Critically Endangered Cooper's Black Orchid Undergoes DNA Testing in Search for Species-Saving Fungi

Cooper's black orchid DNA analysis may reveal the fungus necessary to save the species of this flowering plant.

Cooper's Black Orchid

In the wild, Cooper's black orchid might be mistaken for a stick or possibly a strange potato. This fragile flower, unlike plenty of others of its sort, lacks showy petals and rich green leaves. Most of the year, its stem is submerged in the broadleaf woods of New Zealand; it only emerges in the summer to bear pendulous brown and white blossoms. The orchid also produces a light brown tuber rather than a tangle of roots.

However, the likelihood of seeing a Cooper's black orchid (Gastrodia cooperae) is decreasing, according to the New Zealand Plant Conservation Network.

Critically Endangered

Since Carlos Lehnebach, a botanist, first recognized the species in 2016, less than 250 adult plants were discovered, and they only exist in three locations around New Zealand. The fact that wild pigs, rabbits, and other animals enjoy eating the tubers just makes the situation worse. The orchid-growing woodlands are also being destroyed to make way for agricultural land. The orchid was designated as nationally critical by New Zealand's Department of Conservation in 2018, underscoring its severe risk of extinction.

DNA Testing for Conservation

Scientists at the Lions Ōtari Plant Conservation Laboratory are putting a lot of effort into saving the Cooper's black orchid, a threatened species. Under a microscope, they examine the roots of these orchids to look for helpful fungi that promote seed development. The team determines possible fungal species to support the growth of the orchids through DNA testing and meticulous selection, combining them with the seeds to guarantee their successful regeneration.

Trial-And-Error Finds the Fungi Perfect Match

The conservation team led by Karin van der Walt has difficulty finding a significant number of seeds for the Cooper's black orchid because they are working with a rare species. They initially tested their germination technique on the more widespread orchid Gastrodia sesamoides, which also has tubers. They finally discovered the ideal germination technique for the Cooper's black orchid after a year of trial and error, which required another two to four-month period for the seeds to sprout.

Resinicium bicolor, a white-rot fungus typically seen on Douglas fir trees, has now been identified as a potential symbiotic partner and looks to give the nutrients required for the germination of orchid seeds. The team's next goal is to germinate the Cooper's black orchid seeds to investigate if the same fungus promotes the development of adult plants.

The Backup Plan

Seeds and fungus are kept in cold sleep in one of the sterile rooms of the lab in the interim. While fungi are kept in a cryogenic container with liquid nitrogen at -200° C, seeds are kept in an incubator at -18° C. If the orchid is completely lost, according to Van der Walt, there are seeds stored in the lab that at least part of them can be developed from again.

The team intends to defrost banked seeds and fungus to check their viability and assess how much growth they will produce.

The goal is to eventually seed wild regions with this plant-fungi combination to increase the population without the need for laborious lab procedures. The lab technique is a potent way to prevent extinction, as van der Walt explains, not just for Cooper's black orchid but also for other endangered species, though there are still other variables to work out to make wild growth a reality, ScienceNews reports.