Researchers for the U.S. Department of Agriculture’s (USDA) Agricultural Research Service (ARS) have developed a new variety of sorghum that produces more seeds than conventional varieties. This article from USDA says ARS molecular biologist Zhanguo Xin and plant geneticist Gloria Burow at the Plant Stress and Germplasm Research Unit, along with lab director and research leader John Burke, at the ARS Cropping Systems Research Laboratory in Lubbock, Texas, developed a mutant sorghum plant that produces 30 to 40 percent more seeds.
The researchers developed the higher yielding sorghum by taking advantage of a plant part called a “spikelet.” A spikelet is a cluster of florets within the panicle, a type of flower cluster found in some other grasses, such as millet or rye. Sorghum produces two types of spikelets: the sessile spikelets and the pedicellate spikelets. Normally, only the sessile spikelets are fertile, but the ARS scientists developed a sorghum plant that produces seeds in both types of spikelets.
The team developed the productive sorghum line by inducing a mutation in sorghum plants that allowed infertile spikelets to grow and produce seed, according to Xin. An induced mutation is produced by treatment with a mutagen, like radiation or a chemical agent such as ethyl methane sulfonate. The mutation resulted in an overall increase in size and volume (length, width, and thickness) of the sorghum panicle.
The researchers say all of the spikelets of the new sorghum plant develop into flowers and produce mature seeds, significantly increasing seed production and yield in comparison to conventional sorghum. They also believe these mutants could be crossed with other, larger-seeded sorghum lines to improve overall yields.