The Elementary Analysis of Two Lines "twins" - X186

The sterile lines 36-20S was found in 01-124 paddy fields in 2003 which had no sterile seeds in a two years test under the north-south and low-high temperature condition.In order to retain its sterile gene,the generational expansion method was used.The hybrid sterility rate was as high as 42% in Sep.2011.By using the broad temperature variation in the winter of Nanbin,the rice stubble of sterile rice line X186,fertile individuals and the fertility of the original sterile individuals of the same generation were observed.The results showed that X186G1S and x186HS were temperature sensitive.The starting temperature was 21-22 ℃.X186G2S,x186-1S and X186-2S were antitemperature sensitive sterile line.The critical temperature was 25~26℃.X186 was named as twins since it contains both temperature sensitive sterile gene and anti-temperature sensitive sterile gene.The development of the anti temperature sensitive line X186-1S eliminated the bottleneck of the two-line hybrid rice breeding in the northeast early Japonica rice district.