Source: USDA’s Agricultural Research Service (ARS)

Molecular biologist Zhanguo Xin, plant geneticist Gloria Burow, and lab director John Burke, at the ARS Cropping Systems Research Laboratory in Lubbock, Texas, have bred 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 found in the panicle and is a characteristic of 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 plant that produces seeds in both types of spikelets.

“We developed the productive sorghum line by inducing a mutation of sorghum plants that allowed infertile spikelets to grow and produce seed,” says 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.

“All of the spikelets of the new sorghum plant develop into flowers and produce mature seeds, thereby significantly increasing seed production and yield in comparison to conventional sorghum. The mutants may be crossed with other sorghum lines, particularly elite large-seeded lines, to improve grain yield in sorghum and other related species,” says Xin. “The mutation in the sorghum line we developed is stable and can be passed on to other sorghum lines through breeding.”

A sample of at least 2,500 seeds of the new multi-seeded sorghum has been DEPOSITED with the American Type Culture Collection for future research.-By Dennis O’Brien and Sharon Durham, Agricultural Research Service Information Staff.

This research is part of two ARS National PROGRAMS, Climate Change, Soils, and Emissions (#212) and Plant Genetic Resources, Genomics, and Genetic Improvement (#301).

“Boosting Sorghum’s Growing Range and Yield” was published in the February 2015 issue of Agricultural Research magazine.