Polyploidy has played an important evolutionary role in the genus Festuca (Poaceae), and several ploidy levels (ranging from 2n = 2x = 14 to 2n = 12x = 84) have been detected to date. Our understanding of ploidy diversity has greatly improved over the last two decades owing to the usage of flow cytometry (FCM). This valuable method makes it possible to not only estimate the genome size in a large number of individuals and populations but also infer ploidy levels. FCM has been used successfully in Festuca and its use is very useful in detecting a possible overlooked cytogenetic diversity that is generally manifested in the morphological variability exhibited in some of its taxa.
Subspecies (According to Devesa et al., [13]) | 2n | Method | References |
---|---|---|---|
F. yvesii subsp. yvesii | 2n = 6x = 42 * | Counting 1 | [19] |
2n = 8x = 56 | Counting 1 | [17] | |
F. yvesii subsp. altopyrenaica | 2n = 4x = 28 | Counting 2 | [20] |
F. yvesii subsp. summilusitana | 2n = 6x = 42 | Counting 3,4 | [17][18] |
2n = 10x = 70 | Counting and FCM 4 | [12][17] | |
2n = 12x = 84 | Counting and FCM 4 | [12] | |
F. yvesii subsp. lagascae | 2n = 6x = 42 | Counting 5 | [17] |
2n = 8x = 56 | Counting 1 | [17] |
1 F. yvesii, 2 F. altopyrenaica, 3 F. gredensis, 4 F. summilusitana, 5 F. curvifolia.
Taxon | Mountain Range | Locality | n | 2C Mean ± SD (pg) | 2C Range (pg) | Material | DNA-Ploidy Level | 2n |
---|---|---|---|---|---|---|---|---|
F. yvesii subsp. summilusitana | W range: Serra da Estrela (Portugal) | S1: Castelo Branco, Manteigas | 9 | 22.89 ± 0.96 | 21.44–24.17 | F | 10x | - |
S2: Castelo Branco, Sabugueiro | 8 | 26.60 ± 0.35 | 26.18–27.15 | F | 12x | - | ||
S3: Castelo Branco, Torre | 6 | 26.58 ± 0.87 | 25.20–27.71 | F | 12x | - | ||
C-W range: Sierra de Gredos and Candelario (Spain) | S4: Ávila, Puerto del Pico | 5 | 26.89 ± 0.55 | 25.98–27.48 | F | 12x | 84 | |
S5: Ávila, Plataforma de Gredos | 7 | 30.31 ± 0.49 | 29.68–31.16 | F | 14x | 98 | ||
S6: Salamanca, La Covatilla | 6 | 30.48 ± 0.73 | 29.85–31.91 | F | 14x | 98 | ||
NW mountains (Spain) | S7: León, Villalibre de Somoza | 3 | 24.67 ± 1.47 | 23.01–25.84 | D | 10x | - | |
S8: Zamora, Sierra Segundera | 1 | 24.11 | D | 10x | - | |||
S9: Zamora, Alto de San Juan | 1 | 24.82 | D | 10x | - | |||
F. yvesii subsp. lagascae | n range: Sierra de la Demanda and Cebollera (Spain) | L1: Logroño, Valdezcaray | 6 | 13.79 ± 0.15 | 13.62–13.98 | F | 6x | - |
L2: Burgos, Trigaza | 10 | 14.01 ± 0.32 | 13.60–14.46 | F | 6x | - | ||
L3: Logroño/Soria, Puerto de Piqueras | 10 | 17.42 ± 0.29 | 17.06–18.00 | F | 8x | - | ||
C range: Sierra de Guadarrama (Spain) | L4: Madrid, Puerto de Guadarrama | 7 | 16.76 ± 0.22 | 16.57–17.21 | F | 8x | 56 | |
L5: Madrid, Puerto de Navacerrada | 7 | 16.88 ± 0.24 | 16.63–17.36 | F | 8x | 56 | ||
L6: Madrid, Puerto de la Morcuera | 4 | 17.39 ± 0.65 | 16.71–18.23 | F | 8x | 56 | ||
L7: Madrid, Puerto de Canencia | 9 | 21.18 ± 0.62 | 20.51–22.31 | F | 10x | 70 | ||
North range: Cantabrian mountains (Spain) | L8: Puerto de San Glorio | 2 | 19.31 ± 0.41 | 19.02–19.59 | D | 8x | - |
In general, the largest sizes for all the characters were found in the subsp. summilusitana, with the exception of the auricle and awn lengths. In both subspecies, most of the morphological traits increased in size with increasing ploidy; however, no significant differences were observed with respect to all ploidy levels. The lemma, upper glume and seed lengths in particular responded significantly to changes in ploidy in both subspecies. The differences observed in the arithmetic mean obtained for most of the characters are significant only among the most extreme cytotypes of each subspecies, and even in these cases, the ranges of variation overlap.