Exploration and Discovery
Project Description, from National Geographic Society Grant to D.
Introduction and Progress to Date
Philippine tropical rainforests are among the World’s
Biodiversity Hotspots threatened by human activities. They are home to
the holoparasitic Rafflesia,
famous for possessing the largest single flower in the world
(13). Until 2002, only two species of Philippine Rafflesia were known, but following
many scientific investigations (1-8, 10-11), nine or ten endemic
species are now recognized: R.
baletei, R. leonardi, R. lobata, R. manillana, R. mira, R.
philippensis, R. schadenbergiana, and R. speciosa and two additional
unnamed potentially new species. A molecular study of Rafflesia (9) included 13 of the 23
species (13-15), but only two are from the Philippines.
Our research on Rafflesia
evolution focusses upon the Philippine species. Fieldwork in May 2008
was successful in obtaining data for 6 species. Our preliminary
analyses support Barkman et al. (9) in that 1) the Philippine species
are monophyletic (i.e. more closely related to each other than to those
outside of the Philippines) and 2) genetic variation among species is
low (Figure 1). Our data show that R.
philippensis (small-flowered) is sister to the remaining
Philippine species, not to R. baletei
with which it is morphologically most similar. The large flowered R. schadenbergiana occurs at an
intermediate position on the tree. This demonstrates that floral size
increases and decreases have occurred multiple times independently and
that species relationships are indicated best by geographic location,
not flower size.
Our major objectives are as follows:
1. Conduct two trips over the course of two field seasons to
obtain data from unsampled Rafflesia
species/populations: R. baletei, R.
mira, R. manillana, and two unnamed species (Rafflesia sp. 1 Luzon, Rafflesia sp. 2 Mindanao).
2. Document pollinator visitations, sex ratios, fruit production, and
3. Determine phylogenetic relationships among Philippine Rafflesia and
their host plants using DNA sequence data.
4. Obtain seeds and cuttings of host and parasite for ex situ
cultivation and experimentation.
Fieldwork will be conducted in seven predetermined Rafflesia sites, four in Luzon
Island: Mt. Banahaw for R.
philippensis, Mt. Isarog for R.
baletei, Mt. Natib for R.
manillana, and the Quirino Protected Landscape (QPL) for Rafflesia sp. 1, two in Mindanao
Island: Mt. Candalaga for R. mira and Mt. Matutum for Rafflesia sp. 2, and one in Samar
Island, type locality of R. manillana.
All sites in Luzon and Samar are inside Protected Areas whereas those
in Mindanao are not. At 206,875 hectares, QPL (Presidential
Proclamation 578 dated 2004) is home to rich tropical forests and two
indigenous ethnic groups, the Agtas and Bugkalots. Because QPL is
experiencing pressures from several factions (see Gorospe-Ibuan 2004),
access maybe difficult. We will begin the process of obtaining
collecting permit in QPL immediately. Rafflesia sp. 1, found in QPL, is
morphologically similar to R. tengku-adlinii from Borneo. However,
since molecular data indicate high levels of endemism, Barcelona, et
al. (2008, submitted) is describing this as new.
We will conduct non-destructive sampling by removing small portions of
the petals without negatively impacting floral function. While in the
field, we will determine the number of flowers, buds, and fruits, their
sizes, and GPS coordinates and record pollinator behavior (insect
samples collected) at all open flowers. We will also search for fruits
and collect seeds for ex situ cultivation experiments.
Ex Situ Cultivation Methodologies
Rafflesia cultivation is
reported by Veldkamp in 2007 (15). More recently, Nais (12) reported
success with R. keithii in
the Kinabalu Park, Sabah, Malaysia. Despite these claims, no published
methodologies are available. Moreover, the host plants used were
at locations where Rafflesia
already existed, hence the host may have already contained the
parasite. The lack of basic life history information currently limits
the application of ex situ methods. To date, no observations have been
made of Rafflesia seedlings
attaching to Tetrastigma
(Vitaceae) host tissues.
