If a plant is socio-economically important and produces recalcitrant seeds, like coconuts, conservationists often create what are called “field gene banks,” according to Nigel Maxted, professor of plant genetic conservation at the University of Birmingham, which does the TREES program. These field genebanks have many of the same plants growing in the same area. They take up a lot of space and the proximity of plants to each other also exposes them to other threats. “The disease could very easily cross the whole lot,” says Maxted.
As such, the preservation of plant species by spreading individual plants in many botanical gardens, or other collections, can be a useful bulwark against extinction, as it greatly decreases the likelihood that each plant will die at a time. , says Susan Pell, deputy executive director of the United States Botanical Garden, a TREES participant.
But fostering genetic diversity in botanic gardens can be difficult, especially with rare and finicky plants. Like many plants, corpse flowers can reproduce in different ways. Sometimes they reproduce asexually: A tubercle-shaped bulge at the base of their stem, called a corm, grows and eventually divides, producing several genetically identical plants. While this did increase the raw number of corpse flowers in botanical gardens, it did little for the genetic diversity of the population.
Flowers from corpses can also reproduce sexually, requiring pollination by insects or, in botanical gardens, by humans wielding brushes. There is no fixed time for a corpse flower to bloom; each plant takes a varying number of years and blooms unpredictably depending on conditions such as heat, light, humidity, and other factors.
To help reproduce on this unpredictable schedule, the Chicago Botanic Garden creates a store of cadaver flower pollen, which can be sent across the country when another specimen that isn’t closely related blooms. These targeted cross-pollination efforts could lead to more genetically robust offspring. While TREES has yet to lead to a cadaver flower cross, the Chicago Botanic Garden has used the methodology to strategically cross another plant called Brighamia insignis, also known as cabbage on stick, which is in danger.
The TREES program starts from a place of low genetic diversity for the corpse flower and its peers. In the past 100 years, there have only been 20 documented collections of wild plants destined for botanical gardens.
Sometimes botanical gardens will obtain rare plant genetics from nurseries and private collections. For example, three of the American botanical gardenThe flowers of the corpse were acquired as seeds from a plant grower in Hawaii. But, since collecting plants from the wild can be difficult and expensive, botanic gardens will usually propagate the specimens and share the offspring with other collections. In the case of plants with low genetic diversity, this means an increase in raw numbers, but again, it doesn’t do much for genetic health.
“In terms of genetic diversity, it’s hopeless,” says Maxted.
TREES can help, he adds. The program approach has been successfully deployed in the animal kingdom for a long time. For example, many zoos and conservation efforts are creating studbooks, or records used to track family trees of specific species. This tactic has been used to track the lineages of a myriad of endangered species around the world, including the Red panda.
“In general, all you are looking for is to maximize variation,” says Maxted.
While TREES could To increase the genetic diversity of flowers from domestic cadavers, some researchers are not sure that the flower – and plants more generally – should necessarily be reintroduced into the wild. This is especially true for botanical garden plants that are far from their natural range.