Table 2. Summary of cytogenetic analyses conducted on Brachypodium distachyon (lines Bd21 and Bd3-1), B. stacei (lines ABR114 and Bsta5), their derived autopolyploids (4× followed by same line name), F1 interspecific hybrids, synthetic allotetraploids (generations S0 to S2) and the natural B. hybridum (lines ABR113 and Bhy30).
| Species/cross | Line | Flow cytometry | Mitosis metaphase stage | ||||
|---|---|---|---|---|---|---|---|
| Plants tested | Ploidy level | Plants tested | Chromosome number (DAPI staining) | Number of 45S rDNA sites | Number of chromosomes hybridizing with the BAC ABR1-63E06** | ||
| B. distachyon | Bd21 | 2 | 2x | 1 | 10 | 2 | -* |
| Bd3-1 | 2 | 2x | 1 | 10 | 2 | - | |
| 4×Bd21 | 3 | 4x | 2 | 20 | 4 | - | |
| 4×Bd3-1 | 2 | 4x | 2 | 20 | 4 | - | |
| B. stacei | ABR114 | 2 | 2x | 1 | 20 | 2 | - |
| Bsta5 | 2 | 2x | 1 | 20 | 2 | - | |
| 4×ABR114 | 15 | 4x | 15 | 40 | 4 | - | |
| 4×Bsta5 | 1 | 4x | 1 | 40 | 4 | - | |
| F1 interspecific hybrids | F1_21×114 | 40a | 2x | 8 | 15 | 2 | 5 |
| F1_3–1×5 | 1a | 2x | 1 | 15 | 2 | 5 | |
| Synthetic allotetraploids (S0 generation) | allo21×114 | 23a | 4x | 10 | 30 (6)b | 4(6)b | 10 (6)b |
| 30 and 15 (4)c | 4 and 2(4)c | 10 and 5(4)c | |||||
| allo3-1×5 | 1a | 4x | 1 | 30 | 4 | 10 | |
| Synthetic allotetraploids (S1 generation) | allo21×114 | 10a | 4x | 5 | 30 | 4 | 10 |
| allo3-1×5 | 10a | 4x | 2 | 30 | 4 | 10 | |
| Synthetic allotetraploids (S2 generation) | allo3-1×5 | 10 | 4x | 10 | 30 | 4 | 10 |
| B. hybridum | ABR113 | 2 | 4x | 1 | 30 | 4 | 10 |
| Bhyb30 | 2 | 4x | 1 | 30 | 4 | 10 | |
* Not analyzed
** Specifically hybridizes to B. distachyon chromosomes and the B. distachyon-like chromosomes in B. hybridum.
a These plants were obtained by vegetative cuttings from one initial plant of each category
b Number of plants showing doubled genome karyotype
c Number of plants showing mixed karyotype, indicating chimerci tissues with both cellesof doubled and non-doubled genome