Gimode works in the genetics lab to improve farmers’ results in the field

By Alex C. Merritt
University of Georgia, Peanut & Mycotoxin Innovation Lab

Peanut & Mycotoxin Innovation Lab student Davis Gimode’s road to researching peanut genetics began 12 years ago, as a high school graduate who wanted to give back.

Gimode is a Ph.D. student at the University of Georgia’s Institute of Plant Breeding, Genetics, and Genomics (PBGG). While he’s now studying under world-famous geneticists, Gimode said that this wasn’t always the plan.

“I wanted to be an engineer initially. I only got interested in biotechnology after high school, when I got introduced to Professor Jesse Machuka,” Gimode said.


Davis Gimode, a Kenyan PhD student at the University of Georgia, works in the lab of Peggy Ozias-Akins on the UGA Tifton campus. (Photo by Michael Pannell)


Gimode met Dr. Machuka in their home country of Kenya. More than 60 percent of Kenyans work in agriculture, according to the World Bank, and it was in this highly agrarian context that Dr. Machuka helped Gimode realize his passion: utilizing agricultural biotechnology research to improve the lives of others.

“I remember we used to have many late-night discussions about science, and I could clearly see how powerful plant research is in transforming people's lives. His passion caught on to me and over time I have developed my own motivation,” Gimode said.

Gimode was mentored by Dr. Machuka and received a bachelor’s degree in biotechnology, which prepared him to go after a master’s in biotechnology. He received both degrees from Kenyatta University.

While working toward his master’s, Gimode interned at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in Nairobi. There, he was able to continue pursuing his interest in plant research within an international context. His research focused on developing genomic resources for finger millet, a popularly grown, but little researched, crop.

“Working on finger millet was interesting since it is an orphan crop, so there is considerably less research investment for the crop compared to other crops,” Gimode said. “As a result, my master’s research output is very useful to the finger millet breeding community.”

Gimode now works with renowned plant geneticist Dr. Peggy Ozias-Akins at the IPBGG within the College of Agricultural and Environmental Sciences on the Tifton campus. With support from PMIL, he is in the middle stages of reaching two objectives that could transform the way breeders improve peanuts.

His first objective is to understand the genetic attributes of lines of peanut called Chromosome Segment Substitution Lines (CSSLs). These lines were created by transferring genetic material from wild peanuts into cultivated ones. Gimode hopes to observe what influences these wild genes have on the vegetative and reproductive behavior of peanut as well as their effects on the nutritional profile and yield components of the population.

His second research objective is to use genome spanning single nuclear polymorphism (SNP) markers to build statistical models for evaluating the performance of peanut lines. Combined with trait data collected by previous researchers, Gimode’s research can be used to predict how well future peanut lines perform in various situations due to their genetic constitution.

Gimode hopes that the two lines of his research will help peanut breeders produce better products.

“My CSSL work will be useful because it highlights the possibility to harness diversity from wild peanut relatives to improve cultivated varieties,” Gimode said. “Through genomic selection, it will be possible for breeders to save time and money that would have been used in collecting trait data. By using genomic data to predict future performance, peanut breeding efforts are bound to move faster than before.”

Providing this knowledge to plant breeders and researchers could have a large impact on farmers around the globe. The genetic attributes of key crops like peanuts can make or break the food and financial security of an agricultural household.

“Poor performing varieties can lead to starvation, and in many cases,  poverty for poor smallholder farmers, since they depend on selling their surplus to get some money,” Gimode said. “With cutting-edge breeding techniques, it is possible to release improved varieties of peanuts faster.

“Better and faster selection means better availability of varieties that have superior qualities such as oil composition and disease resistance.”

One trait especially important to peanut farmers, processors and consumers is lower contamination with aflatoxin, the natural byproduct of mold that grows on improperly dried staple crops, such as peanuts and maize. Aflatoxin contamination is estimated to cost $20 billion in lost crops a year, and chronic consumption of aflatoxin is linked to cancer, stunting, wasting, and immune deficiencies.

“These breeding techniques promise to improve breeding for less aflatoxin contamination,” Gimode said. “Reducing aflatoxin levels is critical in developing countries where there is high risk of chronic and acute food contamination that directly and negatively impacts people, especially children.”

When his research is complete in 2019, Gimode hopes that the results will lead to new approaches in peanut research. After receiving his Ph.D., Gimode wants to continue pursuing academic research in order to transform lives, just like he and Dr. Machuka talked about over a decade ago.

“For me, basic plant research and breeding has both near and long-term benefits, especially to people in developing countries,” Gimode said. “Doing this research means that I am participating in developing solutions to the very real problem of food security, which, in my opinion, should be an inalienable right to every single human being.”

– Published June 29, 2017