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At the age of 13, Edgar McFadden had big responsibility. It was 1904 and his father was bed-ridden after being gored by a bull. McFadden was charged with managing the family farm near Webster, South à£à£Ö±²¥Ðã. He planted the crops and watched as his wheat fields turned ripe with a golden hue.

Then, just days before harvest, the stems broke and the kernels shriveled. McFadden watched helplessly as stem rust ravaged months of work and his family’s livelihood.

This had become a familiar pattern for South à£à£Ö±²¥Ðã farmers. Once home to the largest inland wheat market in the world, stem rust epidemics were becoming more and more frequent and, in some years, wiped out entire harvests. 

In 1911 — a particularly bad year for stem rust — McFadden enrolled at à£à£Ö±²¥Ðã Agricultural College, now known as South à£à£Ö±²¥Ðã State University, determined to learn about botany, field crops and diseases. Before leaving for school, McFadden noticed stem rust didn't bother a plot of Yaroslav emmer, an ancient crop that was rather useless to South à£à£Ö±²¥Ðã farmers in 1911. This gave him an idea. Could emmer be bred with a more useful plant to create a disease-resistant variety? 

As a student, McFadden began conducting crossbreeding experiments at the South à£à£Ö±²¥Ðã Agricultural Experiment Station under the direction of assistant agronomy professor Manly Champlain. His plan was to cross emmer with Marquis, the preeminent spring wheat variety, but he was warned breeding the two plants would be nearly impossible.

Through hardship, years of patience and seemingly endless trials, McFadden was able to successfully develop a new cultivar by crossing Marquis with emmer in 1925. He named this variety "Hope," and its ability to resist both stem and leaf rusts is considered one of the great agricultural innovations in history.

According to magazines and newspapers in the 1940s, Hope would save 25 million people globally from starvation and helped fuel the Allies to victory in World War II.

This pioneering research by McFadden laid the groundwork for decades of plant breeding success at South à£à£Ö±²¥Ðã State University. Today, SDSU's wheat breeding programs and breeders continue pivotal work in developing new varieties for farmers in South à£à£Ö±²¥Ðã and the Upper Midwest.

Lab research spurns breeding success

There are six types of wheat grown in the U.S., but South à£à£Ö±²¥Ðã farmers primarily grow two types: hard red winter and hard red spring. South à£à£Ö±²¥Ðã is a relatively unique state in that wheat growing acres are split evenly between winter and spring wheat. As a result, SDSU has two different wheat breeding programs: winter wheat, led by associate professor Sunish Sehgal, and spring wheat, led by professor Karl Glover.

While plant breeding has been going on at SDSU since the incorporation of the Agricultural Experiment Station in 1887, the winter wheat breeding program didn't officially begin until 1950. Started by Darrell (D.G.) Wells, the program's original goals were to select plants that were resistant to both stem and leaf rust.

Winter wheat is used primarily for breadmaking, so good milling and baking characteristics are also needed.

"Winter wheat is the major staple and main ingredient for breadmaking," Sehgal said. "If you are eating bread, it comes from hard winter wheat."

The first variety from the program, released in 1965, was named "Hume." 

Hume's release came at a particularly trying time for South à£à£Ö±²¥Ðã's wheat farmers. In 1962, stem rust losses were severe, and economic losses were estimated to be as high as $20 million. Hume was highly resistant to stem rust and helped farmers overcome the challenges of the disease.

But Hume had its own shortcomings, and in 1969, "Winoka" was released by the program. This became the pattern for SDSU's winter wheat breeding program. Each release is aimed at improving upon previous varieties with better disease-resisting abilities and/or yield potential.

Sehgal, who has led SDSU's program since 2014, has released seven hard red winter wheat varieties from the program. Wheat plants have come a long way since the days of McFadden, Sehgal said, and even in the last 20 years, the crop has seen drastic improvements in disease resistance, yield and weight height.

