A researcher watches the mixture of seawater and freshwater being pumped into paddy fields. [Photo by Zhang Mao/for China Daily]

Each variety of salt-tolerant rice has a distinctive tag. [Photo by Zhang Mao/for China Daily]

Fencing is used to separate different rice varieties so that they can't cross-fertilize naturally. [Photo by Zhang Mao/for China Daily]

Yu Meng does a cross-breeding experiment in the field. [Photo by Zhang Mao/for China Daily]