Genetic diversity within a newly identified population of Adenophora liliifolia (L.) A.DC. in Romania: implications for conservation

Abstract

Abstract. Adenophora liliifolia is a relict plant species, endangered at European level. Its occurrence in Romania is limited to a very few sites. The amount of genetic diversity of plant species is a valuable indicator of population, being the baseline in developing proper strategies for their conservation. Inter-simple sequence repeats (ISSRs) markers were used to analyze polymorphism in A. liliifolia genome and to evaluate the genetic diversity and accordingly, the state of a recently identified population. Five ISSR primers, specially designed for plants, and containing different simple sequence repeat motifs were tested. A total of 52 ISSR fragments were generated of which 41 were polymorphic (78.84%) and 32 (61.53%) specific to Adenophora genus. The value of Shannon's index of genotypic diversity was 0.812. Jaccard similarity coefficient was calculated for pair wise comparisons among all individuals and ranged from 0.17 to 0.83. The genetic variability between individuals was 78.84% which suggests a relative high genetic differentiation. Although the level of genetic variability is moderate to high, the population is declining and exposed to demographic stochasticity. A possible cause is species germination requirements hampered by modification in vegetation structure and abundance. The population survival and reinforcement is conditioned by urgent measures for forest management in order to reduce herbaceous and shrubby vegetation and to limit mowing and grazing. Ex situ conservation measures are also proposed.

Adenophora liliifolia: Condition of its Populations in Central Europe

“…There are only a few studies which investigated the genetic diversity of populations of Adenophora spp., including two isozyme based studies by Ge et al (1999) and Chung and Epperson (1999); and two more recent studies based on ISSR markers by Boronnikova (2009) andManole et al (2015). Boronnikova (2009) analyzed four A. liliifolia populations from the Perm region in Russia using ISSR markers, and detected (similarly to our study) a weak population genetic structure and high intrapopulation variation (nearly 84.5% of the total variation).…”

“…This pattern of genetic variability distribution may be due to vigorous sexual reproduction, which dominates over vegetative spreading within A. liliifolia populations (Manole et al, 2015). Furthermore, the low number of unique markers accompanied by the almost absolute absence of fixed-private markers, low F ST and DW values, and weak inter-population genetic structure suggest that the separation of the analyzed populations took place only sub-recently, because of the short time for population differentiation by genetic drift, which would result in the detection of a clear population genetic structure.…”

“…This can be influence by a) the greater number of sampled plants per population in the study by Boronnikova (2009); and b) the fact that the investigated populations were geographically closer to the species' center of distribution, thus possessing a greater degree of genetic variability. A recent study by Manole et al (2015) investigated 12 mature specimens of A. liliifolia from one Romanian population using ISSR markers. Also in this study, a relatively high intrapopulation genetic variation was observed as measured by Shannon´s index of genotypic diversity (0.812), contrary to our calculations (mean value of I = 0.139, which may be caused by the different type of molecular markers used and/or the different sample size).…”

“…The conservation of A. liliifolia strongly depends on the specific management supporting its seedlings, which are not vigorous enough to survive without protection (e.g., by removing invasive or nitrophilous species; see e.g., Ciosek, 2006;Manole et al, 2015). Such management may be difficult because of the presence of other protected species, thus it should be planned with respect to the whole locality, not only to a single species.…”

“…Only two studies have investigated the population structure of A. liliifolia: Boronikova (2009) analyzed four populations from the Ural region (Perm, Russia), and Manole et al (2015) described the genetic diversity of one A. liliifolia population from Romania. The present study aimed to provide overall information on the current condition of A. liliifolia populations in Central Europe, and thus to better know the factors threatening this species and suggest appropriate management for the current populations.…”