A littoral grass growing inland: genetic diversity of Puccinellia fasciculata around mud volcanoes in Italy

Abstract

Puccinellia fasciculata is a littoral miohalophyte with a Mediterranean-Atlantic distribution, uncommonly found in inland sites. The main Italian inland population is located in the Salse di Nirano Reserve, an area internationally renowned for the phenomenon of mud volcanoes. In this study, molecular markers are used to characterize this population and its possible relationships with the nearest littoral conspecific population. A survey of ISSR markers revealed low levels of genetic diversity (He = 0.081 in the inland population, 0.105 in the littoral one) and a weak genetic differentiation (Gst = 0.24 within the inland population, 0.28 among this and the littoral one). A sequence analysis of three non-coding regions of chloroplast DNA found no genetic differentiation both within the inland population and between the two populations, and revealed a common origin for the two dating back to the middle Holocene. The apparent incongruence between the results from the two approaches may be explained by differences between ISSR and non-coding cpDNA markers in capturing signatures related to gene flow; their integrated information implies a mixed reproductive strategy and a common evolutionary history for the two examined populations. Effective conservation strategies are recommended for the inland population of P. fasciculata and its habitat.

Keywords:

• Gene flow
• genetic drift
• ISSR
• miohalophyte
• MRCA
• rpL16 intron
• rpoB-trnC
• trnC-trnD

Acknowledgments

The authors are grateful to: Marzia Conventi, for granting scientific collection permits in the Salse di Nirano Regional Natural Reserve; Luciano Callegari, Mauro Pellizzari and Roberto Rizzieri Masin, who accompanied us in the field; Lucilla Comparsi, for her technical software assistance; Giovanni Cristofolini, who kindly reviewed a preliminary version of this manuscript.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

This work

was supported by the Research Agreement among the Municipality of Fiorano Modenese, the Emilia Centrale Parks Authority, the University of Parma, the University of Modena and Reggio Emilia and the University of Bologna about Dynamics of halophilous vegetation for the conservation of the 1340* priority habitat in the Salse di Nirano Regional Natural Reserve - Multiannual and Multidisciplinary Research, under Grant No. 1254 (28/6/2017).