We propose beginning a research program to systematically study the
life history of Rafflesia,
particularly the seedling phase. Funding to the Philippine Native Plant
Conservation Society, Inc. (PNPCSI) from the German government has been
approved to construct a botanical garden at the DENR campus in Quezon
City that includes cultivation of Tetrastigma
hosts for possible Rafflesia infection. In collaboration with DENR and
PNPCSI, we will conduct detailed studies of the early infection and
establishment process. Molecular methods will be used to 1) genotype
the host plants used for inoculation experiments and 2) determine
whether the host tissue contains Rafflesia.
The latter is feasible because DNA profiles for host and parasite are
very different and the PCR technique is extremely specific and
sensitive, thus allowing tiny samples to be assayed. Most Filipinos
have never seen Rafflesia,
thus having this plant in an urban botanical garden would increase
public awareness of their country’s natural heritage and
strengthen efforts to conserve threatened natural ecosystems. If
perfected, such cultivation techniques would allow botanical gardens
around the world to grow this amazing host-parasite combination.
Standard procedures that have already been used for extracting DNA,
PCR, and sequencing will be continued. Given the low amount of genetic
diversity between species, additional molecular markers will be sought
to increase resolution of phylogenetic relationships. The molecular
tools are essential to all phases of this project because they allow us
to 1) assess interspecific relationships, 2) determine whether
potential new species are genetically distinct, 3) provide data useful
in studies of the biogeography and floral size evolution of Rafflesia,
and 4) provide genetic markers that can be applied to ex situ
cultivation experiments. For the latter, both host and parasite
can be “fingerprinted”, thus guiding inoculation
experiments. The taxonomy of Tetrastigma
is problematic because plants often present only vegetative features
(not flowers), thus these molecular studies will help with species
identifications. A better understanding of species relationships in Rafflesia also has implication for
local politics, ecotourism, management and conservation. Additional
projects that will develop as this research program matures involve
monitoring Tetrastigma host
vine populations for Rafflesia.
Given the specificity and sensitivity of PCR, populations will be
surveyed to determine incidence of infection by Rafflesia, even in the absence of
external flowers or buds. This type of study would provide the
first data useful in determining sizes of the parasite populations.
Time Frame Justification
Our request for two years of support is made with the understanding
that such awards are rare. We believe that our project is exceptional
for the following reasons. Only certain times are available to conduct
fieldwork owing to weather conditions and the PI’s academic
schedule (December through April). The time frame for one collection
trip is generally four weeks, however, not all of the proposed sites
can be visited in that time period. In some cases (e.g. Rafflesia manillana, R. philippensis, R.
baletei) the populations are readily accessible and the
likelihood of finding flowers is high. In other cases (R. mira, Rafflesia sp. 1, Rafflesia sp. 2) the populations
are remote and finding flowers may require more time. Moreover,
if flowers of these rarely seen species are found, several days of
fieldwork will be expended to properly document their
populations. Since security is an issue in Mindanao and Samar
Islands, we need more time to carefully assess the situation by seeking
assistance of local officials, DENR, and NGO to access the sites
without jeopardizing our safety.
We have strictly followed Philippine regulations in conducting
research. By virtue of a Memorandum of Agreement (Feb. 14, 2008)
between the Philippine DENR and SIUC entitled “Systematics of
Parasitic Plants of the Philippines,” a Wildlife Gratuitous
Permit (no. 175) was issued May 5, 2008 to collect specimens for
scientific research purposes. Local Transport Permits and Municipal
Clearances were obtained for all sites from the local DENR Office. We
also obtained Phytosanitation Certificates from the Bureau of Plant
Industry, Philippine Dept. Agriculture that allowed export of samples.
These guidelines will be followed for all future fieldwork.
This project provides a unique opportunity to develop a truly
international cooperative effort to better understand and conserve Rafflesia. The planned Tetrastigma plots at the Quezon
City botanical garden will provide a controlled environment to conduct
detailed studies of Rafflesia
parasitism. Dr. Antonio Manila (DENR, PNPCSI) has requested our
technical assistance in this endeavor. Following a seminar at the
University of the Philippines (May 12, 2008), several students
expressed interest in Rafflesia.
