Preliminary insights into genetic diversity and history of Nuphar lutea and N. pumila (Nymphaeaceae) in isolated southwestern European populations

Genetic Diversity and Population Structure Assessed Using Microsatellite (SSR) Markers from Relict Populations of Nuphar pumila (Nymphaeaceae)

“…(1821) in Japan; the degradation of their habitat due to human activity (e.g., forestry clearance or leisure activities); the eutrophication of water (i.e., increase in water hardness and humid compounds); or the decrease in water levels [5,10,19,23,24]. This situation is especially dramatic in the southernmost populations of Western and Central Europe, which inhabit the Alps and their surrounding mountainous systems, the Massif Central and the Cantabrian Mountains, where the isolation of these relict populations with high conservational interest corresponds to the previously described threats [4,9,10,25]. These factor have led to the inclusion of N. pumila in several European red lists with different degrees of concern, such as Least Concern (LC) at a continental and global scale in the European red list of vascular plants [26] and The IUCN Red List of Threatened Species [27]; Vulnerable (VU) in France at a national level and in the French region of Lorraine [28]; Endangered (EN) in Belarus, Poland, Switzerland, Spain and the French region of Franche-Comté [10,[28][29][30][31][32]; and Critically Endangered (CR) in Austria, the Czech Republic, Germany and the French Regions of Alsace and Auvergene [10,28,[33][34][35].…”

“…The Nymphaeaceae genus Nuphar Sm. (1809) comprises 11 perennial herbaceous aquatic species, commonly known as yellow water-lilies, which inhabit freshwater bodies of the Northern hemisphere temperate regions [1][2][3][4]. In the European continent, only two representatives of this genus can be found: Nuphar lutea (L.) Sm.…”

“…Both species are distributed through the lakes of Eurasia, being widespread in northern latitudes [6,[11][12][13]. However, while N. lutea occupies vast territories in southern latitudes extending from the British Islands and the Mediterranean basin in the West-including the Balkans and most the Italic and Iberian Peninsulas-to China and Japan in the East [3,4,[14][15][16][17], the southern distribution of N. pumila comprises a series of relict populations confined to the British Islands and European mountainous areas of the Alps, the French Massif Central and the Cantabrian Mountains (North Spain) in the West, and the northern lakes of Mongolia, east China and Japan in the East [3,4,6,9,14,15,[18][19][20][21][22]. In recent decades, many N. pumila populations in their natural range have been reported to have disappeared due to hybridization with N. lutea-which generates the fertile hybrid Nuphar × spenneriana Gaudin-and Nuphar japonica DC.…”

“…Regarding the N. pumila populations isolated from Western Europe, a recent molecular study based on an Internal Transcribed Spacer (ITS) and the plastid markers trnL-F and trnH-psbA, which focused on the Massif Central and the Cantabrian Mountains, did not find evidence of hybridization with N. lutea; suggesting that other factors-such as desiccation of water bodies-could represent a greater threat in southwest Europe [4]. Nevertheless, as highlighted by Volkova et al [6], more sensitive molecular markers, such as microsatellites, should be employed to corroborate this absence of hybridization between the two species in southwest Europe.…”

“…Nevertheless, as highlighted by Volkova et al [6], more sensitive molecular markers, such as microsatellites, should be employed to corroborate this absence of hybridization between the two species in southwest Europe. Furthermore, given the isolation of the Iberian population, which is separated by more than 800 km from the nearest known population, and the tendency of N. pumila to reproduce via clonal reproduction, more genetic information is needed to correctly implement conservation plans in order to guarantee the mid-and long-term viability of this population [4,20,25]. In this context of isolated relict populations that could be hybridizing with N. lutea, we aim to use SSRs to (1) determine whether there is hybridization between the Iberian Peninsula and Massif Central N. pumila populations and their neighboring N. lutea populations, and (2) to compare the genetic composition of the Iberian Peninsula and Massif Central N. pumila populations with the populations in the Alps and their surrounding areas in order to determine the number of conservational units, their genetic affinity and the spatial genetic patterns existing between the three N. pumila refugia.…”