The vast fields of wheat in Northeast China are no ordinary plants—they were created in outer space. They are a variety known as Luyuan502 and are China's second most (wide) grown type of wheat. The plants were bred from seeds (fly) into orbit 340 km above the Earth's surface. In the unique low gravity environment, they picked up subtle（微妙的） changes to DNA that gave them new qualities, made them more tolerant to drought and able to better resist certain diseases.
They are an example of a growing number important food crops that are being bred on spacecraft and space stations while orbiting our planet. some of the mutations （突变） leave the plants unable to grow, others can be advantageous. Some plants become (strong) than previous ones. Besides, they are able to resist more extreme growing conditions, but others produce more foods from a single plant or grow faster or require less water.
China (experiment) with space mutagenesis since 1987. Since then it has conducted dozens of missions (carry) crop seeds into orbit. "We benefit from China's strong space programme," says one of the (expert) in China's space mutagenesis project. "We can use recoverable satellites, high-altitude platforms and manned spacecraft to send our seeds to space up to (two) a year and use those space utilities for crop improvement."
