Table 1.
Results of screening for seedling cold tolerance (CT) of four BC 2 F 2 populations derived from crosses between C418 ( japonica ) and four indica donors and introgression patterns of the resultant 30 verified cold-tolerant introgression lines
| Population code | Donor | N 1 1 | N 2 1 | SI (%) 1 | N 3 1 | B 2 | H 2 | IF 2 |
|---|---|---|---|---|---|---|---|---|
| A |
Zihui100 |
800 |
8 |
1.0 |
6 |
0.086 |
0.179 |
0.175 |
| B |
Bg300 |
800 |
11 |
1.4 |
6 |
0.035 |
0.373 |
0.222 |
| C |
Cisanggarung |
800 |
15 |
1.9 |
13 |
0.086 |
0.289 |
0.231 |
| D |
Manawthukha |
800 |
7 |
0.9 |
5 |
0.018 |
0.315 |
0.176 |
| Average | 800 | 10.3 | 1.3 | 7.5 | 0.056 | 0.289 | 0.201 |
1N1 is the original size of the BC2F2 population used for screening seedling CT. N2 is the number of surviving plants selected from each population after exposure at the seedling stage to a 20-d cold treatment. N3 is the number of selected BC progeny with significantly improved CT as confirmed by progeny testing of their derived BC2F6 ILs under 7-d cold treatment in a phytotron at the seedling stage. SI is the selection intensity.
2B, H and IF are frequencies of the donor homozygote, heterozygote, and donor introgression, respectively, in the selected CT ILs.