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The hybrid Potamogeton × salicifolius Wolfg. (P. lucens L. × P. perfoliatus L.) is confirmed in Russia by morphology and nrDNA polymorphism. All analyzed hybrid plants had monomorphic nrDNA ITS fragments. In the studied river P. × salicifolius with intermediate characters grows in more or less flowing water, whereas the hybrid with P. lucens-like m...
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... Table 1 demonstrates that P . × salicifolius occupies an intermediate position between the parental species P . lucens and P . perfoliatus in many characters. Stem thickness of the hybrid, on average, is same as that of more vigorous P . lucens or even slightly greater. Leaf length and width of P . × salicifolius also have intermediate values (fig. 2). Besides, it differs from P . lucens by the absence of distinctly mucronate and petiolate leaves; from P . perfoliatus by sessile, sometimes very shortly petiolate leaves with cuneate or rarely rounded base (but not amplexicaul, cordate base). Interestingly, in the lowest site in Sit-Pokrovskoe village (4) some leaves of the hybrid have slightly more expressed mucrones and short petioles (up to 2 mm). Stipule characters of P . × salicifolius are intermediate. Plants from site 4 can be distinguished by the larger stipules. Generative parts are all of more or less intermediate ...
Citations
... Fruits are often not produced in running water, which can sometimes be incorrectly interpreted as evidence of sterility (Kaplan, 2008). Although hybrids in Potamogetonaceae were first recognized already in the late 19th century (see for a brief review), molecular evidence became available only during the past decades by using isozyme electrophoresis (e.g., Hollingsworth & al., 1995;Fant & al., 2001;Iida & Kadono, 2002;Kaplan & al., 2002;Kaplan & Wolff, 2004;Kaplan, 2007;Bobrov & Sinjushin, 2008) and DNA-based techniques (e.g., King & al., 2001;Fant & al., 2003;Kaplan & Fehrer, 2004, 2009Ito & al., 2007Ito & al., , 2014Du & al., 2009Du & al., , 2010Les & al., 2009;Zalewska-Gałosz & al., 2009, 2010Aykurt & al., 2017;Iida & al., 2018). While these studies focused on hybrids, a few of them performed also phylogenetic analyses (e.g., Les & al., 2009;Ito & al., 2014;Zalewska-Gałosz & al., 2018), but these include only taxa relevant for the identification of hybrids. ...
The family Potamogetonaceae has been taxonomically re‐evaluated in Turkey, employing traditional morphological as well as molecular approaches (rbcL, ITS). Our fieldwork, herbarium studies and molecular analyses proved the existence of 22 taxa, of which 18 belong to Potamogeton (including 4 interspecific hybrids), 3 to Stuckenia and 1 to monotypic Groenlandia. Morphological re‐descriptions of the recognized taxa were prepared, and the information concerning their distribution in Turkey was refined, based on plant material from extensive fieldwork and on specimens stored in herbaria that were previously not examined. Additionally, new identification keys to genera and species, and distribution maps of the species were prepared. Phylogenetic relationships and intraspecific variations were assessed by including samples from other regions. The status of the Zannichelliaceae was investigated using nuclear and chloroplast DNA markers. Our results from ITS sequence divergence corroborate the separation of the two families noted by some authors, and are in accordance with the substantial morphological differences between them. Relatively large genetic distance and non‐monophyly indicate that two genotypes of P. gramineus constitute cryptic species, for which the Turkish localities expand upon the previously known distribution areas. We identified P. schweinfurthii as a new species for Turkey and report P. ×angustifolius for the first time for this country. Weak morphological differentiation and high sequence similarity did not permit reliable differentiation between the closely related Stuckenia amblyphylla and S. filiformis.
