Authors: SHABNAM ABBASI, SAEED AFSHARZADEH, MEHRI DINARVAND
Abstract: Zannichellia L. (Potamogetonaceae) is a widespread aquatic genus that is distributed in temperate and subtropical aquatic ecosystems worldwide. Because the biogeographical location of Iran includes mountain ranges and deserts that may cause different habitat types, it was assumed that these Zannichellia populations would be stronger differentiated than observed in Zannichellia from temperate regions. The present study aimed to test whether Z. palustris would demonstrate high levels of genetic differentiation over long distances and across mountain ranges. The genetic structure of the populations of Zannichellia was investigated using inter simple sequence repeats (ISSR) and sequence-related amplified polymorphism (SRAP) as molecular markers. The results demonstrated overall high levels of genetic differentiation among populations (GST = 0.53) and isolation by distance. Bayesian assignment analysis at the population level grouped individuals into eight genetic clusters (K = 8) that largely correspond to the topographic barriers. Alongside the same mountain ridge, the freshwater and saltwater habitat differences corresponded to Z. palustris var. palustris and Z. palustris var. pedicellata, respectively. Our results support the hypothesis of isolation by distance. This high level of genetic differentiation argues for a conservation strategy to maintain a diversity of populations of in mountainous regions.
Keywords: Aquatic plant, genetic structure, geographical barriers, Potamogetonaceae
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