Rafflesia spp.: propagation and conservation

Abstract

The propagation of Rafflesia spp. is considered to be important for future development of ornamental and other applications. Thus far, the only successful propagation technique has been grafting. This mini-review succinctly emphasizes what is known about Rafflesia species. Members of the genus Rafflesia (Rafflesiaceae), which are holoparasitic plants known to grow on a host vine, Tetrastigma sp., are widely spread from the Malayan Peninsula to various islands throughout Indonesia. The plant's geographical distribution as well as many other aspects pertaining to the basic biology of this genus have still not been studied. The young flower buds and flowers of wild Rafflesia hasseltii Suringar, Rafflesia keithii Meijer and Rafflesia cantleyi Solms-Laubach are used in local (Malaysia and Indonesia) traditional ethnomedicine as wound-healing agents, but currently no formal published research exists to validate this property. To maintain a balance between its ethnomedicinal and ornamental use, and conservation, Rafflesia spp. must be artificially cultivated to prevent overexploitation. A successful method of vegetative propagation is by host grafting using Rafflesia-impregnated Tetrastigma onto the stem of a normal Tetrastigma plant. Due to difficulties with culture contamination in vitro, callus induction was only accomplished in 2010 for the first time when picloram and 2,4-D were added to a basal Murashige and Skoog medium, and the tissue culture of holoparasitic plants continues to be extremely difficult. Seeds harvested from fertile fruit may serve as a possible method to propagate Rafflesia spp. This paper provides a brief synthesis on what is known about research related to Rafflesia spp. The objective is to further stimulate researchers to examine, through rigorous scientific discovery, the mechanisms underlying the ethnomedicinal properties, the flowering mechanisms, and suitable in vitro regeneration protocols that would allow for the fortification of germplasm conservation.

Reading between the vines: Hosts as islands for extreme holoparasitic plants

“…On the other hand, if the large immobile fruits have been retained over time due to structural constraints associated with the production of their immense flowers, then the patterns we have documented could be nonadaptive in Rafflesia and Sapria . Unfortunately, distinguishing between these various hypotheses is difficult and at a minimum would require manipulative experimentation on a scale that is not currently feasible for Rafflesia or Sapria (Wicaksono et al, 2016).…”

Genetic Diversity and Structure in the Philippine Rafflesia lagascae Complex (Rafflesiaceae) inform its Taxonomic Delimitation and Conservation

“…Previously, however, Rafflesia was hypothesized to be dioecious (e.g. Olah 1960;Beaman et al 1988;Renner and Feil 1993;Bellot and Renner 2013;Wicaksono et al 2016; but see Nais 2001 for more cautious statements). This reproductive strategy was considered more likely because Rafflesia species are rare and populations are far apart.…”

Use and Community Attitute Toward Rafflesia Zollingeriana and Its Conservation in Meru Betiri National Park

“…Masyarakat perlu diingatkan dan disadarkan bahwa bunga Rafflesia adalah bunga terbesar di dunia. Bunga tersebut misterius karena wujudnya hanya berupa bunga, tidak memiliki daun, akar, organ fotosintesis, dan tumbuhnya parasit pada inang (Wicaksono, Mursidawati, Sukamto, & Teixeira, 2016). Rafflesia juga berstatus langka.…”

“…Masyarakat juga perlu diingatkan bahwa Rafflesia secara imiah memiliki banyak misteri yang masih belum terpecahkan hingga kini. Potensinya masih belum banyak dikaji sehingga harus dijaga keberlanjutannya (Wicaksono et al, 2016). R. zollingeriana harus dilestarikan supaya bisa dipelajari, dinikmati, dan dimanfaatkan lebih luas oleh generasi mendatang.…”

“…Keempat stakeholder ini juga harus berkolaborasi dalam upaya propagasi. Propagasi ini diperlukan untuk menjaga populasi R. zollingeriana tetap seimbang sehingga dapat dimanfaatkan untuk berbagai keperluan dan tidak over exploitated (Wicaksono et al, 2016). Hingga saat ini, metode propagasi yang dilaporkan berhasil dilakukan adalah sambung akar (Mursidawati, 2017;Wicaksono, Teixeira da Silva, & Mursidawati, 2017).…”