Seeds of Research: Graduate researchers study "superfood"

Seeds of Research

The Alabama Agricultural Experiment Station’s Agricultural Enhancement & Seed Funding Program is designed to foster innovation, enhance research capabilities, and support emerging and established scholars through targeted research opportunities. For the first time this year, post-doctoral and graduate students are eligible for these grants. Seeds of Research is an occasional series of articles that will take a unique look at these research projects in their infancy and the scientists behind them.  

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Blueberries have rightfully earned their place among fruits as a “superfood,” and with July being National Blueberry Month, the spotlight is shining even brighter on this popular fruit. While “superfood” is more of a marketing term than a scientific one, blueberries easily earn the title because they are exceptionally dense in nutrients.  

Blueberries are such an important crop to Alabama producers that a group of four graduate researchers from Auburn University’s College of Agriculture have chosen them as the focus of their research projects. This group is among 33 graduate and post-doctoral students who received grants from the Experiment Station's PEER Program, or Professional Enhancement for Emerging Researchers. This marks the first year of the program, offering grants of $5,000 for one year. 

The students’ research covers a wide range of topics, including improved drought resistance, cultivar selection, fruit texture, and assessing general fruit quality and sensory traits throughout postharvest storage. 

Understanding drought tolerance

Savannah Busby of Vestavia Hills knew Auburn University was the right place for her when she visited for the first time, which just happened to coincide with the Department of Horticulture’s end-of-the semester potluck supper. 

“I loved the environment that I saw within the department,” Busby said. “It was nice to see such a small, tight-knit community within the larger university.” 

After receiving her B.S. in biology from Birmingham-Southern College in 2021, she began her M.S. in horticulture under Sushan Ru, an assistant professor at Auburn who, in 2021, began the state’s first small fruit breeding program. She is also serving as Busby’s mentor for the grant. 

“I decided to pursue my graduate education specifically because of Sushan,” Busby said. “After meeting her, I knew that her personality and the work environment she created would allow me to flourish academically, so it was natural that I would stay in the same lab to work on my PhD.” 

Busby focuses on drought tolerance for her research. She primarily studies the drought tolerance of southern highbush and rabbiteye blueberries, specifically looking at changes in growth, fruit quality, physiology and transcriptomics or gene expression under drought stress.  

“I received the grant to further the molecular part of the study, and I will be evaluating transcriptomic differences between the berries of the best and worst performing cultivars from the two species we studied,” she said. 

Alabama farmers, she said, are especially susceptible to drought stress, with only 10% having access to reliable irrigation. Blueberries are especially prone to drought stress due to shallow roots which lack root hairs, limiting water uptake.  

“To better understand the genetic mechanisms behind drought tolerance, we propose a transcriptomic analysis of tolerant and susceptible cultivars to identify key drought-response genes and validate previous findings on drought responses,” Busby said. 

Photosynthesis, stomatal conductance, and electron transport rate will be measured biweekly and taken concurrently with two biological repetitions for RNA samples of leaves and berries. Transcriptomic analysis will be completed on these samples along with samples from a previous study with the same experimental design.  

“Yield, average berry weight, total soluble solids, titratable acidity and berry firmness also will be measured,” Busby said. “We expect to find specific differentially expressed genes that are associated with drought-tolerant traits. These traits can then be used to inform targeted breeding practices to cultivate high-yielding drought-tolerant cultivars.” 

Assessing variations in texture and firmness

Experiencing the food processing industry first-hand, in addition to personally witnessing widespread postharvest losses in Malawi and globally, led Peter Ephraim to adopt a broader perspective on food systems. 

“I came to understand that transforming raw agricultural products into finished foods on grocery shelves is only part of the solution,” said Ephraim, who was born and raised in Malawi, where he earned his B.S. in food science and technology from Lilongwe University of Agriculture and Natural Resources. 

Ephraim’s passion for understanding food science motivated him to pursue an M.S. in food science, which he completed in 2023 at North Carolina State University.  

