PQ
Peanut Genomics Bring the Future Closer: Q &A
By: Lindsay Stevens
with
Dr. Corley Holbrook
NPB: What made you interested in this type of research?
Corley Holbrook, USDA-ARS, Tifton.
There’s a quote that goes, “many hands make light work.” When we think teamwork, rarely is the first image in our mind research. But the collaboration being done by Dr. Corley Holbrook, a USDA supervisory research geneticist, has brought new meaning to this old phrase. Through his work with collaborators like Dr. Peggy Ozias-Akins and Dr. Ye (Juliet) Chen, Holbrook estimated they annually genotype1 over 15,000 seeds using genetic markers. This work has and will continue to lead to scientific breakthroughs, including Holbrook’s latest advancement. Recently, a peanut variety was developed using genetic markers resistant to leaf spot. This development could lead to reduced or eliminated spraying for leaf spot.
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HOLBROOK: When I first started my position in Tifton, I decided a large part of my research would be directed toward breeding peanuts for disease resistance. I screened most of the U.S. germplasm collection for leaf-spot resistance in field studies and for peanut root-knot nematode resistance in greenhouse trials. Unfortunately, the collection of cultivated species only contained moderate levels of resistance to these pathogens. More recently, we got access to genes for resistance from related wild species and this has been a game-changer. For example, Dr. Charles Simpson introgressed2 genes for near immunity to the peanut root-knot nematode, and in the past 15 years, we have used those genes to develop four peanut varieties that are nearly immune to this nematode. More recently, we have begun to use genes for leaf-spot resistance from wild species. We plan to release varieties with high-resistance levels to leaf spot this year. NPB: You are known for collaborating with other researchers at other institutions. How did that come about? HOLBROOK: I greatly enjoy doing peanut breeding and genetic research. I had excellent mentors early in my career that showed me the more I cooperated with other scientists, the more research I could be involved in. Therefore, I have tried to surround myself with as many collaborative scientists as I could find. This has been a huge win for me. I also try to make sure it is a win for them. Usually, it works out that way. NPB: What have been the benefits of collaborating with other researchers? HOLBROOK: I will answer this question with a real-life example. Dr. Peggy Ozias-Akins started her career in Tifton, Georgia, a few years after I had started. Part of her research assignment was molecular-genetic research in peanut. We have been seeking opportunities to collaborate since her start, and for several years, these opportunities were limited due to the primitive (relative to other crops) state of genetic technology in peanut. In 2008, OziasAkins made research breakthroughs that enabled us to begin using markerassisted selection (MAS) in the breeding program. Our research progress was
1Genotyping is a DNA analysis to determine the genes present in a plant to determine if the plant is a suitable parent for future breeding. 2Introgression is the transfer of genetic material from one species into the gene pool by repeated breeding of a specific hybrid with one of its parent species. In this case, the trait was bred in from wild species.