... However, the difference in relief and geological structure along with the character of Quaternary deposits determine some differences between the watercourses in lowlands and plains, highlands, and karst regions [5]. Pondweed species are common in river stretches with a weak flow (0-0.2 m/s) and silty grounds (reaches), where they often form inshore stands, while hybrids occur mostly in stretches with a rapid current (0.3-0.8 m/s) and sandy, sandy-stony grounds (riffles and rapids), where they are represented by spots or continuous stands [2,[4][5][6][40][41][42]. Pondweed species were observed in all studied streams and rivers, while hybrids occurred iñ 2/3 of the examined small and medium rivers. ...
... The hybrid forms were identified by morphological and molecular genetic methods [2,6,[40][41][42]47]. ...
... In the overwhelming majority of cases, the hybrids are sterile; they can occupy free econiches and do not compete with parent species [2,4,6,40,41] and other macrophytes [42]. In the rivers of the region, this allows them to dominate in many riverine ecotopes, to form dense stands with 100% cover and considerable area, and to produce a considerable mass of primary organic matter. ...
For the first time, summarized data on the production of nine species and ten hybrids of pondweed (Potamogeton, Stuckenia, and Potamogetonaceae) are given for ecosystems of small and medium rivers of the northern European Russia. The pondweed is shown to be an important producer of primary organic matter. A significant contribution to primary production in rivers in the region is due to large-size pondweeds and their hybrids, which form dense monodominant stands: P. lucens, P. natans, P. perfoliatus, P. × angustifolius, P. × nitens, P. × salicifolius, P. × sparganiifolius. The production characteristics for the widespread species (P. lucens, P. natans, P. perfoliatus) in the rivers of the region are more than 1.5 times greater than those in reservoirs. Most pondweed species and hybrids show medium productivity and produce < 1 kg/m2 organic matter per year, and only P. lucens, P. × vepsicus, S. × fennicа are classifed as having a high productivity.
The English version of Чемерис Е. В., Бобров А. А. Продуктивность рдестов (Potamogeton, Stuckenia, Potamogetonaceae) в реках севера европейской России // Водные ресурсы. 2020. Т. 47. № 1. С. 114—120. doi: 10.1134/S0321059620010198
... Однако различия рельефа, геологического строения и характер четвертичных отложений определяют некоторые отличия водотоков низин и равнин, возвышенностей, карстовых районов [5]. Виды рдестов обычны на участках рек со слабым течением (0-0.2 м/с) и заиленными грунтами (плесы), где чаще образуют прибрежные заросли, а гибридыв местах с более сильным течением (0.3-0.8 м/с) и песчаными, песчано-каменистыми грунтами (перекаты и стремнины), где представлены пятнами или сплошными зарослями [2,[4][5][6][40][41][42]. Практически вo всех изученных ручьях и реках встречаются виды рдестов, а гибриды отмечены в 2/3 исследованных малых и средних реках. ...
... Гибридные формы идентифицированы морфологическими и молекулярно-генетическими методами [2,6,[40][41][42]47]. ...
... Гибриды в подавляющем большинстве случаев стерильны, способны занимать свободные экониши и практически не испытывают конкуренции с родительскими видами [2,4,6,40,41] и другими макрофитами [42]. В реках региона это позволяет им доминировать во многих речных экотопах, формировать значительные по площади плотные заросли с 100%-м проективным покрытием и производить значительную массу первичного органического вещества. ...
For the first time, summarized data on the production of nine species and ten hybrids of pondweed (Potamogeton, Stuckenia, and Potamogetonaceae) are given for ecosystems of small and medium rivers of the northern European Russia. The pondweed is shown to be an important producer of primary organic matter. A significant contribution to primary production in rivers in the region is due to large-size pondweeds and their hybrids, which form dense monodominant stands: P. lucens, P. natans, P. perfoliatus, P. × angustifolius, P. × nitens, P. × salicifolius, P. × sparganiifolius. The production characteristics for the widespread species (P. lucens, P. natans, P. perfoliatus) in the rivers of the region are more than 1.5 times greater than those in reservoirs. Most pondweed species and hybrids show medium productivity and produce < 1 kg/m2 organic matter per year, and only P. lucens, P. × vepsicus, S. × fennicа are classifed as having a high productivity.
