Technique for Temperature-Dwarfed Corn

A Purdue University study shows that lowering temperatures for two hours each day reduces the height of corn without affecting its seed yield. Cary Mitchell, horticulture professor at Purdue said the technique could be useful for growing transgenic crops to produce high-value medicinal products for the budding plant-derived industrial and pharmaceutical compounds industry. According to him, corn is a good candidate crop because of the plant's bounty of seeds and well-characterized genome.

But corn needs bright light and heat, and growing the crop in a controlled environment presented a challenge to Mitchell and then-postdoctoral researchers, Yang Yang and Gioia Massa. To reduce the crop height, they borrowed a trick used to dwarf Christmas poinsettias and used a growth chamber where they dropped the temperature to 60 degrees Fahrenheit for the first two hours of each photoperiod, the time when corn receives light. The temperature was restored to 80 degrees for 14 hours and then lowered to 65 degrees for eight hours of darkness. The dips in temperature dwarfed stalk height by 9 to 10 percent and reduced stalk diameter by 8 to 9 percent without significantly affecting the number and weight of the seeds.

Mitchell said, "This is a technique you could easily do in a mine or cave. It is an affordable, non-chemical means of taking genetically modified crops to harvest maturity without getting any kind of pollen or seed into the ecosystem."

The study is available at http://www.sciencedirect.com/science/article/pii/S0926669013006791. To read the news release, visit http://www.purdue.edu/newsroom/releases/2014/Q2/corn-dwarfed-by-temperature-dip-suitable-for-growing-in-caves,-mines.html.