New sorghum ideal for both fuel and feed

Lignin is a “cellular glue” of sorts that imparts rigidity and strength to
plant tissues. It also helps plants fend off attacking insects and
pathogens.

However, studies by ARS scientists Deanna Funnell, Jeff
Pedersen and John Toy in Lincoln, Nebraska, show that reducing sorghum’s lignin
content can also be beneficial.

Take, for example, Atlas bmr-12, one of
20 low-lignin lines the ARS team developed and tested in collaboration with
University of Nebraska-Lincoln scientists Richard Grant and Amanda
Oliver.

High fibre digestibility
In the laboratory, the line
scored higher on fibre digestibility than standard sorghum, which should result
in higher milk production and higher beef gains when Atlas bmr-12 is fed to
cattle.

On the fuel front, the line’s high fibre digestibility could also
mean improved sorghum-to-ethanol conversion at processing plants, notes
Funnell.

Interestingly, reducing the sorghum line’s lignin didn’t leave
it more vulnerable to fungal attack in laboratory trials.

Funnell
determined this by inoculating Atlas bmr-12 and another line, bmr-6, with
Fusarium moniliforme fungi and examining the length of red-pigmented
lesions that formed as the pathogen spread.

Fungus
resistence
Both lines showed greater resistance to the fungus than a
control group of standard sorghum that was used. Inside the stems of Atlas
bmr-12, for example, fungal lesions were 78 millimeters (mm) long, versus 117 mm
in other plants used for comparison in the trials.

Atlas bmr-12 and bmr-6
owe their unique balance of fibre digestibility and disease resistance to two
genes for the brown midrib trait, which Pedersen incorporated into the sorghum
lines during breeding stages.

Read more about the research in the
September 2007 issue of Agricultural Research magazine.

ARS is the US
Department of Agriculture’s chief scientific research
agency.