The Russian version of Chemeris E. V., Bobrov A. A. Production of pondweeds (Potamogeton, Stuckenia, Potamogetonaceae) in rivers in the north of European Russia // Water Resources. 2020. Vol. 47. N 1. P. 171—177. doi: 10.1134/S0097807820010194
... DNA sequences have confirmed the morphological identification of the Potamogeton samples from the Fortescue River as a hybrid P. lucens × P. perfoliatus. This hybrid is known from Eurasia under the binomial P. ×salicifolius, where it has been recorded in several European countries (Preston 1995, Zalewska-Gałosz 2003Kaplan and Zalewska-Gałosz 2004;Kaplan 2007;Bobrov and Sinjushin 2008;Wiegleb et al. 2008;Lastrucci et al. 2010), in Turkey (Aykurt et al. submitted) and southern Siberia (Kashina 2000). In none of these regions is it common, instead P. ×salicifolius is confined to a single or a few sites. ...
... (2) Long-distance dispersal of a hybrid seed: The parental species need not be present in Western Australia, but the hybridization event may have occurred in the area of sympatry of the parental species in Asia, perhaps in Japan according to the particular chloroplast haplotype of P. lucens, with the hybrid seed transported to Australia via birds, in their guts or embedded in their feather matrix. Both continents are indeed connected by bird migration routes (e.g., Alerstam 1990, Berthold 2001, Newton 2008, which are known as a means of transport of plant propagules (e.g., Green 2002, Santamaría et al. 2002). However, this opens up the question of why it was only the hybrid seed that was transported but not a seed of the parental species, considering the fact that in the regions where P. ×salicifolius was recorded, it is always rarer than the parental species. ...
The interspecific hybrid Potamogeton ×salicifolius (= P. lucens × P. perfoliatus), so far known only from several countries of Europe and a few countries of Asia, was discovered in Western Australia. Morphology of the Australian specimens fits the range of variation observed in Eurasian specimens. DNA sequencing confirmed the morphological identification as a hybrid P. lucens × P. perfoliatus, and identified P. lucens as the maternal parent. This identity is surprising because neither of the parental species are known to occur in Western Australia and P. lucens currently does not even occur in the continent. Three possible explanations for the occurrence of P. ×salicifolius in Western Australia are discussed: its relictual occurrence from a time when both the parental species occurred there, long-distance dispersal of a hybrid seed from Eurasia and the remnant of local cultivation or intentional planting.
... The identity of Potamogeton × salicifolius as P. lucens × P. perfoliatus was confirmed by direct sequencing of the ITS region as described in Kaplan and Fehrer (2007). As this hybrid has already been studied thoroughly in previous studies (e.g., Fant and Preston, 2004;Kaplan, 2007;Bobrov and Sinjushin, 2008), the details on the molecular prove are not presented in this paper. ...
More than a century ago, an extremely high diversity of Potamogeton hybrids was recorded in several rivers and streams in Jutland, Denmark. Accuracy of their identification was doubted by some later authors who were sceptical about the existence and co-occurrence of so many hybrids. Selected original localities were investigated for the presence of morphologically matching plants after more than 100 years. In spite of profound changes in landscape and considerable deterioration of aquatic habitats during the 20th century resulting in a significant decline of submerged vegetation, three of ten previously recorded hybrids were recently found that had persisted at their original localities. Two of them, whose existence had not been proved previously, were subjected to molecular analyses. RFLP, direct sequencing and cloning of the ITS region confirmed their previous morphological identification: P. × undulatus as P. crispus × P. praelongus and P. × cognatus as P. perfoliatus × P. praelongus. Chloroplast DNA sequencing identified P. praelongus as the maternal parent in both crosses. The existence of most of the other hybrid combinations recorded from Jutland was proved by means of molecular analyses conducted on plants from other regions. Their morphologies perfectly correspond to old herbarium vouchers from Jutland and support their original identifications. These observations indicate that Jutland rivers and streams hosted a high species and hybrid diversity still in the late 19th century, but most of this richness has meanwhile disappeared.
