Conventional crop-breeding techniques that rely on examining plants' physical characteristics and selecting for desirable traits are outpacing the high-tech route of GM
An article in Nature entitled ‘The Race to Create Super-Crops’ discusses the global race to develop crops that grow well in soils depleted of nutrients, reports the Third World Network. Conventional crop-breeding techniques that rely on examining plants' physical characteristics and then selecting for desirable traits, such as growth or the length of fine roots, appear to be outpacing the high-tech route of genetic engineering.
The article highlights milestone research that has produced a variety of common bean (Phaseolus vulgaris), with a combination of root traits that allowed it to absorb phosphorus from the soil with improved efficiency. In experimental plots, the plants produced triple the bean yields of typical varieties. In field trials in Mozambique, beans with shallow roots and long root hairs gave yields of 1,500 kilograms per hectare in phosphorus-depleted soils, compared with local varieties that normally produce just 500 kilograms per hectare. The beans could be a boon for African farmers who struggle with depleted soils. The discovery has already helped improve growth in soya beans in China where the improved soya beans have been planted on 67,000 hectares so far.
Meanwhile, tests in US fields starved of nitrogen showed that maize with few long lateral roots produced yields more than 30% higher than maize with many short lateral roots. The long-lateral-root variety performed even better when tested under drought-like conditions, showing a 144% yield increase. For the past six years, a group at the International Maize and Wheat Improvement Centre (CIMMYT) has been successful in using conventional breeding to create maize that grows well in the nitrogen-starved soils of Africa. Field trials showed that CIMMYT's maize could produce up to 20% higher yields than existing commercial maize varieties in low-nitrogen soils.
Despite the hype, and after more than a decade trying to develop improved crops through genetic engineering, there are still no fertilizer-frugal GM crops on the market. The approach has simply not been as fruitful as conventional techniques. A key challenge for the transgenic varieties is that traits such as nutrient-use efficiency are influenced by a complex web of genes that interact with each other and the environment.
The article is available at: http://www.nature.com/news/the-race-to-create-super-crops-1.19943#/correction1
Source: Third World Network Biosafety Information Service