Japonica rice can't be grown in the south. Japonica rice is planted for a long time, only in places where it is harvested once a year. Japonica rice varieties are still hybrid. Now almost all rice is hybrid rice. Indica rice and japonica rice are only the classification of rice species, and have nothing to do with hybridization or not. There is also a hybrid variety of indica rice and japonica rice-long grain fragrant rice.