Category — plant research
The Plant Division at CREW is now using time-lapse photography to capture the growth of plants in vitro. Using a digital SLR camera, we program the camera to take a photograph of the plants every 30 minutes.
In general, it takes about two months before the test tube plants need to be subcultured onto fresh media. Now we can condense weeks of growth images into a 1-minute video. Watch the awned meadowbeauty (Rhexia aristosa), a flowering perennial from the Eastern United States,grow!
We initially observed the plants responding to the daily 16-hour light/8-hour dark cycle in the growth chamber. The leaves of the plants appear to “pulse” upward as the light automatically turns on each morning. The “sleep movements” of plants are well documented in terrestrial settings, but until now we had not observed them in plants grown in vitro at CREW. Time-lapse photography has also been a useful tool in comparing different types of media. We photograph a single species on different media to detect changes in growth patterns depending on the medium.
To date we have completed time-lapse videos of three species. The goal is to create a video for every species in the growth chamber. Since a single sequence can take up to six weeks to complete, we have our work cut out for us to create videos for the 35 to 50 species in the growth chamber!
(Reprinted from the Fall 2015 CREW Review)
March 2, 2016 No Comments
Guest blogger: Suzanne Yorke, CREW Research Lab Assistant
Plant conservation work at the Cincinnati Zoo & Botanical Garden’s Center for Conservation and Research of Endangered Wildlife (CREW) was featured in The Public Garden, the journal of the American Public Gardens Association, earlier this year in an article entitled “The Race for Plant Survival” written by Janet Marinelli. The article discussed the important role that public gardens like the Cincinnati Zoo & Botanical Garden (CZBG) play in plant conservation, the technological advancements that are being made in this challenging work, and the goals for plant conservation in the future.
The article begins with the story of the 24-year (and counting!) conservation quest to bring the autumn buttercup, Ranunculus aestivalis, back from the brink of extinction, and how such large-scale conservation efforts have become increasingly collaborative.
Shortly after The Nature Conservancy purchased land in 1991 to protect the habitat of the autumn buttercup along Utah’s Sevier River, they realized that just setting aside protected land wouldn’t be enough. The population was dwindling too fast, and additional partners would be needed to save this federally listed species. Seeds were collected from the mere 20 remaining plants at the preserve and sent to CREW. Valerie Pence, CREW’s Director of Plant Research, germinated the seeds to grow a handful of genetically unique individuals. She then used her expertise in micro-propagation to develop tissue culture protocols for the autumn buttercup and the power of tissue culture to make hundreds of “copies” of these plants in vitro in test tubes.
The tiny plants were sent to Arizona to enter the care of the next partner in the process, the Arboretum at Flagstaff, which potted the plants in soil and prepared them for out-planting in their native habitat. The out-plantings and subsequent monitoring of the plants was achieved through additional partnerships with the U.S. Fish & Wildlife Service and Weber State University.
Three out-plantings since 2007 demonstrate how this reintroduction effort has required the long-term commitment and collaboration of several stakeholders to continue to boost the autumn buttercup population until it is self-sustaining. The autumn buttercup story is a great example of “integrated conservation”, whereby public gardens partner with government agencies, non-profit organizations, and universities to preserve endangered plant species. Learn more here.
Multifaceted conservation strategies are increasingly incorporating technology into species survival plans, which often combines reintroduction of plants into their native habitat, banking seeds and tissues in long-term storage, and maintaining living collections in gardens and arboreta. For example, the Frozen Garden in CREW’s CryoBioBank uses liquid nitrogen and cryogenic technology to store seeds and shoot tips of some of the most threatened plant species, like the autumn buttercup, at very cold temperatures.
However, even if species are banked, their native habitat may be changing faster than the plants can adapt to the changes. Advancements in molecular genetics ensure that public gardens are also preserving the genetic diversity of the species that are banked and in living collections. Therefore, when plants are ready for reintroduction, higher genetic diversity should increase their chances of survival in the wild and ability to adapt to changing conditions. Plants that are especially vulnerable to changes in climate include certain long-lived, slow growing tree species.
Globally, more than a thousand tree species are considered critically endangered. One aspect of their biology that makes them a conservation challenge is that many species of trees produce seeds that are not easily frozen in seed banks. Oaks, for example, produce large acorns that don’t survive freezing. CREW scientists helped develop techniques to dissect the tiny oak embryos out of the acorns, which they were then able to cryopreserve.
CREW scientists tested the technique using four endangered oaks and three were successful! More research is needed, but these advancements at CREW will improve conservation strategies for endangered oaks and other large-seeded tree species.
Unifying the plant conservation effort is the Center for Plant Conservation, which is made up of 39 gardens, including CZBG. This network of gardens safeguards seeds, tissues, and specimens of 788 of the rarest native plant species in the United States. With nearly 5,000 species considered at risk, there is much work ahead to achieve the goals of the Global Strategy for Plant Conservation, which includes preserving 75% of plant species in living collections and seed banks by 2020.
While achieving these goals may seem daunting, what is known is that the future of plant conservation will continue to be collaborative, it will rely on technological advancements like those developed at CREW, and public gardens like CZBG will continue to be at the forefront of this critical conservation effort.
July 13, 2015 1 Comment
Florida has more fern species than any other state in the mainland United States, and CREW is working with partners at Fairchild Tropical Botanic Garden in Miami, Florida, to help propagate several of the most endangered from rapid urbanization and habitat loss.
The gridscale maiden fern, Thelypteris patens, is a large, beautiful fern that can reach over five feet in height. The patens variety is known only from the pine rockland habitat in Miami-Dade County and is listed as endangered in Florida. The population in one particular preserve declined to a single plant, which died in 2013.
However, before it died, researchers from Fairchild Tropical Botanic Garden collected spores from that plant and sent them to CREW’s Plant Lab here at the Cincinnati Zoo & Botanical Garden. CREW plant scientists germinated the spores in test tubes (in vitro) to produce tiny gametophytes, which represent the first stage in the fern life cycle.
These were then nurtured further in culture to produce sporophytes, which represent the second stage of fern growth and are the plants we normally think of as ferns. The sporophytes were acclimatized to soil at CREW, and then over 200 of these plants were sent to collaborators at Fairchild Tropical Botanic Garden where they were grown further in their greenhouses.
Finally, in May and June of last year, over 150 of the ferns propagated at CREW were outplanted back into the preserve where the species had been extirpated.
The plants are being monitored by Fairchild Tropical Botanic Garden. As of February 2015, the plants have had an 89% survival rate.
June 23, 2015 1 Comment