Estimation of genome size in Brachypodium species
| Species | Ecotype | 2n | Microdensitometry | Flow Cytometry2-a | ||||
|---|---|---|---|---|---|---|---|---|
| N | IC/pg | Mbp2-b | N | IC/pg | Mbp | |||
| B. sylvaticum | B28 | 18 | 31 | 0.22 (0.026)2-c | 180 (21) | 6 | 0.27 (0.01) | 221 (9) |
| B. pinnatum | B144 | 18 | 28 | 0.27 (0.019) | 221 (16) | –2-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. distachyon2-e | ABR99 | ?2-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) | |
↵F2-a 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 ofArabidopsis = 165 (±9 se)n = 6. Results for genome sizes in Mbp are rounded up to the nearest whole number.
↵F2-b Scanning microdensitometry data (pg/IC) were converted to Mbp on the basis of 0.1 pg = 82 Mbp (Bennett et al., 2000).
↵F2-c Nos. in parentheses are these.
↵F2-d –, Not done.
↵F2-e B. distachyon is the only annual species.
↵F2-f ABR99 could not be revived from stocks and was replaced with ABR100, which had a chromosome complement of 30.