Advancing plant breeding for the organic industry

October 15, 2020

A new federal grant from the U.S. Department of Agriculture Organic Agriculture Research and Extension Initiative (OREI) will support Iowa State scientists and collaborators as they develop improved seed corn tailored to the needs of the rapidly growing organic industry.

The lead investigator for the four-year, $1,996,500 grant is USDA Agricultural Research Service research geneticist Paul Scott, an affiliate professor of agronomy at Iowa State. Thomas Lübberstedt, the Frey Chair in Agronomy and Director of the Raymond F. Baker Center for Plant Breeding at Iowa State, will partner on the project, along with Martin Bohn from the University of Illinois Urbana-Champaign and Angela Linarez from the University of Puerto Rico.

The award is part of a $17 million national initiative to improve yields, quality and profitability for producers and processors who use organic standards. The project builds on the germplasm, methods and technologies Scott and Lübberstedt have developed in previous OREI projects.

Corn is the second largest organic grain/seed crop in the U.S. behind wheat. However, only a small proportion of the seed sold to organic farmers is produced using certified organic practices. While several seed companies sell seed that can be used in certified organic systems, few of the varieties available were developed specifically for organic production systems or have been evaluated in organic-production environments.

According to Scott, this research takes new steps to develop three-way hybrids better suited to organic seed production than the single-cross hybrids currently marketed by most companies. The research team is focused on developing hybrids that carry traits desired by organic farmers, especially those identified as priorities during stakeholder meetings the researchers held as they prepared the proposal. These traits include high levels of the essential nutrient methioinine and the ability to withstand weed pressure. Another goal is to create a mechanism for organically grown corn to resist pollination by transgenic pollen floating in from conventional fields, which results in huge losses for organic farmers.

A unique aspect of the project will be two Organic Corn Breeding Boot Camps held at a cooperating winter nursery site in Puerto Rico. These will be attended by farmers, business representatives, and student interns in Puerto Rico, who will work together to produce seed and plan on-farm trials in the Midwest for the following year. The interns will then travel to the farmers' locations the next summer to assist with the trials.

“This is one of the most exciting components of the research,” Scott said. “It’s a rare chance for people who don’t usually interact to dive deep into the process and learn from each other. We will all be students and teachers together.”

The researchers expect the support for the winter nursery in Puerto Rico, where two to three generations of corn can be grown annually, will help establish it as a long-term plant breeding resource.

“This work is important to the organic production industry,” said Alix Paez, a private corn breeder with Genetic Enterprises International (GEI) located in Luther, Iowa, which works with non-GMO conventional and specialty corn hybrids for the central corn belt. “The seed industry has not put enough resources to accelerate creation of new hybrids and varieties for the organic farmer. These OREI-funded projects have been a very valuable resource to develop new products for the seed industry and the organic farmers that need these hybrids.” 

An important component of the project is refinement of a new rapid cycling breeding method, which combines contemporary methods of genomic selection and “doubled haploid,” or DH, breeding, with an organic-friendly breakthrough technology called Spontaneous Haploid Genome Doubling that produces DH-inbred lines.

“This rapid cycle breeding strategy can allow recombination and seed increase to occur in the same generation. That could cut development time for a seed-corn variety down to one-fourth the typical time the pipeline takes now,” said Lübberstedt, who also serves as director of the Doubled Haploid Facility at Iowa State.

“Also, importantly, our novel DH technology avoids using the toxic chemical colchicine, adapting the technology for organic production systems,” Lübberstedt said.

The process requires selection of millions of haploid kernels. This usually requires extensive manual labor. However, the researchers are developing an automated process for single kernel evaluation using near-infrared reflectance spectroscopy for haploid selection and grain quality that will significantly increase efficiency.

The doubled haploid lines and test-crosses will be evaluated under organic conditions in Iowa, Illinois and Puerto Rico where they will be monitored to select for a variety of desired traits, including pest resistance, tolerance to stress factors, lodging tolerance and ability to set seed.

The results of the project will be publicly accessible to researchers and breeders around the world.