Yuan Longping, a renowned agronomist who developed the first hybrid rice strains, has died at the age of 91 in Hunan Province.

Yuan, born in September 1930, cultivated the world's first high-yielding hybrid rice, which has helped feed nearly one-fifth of the world's population.

His discovery in 1973 was especially important because hybrid rice could produce an annual yield about 20 percent higher than conventional rice strains, and could feed an extra 70 million people a year.

After fighting China's food shortages, Yuan turned his attention to a much bigger problem, solving world hunger.