A sorghum hybrid that does not flower and accumulates as much as three times the amount of stem and leaf matter may help the bioenergy industry, according to a study appearing in the Proceedings of the National Academy of Sciences.

A team at Texas AgriLife Research has discovered a gene that regulates sorghum flowering, according to the proceedings.

“For energy crops, we want to prevent plants from flowering so they accumulate as much biomass as possible for bioenergy/biofuels production,” said Dr. John Mullet, AgriLife Research biochemist.

Sorghum is a grass native to Africa, which provides an indispensable food source for more than 300 million people in countries where food supplies are insecure, according to the paper’s authors. They noted that though primarily grown for its grain and forage, high biomass sorghum is also an excellent drought-tolerant energy crop for sustainable production of lignocellulosic-based biofuels.

“We were able to identify a gene in sorghum that controls flowering in response to day length, and we discovered that the gene is regulated by the plant’s internal ‘clock’ and light enabling the plant to flower at approximately the same date each growing season,” Mullet said.

Research team member Rebecca Murphy described “walking along the chromosome” of sorghum using genetic mapping techniques until landing on what she calls Maturity Locus 1, a historically important genetic determinant of flowering time originally discovered by AgriLife Research scientists in 1945.

“Flowering time is important for sorghum no matter what type of sorghum is grown,” said Murphy, a biochemistry doctoral student at Texas A&M University. “In the case of bioenergy sorghum, you want to delay flowering because the more you delay flowering, the more biomass sorghum will accumulate.

“Before this discovery, a sorghum breeder would have to wait for a plant to flower to see what type of flowering time genes were in the sorghum,” she said. “Now we will be able at a very early stage to look at the molecular level and determine a plant’s flowering type genotype. Then, a breeder can pretty accurately predict flowering time without having to wait for the plant to mature.”

“Understanding how and when sorghum flowers has been studied for decades, Mullet explained. Initially, many sorghum varieties brought to the U.S. from Africa would not flower or flowered too late to develop grain. That made the crop useless for grain production until scientists began breeding plants to flower early enough to avoid drought in the southern states or in time to mature before frost in the north.