Drought-tolerant corn on the left, non-drought-tolerant hybrids on the right.
The science of breeding in drought tolerance
Two years of extreme drought made Amarillo, Texas, perfect for testing drought-tolerant hybrids. Last summer,Qingwu Xue, Texas A&M assistant professor of crop stress physiology, and research assistant Jake Becker planted test plots of drought-tolerant hybrids from DuPont Pioneer and Syngenta under the same center pivot.
“The most significant thing we saw here was better kernel set among the drought-tolerant corn compared to the check hybrids,” says Xue.
Becker adds, “Drought-tolerant hybrids really do well at exerting silks, even during very harsh conditions, at the same time tassels are shedding pollen. Many hybrids may even sense moisture deep in the soil and develop root systems that can seek out water.
“It is very challenging to breed for drought tolerance,” Becker says, explaining that all seed companies employed genetic mapping to identify the various genes that control how plants react to stress. “Syngenta and Pioneer have taken a native approach that uses genetic markers to cross germplasm lines containing certain genetic characteristics with others known to have good drought tolerance. While also using genetic mapping, Monsanto’s DroughtGard hybrids are the result of a single gene event created using biotechnology to transgenically add to corn drought tolerance genes found in bacteria,” he says.