Low Genetic Diversity of Declining Viola uliginosa (Violaceae) at its Southern Range Limits in Poland

Abstract

Viola uliginosa (bog violet) is a declining species throughout its range due to -mostly anthropogenic -drying out of the wet habitats it occupies. Using AFLP markers, we aimed to estimate the genetic diversity in Polish populations, that may give an insight into the situation of plant populations facing rapid loss of natural habitats. Bog violet from several dispersed Polish populations is generally characterized by very low genetic diversity (H T = 0.048), even lower than several other endangered violets; therefore, we suggest that it should preserve at least EN rank in the red lists/red data books. The mean gene diversity within all populations (H S ) was much lower than gene diversity (G ST ) between populations (0.020 versus 0.583, respectively) which supports the prevalence of clonal propagation of the species (mainly by stolons) but may also point to some significance of autogamy in cleisto-and chasmogamous flowers. A high F ST value and the Mantel test for all populations revealed significant isolation by distance. Geographically neighboring pairs of populations formed genetic clusters supported by all (in the case of two closest populations) or most statistical analyses applied. Special attention should be paid to the locus classicus of the species in Rząska, consisting of a small number of individuals, forming a genetically distinct group, revealing very low gene diversity (H j = 0.009) and the longest genetic distance to the remaining populations. Our results can contribute to planning future protection measures for the species at this and other locations. Genetic structure of the studied populations suggests local affinities of populations but does not generally support hypothesized recent continuity of V. uliginosa range along the river valleys of southern Poland; this view may, however, be altered with widening of the scope of studied populations and chosen molecular markers.

Using genomic information for management planning of an endangered perennial, Viola uliginosa

“…Viola uliginosa reproduces primarily by clonal propagation using subterranean stems (Cieślak, Paul, & Ronikier, ; Paul et al, ), but it also forms seeds that are able to exist in a seed bank and can be viable for years (Ranta & Siitonen, ). Individual plants can develop both chasmogamous (CH, open flowers, enabling cross‐pollination) and cleistogamous (CL, closed flowers, resulting in obligatory self‐pollination) flowers, as well as intermediate forms (semi‐CL) (Małobęcki et al, ).…”

“…Viola uliginosa reproduces primarily by clonal propagation using subterranean stems (Cieślak, Paul, & Ronikier, 2006;Paul et al, 2016), but it also forms seeds that are able to exist in a seed bank and can be viable for years (Ranta & Siitonen, 2011 (Małobęcki et al, 2016). Pollination in this species has not been studied in detail, but cross-pollination occurs by several species of bees, hoverflies, and flies, as in other Viola species, in addition to self-pollination (Beattie, 1971).…”

Seasonal and Simultaneous Cleistogamy in Rostrate Violets (Viola, subsect. Rostratae, Violaceae)

“…Our results documented constant differences between CH and CL flowers at different stages of their development and at fruiting, allowing for the easy recognition of fruits derived from CH or CL flowers. CH flowers attract insect pollinators and promote cross-pollination and potential genetic diversity within populations [ 34 , 35 , 36 , 37 , 38 , 39 , 40 ]. In contrast, obligate self-pollinated CL flowers produce pure lines.…”

Postglacial history and current population genetic diversity of a central-European forest plant Hacquetia epipactis

“…This recent colonization could also concur with postglacial northward expansion of beech. It should be noted, however, that low diversity and homogeneity of these populations may also be influenced by the potential role of clonality (Paul et al 2016). …”