What is the scale of hybrid rice combination planting in excellent varieties?

During the 20 years from 1976 to 1997, China planted 220 million hectares of hybrid rice, increasing the rice yield by 300 million tons. At present, the annual planting area of hybrid rice in China is 6.5438+0.533 million ~ 6.5438+0.6 million hm2, accounting for about 50% of the total rice area and 57% of the total rice output. According to the statistics of National Agricultural Technology Extension Service Center, there are 1993- 1997 combinations in China, with an annual extension area of 6,667 hm2 (654.38+10,000 mu), of which 1 19 ~ 168. Among them, there are 30 hybrid rice with an annual planting area of over 6.5438+0.33 million hectares (2 million mu) (Table 2-654.38+08), and the hybrid rice with an annual planting area of over 667,000 hectares (6.5438+0 million mu) are Shanyou 63, Shanyou 64, You Gang 22, Diyou 63 and Shanyouduo. Shanyou has the largest planting area of 4.87 million hm2 in 63 years, which is the most widely distributed, largest area and best benefit hybrid rice combination in China.

Table 2- 18 The indica hybrid rice (1993- 1997) with an extension area of133,000 hm2 comes from Minghui 63/teteep// Minghui 63/.

Table 2- 19 Cytoplasmic Sources and Main Male Sterile Lines of Main Hybrid Rice

Parental analysis of main hybrid rice combinations showed that there were five types of cytoplasm of male sterile lines, and 9 male sterile lines were mainly used (Table 2- 19). Among them, the sterile lines of three-line hybrid rice derived from wild abortion and their homotypic maintainers Zhenshan 97A and B, V20A and B, and Xieqingzao A and B derived from dwarf abortion have the largest utilization area in production, accounting for about 40% of the hybrid rice area.

Because of the different cytoplasm sources, the restorer genes of indica hybrid rice sterile lines have different geographical distribution. At present, the widely used wild abortion restorer lines mainly come from IR8 and its derived international rice infrared system (Lin Shicheng, Fujian, 199 1). The restorer lines Gui 33(IR36/IR24) derived from IR24, Minghui 63 and Minghui 66 (IR24/TKM6/IR20/4/Italiconivara) derived from IR30 and Ce 64-7 derived from IR36 played a key role in hybrid rice production in China, among which Minghui. Since 1983, five combinations with strong advantages, such as Shanyou 63, Dayou 63, Xieyou 63, Ⅱ You 63 and Teyou 63, have been prepared successively, and the popularization area of 1993 has reached 6.2 million hm2. Ce 64-7 is the restorer line whose application benefit is second only to Minghui 63 in China. The three combinations of Wei You 64, Xieyou 64 and Boyou 64 have also reached 6.5438+0.66 million hm2 in 1.993.