Resisting drought: conventional plant breeding outperforms GM Updated for 2024

Updated: 05/05/2024





Since its launch in 2010, the Improved Maize for African Soils Project (IMAS) has developed 21 conventionally bred varieties which have increased yield by up to 1 tonne per hectare.

The plan is to commercialise these varieties and introduce them in eight countries.

In contrast, the project’s researchers say that they are at least 10 years away from developing a comparable GM variety.

In another programme – The Drought Tolerant Maize for Africa project – 153 new, conventionally bred varieties have improved yields in 13 countries.

In field trials, these varieties increase yields by up to 30% under drought conditions.

It is estimated that by 2016 the extra yields from these conventionally bred, drought-tolerant maize varieties could help reduce the number of people living in poverty in these 13 countries by up to 9%.

Conventional breeding proving “far more successful” than GM

According to the leading science journal Nature, these successes are based on access to the large seed bank managed by the International Maize and Wheat Improvement Center (CIMMYT) in Mexico City.

Breeders from CIMMYT and the International Institute for Tropical Agriculture (IITA) in Nigeria identified maize varieties that thrive in water-scarce regions.

They cross bred these var­ieties and mated the most drought-tolerant of their offspring. The result – after several breeding cycles – is seed that is even better adapted to drought conditions.

Finally these plants were crossed with varieties that had been successfully grown in Africa.

According to Kevin Pixley, director of CIMMYT’s genetic resources programme, it is a “painstaking process”, but it is proving far more successful than genetic engineering approaches.

Drought tolerance is a complex trait that involves multiple genes and genetic engineering techniques which target one gene is taking longer and is significantly less effective.

Understanding ecology led to breakthrough

The CIMMYT researchers established that a key characteristic in the plants ability to withstand drought is the number of days between when the plant’s male organs shed pollen and when the female silks emerge.

When water is scarce, the silks emerge late. If the delay is long enough, they emerge after the plants have released their pollen and are not fertilized.

“Finding out this relationship was very important to be able to select for drought tolerance”, says Pixley.

By favouring plants with shorter intervals between pollen release and silk emergence, breeders were able to produce maize that was more resistant to drought.

GMO crops – and the food system – is not fit for purpose

CIMMYT and six other research organizations are collaborating with Monsanto on genetically engineered drought resistant maize varieties but admit they are several years away from any success.

Of course this is not the story we usually hear from the research establishment and the media.

Unusually the journal Nature has broken ranks and highlighted that far from being essential in ‘feeding the world’ – and especially the drought prone areas such as Africa – genetic engineering is less useful than conventional breeding.

The evidence that GMO crops are not fit for purpose in Africa has been apparent for some time.

Yet we are still being force fed the line that a genetic engineering techno fix is essential to combat climate change and nourish the world’s growing population.

The complex ecological relationships and part played by; e.g. soilmicro-organisms and fungi, is largely ignored. So are agro-ecological methods such as Sustainable Rice Intensification (SRI).

And so is the most crucial fact of all: the world already produces enough calories to feed 14 billion people and the problem is not production; it is waste, inequitable distribution and lack of access to land, water and supply chains for small farmers and communities.

But that is dismissed as irrelevant or skated over in the interests of maintaining a corporate dominated, commodity trade focussed agriculture and food system where the overwhelming goal is the generation of short term profit.

 


 

Lawrence Woodward is founder and director of GM Education, where this article was originally published. 

Source:Cross-bred crops get fit faster‘, Nature.

 

 






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