Promise For Sorghum Depends On Genetic Work

Grain sorghum falling behind corn, rice. Bill Spiegel

Published on: Feb 25, 2005

It is no secret that when it comes to implementing biotechnology, grain sorghum is far behind other crops. But "mapping" the grain sorghum genomic sequence could bring about biotechnology traits in both genetically modified and conventional methods.

That's according to Bob Klein, with USDA Agricultural Research Service in College Station, Texas, who spoke at the Sorghum Improvement Conference of America (SICNA) meeting during the North American Grain Congress in Reno earlier this week.

Klein says the study of genomics has been overwhelmingly successful in the field of medicine. "Gene discovery has led to testing that can show whether a person has a genetic predisposition to a particular disease. Also, scientists can design custom drugs based on individual genetic profiles or molecular information."

So what does that mean to farmers? "We can do gene testing in human beings. We can do that in plants, too, with marker-assisted selection," he says. In other words, every plant has a genetic sequence that indicates just how tolerant to diseases, insects, drought, yield – you name it, the plant's genetics dictate how it copes with a myriad of environmental and agronomic factors.

Klein says the industry has two "roadmaps" of sorghum genetics. "We have genetic and physical maps; we know where most things are. But we need to integrate them," he says.

Scientists have the rice genome mapped; they are close to doing the same with maize. Sorghum's 30,000 genes align closely with the rice map and that helps scientists learn how these genes are "expressed," or interact with each other to fend off diseases, create yield and so forth.

Scientists at Texas A&M have learned which genes influence pollen fertility; aluminum tolerance and plant color. They are learning how to input stay-green genes from Australian grain sorghum hybrids into American hybrids. Eventually, Klein says, an accurate genome map can help farmers grow hybrids that target drought tolerance; disease resistance and other key agronomic characteristics.

"Ultimately, we want all gene sequences [in the sorghum plant] revealed. We don't want this industry to be left behind. Rice, poplar, corn all are priorities. Down on the bottom of the list is sorghum and I don't want to be left behind," he says. "Once you don't have [gene sequencing] and you see the progress other groups are making, you realize the need to push forward."

Klein says the sorghum industry needs to develop more collaborations with interested parties; public and private pathologists, entomologists, agronomists and so on. "Sorghum is a small research community," he says. "We need to find a way to get funds."