Table II.
Estimation of genome size in Brachypodium species
| Species | Ecotype | 2n | Microdensitometry
|
Flow Cytometrya
|
||||
|---|---|---|---|---|---|---|---|---|
| N | IC/pg | Mbpb | N | IC/pg | Mbp | |||
| B. sylvaticum | B28 | 18 | 31 | 0.22 (0.026)c | 180 (21) | 6 | 0.27 (0.01) | 221 (9) |
| B. pinnatum | B144 | 18 | 28 | 0.27 (0.019) | 221 (16) | –d | – | – |
| B11 | 28 | 30 | 0.49 (0.067) | 402 (55) | 6 | 0.57 (0.01) | 468 (9) | |
| B. phoenicoides | B39 | 28 | 40 | 0.45 (0.077) | 328 (26) | – | – | – |
| B. arbuscula | B96 | 18 | 51 | 0.35 (0.039) | 287 (32) | – | – | – |
| B. distachyone | ABR99 | ?f | 20 | 0.30 (0.024) | 246 (19) | – | – | – |
| ABR100 | 30 | – | – | – | 6 | 0.65 (0.01) | 530 (12) | |
| ABR1 | 10 | 43 | 0.15 (0.023) | 123 (18) | 6 | 0.21 (0.001) | 172 (1) | |
| ABR2 | 10 | 20 | 0.15 (0.033) | 123 (27) | 6 | 0.21 (0.004) | 172 (3) | |
| ABR3 | – | – | – | – | 6 | 0.21 (0.002) | 165 (2) | |
| ABR5 | – | – | – | – | 6 | 0.19 (0.004) | 158 (3) | |
For the flow cytometry, genome sizes were calibrated from the standard genomes listed in “Materials and Methods” from which the following formula was derived: Genome size (Mbp) = Flow cytometer peak −7.5846/0.0265 (R2 = 0.9976). Given this formula our results gave the genome size of Arabidopsis = 165 (±9 se) n = 6. Results for genome sizes in Mbp are rounded up to the nearest whole number.
Scanning microdensitometry data (pg/IC) were converted to Mbp on the basis of 0.1 pg = 82 Mbp (Bennett et al., 2000).
Nos. in parentheses are the se.
–, Not done.
B. distachyon is the only annual species.
ABR99 could not be revived from stocks and was replaced with ABR100, which had a chromosome complement of 30.