Brassica genome sizes

Overview

Even with large-scale assembled genomes, there is considerable uncertainty surrounding the accurate estimation of genome size. This in part is due to the under-representation of extensive arrays of repeated sequence associated with rDNA/rRNA (NORs) and poorly characterised centromeres. Thus the size of the various Brassica species genomes can only be estimated. There are several convetional established methods of estimation, including Feulgen microdensity measurements and flow cytometry. The values quoted are the haploid genome (1C) equivalents in Mbp. For information on the genome composition and U's triangle see here

Species	MBp	Source	Method	Reference
B. rapa (A)	468 - 516		Flow cytometry	1
	507	var. chinensis Pak choi		1
	511	var. rapifera turnip		1
	529			5
	564			4
	784			3
B. nigra (B)	468	black mustard	flow cytometry	1
	632		flow cytometry	5
	760		feulgen	2
B. oleracea (C)	599 - 618	var. italica broccoli	flow cytometry	1
	603	var capitata cabbage	flow cytometry	1
	628	var gemmifera Brussels sprout	flow cytometry	1
	628 - 662	var botrytis cauliflower	flow cytometry	1
	696		flow cytometry	5
	752		feulgen	4
	868		feulgen	2
B. juncea	1068	brown mustard	flow cytometry	5
	1105		flow cytometry	1
	1495		feulgen	2
B. napus	1129-1235	rapeseed	flow cytometry	1
	1127		feulgen	x
	1132		flow cytometry	5
B. carinata (BC)	1284	Ethiopian mustard	flow cytometry	5
	1544		feulgen	2

References

• 1: Arumuganathan, K. and Earle, E.D. 1991. Nuclear DNA Content of Some Important Plant Species. Plant Molecular Biology Reporter 9(3): 211-215. Table I (Nuclear DNA content of a number of important plant species as determined by flow cytometry)
• 2: Bennett and Smith, 1976, Nuclear DNA amounts in angiosperms. Philosophical Transactions of the Royal Society of London B 274: 227-274
• 3: Bennett MD, Smith JB, Heslop-Harrison JS. (1982). Nuclear DNA amounts in angiosperms. Proceedings of the Royal Society of London B 216:179-199
• 4: Bennett MD, Smith JB (1991) Nuclear DNA amounts in angiosperms. Philosophical Transactions of the Royal Society of London B 334: 309-345
• 5: Johnston JS, et al. (2005). Evolution of Genome Size in Brassicaceae. Annals of Botany. 95:229-235

Links

• The C-value database is maintained at the Royal Botanic Gardens Kew by Bennett and Leitch and has all the appropriate bibliography etc.
• There are estimates from Arumuganathan & Earle (1991) at the National Agricultural Library, USDA
• A preliminary Gene List in Brassica oleracea (Wills, 1977)