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Commonly known as the “corpse flower,” Amorphophallus titanum faces multiple threats to its survival, including habitat loss, climate change, and competition from invasive species.
Recently, researchers from Northwestern University and the Chicago Botanic Garden have identified an additional significant challenge: incomplete historical records regarding the plant’s lineage and breeding.
In their latest study, the team mapped the lineage of corpse flowers housed in botanical collections around the globe. They discovered a pronounced lack of reliable and standardized data about these plants, which hampers efforts by conservationists to make informed breeding decisions. Notably, their findings revealed that 24% of the studied corpse flowers were clones, while 27% descended from two closely related parent plants.
This research paper is set to be published on April 3 in the Annals of Botany.
“Genetic diversity is crucial for the health of a population,” stated Olivia Murrell, the lead researcher. “When genetic diversity declines, it adversely affects fitness. Inbred plants may produce less pollen or even perish shortly after flowering. One institution noted that due to potential inbreeding issues, all their corpse flower offspring emerged as albino, lack the chlorophyll necessary for photosynthesis, which ultimately leads to their demise. A population that lacks genetic variation is particularly vulnerable; if a disease or pest impacts genetically similar plants, the entire population risks significant harm. The dearth of data is not a deliberate choice by conservators; they simply lack the necessary information.”
At the time of this research, Murrell was working towards her master’s degree in plant biology through the Program in Plant Biology and Conservation, a collaboration between Northwestern’s Weinberg College of Arts and Sciences and the Chicago Botanic Garden. She is currently pursuing her Ph.D. at Manchester Metropolitan University in the U.K. and serves as a conservation scholar at Chester Zoo. The senior authors of the study include Jeremie Fant, Nyree Zerega, and Kayri Havens, all of whom are conservation scientists affiliated with the Negaunee Institute for Plant Conservation Science and Action at the Chicago Botanic Garden.
A finicky flower
The corpse flower, named for its distinctive odor, emits a scent reminiscent of decaying flesh when it blooms. This powerful smell is an evolutionary strategy to attract flies and carrion beetles, which are vital for its pollination. Due to the flower’s infrequent and fleeting bloom—lasting only 24 to 48 hours—botanical gardens often sponsor events around its blooming to allow the public to experience its infamous aroma.
“Typically, one must get close to a flower to detect its scent, but with the corpse flower, the smell hits you as soon as you enter its greenhouse. It’s intensely potent,” Murrell explained. “Additionally, the plant generates heat during blooming, helping its scent permeate further.”
Botanical gardens invest considerable effort in the care of these remarkable plants. The corpse flower is classified among “exceptional plants,” a category reserved for species whose seeds cannot be effectively preserved in seed banks. In the instance of the corpse flower, its seeds lose viability post-drying, which is a critical step for enduring seed storage. Consequently, these plants must be conserved in “living collections” situated within research facilities, botanical gardens, and arboreta.
The fact that male and female corpse flowers bloom at different times adds complexity to their conservation. This unique attribute necessitates human intervention to sustain their genetic lineages. However, their caretakers face numerous hurdles in this process.
“Female flowers bloom first, followed by male flowers,” stated Murrell. “By the time pollen is produced, the female flowers are often no longer viable. The plant blooms unpredictably and infrequently, sometimes taking seven to ten years between blooms. When the blooms do finally arrive, the window for pollination is just a few hours. During this tight timeframe, conservationists must act quickly to use the available pollen, which may come from the same individual, inadvertently leading to inbreeding.”
Wilted records
To further comprehend the challenges faced in managing these plants, Murrell investigated the global living collections of corpse flowers. She garnered data from approximately 1,200 individual plants across 111 institutions located in North America, Asia, Australia, and Europe. This data comprised handwritten notes, narratives, lists, and spreadsheets.
For effective conservation, ideally, a plant’s records should encompass comprehensive details about its lineage, including parentage, characteristics, health status, and propagation techniques. This information is vital for maintaining genetic variety and the overall health of the plants, as it informs decisions on optimal breeding practices. The lack of such data can severely impede conservation efforts.
Upon compiling and analyzing the received information, Murrell identified significant gaps. Many institutions failed to document the origins and sources of their plants, and even when seed origins were noted, details about which pollen was used for breeding were often omitted.
“The most significant loss of data occurred during plant relocations,” Murrell remarked. “While the plants were transferred, the accompanying records were frequently not updated or moved alongside them, resulting in a loss of crucial information over time.”
Clones and crosses
To assess the extent of inbreeding, Murrell’s research team scrutinized the records for clones and instances of breeding between genetically similar plants. Out of the 1,188 individual plants in the dataset, 287 (24%) were identified as clones, with 27% being progeny from closely related parent plants. Furthermore, less than one-third of cross-pollinations involved unrelated individuals.
To reinforce their findings, Murrell conducted a molecular genetics analysis on a subset of 65 plants. The DNA sequencing confirmed the presence of low genetic diversity and high levels of inbreeding among the examined collections.
Native exclusively to Sumatra, the corpse flower population continues to decline, with recent estimates suggesting that only about 162 individual plants remain in their natural habitat, highlighting the urgent need to ensure their sustainability in living collections for potential reintroduction into the wild.
“A healthy population requires genetic variation for long-term survival,” stated Murrell. “If current trends continue, they may face inbreeding to the point of extinction. This emphasizes the importance of maintaining consistent, standardized, and centralized records. The implications of lacking data for conservation are significant. Our study provides critical insights into the genetic relationships among existing collections, which can guide successful breeding strategies.”
To enhance the management of corpse flowers and other plant species, Murrell and her coauthors proposed five actionable recommendations: (1) document the parentage and origins of plants collected from the wild, (2) standardize data practices across collections, (3) ensure the tracking of parent plants as they move between institutions, (4) transfer data along with plants during relocations, and (5) develop a shared vocabulary for recordkeeping to ensure consistency in definitions.
The study, titled “Using pedigree tracking of the ex situ metacollection of Amorphophallus titanium to identify challenges to maintaining genetic diversity in the botanical community,” received support from the Institute of Museum and Library Services, the Northwestern University Plant Biology and Conservation Award, a Botanical Society of America Graduate Student Research Award, and The Walder Foundation.
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