Table 1.
Copy number of rRNA genes in B. napus and progenitor species determined from NGS reads
| Read archive accession | Mapped reads* | Total reads | GP† (%) | rDNA (Mb) | Copies‡ 1C | |
|---|---|---|---|---|---|---|
| B. rapa | SRR1296482 | 1 453 334 | 78 528 998 | 1·86 | 5·80 | 1709 |
| B. oleracea | SRR074124 | 1 437 383 | 146 402 687 | 1·06 | 5·78 | 1162 |
| B. napus ‘Darmor’ | ERR457740, ERR457754, ERR457738 | 838 265 | 60 083 363 | 1·39 | 11·68 | 2832 |
| B. napus ‘Yudal’ | ERR457757 | 780 687 | 72 174 366 | 1·08 | 9·08 | 2201 |
*
All consensus sequences were 5803 bp long and included the complete 18S–ITS1–5·8S–ITS2–26S subregion.
†
Genome proportion (GP) is defined as number of reads mapped to rDNA divided by the number of total reads (as a percentage). It would be ∼60 % larger if IGS regions are considered.
‡
From genome proportions copy numbers of rDNA sequences were estimated according to the formula: genome size × genome proportion of rDNA units. The following genome sizes were considered: B. napus, 1182 Mb; B. oleracea, 630 Mb; B. rapa, 530 Mb (Bennett and Leitch, 2012).