Crop Biotech Update

Photoperiod Sensitivity in Tropical Maize Up for a Change

March 31, 2010

Scientists at the U.S. Department of Agriculture Agricultural Research Service, Plant Science Research Unit at North Carolina State University are finding ways to improve temperate maize varieties. "Photoperiod response is the major barrier to using tropical maize for the improvement of temperate maize varieties," said Dr. James B. Holland, a researcher involved in the project.

To understand the barrier to corn production in the temperate countries, the researchers interbred two tropical photoperiod sensitive corn lines with two photoperiod-insensitive corn lines from the United States, and grew out hundreds of progeny lines in North Carolina (long day-length summers) and in Florida (short day-length winters). Lines with strong photoperiod response were identified as those flowering much later in North Carolina. Genetic mapping of the lines was conducted using identified DNA markers associated with photoperiod response which could lead to the identification of photoperiod responsive genes.

The research also suggests that the genes controlling the photoperiod response in corn may be partly distinct than those believed to control photoperiod response in model plant species such as Arabidopsis and rice. Further studies to pinpoint the specific genes involved in the photoperiod response is needed which will be used for a better understanding of the relatedness of plant species.

For details, see the research abstract at