For years, GM proponents have been claiming breakthroughs in developing crops that tolerate saline soils. But none have been commercialised. An article from 2009 said only that GM scientists "are close to developing crops that are tolerant of salt".
The difficulty is that salt tolerance in plants is regulated not by one or two genes but by a complex network of genetic functioning that cannot be replicated by the crude methods of the genetic engineer.
GM salt tolerant crops, if they existed, would be a band-aid solution to a problem that intensive and chemical agriculture has caused. The sensible answer to salination of soils is prevention by sustainable farming and water management techniques. If it's too late for prevention, then the soil must be rebuilt by incorporating plenty of organic matter into it and planting different crops in stages according to its recovery.
As any coastal grower knows, there is no shortage of naturally salt tolerant plants and crops. In India, Dr Vandana Shiva's biodiversity organisation Navdanya has collected indigenous varieties of salt tolerant crop seeds for years. Following the 2004 tsunami, scientists said that local farming would have to be put on hold for five years because too much salt had been washed into the soil. But Navdanya dug into its seed bank and distributed salt-tolerant crop seed to farmers, enabling them to keep producing.
While GM struggles to get out of the starting blocks in producing salt-tolerant crops, conventional breeding forges ahead. Here are some examples.
Potato
Dutch saltwater potatoes offer hope for world's hungry (April 2015)
Could “salt potatoes” create a food revolution? (video) (January 2015)
Salt tolerant potato poised to launch a world food revolution (October 2014)
Rice
"Sea rice": As genetic modification struggles, crossbreeding succeeds (October 2018)
Tanzanian rice swells yield from salty soil (March 2016)
“Green Super Rice” is saline-tolerant, drought-tolerant, disease-resistant, and high-yielding without the use of fertilisers and pesticides (November 2014)
Baby rice plant may be breakthrough in salty farming (April 2013)
Wild parent spawns super salt-tolerant rice (April 2013)
New salt-tolerant rice strain could help in fight for food security (April 2013)
Soybean
Research finds salt tolerance gene in soybean (January 2015)
Associate Professor Gilliham said, “We can now use this information to find similar genes in different crops such as wheat and grapevine, to selectively breed for their enhanced salt tolerance.”
Wheat
Salt-tolerant wheat developed in Australia (April 2010)
CSIRO researchers have developed a salt tolerant durum wheat that yields 25 per cent more grain than the parent variety in saline soils.
New salt-tolerant wheat set to bring life to "dead" farmland (July 2004)
Scientists have developed a non-GM salt-tolerant wheat which could allow farmers to crop a third of the 1.8 million hectares of agricultural land lost to salinity across Australia's wheat belt.