Mike Giroux

Mike Giroux, MSU Interim Department Head of the Plant Sciences and Plant Pathology department and durum breeder, talks about the intra-state durum trials at Sidney field days.

SIDNEY, Mont. – How do you create a better durum for Montana growers?

Intra-state durum yield trials allow the Montana State University durum breeding program, using funding from the Montana Wheat and Barley Committee and the Montana Agricultural Experiment Station, to compare durum varieties side-by side.

“Behind me here (at Sidney’s Eastern Ag Research Center) is our intra-state trial, which is in its second year,” said Mike Giroux, MSU Interim Department Head of the Plant Sciences and Plant Pathology department and durum breeder.

Giroux works with Research Associate Andy Hogg, also in the Plant Sciences department, on durum crosses to create new and better varieties.

Giroux and Hogg are focusing on developing durum varieties with low pH tolerance; developing height to be intermediate between current semi-dwarf durum and the standard height; improving yields under drought conditions; and adding novel traits, such as pasta firmness, pasta color retention, and low-cadmium uptake.

“We have entries in the intra-state trials that we have developed to incorporate two novel traits – increased pasta firmness and reduced cadmium,” Giroux said.

In 2018, Joppa and Alzada were the two most common durum varieties in Montana, which have largely replaced the two older varieties, Mountrail and Divide.

“Many of the lines we have (in the intra-state trial) look like NDSU varieties, and that is because we crossed them with these varieties and varieties from the USDA seed bank collections. Some of our lines have comparable or better yields than currently grown varieties,” he said.

About eight years ago, Giroux and Hogg began making crosses with currently grown publicly released cultivars with some world collection lines as part of genetic studies to examine the role of starch type in pasta quality.

The world collection lines contributed a trait for pasta firmness and for low cadmium.

“Most recently, we are making crosses with some Canadian varieties and with other varieties known to have enhanced pasta color retention,” Giroux said. Many of the Canadian varieties were used for high protein content, although Giroux noted that it is often the case that lines with very high protein content do not have the highest agronomic yield.

“Progeny lines are then selected for certain traits, such as yield, low lodging, seed size and color, protein content, disease resistance, protein strength, and pasta firmness,” Giroux said.

One of the agronomic traits MSU is now breeding for is a durum with low pH tolerance.

Many soils in Montana have low pH in the top 6 inches of the soil, which has led to low yields. As the pH drops, aluminum in the soil becomes soluble, which is toxic to plants at high concentrations.

“No current durum varieties have low pH tolerance. Luther Talbert (MSU spring wheat breeder) found about half of his varieties carry the low pH tolerance gene, but no durum varieties have it since the gene isn’t found in durum wheat,” Giroux said. “To get low pH tolerant durum, you have to cross durum wheat with spring wheat to move the gene for low pH tolerance into durum wheat, and some Australian scientists have done that.”

A bar chart Giroux handed out at the field day showed the length of roots in durum having the low pH tolerance gene. They were significantly longer than control durum lines lacking the low pH tolerance gene.

“To create a low pH tolerance durum variety (crossing the low pH gene to Montana durum lines) is going to take us 5 to 10 years, because we have just started the process,” he said.

Novel traits, such as fusarium resistance in durum, and disease resistance, have also been the focus of durum development.

The MSU team plans to work with Frankie Crutcher, MSU plant pathologist, on selecting fusarium tolerant lines. While there are no durum varieties that are totally resistant to fusarium at present, there is “significant fusarium resistance variation among the lines, so we are working on selecting the best level of resistance.”

Another novel trait the team is working on is low cadmium.

“Low cadmium is preferred by export markets, and it may become an important trait to have in Montana varieties,” Giroux said. “It doesn’t affect the micronutrition of the plant, other than cadmium, nor does it affect yield or other agronomics, so there is no reason not to select for reduced cadmium uptake.”

Some of the new Montana durum lines have the low cadmium accumulation gene and some also have a licensed pasta firmness gene, another desirable trait.

The modified amylose content is a trait owned by MSU and it increases pasta firmness.

“We know that starch type is important, because it affects not only how we digest starch, but it affects the glycemic index,” he said. “If you have higher amylose, it can reduce glycemic index and make a firmer pasta at the same time.”

Pasta color retention is another important trait the team is working on and increased color retention can be accomplished by selecting for reduced lipoxygenase activity.

Reducing seed lipoxygenase results in pasta that retains its yellow color for a longer time.

“Some of the Canadian lines have the reduced lipoxygenase trait and it is controlled by a single gene, so we plan to integrate the color retention trait into new durum varieties,” he said.

Current semi-dwarf durum varieties do not have the same yield advantage as spring wheat or winter wheat semi-dwarf varieties over standard height varieties.

That is especially true when the varieties are grown in a stressful environment, such as at Sidney.

“Two of the varieties being grown here at Sidney are semi-dwarfs and under drought conditions, they are often too short,” he said.

They are creating and testing new semi-dwarf wheats with height intermediate to that of current semi-dwarf and full height durum to reliably increase durum yields by increasing tillering and seed numbers per plant.

The proper semi-dwarf height also may lead to increased yield and protein relative to current durum semi-dwarfs.

In the intra-state durum trials in 2017, there were several Montana developed durum lines that performed well averaged against popular durum varieties in all locations planted.

For yield, the five highest yielding varieties were: MTD16007 (with low cadmium accumulation gene present) at 65.4 bushels/acre; MTD16004 (with licensed pasta firmness gene) at 65.1 bushels/acre; ND Grenora, at 63.9 bushels/acre; ND Carpio, at 63.7 bushels/acre; and MTD16011 (with low cadmium accumulation gene and pasta firmness gene) at 63.3 bushels/acre.

Highest protein percent was CDC Dynamic (with low cadmium accumulation gene) at 16 percent, which was followed by CDC Fortitude (with low cadmium accumulation gene) at 15.8 percent tied with MTD16009, also at 15.8 percent.

Highest test weight was MT112219 (with (with low cadmium accumulation gene) at 61 pounds/bushel, and several varieties had 60 pounds/bushel.