University of Queensland scientists have identified a sorghum gene which could lead to development of more digestible feedstocks for farm animals and much-improved nutrition for some of world's poorest nations.

Known around the world for its drought-tolerance and florid heads of grain at harvest time, a more digestible sorghum would allow better uptake of vital nutrients.

For people living on marginalised farmland and dependent on sorghum as a fodder or food crop, these findings could prove to be life-saving, while also maximising water and land-use efficiency.

A team led by UQ plant scientist Professor Ian Godwin and colleagues from the Queensland Alliance for Agriculture and Food Science (QAAFI) has shown that selecting for a specific sorghum gene could mean the grain from these hardy plants will be much easier to digest.

“Sorghum is drought tolerant and can grow in regions otherwise unfit for other cereals, but unfortunately suffers from lower digestibility compared with other cereals,” Professor Godwin said.

“Most importantly, while the gene identified appears to improve digestibility, the gene's presence does not appear to diminish a sorghum plant's growth or yield.”

Queensland Minister for Agriculture, Fisheries and Forestry John McVeigh said the research was a major boost for Queensland, with sorghum already contributing an estimated $600 million to the rural economy annually.

“Any improvement to the digestibility of sorghum will add value to the grain and have a knock-on effect for the myriad of rural producers who use sorghum as a feedstock,” Mr McVeigh said.

“This is a significant milestone for the UQ and Department of Agriculture, Fisheries and Forestry scientists who have been working on the project.

“We have a goal to double the value of our food production by 2040 and this is another step in the right direction towards fulfilling that commitment and making Queensland a world leader in food and fibre production.”

While the gene variant is at low frequency in most sorghum populations, QAAFI scientist A/Professor David Jordan and collaborators at the Queensland Department of Agriculture, Fisheries and Forestry have shown that the gene is already in elite germplasm, arising from their sorghum pre-breeding program.

Preliminary studies have been done using a lab system which mimics monogastric digestion. UQ postdoc Dr Ed Gilding has demonstrated the variant gene leads to higher activity of an enzyme involved in starch biosynthesis in the developing grain.

Next step in the research will be to grow significant quantities of the selected sorghum line to test its digestibility, initially, in pigs and poultry. 

Source: UQ