A team of researchers from the Deep South sent sweet potato plants into space, as part of an experiment aimed at providing food for long-term space missions.
Desmond G. Mortley, from the G.W. Carver Agricultural Experiment Station at Alabama’s Tuskegee University, and his colleagues launched the sweet potato cuttings on a five-day mission aboard the space shuttle Columbia, and compared their success to ground-based cuttings at Kennedy Space Center in Florida.
“The intent of the experiment was to study if stem cuttings would be a successful means of propagating plants in space, just as they are on Earth,” said Raymond Wheeler, a study co-author from NASA’s Biological Science Office at the Kennedy Space Center. “The results showed that the cuttings did indeed produce adventitious roots in microgravity, suggesting that cuttings should work well in space settings.”
The sweet potato experiment was flown on Columbia’s July 1999 mission to the Chandra X-Ray Observatory. The study findings were published in the May 2008 issue of the Journal of American Society for Horticultural Science, although a public press release was issued just this week.
Seeds of several crops have been grown in microgravity, but this was the first test for plants grown from cuttings. Cuttings grow roots faster than seeds do, and sweet potato cuttings regenerate very easily. This made them ideal for the study.
According to the study authors, all of the cuttings produced roots and growth was “quite vigorous in both ground-based and flight samples.” Except for a slight browning of some root tips in the flight samples, all of the stem cuttings appeared normal, they added. The roots on the flight cuttings tended to grow in random directions, sometimes perpendicular to the stems. Also, stem cuttings grown in microgravity had more roots and longer roots than ground-based controls.
The next step, Mortley and his colleagues say, will be to experiment over longer space missions to test root cuttings’ ability to grow plants.