His interest in postharvest physiology led him to pursue a Ph.D. in the Department of Horticulture under Marlee Trandel-Hayse, assistant professor and Ephriam’s mentor for his grant. 

His current research focuses on assessing variations in texture and firmness among rabbiteye and southern highbush blueberry cultivars grown in Alabama.  

“Supported by an AAES PEER grant, my work combines advanced texture analysis, microscopy and cell wall polysaccharide characterization to investigate cellular factors driving variation in fruit texture, quality and shelf-life,” Ephraim said.  

His work aims to provide information that can help breeders develop rabbiteye blueberry cultivars with improved texture, consumer acceptance and marketability; and guide growers to select cultivars with improved firmness retention and extended shelf-life during storage. 

Improving the genetic diversity of rabbiteye blueberries

Sakshi Pathania, a Ph.D. student in the College of Agriculture’s Department of Horticulture. has always had an interest in working in small fruit crop breeding, especially with blueberries. 

So, when she got the opportunity to work on her PhD. in Alabama’s first small fruit breeding program under the direction of Sushan Ru, she jumped at it.  

Pathania — who received her B.S. in agriculture at Punjab Agricultural University, India, and her M.S. at the University of Georgia — was influenced by the many challenges faced by small blueberry growers in Alabama, including unpredictable weather conditions, limited resources, and increasing competition from large corporations. 

“Most of these growers depend on rabbiteye blueberries, the dominant blueberry species grown in the Alabama,” Pahania said. “Compared to southern highbush, rabbiteye blueberries offer several advantages, such as resistance to abiotic and biotic stresses, a unique berry flavor, and good post-harvest shelf life.” 

However, insufficient breeding efforts have left growers dependent on cultivars released more than 40 years ago that no longer meet current market demands or climatic conditions. Breeding efforts are further limited by a narrow genetic base from repeated use of the same founder parents,” she said.  

“To address this, we will evaluate new rabbiteye varieties for yield, fruit quality and bloom-to-harvest period at central and south Alabama locations,” Pathania said. “We will also assess the genetic diversity of existing germplasm using DNA markers to broaden the breeding base and ultimately release improved cultivars adapted to Alabama that provide small farmers with profitable and nutritious options.” 

Evaluating fruit quality and sensory traits in postharvest storage

Having a passion for improving the quality of fresh produce and understanding cultivar performance during cold storage led Clarisse Cochran-Chipura to pursue graduate studies at Auburn University under the guidance and mentorship of Assistant Professor Marlee Trandel-Hayse. 

Cochran-Chipura was born far from the Deep South in the Boston area and was raised between Boston and Chicago. She earned her bachelor’s degree in horticulture with a specialization in general production from Southern Illinois University, Carbondale, in 2024. 

“During my undergraduate studies, I developed a strong interest in fruit crop production,” Cochran-Chipura said. “While Southern Illinois University provided a solid foundation in horticulture, I became particularly interested in postharvest produce quality and sought to explore this area further through graduate training and research.” 

Pursing an M.S. allowed her to build on her horticultural foundation while gaining specialized training in postharvest physiology, fruit quality and sensory science. 

“At Auburn, I am backed by a wonderful committee with extensive knowledge and the tools to assist me in achieving my goals,” she said. 

Cochran-Chipura’s current research focuses on assessing general fruit quality and sensory traits throughout postharvest storage on both rabbiteye and southern highbush blueberry cultivars grown in Alabama.  

“Utilizing the PEER grant, my work combines instrumental fruit quality measurements and sensory evaluation to tell the full story behind the aroma, taste, flavor and textural differences between rabbiteye and southern highbush blueberries,” she said. 

Her research aims to provide information that can 1) assist breeders and growers better understand how blueberry cultivar selection and postharvest storage conditions influence fruit quality, flavor and cultivar differences; and 2) support the selection of blueberry cultivars with improved eating quality, shelf-life and marketability for consumers.