflesia survival rate in the wild. In its range of distribution, Rafflesia species are rare and their habits are geared towards a stable habitat. From the earliest bud stage in their life, when the flower appears as small tubercle covered by cupule derived from the tissue of the host plant, it will take about 4 to 9 months before the flower blooms fully. In some species it will take no less than 6-8 months. In the process, two-thirds of them die before reaching maturity and only a small number will reach blooming stage.

Figure 1 Could a visitor to the park be photographed with a Rafflesia bloom by his side?

The flower will be aborted even when the bud is on the verge of blooming hence the rate of mortality is high. The consequences of its biological behaviour result in extremely low occurrence for Rafflesia bloom in the wild. It may take a very long time for populations to recover with this high mortality rate when once their ecosystem or habitat is disturbed. Any extra ecological pressure such as habitat disturbance due to forest clearance and uncontrolled tourism would easily push it over the brink. Although habitat lost and increasing threats from ecotourism is the main challenge to the survival of Rafflesia, the species have been documented to thrive once disturbance was minimized. Rafflesia face even greater risk as the forests are fragmented due to logging. They are more vulnerable because of direct exploitation of the flower buds as traditional medicine. In Peninsular Malaysia, the Rafflesia "cabbage-heads" stage is highly sought after by village medicine men for its purported medicinal attributes. The post-partum decoction prepared by boiling buds in water are taken by mothers recuperating from childbirth, in the belief that the liquid can help restore their health and strength. The Rafflesia flowers also suffer from over-collection by illegal souvenir hunters.

Approaches for conservation

To conserve Rafflesia, one has to deal with several important aspects such as maintaining viable population size, life cycle, reducing the pressure of human and wildlife activities, and managing their habitats. Such complicated attributes could lead the difficulty to predict the future of the Rafflesia. Therefore, we should consider all possible means to conserve the species. There are, at least, two major approaches to conserve the Rafflesia, in situ and ex situ approaches. The most promising approach is in situ conservation which should be based on the special ecological, environmental, biological characteristics and attributes of local habitat and social economics of surrounding villages where rafflesias occur. This approach can be differentiated into two major conservation managements, based on the where the Rafflesia are found. The first category is conservation scheme for Rafflesia within the protected forest areas, and the second is in any working scheme outside the protected forest areas, which can be in private lands. Many private land owners and parks wish to have these gigantic and iconic parasites growing in their vicinity, hence the question is herein posed, is it viable to have them in the garden or park. The ex situ approach that the propagation of Rafflesia outside their natural habitats is a possible mean to conserve the plants. Yet, there are two important aspects that should be taken into careful consideration, before applying this approach. First, the experiments in Bogor Botanical Garden were conducted through transplanting Rafflesia including their host plants into the garden.

Even if the host plant, Tetrastigma is common in the forests, this method should be conducted on rigid considerations, such as if the population size is much above the threshold of extinction, which is very rare for recent time, or if in some reasons, there is no other ways to protect the species population. For example, the forest where Rafflesia occurs, might be logged, or converted to plantations or other land-uses. It should be kept in mind that transplanting a single old stem of Rafflesia infested vine could mean transplanting the whole all flower buds from its wild into ex situ area. The unsuccessful transplantation means the disappearing of the whole local population. After all, it is hard to imagine that conservation can be done by destruction ways.² when reading the Teijsmanns’ papers indicated that R. patma was transplanted in Bogor Botanical Garden in March 1850, subsequently R. rochussenii in July 1850, and latter on R. arnoldii. By 1886, those three species were flowering in the garden. The last report on flowering of these domesticated species was in 1929 and none thereafter. Leiden Botanical Garden horticulturist conducted another success story, when he successfully inoculated seeds of R. rochussenii on Tetrastigma rafflesiae in 1924. Four year later, the Rafflesia flowered. Since then, there has been no report on the Rafflesia blooming in the garden. The second factor is the low reproductive success of Rafflesia.

The inoculation of single seed of Rafflesia into the vine is very difficult, even if it occurs, then we do not know for certain whether the seed turns to a mature bud, and further, a flower. The Bogor Botanical Garden as well as Leiden Botanical garden experiments seemed to successfully inoculate and, to produce the flowering Rafflesia, for some early period of time, but they did not last long. The last report on flowering Rafflesia in both places was 1929. This could indicate that the low reproductive success of plants in experimental setting could not maintain enough population size for long period of time. The earliest records was attempt to cultivate Rafflesia were made in Bogor Botanical gardens in 1850 and succeeded in 1857.³ Then in 2004 the infected stems of T. scariosum were transplanted and the buds of R. patma emerged in 2006 but failed to develop into a full bloom until 2010.⁴^,5Dr. Jamili Nais claimed the successful germination of R. keithii on the stems of T. diepenhorstii by placing the artificially pollinated fruits, the seeds in a shallow incision of the host stems⁶ also reported that to culture seeds in vitro through tissue culture also failed since 2001. In conclusion, we might have learnt from the above trials and experiments in both the Bogor Botanical Garden and Leiden Botanical Garden, including the success story as claimed and described but there was no certainty that it would last. Attempts to culture the seeds proved equally futile. The author believes field trials and laboratory experiments may be repeated and attempted but to have the blooming rafflesias in our garden in the near future is rather bleak.⁷