"We have more winter hardiness, and we have increased the yield by miles," Sehgal said. "It's a 10-bushel yield difference in just the last 20 years. We have enhanced resistance to disease, drought, end-use quality and reduced plant height."

These innovations are thanks to not just breeding success but also the lab research at SDSU. There, a team of graduate students and Sehgal use cutting-edge technologies to identify desirable traits and genes.

"In addition to breeding, we do trait discovery," Sehgal said. "We need to understand the genetics and details of the genes that control those traits. All of the (Ph.D. and graduate-level) student research is focused on the discovery side."

Sehgal's team also does a significant amount of research focused on increasing the efficiency of breeding programs through the use of techniuqes like speed breeding, genome-wide selection and high throughput phenotyping. For example, Sehgal equips drones with high-powered spectral cameras, which can identify disease on the wheat plants.

"We take a lot of data from the drones and artificial intelligence-based modeling to be able to predict the yields prior to harvest," Sehgal explained.

The research team is also using these cameras in the lab to identify quality or problems at the seed level.

"Scab fungus grows on the seed and produces vomitoxin," Sehgal said. "We have high-speed multispectral cameras that gets a picture of every seed — 30 seeds per second — and it gets a spectrum of the light absorbed and reflected from it. Based on those patterns, we can tell if this seed has what amount of the warning toxin or what amount of fungus."

The camera helps Sehgal better select plants for improved varieties. The program's use of state-of-the-art technology is one of the reasons Sehgal is largely recognized as the preeminent winter wheat breeder in the U.S.

"Of the two dozen winter wheat breeding programs (in the U.S.)," Sehgal said, "we are second to none in all of these technologies."

The breeding process

Leeston, New Zealand, is over 8,000 miles away from the SDSU campus but is a key part of the spring wheat breeding program. Leeston is roughly the same distance south of the equator as Watertown, South à£à£Ö±²¥Ðã, is north, making it a perfect location for Glover, the program's leader, to grow, select and test materials for new spring wheat varieties.

"The plants don't know they are not in South à£à£Ö±²¥Ðã because during the New Zealand spring/summer, the day and night periods are the same as they are here," Glover explains.

The New Zealand nursery, which has been used by the program since the late 1990s, is one of the locations SDSU utilizes to expediate its spring wheat variety development. Photoperiod duration (i.e., hours of sunlight) can influence the growth and development of spring wheat. A nursery in Yuma, Arizona, plays an equally key role in increasing a new varieties’ seed. Utilizing nurseries over South à£à£Ö±²¥Ðã's winter months allows for Glover's program to have two growing cycles per year. This speeds up the breeding process, which can take up to a decade from the initial cross to seed release.

SDSU's spring wheat breeding program began in 1977, and Glover became the program's leader in the early 2000s. Like Sehgal, Glover is widely regarded as one of the country's preeminent hard spring wheat breeders and has released 15 varieties during his time at SDSU.

Wheat breeding — whether its winter wheat or spring wheat — is a long and deliberate process that requires a keen eye for detail and some nuance. For Glover and Sehgal, the first step is to define the problem and objective. This revolves around discussions with South à£à£Ö±²¥Ðã's farmers to assess their needs and the challenges they face.

Once they have the breeding objectives set, genetic material — known as germplasm — is selected. The desired germplasm is chosen from a massive genetic pool of past varieties or wild wheat relatives. Technology has played a significant role in improving this selection process and is one of the primary reasons plant breeding has moved from a 20-plus year timeline to what it is today.

The breeder will then cross the plant materials. This is known as "crossbreeding" and is done by hand as the breeder mimics the natural fertilization process by removing the male organs out from the donor plant. A breeder might make upward of 1,000 crosses in a single year. The experimental lines are then grown in the university's greenhouse.

