Contact: Michael W. Neff
American Society for Horticultural Science
Sweet potato takes a ride on space shuttle Columbia
Study shows roots can regenerate in microgravity
AL—Because of the distinct lack of grocery stores in outer space,
scientists are looking for ways to provide food for long-term space
Desmond G. Mortley and colleagues from the Center
for Food and Environmental Systems for Human Exploration of Space, G.W.
Carver Agricultural Experiment Station, and the Kennedy Space Center
undertook a study on microgravity's effects on sweetpotato. The study
findings were published in the
Journal of American Society for Horticultural Science.
of several crops have been grown in microgravity, but this was the
first test for plants grown from cuttings. Cuttings grow roots faster
than do seeds, and sweetpotato cuttings regenerate very easily. This
made them ideal for the study, half of which took place on a 5-day
space mission on the shuttle Columbia.
The other half of the
cuttings remained on earth as the ground-based control group at Kennedy
Space Center in Florida. Conditions were similar for both growing
Both environments resulted in similar root
growth development, though the microgravity roots tended to grow
perpendicular to the cuttings. The number of roots was almost the same
in both samples. However, the length of roots grown in microgravity was
significantly greater. Microgravity cuttings contained significant
accumulation of soluble sugars and higher starch concentration than
ground cuttings; the starch grains appeared smaller in microgravity
Despite these differences, the study was successful
in showing that stem cuttings, at least those started in normal gravity
conditions, can regenerate roots in microgravity. "This suggests that
the space flight environment has no negative effect on the ability of
vegetative cuttings to form roots and that use of cuttings should be an
acceptable means for propagating sweetpotato for future space
applications," summarized the researchers.
The next step will be to experiment over longer space missions to test root cuttings' ability to grow plants.
The complete study and abstract are available on the ASHS
J. Amer. Soc. Hort. Sci. electronic journal web site: http://journal.ashspublications.org/cgi/content/abstract/133/3/327
in 1903, the American Society for Horticultural Science (ASHS) is the
largest organization dedicated to advancing all facets of horticultural
research, education, and application. More information at ashs.org