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Farmers transplant rice seedlings in paddy field

But some researchers are trying to introduce GM into successful conventional breeding programmes. Report: Claire Robinson

China's salt-tolerant "seawater rice" has once again made headlines, with assertions that it could feed 80 million people. One report says, "The salt-tolerant rice type developed in test fields in Tianjin is expected to help ensure food security. It recorded a yield of 4.6 metric tons per acre last year, which is more than China's national average for the production of standard rice varieties."

A report in Bloomberg says, "the strains were created by over-expressing a gene from selected wild rice that’s more resistant to saline and alkali".

GMWatch readers have questioned whether this salt-tolerant rice is GM. In fact, it is the product of a successful conventional breeding programme led by agricultural scientist Yuan Longping of the Qingdao Sea Rice R&D Centre, who died in 2021. The programme has been in progress since at least 2014.

Use is being sought for GM

In an important caveat, however, researchers are reportedly attempting to introduce GM into the salt-tolerant rice breeding programme. One report says, "In addition to working with the 176 selected strains, researchers in Hainan are also making efforts to use hybrid technologies and genetic engineering to breed more strains of saline-alkali-resistant rice for further trials."

This is no doubt because GMOs can be patented, whereas non-GMOs present far more difficulties around patenting.

However, researchers will struggle to use genetic engineering to produce salt-tolerant rice. This is because salt tolerance is a complex genetic trait – the product of many genes working together – whereas GM (including gene editing) can only manipulate one or a few genes at a time. The way GMO developers often get around this problem is by selecting (some would say "pirating") a conventionally bred crop that already has the traits they want and adding a GM Bt insecticidal or herbicide tolerance gene in order to claim patents and gain headlines about the supposed success of GM. We can't rule out that they will use this tactic with salt-tolerant rice.

While GM struggles to get out of the starting blocks in producing salt-tolerant crops, conventional breeding is forging ahead. The salt-tolerant rice is one of many examples of conventional breeding being successfully used to develop crop plants with this trait – other such crops include potatoes, soybean, and wheat.

Other non-GM rice successes from China

Salt tolerance is not the only trait that Chinese researchers have developed in rice by applying conventional breeding. In an article published in Nature Reviews Genetics in 2021, the rice researcher Qifa Zhang reported that he had decided to switch the focus of his research from improving yields to improving nutritional value.

He wrote that "advances in genomic research have made it feasible to breed black rice varieties with improved texture and flavour. In particular, my research group has found landrace varieties of black rice with good cooking quality and palatability, and we have applied genomic breeding technologies to increase their yield and their resistance to disease and insects. These improved rice lines have now been under field trials in multiple locations with promising results."

While "genomic breeding technologies" is a vague term, we interpret it as meaning conventional breeding assisted by modern biotechnologies that provide knowledge of the genome in general and the genes of interest in particular. This interpretation is backed by a scientific paper authored by Zhang in which he describes his team's development of "Green Super-Rice" through "genomic breeding", which is defined as involving a suite of techniques, including marker assisted selection, but not including GM. A press article also reports that GM was not used.

Journey of a GMO promoting researcher

In an ironic twist, Qifa Zhang was a notorious GMO promoter in China who in 2014 was suspected of being involved in the illegal and deliberate spread of GM Bt rice, which he developed but which has not been approved for commercial cultivation or consumption. And in his Nature Reviews Genetics paper, Zhang claims to have gained inspiration for his nutritional rice breeding programme from a paper on Cathie Martin's GM purple "cancer-fighting" tomato.

Yet while delivering the obligatory public bow to the supposed power of GM to confer healthy traits in crop plants, Zhang appears to have returned to the far more promising approach of conventional breeding for his rice programme. GMWatch's email to Zhang, in which we asked him to confirm whether he was using GM in the research he reported in Nature Reviews Genetics, went unanswered. Given his historical enthusiasm for GM, it's probable that if he were using the technology, he would take this opportunity to say so.

Given the proven spectacular success of China's non-GM rice breeding programmes, it should resist attempts to introduce the substandard and risky technology of genetic engineering into this staple crop.