What is hybrid rice? What are the types of hybrid rice?

Hybrid rice refers to the hybridization of two genetically different rice varieties or types to produce a hybrid combination of offspring. Unlike conventional rice, which is genotypically pure, hybrid rice is genotypically heterozygous, with its cytoplasm originating from the mother, and half of the genetic material in the cell nucleus coming from the mother and half from the father.

Since the genes between individuals in the hybrid generation are the same, the population traits are neat and consistent, and can be used as production seed. And from the 2nd generation onwards, due to gene separation, there will be plant height, tasseling stage, tillering power, spike type, grain type and rice quality and other traits separation, resulting in the decline of the advantage, yield decline, can not continue to be used as seed.

Therefore, hybrid rice needs annual productive seed production to obtain enough hybrid generation seeds to meet production needs. According to the hybrid rice parental genetic differences and different seed production pathways, China's production and application of hybrid rice are mainly three lines of hybrid rice, two lines of hybrid rice. Three-line hybrid rice is the use of sterile lines, maintaining and restoring three lines, through two hybridization procedures to produce hybrid rice seeds.

Two-line hybrid rice is the use of light temperature-sensitive nuclear sterile lines and recovery lines to produce hybrid rice seeds by one hybridization. According to the indica-japonica type and kinship, it can be divided into three lines of hybrid indica rice, three lines of hybrid japonica rice, three lines of indica-japonica subspecies interspecies hybrid rice, as well as two lines of hybrid rice, two lines of hybrid japonica rice, two lines of subspecies interspecies hybrid rice and other different types.