Jonathan Lynch likes to look beneath the surface. In his quest to breed better crops, the plant physiologist spends a lot of time digging up roots to work out what makes some varieties extremely good at extracting nutrients from the ground. Lynch wants to use this knowledge to develop plants with extra-efficient roots--crops that grow well in the nutrient-starved soils of the developing world. These plants could also reduce the use of fertilizers in richer nations.
Last year, Lynch's forays into the dirt paid off. He and his team at Pennsylvania State University in University Park reported (1) that they had produced a variety of common bean, or string bean (Phaseolus vulgaris), with a combination of root traits that allows it to take up phosphorus from the soil with improved efficiency. In experimental plots, the plants produced three times the bean yield of typical varieties.
That result has raised hopes in Africa, where common beans are one of the most important sources of protein for poor people. Researchers in Mozambique are testing how Lynch's beans perform in the country's ecological zones, and they expect to win regulatory approval to bring the crop to market by next year.
Lynch's beans are among the first successful attempts in a global race to develop crops that grow well in soils depleted of nutrients. "Low availability of nitrogen, phosphorus and water are the main limitations of plant growth on Earth. We desperately need this technology," says Lynch.
His work stands out because he has taken an old-school approach. He is leading a renaissance in some conventional crop-breeding techniques that rely on laboriously examining plants' physical characteristics and then selecting for desirable traits, such as growth or the length of fine roots.
And surprisingly, this approach seems to be outpacing the high-tech route.
Big corporations such as DuPont Pioneer in Johnston, Iowa, have spent more than a decade developing improved crops through genetic engineering, and some companies say that their transgenic varieties look promising in field trials. But there are still no fertilizer-frugal transgenic crops on the market, and several agricultural organizations around the globe are reviewing their biotechnology initiatives in this area.
Plant biologist Allen Good of the University of Alberta in Edmonton, Canada, spent years working with companies to develop genetically modified (GM) crops that require little fertilizer, but he says that this approach has not been as fruitful as conventional techniques. The problem is that there are so many genes involved in nutrient uptake and use--and environmental variations alter how they are expressed.
"Nutrient efficiency was supposed to be one of those traits with broad applicability that could make companies lots of money. But they haven't developed the way we thought," says Good.
Despite the scientific and breeding challenges, some researchers say that all strategies must be explored to develop crops that are less nutrient needy. With the global population heading towards 10 billion people by 2050, frugal crops could be essential to feed the planet. "There is a huge worldwide potential...
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