What does the use of big data in corn genomics mean for today’s producers? “If we can understand what makes a particular hybrid perform the way it does in a particular environment, different hybrids could be placed strategically where they would perform the best,” states Dr. Candice Hirsch, a corn geneticist and genomics professor at the University of Minnesota.
Hirsch’s Maize Translational Genomics lab generates big data to study these relationships between corn genetics, the environment and phenotypic variation under different growing conditions. Getting that data, however, is labor intensive. Plants are sampled from the field, then DNA is isolated and sequenced. The result is terabytes worth of data to try and make sense of. Each plant has 2.3 billion genomic bases and these are compared against all other plant samples.
There is a surprising amount of genetic diversity among corn hybrids, according to Hirsch. To illustrate, 26 corn plants were analyzed and each had about 40,000 genes. However, they found 100,000 unique genes across all varieties. That translates into 60,000 extra genes that are sometimes present within each genotype.
As corn genomic data expands, it will allow plant breeders to predict performance for a large number of progeny without having to grow every individual in every field envi-ronment. Big data can help us understand how different genotypes interact with the environment.
Recent studies have shown that different genes control a plant’s performance potential versus its ability to react to its environment – or plasticity. Other studies suggest that corn breeding may have reduced this genomic plasticity.
To study plasticity, Dr. Hirsch’s group measured the height of every plant in 500 different varieties in several environments at several times during the growing season using drones. The resulting plant growth curves could be compared.
Their results showed significant diversity in the growth curves, even when varieties ended the season at the same height. Data like this helps quantify the genetic elements that contribute to stable growth patterns across environments and improved corn crops.
Hirsch’s group wondered if they could also use drones to study how plants interact with different management practices. Unfortunately, a massive wind event occurred, and their plans shifted into studying lodging and recovery.
A repeated study the following year also had a lodging event, so they took a closer look at the underlying variation affecting lodging and recovery instead. They identified high plant densities and corn stage as important factors affecting lodging and recovery.
What about climate change? Tom Hoverstad, researcher at the Southern Research and Outreach Center, observes that as the climate gets warmer and wetter, corn genetics also change. “Since corn is bred, selected and tested where they’re going to be grown,” he states, “new hybrids are adapted to that changing environment.” However, if the climate starts to change more rapidly, it may be a challenge for corn genetics to keep up.
Will the warming climate translate into growing longer relative maturity hybrids? Not necessarily, according to Hoverstad. “Even if we gained a few growing degree days during the spring, soils still need to dry out before planting. More importantly, the risk of frost hasn’t changed,” he states. Since first fall frost dates haven’t shifted dramatically, maturity ratings haven’t moved.
Hirsch’s lab has documented an incredible amount of genetic diversity in corn plants. “The use of big data allows us to maximize yield increases under increasingly stressful conditions,” concludes Hirsch.
For more information from University of Minnesota Extension, visit extension.umn.edu/ crop-production.
Thanks to the Soybean Research and Promotion Council and the Corn Research and Promotion Council for their generous support of this program.
