Annals of Botany 85: 557-561, 2000

Nuclear DNA Amounts in Roses

K. Yokoya, A. V. Roberts, J. Mottley, R. Lewis and P. E. Brandham

Nuclei
isolated from young leaves were stained with propidium iodide (PI) and their
fluorescence intensities were measured by flow cytometry. The ratio of
fluorescence intensities of four calibration standards and 34 roses to an
internal standard, parsley (*Petroselinum crispum*), provided a basis for estimating the
DNA amounts of *P. crispum* and rose. The 2C DNA amount of *P. crispum* (2n = 22) was estimated as 4.46 pg (s.d. ± 0.08 pg). The 2C DNA amounts of diploid
roses (2n = 14) varied between subgenera,
sections and cultivars, and ranged from 0.78 pg (s.d. ± 0.08 pg) in *Rosa
xanthina *and *R.
sericea* (section
Pimpinellifoliae) to 1.29 pg (s.d. ± 0.08 pg) in 'Félicité
et Perpétue' (Hybrid
Sempervirens). Within each section, the DNA amounts of diploid species were
similar. In the sections Carolinae and Cinnamomeae, DNA amounts were
proportional to ploidy numbers. **In the Pimpinellifoliae, DNA amounts of
tetraploids were disproportionately larger than those of diploids which suggests
that they originated as hybrids with species of sections with larger DNA
amounts. **Ratios of
the fluorescence intensities of nuclei of roses to *P. crispum* (internal standard) were also
measured using 4',6-diamidino-2-phenylindole (DAPI) which binds preferentially
to AT base pairs. These DAPI ratios were lower than, but closely correlated (r^{2} = 0.997) with PI ratios. Fluorescence
intensities of either PI or DAPI-stained nuclei of roses can be used as rapid
indicators of ploidy if variation in the DNA amounts between different taxonomic groups is taken into account.

Pimp. | BB | R.
xanthina Lindl.
'Canary Bird' |
2x = 14 | 0.78 ± 0.08 |

Pimp. | BB | R. sericea Lindl.
f. pteracantha (Franch.) Rehd. & Wils. |
2x = 14 | 0.78 ± 0.08 |

Hulth. | BB? | R.
persica Michx. |
2x = 14 | 0.84 ± 0.08 |

Hesp. | BB? | R.
stellata Woot.
var. mirifica (Greene) Cockerell |
2x = 14 | 0.86 ± 0.08 |

Cinn. | BB | R.
willmottiae Hemsl. |
2x = 14 | 0.92 ± 0.08 |

Carol. | DD | R.
foliolosa Nutt. |
2x = 14 | 0.94 ± 0.08 |

Platy. | BB? | R.
roxburghii Tratt.
var. hirtula (Reg.) Rehd. & Wils. |
2x = 14 | 0.95 ± 0.08 |

Cinn. | DD? | R.
iliensis Chrshan. |
2x = 14 | 0.95 ± 0.08 |

Carol. | CC | R.
nitida Willd. |
2x = 14 | 0.95 ± 0.08 |

Cinn. | CC | R.
rugosa Thumb.
var. alba W. Robins |
2x = 14 | 0.98 ± 0.08 |

Bank. | AA | R.
banksiae Ait.
var. lutea Lindl. |
2x = 14 | 1.04 ± 0.08 |

Syn. | AA | R.
arvensis Huds. |
2x = 14 | 1.12 ± 0.08 |

Syn. | AA | R.
wichuraiana Crép. |
2x = 14 | 1.13 ± 0.08 |

Laev. | AA | R.
laevigata Michx. |
2x = 14 | 1.14 ± 0.08 |

Syn. | AA | R.
sempervirens L. |
2x = 14 | 1.14 ± 0.08 |

Bract. | R.
bracteata Wendl. |
2x = 14 | 1.15 ± 0.08 | |

Ind. | AA | R.
chinensis Jacq. |
2x = 14 | 1.16 ± 0.08 |

Hort. | AA | 'Ballerina' | 2x = 14 | 1.18 ± 0.08 |

Hort. | AA | 'Félicité et Perpétue' | 2x = 14 | 1.29 ± 0.08 |

BBBB | Hypothetical amphidiploid of xanthina and sericea |
4x = 28 | 1.56 ± x.xx | |

Hort. | 'New Dawn' | 3x = 21 | 1.76 ± 0.08 | |

Hort. | 'Frensham' | 3x = 21 | 1.79 ± 0.08 | |

Pimp. | BBCC | R spinosissima L. var. hispida (Sims) Koene |
4x = 28 | 1.85 ± 0.08 |

Cinn. | BBEE | R.
latibracteata Boul. |
4x = 28 | 1.91 ± 0.08 |

Cinn. | BBDD | R.
fedtschenkoana Reg. |
4x = 28 | 1.94 ± 0.08 |

Cinn. | BBEE | R.
bella Rehd.
& Wils. |
4x = 28 | 1.94 ± 0.08 |

Pimp. | BBDD | R.
foetida Herrm. |
4x = 28 | 1.95 ± 0.08 |

Carol. | CCDD | R.
virginiana Mill. |
4x = 28 | 1.95 ± 0.08 |

Gal. | AACC | R.
damascena Mill. var. versicolor West. |
4x = 28 | 2.16 ± 0.08 |

Gal. | AACC | R.
gallica L.
var. officinalis Thory |
4x = 28 | 2.20 ± 0.08 |

Gal. | AACC | R.
centifolia L. |
4x = 28 | 2.23 ± 0.08 |

Hort. | 'Mountbatten' | 4x = 28 | 2.30 ± 0.08 | |

Cinn. | AABBEE | R.
moyesii Hemsl.
& Wils. |
6x = 42 | 2.88 ± 0.08 |

Can. | AABDE | R.
canina L. |
5x = 35 | 2.91 ± 0.08 |

Cinn. | BBDDEE | R.
acicularis Lindl. var. engelmannii S. Wats. |
6x = 42 | 3.04 ± 0.10 |