Selection of Submergence Tolerant Homozygous Line by STS Marker and Twice Submergence Stress

One sequence tagged site marker Sub1-1 and twice submergence stress method were used in selection of submergence tolerant homozygous line from Sub-1BS, a submergence tolerant, bentazon sensitive and photoperiod-sensitive and/or thermo-sensitive genic male sterile line that developed by our laboratory. The results revealed that the original Sub-1BS was heterozygous in Sub1A-1 locus even though it was identical in almost all of agronomical traits and the segregation of Sub1A-1 was in accordance with Mendelian law based on chi-square test. And then the original Sub-1BS was divided into two groups: one was of Sub1A-1 introgression and the other was not; and the two groups were tested by twice submergence stress method. After the first submergence stress that lasted for 12 d, the average plant heights were significant difference at the 1% level between the two groups. After recovery for 10 d, the second submergence stress sustained for 18 d was carried on; and the group with Sub1A-1 gene was found apparently tolerant than the other group in submergence tolerance.