Doctoral Students Tackle Impactful Research

By Jess Clarke

As an Illinois native who’d lived all her life there, Nicole Choquette wanted a new state and different crop focus as she considered doctoral programs in plant breeding.

She had planned to go beyond corn and soybeans, key research areas at the University of Illinois Urbana-Champaign, where Choquette earned undergraduate and graduate degrees.

“Toward the end of my master’s program, I said I’d never study corn again,” she recalls. “But then a great opportunity came up at NC State University, and I said, ‘OK, I’m going to go study corn there.’”

So, Choquette headed to North Carolina and worked as a graduate research assistant for Jim Holland, a United States Department of Agriculture (USDA) professor in the Department of Crop and Soil Sciences

She has no regrets — Choquette ultimately was recognized for her scholarship as an NC State crop science doctoral student in the College of Agriculture and Life Sciences.    

Choquette and animal science Ph.D. student Emmanuel Lozada-Soto, both 2023 graduates, are the 2024 winners of CALS’ Kenneth R. Keller Award, a $2,500 prize for excellence in doctoral dissertation research within the college. The award’s namesake is a late CALS faculty member, recognized for his work for the university and agricultural development.

Lozada-Soto also originally thought he’d pursue a different doctoral path at CALS than the one he chose. He’d planned to study molecular biology but faced an unexpected obstacle: “I fell in love with quantitative genetics,” he says.

His interest shifted when he was invited to help with the animal breeding and genetics research of then-CALS professor Francesco Tiezzi, who became Lozada-Soto’s adviser when he was an NC State animal science master’s student.       

In quantitative genetics, he was intrigued by how many traits, including weight and milk production with cows, were controlled by genes and the environment. “We can see the genetic structure of the traits, so we can improve them,” Lozada-Soto says. “We can use science to uncover this hidden genetic architecture.”

His dissertation research stemmed from that, helped by an NC State master’s degree in statistics he’d already earned, and overseen by his doctoral adviser, CALS professor Christian Maltecca.   

Promising Research

Lozada-Soto examined the best ways to measure inbreeding and genetic diversity in cattle to determine how inbreeding affects their health and milk and meat production. The aim was to find out how harmful inbreeding potentially could be to animals and production.

He used molecular tools to study the cows’ genetic composition — half a million beef cattle and over four million dairy cows. With such a large and broad sampling, “I could more accurately quantify the genetic diversity and levels of inbreeding,” Lozada-Soto says.

The main conclusions of his research: In dairy cows, inbreeding can increase the incidence of reproductive disease; in beef cattle, inbreeding reduced growth and weight on average. Now dairy and beef producers can use the data to impact mating decisions, with the ultimate goal to increase food production.   

Lozada-Soto’s doctoral work eventually could increase genetic diversity and possibly counteract impacts of disease and climate change. Choquette’s dissertation research also has that potential.

The objective of her research was to try adapting tropical corn to temperate environments. With more plant diversity from different corn varieties, “That can help make our current corn breeding lines more resistant to climate change,” Choquette says.

Her focus was on quickening adaptation. The process is difficult because of the overall shorter daylight hours over a year’s time in tropical areas than in North Carolina. Introducing new varieties to longer day lengths “kind of freaks them out,” so the plants don’t flower and develop kernels on time, which can reduce their yield, she notes.

Choquette selected for the flowering time to be earlier, so plants could go through their developmental process in a single season. That entailed cross-pollinating tropical corn, taking pollen from one plant and putting it on another plant to select for the traits she wanted. “As we did that, we got rid of those bad individuals that were late flowering,” she says.   

Her research concluded that selecting for flowering time in breeding programs can make plants flower earlier, “so you can adapt tropical germplasm to new environments,” she notes.

Choquette’s research and the new, diverse plant populations she created can be used broadly by corn breeding programs. “Someone might discover that these plants have good resistance to disease,” she says. “This is an important resource they wouldn’t have access to otherwise.”

Breeding Possibility

As CALS students, Choquette and Lozada-Soto had resources and opportunities they may not have had otherwise.

Choquette thrived in the tight-knit graduate student community. “In the Plant Breeding Consortium,” she says, “it was easy to make your friends and find your people. That was huge.”

Huge for Lozada-Soto were the conferences where he presented papers on his research and the paid research jobs he had in Canada and Italy. “That filled my Rolodex of contacts. Once I graduated, that became a great resource for me to expand my network,” he says.

Now Lozada-Soto and Choquette have full-time positions that overlap with their dissertation research.

Lozada-Soto is an animal scientist in Colorado for the USDA’s National Animal Germplasm Program, which maintains a collection of nearly 1.3 million tissue samples that represent about 65,000 animals. The program safeguards genetic diversity of agricultural animals to potentially expand food production and counteract climate change and disease.  

“I’ll be a lifelong geneticist. I’ll always be in this field,” he says.

In a different field, Choquette is a diversity breeder for Benson Hill, a Missouri breeding company. The business focuses on quality traits in soybeans’ protein and oil to ultimately grow healthier beans for animals. She adds new types of soybeans to their database that could potentially unlock new genetic traits for more nutritious animal feed.

As Choquette builds on the research that led to her Keller Award, that recognition — which she’s been told only a few crop science students have received — boosts her confidence.

“That honor makes me carry my head higher,” she says. Whatever her eventual career direction, she says “the possibilities are endless.”

This post was originally published in College of Agriculture and Life Sciences News.