Wheat is one of the last commodity crops to be hybridized in the United States. the process is difficult because wheat self-pollinates. Europe and India markets offer limited wheat hybrids, and three companies — Bayer, AgriPro Syngenta and DuPont Pioneer — are developing wheat hybrids for the U.S. market.
“When farmers plant winter wheat in September,” says Jon Rich, AgriPro Syngenta wheat breeder and product manager, “it’s hard for them to predict if it will be a wet fall, a dry fall, a really cold winter, a warmer winter or how spring will be. Hybrid wheat provides more predictability over time. The ability of heterosis — hybrid vigor — to show qualities superior to both plant parents makes hybrids more stable and able to increase on-farm averages each year.”
Jon Rich, AgriPro
Hybridizing wheat is not a new effort. Pioneer developed and marketed hybrid wheat nearly 40 years ago. “We have a lot more tools available today,” says David Miller, DuPont Pioneer research director for wheat. “New breeding technology applied to other crops includes doubled haploids and molecular breeding.”
David Miller, DuPont Pioneer
Doubled haploids allow plant breeders to achieve uniformity quickly by doubling chromosomes of either female or male gamete in one generation of a wheat plant. “We now work under what I like to call a ‘hybrid breeding philosophy,’" Miller continues. “Most crops — whether corn, canola, sunflowers, sorghum, rice or millet — are hybridized for better vigor and yield.”
Today’s precision agriculture methods support hybrid development through tillage and inputs. “The same technology utilized in high-value crops, such as corn and soybeans, will help cereals become more profitable for farmers,” Rich says. “We have plant genetics that continually push yields higher, but we also have to work with producers. They need to understand how to properly grow the hybrid to maximize its genetic potential with fertility techniques, crop protection products and seed treatments.”
It takes years
Breeding crop hybrids, even with today’s technology, takes years. AgriPro Syngenta expects to release its wheat hybrid seed in 2020. DuPont Pioneer’s hybrid is a decade out from market, and Bayer also aims to launch in the mid-2020s.
“This is an exciting time for wheat,” Rich says, “because the investment and research into better genetics is the highest it’s ever been. Having several companies and public universities working in concert will bring wheat to the next level. Wheat has lost acres to other crops over the last couple of decades, and we need innovations for wheat producers to be more profitable.”
Hybridizing wheat is more complex than other crops, and molecular genomic sequences accelerate the process. “In my graduate work 30 years ago,” explains Ed Souza, wheat breeding research director, Bayer, “I spent three years trying to get chromosome markers on cereal plants. Now we can do 100,000 markers in a day for $20. What used to take years for hybrid genetics, we are now able to do in 12 to 18 months.”
The anther, ovary and stigma reside in the same flower compartment in the wheat plant. The challenge for plant breeders is to sterilize the anther so the plant will cross-pollinate with another wheat variety’s pollen. “Wheat doesn’t exchange pollen much between plants,” Miller says, “so we are trying to bend Mother Nature and move pollen in ways we haven’t asked it to move before.”
To determine which male and female plants to cross-pollinate, researchers select for winter-hardiness, drought resistance, disease tolerance and high-yield performance to improve end-use quality for consumers. “We also look at smaller traits, for regional climate adaption from Montana to Texas,” Rich says.
Hybrids bring higher yields
As a staple of human diets worldwide, increasing wheat yields on existing farm acres will help meet the food need of the growing global population. “Wheat hybrids could really make a difference in agriculture for the farmer,” Souza says.
Hybrid crops hold a 5% to 20% yield advantage over nonhybrid varieties. Also, hybrid seed is a risk management tool for farmers, as it tolerates weather and disease stresses in the field. “I think Mother Nature influences yield level the most through weather,” Miller says. “Hybrids can provide an advantage under a broad range of growing conditions, and reduce environmental footprint by producing more food on fewer acres.”
It’s important for wheat growers to not solely rely on wheat hybrid seed to increase yields, but to keep a holistic focus. To reach full hybrid potential, Rich recommends farmers use soil tests, proper fertilization, correct rates of seed per acre, protect against disease, and — if under irrigation — efficiently and properly apply water. “It not only takes us, the plant breeders,” he says, “but also the farmers — down to the field level — to maximize genetics.”
Hemken writes from Lander, Wyo.