Table 5.
Characterization of the Transgenic Lines Used in This Study
| Cosegregation of the Transgene with Herbicide Resistance a
|
Transgene Segregation
|
||||
|---|---|---|---|---|---|
| Genetic Locus | T0 Plant | T1 Seedling | T1 Plant | T2 Plant | Transgene/Herbicide Stability (Progression from T0 to T2) |
| Anti-mudrA-3 | 3/3 b, medium c | 3/3 d | 11 (40/120) e,f | N.D. g | Moderate to poor h |
| Anti-mudrA-4 | 3/3, weak | 1/1 | 8 (34/75) | 4 (24/54) e,f | Moderate to good |
| Anti-mudrA-5 | 3/3, weak | 2/2 | 4 (29/59) | 4 (24/54) | Good |
| Anti-mudrA-11 | 3/3, medium | 1/1 | 8 (49/83) | 1 (6/12) | Moderate to good |
| Anti-mudrA-12 | 3/3, medium | 1/1 | 8 (28/73) | 3 (1/41) | Poor |
| Anti-mudrB-1 | 3/3, medium | 2/2 | 3 (30/39) | 3 (12/35) | Moderate to poor |
| Anti-mudrB-2 | 3/3, weak | 1/1 | 6 (29/83) | 2 (2/28) | Poor |
| Anti-mudrB-3 | 3/3, weak | 2/2 | 8 (43/65) | 4 (20/45) | Moderate |
| Anti-mudrB-8 | 2/3, weak | N.D. | 9 (15/88) | N.D. | Poor |
| Anti-mudrB-10 | 2/3, strong | N.D. | 9 (4/79) | 2 (0/35) | Poor |
Cosegregation (linkage) of transgene expression and herbicide resistance was evaluated by RNA gel blot analysis and a Basta sensitivity test, respectively, for the indicated samples.
Number of plants expressing the transgene in the eighth leaf/number of Basta-resistant plants.
Relative level of transgene expression determined by an RNA gel blot analysis. Assigning weak expression as 1.0, medium corresponds to fourfold to eightfold higher and strong corresponds to more than eight times higher expression than the weak level.
Number of plants expressing the transgene in the fifth leaf/number of Basta-resistant plants.
Number of ear families tested in each transgenic line (number of Basta-resistant plants/total plants tested). Data are the sum of results obtained from all families of that line. Transgenes were transmitted through the egg.
Transgene expression was determined in families of plants by examining resistance to Basta applied to the tenth leaf.
N.D., not determined.
Families were ranked by the ratio of T1 or T2 plants expressing the transgene to those lacking it. Maintenance of ranges of the ratio from the T0 to the T2 generation was scored as good (1 ± 0.2), medium (1 ± 0.4), or poor (<0.5). A ratio <0.5 predicts a high probability of transgene silencing in the next generation.