Hybrid rice, hybrid rice (hybrid rice) refers to the selection of two genetic differences, at the same time, their excellent traits and complementary rice varieties, crossbreeding each other produced by the son of a generation with hybrid advantage. The genotype of hybrid rice is heterozygous, but the genotype between individuals is the same, so the group traits are neat and consistent, can be used as a production seed. Hybrid rice sub-2 generation, factor 1 generation genotypes of heterozygosity and produce trait separation, growth is not neat, the advantage of the decline, the yield of varying degrees of decline, so the sub-2 generation can not continue to be used as seed, so hybrid rice needs to be made every year. Hybrid rice sub 1 generation seed production pathway has three lineage method, two lineage method and chemical killing method. The use of hybrid advantage to improve crop yield and quality is one of the major achievements of modern agricultural science. Japonica rice. Japonica rice, a type of rice (Oryza saliva subsp keng), has a shorter stem, narrower, darker green leaves, and broad, shorter, thicker, elliptical or ovoid Japonica rice seeds. Japonica rice requires a short period of sunlight, but has a long growing period and is relatively hardy. The rice is sticky and has a high protein content and good flavor. Seed strength, good pressure resistance, processing is not easy to produce broken rice, higher rate of rice, rice bloating is smaller. Japonica rice has a lower content of straight-chain starch and a soft gelatin consistency. Japonica rice milled rice called "Japonica rice", some places call "Japonica rice" as "rice", in fact, Japonica rice is only a variety of rice (rice). Japonica rice because of many morphological features and physiological characteristics on the obvious difference from indica rice, and with indica rice between the existence of reproductive isolation and become subspecies, such as hybrid indica rice in the fall when the seed system if strung into the japonica pollen, the first generation of hybrids (f1) will be a lot of sterile "big green tree". Japonica rice stalks are tough, the plant is more bundled, weak tillering; the grain is not easy to thresh, grain or rice in 1% carbolic acid solution impregnation will not be stained.