The green revolution in rice was defined by an unprecedented increase in rice production that saved the world from an impending famine in the 1960s. Driving this revolution was the semi-dwarf 1 (sd1) gene conferring the semidwarf phenotype to the rice plant. The shorter stature conferred by sd1 gives the plants resistance to lodging even under heavy doses of nitrogen fertilizer. IR8 carrying sd1, also known as the miracle rice, was the first high-yielding rice variety that came out as a result of intensive research and breeding efforts that capitalize on the use of the semi-dwarf trait to significantly improve rice yield. Although the rice green revolution gene has been used for breeding for decades, the sd1 gene was not identified for a long time. Advancement of rice genomics facilitated the discovery that SD1 encodes the GA biosynthesis gene, GA20ox2. Genome sequencing revealed that several of the varieties used as donor lines in breeding for the semidwarf phenotype in rice possess different alleles of sd1. Apart from breeding applications, dwarf mutants have also been instrumental in uncovering the molecular mechanisms underlying gibberellin biosynthesis and signaling.
- Green revolution
- Rice breeding