Perla Visorro, President/CEO, Cagayan Valley Partners in People
Development (CAVAPPED) is actively seeking Protective status for the
habitats of Rafflesia manillana and R. leonardi in Cagayan Province. It
was here that Sumper Aresta (Agta-People’s Organization member)
discovered R. leonardi on
April 13, 2005. In May 2008, we participated in a conservation
management workshop for R.
schadenbergiana in Baungon, Bukidnon Province, Mindanao. This
meeting demonstrated the commitment of local people to preserve Rafflesia and their understanding
of the complexities of conservation biology when weighed against other
issues, e.g. subsistence agriculture and ecotourism.
1. Barcelona, J. F., and E. S. Fernando. 2002. A new species of Rafflesia (Rafflesiaceae) from
Panay Island, Philippines. Kew Bulletin 57: 647-651.
2. Barcelona, J. F., M. A. O. Cajano, and A. S. Hadsall. 2006. Rafflesia baletei, another new
Rafflesia (Rafflesiaceae) from the Philippines. Kew Bulletin 61:
3. Barcelona, J. F., P. B. Pelser, and M. A. O. Cajano. 2007. Rafflesia banahaw (Rafflesiaceae),
a new species from Luzon, Philippines. Bumea 52: 345-350.
4. Barcelona, J. F., P. B. Pelser, E. Cabutaje, and N. A. Bartolome.
2008. Another new species of Rafflesia
(Rafflesiaceae) from Luzon, Philippines: R. leonardi. Blumea 53:
5. Barcelona, J. F., P. B. Pelser, D. S. Balete, and L. L. Co. In
press-a. Taxonomy, ecology, and conservation status of Philippine Rafflesia (Rafflesiaceae). Blumea.
6. Barcelona, J. F., P. B. Pelser, A. M. Tagtag, R. G. Dahonog, and A.
P. Lilangan. In press-b. The rediscovery of Rafflesia schadenbergiana
Göpp. ex Hieron. (Rafflesiaceae). Flora Malesiana Bulletin.
7. Barcelona, J. F. 2007-onwards.
8. Barcelona, J. F., L. L. Co, D. S. Balete, and N. A. Bartolome.
submitted. Rafflesia aurantia
(Rafflesiaceae): a new species from northern Luzon, Philippines.
Gardens’ Bulletin Singapore.
9. Barkman, T. J., M. Bendiksby, S.-H. Lim, K. Mat Salleh, J. Nais, D.
Madulid, and T. Schumacher. 2008. Accelerated rates of floral evolution
at the upper size limit for flowers. Current Biology 18:
10. Fernando, E. S., and P. S. Ong. 2005. The genus Rafflesia R. Br. (Rafflesiaceae) in
the Philippines. Asia Life Sciences 14: 263-270. [R. mira]
11. Galang, R., and D. A. Madulid. 2006. A second new species of Rafflesia (Rafflesiaceae) from
Panay Island, Philippines Rafflesia. Folia Malaysiana 7: 1-8. [R.
12. Madulid, D. A., I. E. Buot, and E. M. G. Agoo. 2007. Rafflesia panchoana
(Rafflesiaceae), a new species from Luzon Island, Philippines. Acta
Manilana 55: 43-47.
13. Nais, J. 2001. Rafflesia of the World. Sabah Parks, Kota Kinabalu.
14. Nickrent, D. L. 1997 onwards. The Parasitic Plant Connection.
College of Science, SIUC. http://www.parasiticplants.siu.edu/ [see
15. Philippine Native Plant Society, Inc. Manila. 2008 onwards.
16. Veldkamp, J. F. 2007. Some notes on the cultivation of Rafflesia. Flora Malesiana Bulletin
14 (1 & 2): 50-3.
SIUC / College of Science / Philippine Rafflesia / Project