Frances Gould, Bogren, Richard C.
Yenjit Raruang, a graduate student working with Zhi-Yuan Chen, plant pathologist, bags corn tassles for collecting pollen to be used the next day for hand pollination to increase the seeds of the transgenic corn plants that have the potential to suppress Aspergillus flavus infection and reduce aflatoxin contamination. Photo by Zhi-Yuan Chen
LSU AgCenter scientists are continuing their research on aflatoxin and Aspergillus flavus, the fungus that produces it.
Zhi-Yuan Chen, AgCenter plant pathologist, is in the second year of identifying a genetic change that could impart resistance to Aspergillus flavus in corn.
In a process that’s already been used in wheat and tobacco, Chen collaborated with scientists at Iowa State University and inserted genes from Aspergillus flavus into an inbred corn line. The genetic material from the pathogen was inserted into the corn in such a way that the plant sees it as an invasive organism and triggers a defense response to generate plant resistance, Chen said.
Last year, Chen received a handful of transgenic seeds that contained a section of DNA from Aspergillus flavus. The challenge is to create plants that contain the gene in every plant in every generation.
To address this, Chen’s team has been increasing these seeds in a research plot over the past two seasons. This process involves growing the seeds into whole plants and making sure each plant is fertilized by its own pollen through manual hand pollination.
It’s important that the seeds are grown in isolation to comply with USDA Animal and Plant Health Inspection Service regulations, Chen said. To prevent any pollen from reaching other corn plants, the research plots are at the Botanic Gardens at Burden in Baton Rouge, far away from any corn field.
Although the gene is not in every seed in the first generation, the process of self-pollination can create homozygous plants over the course of several generations.
If the transgenic seeds have the genes, they will be less susceptible to fungal infection and aflatoxin production. Chen’s team is collecting seeds from the field and testing seeds from each of 600 plants to determine which contain the gene of interest.
Those seeds will then be used to produce new plants that can be used in future corn breeding programs.
The project is supported by the Aflatoxin Mitigation Center of Excellence administered by the National Corn Growers Association with funds contributed by state field corn commodity boards acros the Southeast. Rick Bogren
The LSU AgCenter and the LSU College of Agriculture