The seeds from the crossbred plant are then planted at different testing locations, thus beginning a labor-intensive cycle of growing, analyzing, selecting and planting again. SDSU's spring wheat program tests around 13,000 performance trial plots for productivity, disease resistance and end-use characteristics each year.

Glover's job is to select the plants with the right characteristics as they move through the breeding process. If there are 500 plots in a field plot, Glover might only collect 20 plants to move on to the next cycle — underlining the close eye and knowledge successful plant breeders, like Glover, must have. 

Following the initial crossbreeding process, at least three years are required to stabilize the variety and create a level of uniformity. Year-round nurseries play a crucial role in this step. An additional three years of advanced yield trial evaluations, conducted at 15 locations around South à£à£Ö±²¥Ðã, are then required before a variety can moved forward. In total, the breeder is growing thousands of plants and continuously selecting the best ones for the given breeding objectives as the process moves forward.

The intensive performance trials evaluate yield potential and quality characteristics of the experimental varieties. Data collected includes grain yield, protein content, disease resistance, response to fungicides, heading, plant height, straw strength, and milling and baking characteristics. The varieties are tested under various conditions. In the winter wheat program, Sehgal's experimental varieties under no till management are tested in fields with soybean, corn and flax residue on the soil at 15 different locations for three years.

"This gives us the ability to evaluate our varieties under different situations that are realistic for South à£à£Ö±²¥Ðã's farmers," Sehgal added.

The experimental varieties are grown alongside around 25 commercially released varieties — including past wheat varieties released by SDSU — and if the experimental variety is superior, it may be considered for release.

From research to product

For a new wheat variety to get into the hands of South à£à£Ö±²¥Ðã's producers, it must go through the Foundation Seed Conditioning building, situated on the north end of SDSU's campus. Run by the SDSU Foundation Seed Stocks Division, the organization serves to connect SDSU's plant breeding programs with the state's producers by increasing and distributing new varieties of seed developed by SDSU researchers. 
 

Jack Ingemansen is the superintendent of SDSU Foundation Seed and is responsible for increasing seed for new varieties. When a variety is likely to be released, Ingemansen will receive a bag of breeder seed that is then planted on acreage in the Brookings area or in Arizona during the winter months.

Foundation Seed operates in the way a normal farm does. It has a full line of farm equipment, 39 gravity flows and eight dryer bins with a storage capacity for up to 105,000 bushels. An absolute necessity to Ingemansen's work is ensuring every combine, drill, truck or any other seed handling machinery is thoroughly cleaned to prevent mixtures of varieties.

"This process is very labor intensive and time consuming but necessary in order to maintain genetic purity," Ingemansen.

Within two to three years of receiving just a few pounds of seed, Ingemansen can cultivate between 500 to 10,000 bushels of a new variety. The seed is then distributed to seed companies and seed producers throughout the state based on a set of criteria approved by the South à£à£Ö±²¥Ðã Crop Improvement Association. Foundation Seed is a self-sustaining entity as all sales are used to fund its expenses, salaries and further plant breeding research at SDSU.

Before a variety is released to the general public, SDSU's Plant Variety Release Committee will meet and vote. Sehgal, Glover and Ingemansen (and others) are all members of this committee (although breeders cannot vote on their own variety), which meets twice a year. The last meeting resulted in SDSU releasing "Enhance-SD," a spring wheat variety.

Releasing new varieties is important, not just for the breeder and the program, but for the state as well. It's estimated that for every $1 invested in the wheat breeding programs, $20 is returned to the state's agricultural economy through increased productivity.

McFadden statue

While things have changed considerably since McFadden's time on SDSU's campus, the impact of his research is still felt to this day. Sehgal's graduate-level work revolved around McFadden's crossbreeding of Marquis and emmer, and Hope's genetic material can still be found in many of the winter and spring wheat varieties developed from SDSU's breeding program.

To commemorate the 100-year anniversary of Hope, a sculpture celebrating McFadden's work will be erected on the SDSU campus this summer.