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34Saccobasispolita var. arctica (Scapaniaceae, Marchantiophyta) from Novaya Zemlya Archipelago (European Russian Arctic)
A. D. Potemkin1, A. A. Vilnet2, I. V. Czernyadjeva1
'Komarov Botanical Institute of the Russian Academy of Sciences, St. Petersburg, Russia 2Polar-Alpine Botanical Garden-Institute of the Kola Science Centre
of the Russian Academy of Sciences, Apatity, Russia Corresponding author. A. D. Potemkin, potemkin_alexey@binran.ru
Abstract. Saccobasis polita var. arctica is firstly reported for Novaya Zemlya Archipelago, from its Yuzhny (southern) Island. It is the third record of this variety from Russia. This report is supported by comparison of ITS1-2 nrDNA and trnL-F cpDNA nucleotide sequences with known molecular data of Saccobasis polita var. arctica, and by morphological study. Distinctions from earlier described specimens and extended description of the variety supplied by photomicrographs of specimen from Novaya Zemlya are provided. The arctic plants of Saccobasis polita var. arctica have lophozioid appearance, which may results in its misidentification and distorted data on its distribution. Variation, differentiation and approaches to identification of critical specimens of S. polita var. arctica are discussed.
Keywords: hepatics, liverworts, integrative taxonomy, morphology, Arctic, Arkhangelsk Region, Russia.
Saccobasis polita var. arctica (Scapaniaceae, Marchantiophyta) с архипелага Новая Земля (Европейская Российская Арктика)
А. Д. Потемкин1, А. А. Вильнет2, И. В. Чернядьева1
'Ботанический институт им. В. Л. Комарова РАН, Санкт Петербург, Россия 2Полярно-альпийский ботанический сад-институт им. Н. А. Аврорина Кольского научного центра РАН, Апатиты, Мурманская обл., Россия Автор для переписки. A. D. Potemkin, potemkin_alexey@binran.ru
Резюме. Saccobasis polita var. arctica впервые приводится для архипелага Новая Земля, где выявлен на Южном острове. Это третья находка этой разновидности в России. Указание подтверждено сравнением нуклеотидных последовательностей ядДНК ITS1-2 и хпДНК trnL-F с известными молекулярными данными по Saccobasis polita var. arctica и морфологическим исследованием. Приведены отличия от ранее описанных образцов и расширенное описание разновидности, дополненное микрофотографиями образца с Новой Земли. Арктические растения Saccobasis polita var. arctica имеют лофозиоидный облик, что может привести к неправильной идентификации и искаженным представлениям о распространении. Обсуждены изменчивость, отличительные признаки и походы к определению критических образцов S. polita var. arctica.
Ключевые слова: печеночники, интегративная систематика, морфология, Арктика, Архангельская область, Россия.
https://doi.org/10.31111/nsnr/2023.57.1.143 Received. 3 February 2023 Accepted: 9 March 2023
Published: 2 April 2023
The genus Saccobasis H. Buch (1933) was segregated from the genus Tritomaria Schiffner ex Loeske and based on Jungermannia polita Nees (Nees von Esenbeck, 1836). Schuster (1969) described Tritomaria polita susbsp. polymorpha R. M. Schust., which was raised by Schljakov (1979) to S.polymorpha (R. M. Schust.) Schljakov. Integrative study of Saccobasis by Konstantinova et al. (2022) resulted in rejection of S. polymorpha, its inclusion in synonyms of Saccobasis polita (Nees) H. Buch. and description of new variety Saccobasis polita var. arctica Konstant. et al.
Study of liverwort collections gathered in 2020 in Yuzhny (southern) Island of Novaya Zemlya Archipelago resulted in find of unknown liverwort of Lophozioid s. l. appearance. At first, it was identified as obscure Orthocaulis H. Buch s. l., due to presence of variable 2-3(4)-lobed leaves and once found stalked slime papilla near ventral leaf base (Fig. 1E). The molecular study revealed its position within Saccobasis H. Buch. After publication by Konstantinova et al. (2022) it became evident that our specimen fits well in S. polita var. arctica, variety that has been described from Svalbard (Norway) and reported from the Trans-Baikal Territory and Franz Josef Land of Russia. The cited above morphological features of specimen from Novaya Zemlya and possible confusion with Lophozioid hepatics persuade us to provide an extended description of this variety with illustrations, and notes on its variation and differentiation. Such an approach appears important to avoid possible misidentifications of S. polita var. arctica and facilitate its distinguishing in critical collections. An extensive description and analysis of variability of S. polita by Konstantinova et al. (2022) were made without separate descriptions of var. polita and var. arctica. This complicated separation of their distinctive characters. Our work aims to fill this gap.
Materials and Methods
Specimens examined: Norway, Svalbard, Wedel Jarlsberg Land, Recherchefjorden, Lagerneset, 77°31'31.8"N, 14°45'54"E, river terrace, patterned ground tundra on gentle slope, on frost boils, on side of micro-bumps and in crevices, 19 VIII 2018, N. A. Konstantinova, A. N. Savchenko K45-3a-18, LE B-0026978 (isotype); Russia, Arkhangelsk Province, Novaya Zemlya Archipelago, Yuzhny (southern) Island, Southwest coast, Rusanov Peninsula, Reineke Gulf, Shaposhnikov Bay, vicinity of Kambalny Cape, rocky outcrops, on soil, 70°36'18"N, 56°29'27.4"E, 24 VIII 2020, S. V. Sidorenko, Czernyadjeva 18-20, LE B-0026973.
The procedures of DNA extraction and amplification were carried out according with protocols described in Konstantinova et al. (2022). Obtained sequences of ITS1-2 nrDNA and trnL-F cpDNA were assembled in BioEdit ver. 7.0.1 (Hall, 1999) and then combined in two datasets with published accessions of Saccobasis polita var. arctica downloaded from GenBank (0P584670-75 for ITS1-2 and 0P573508-14 for trnL-F). The molecular variability of both nucleotide regions was estimated as the value ofp-distances in Mega ver. 11 (Tamura et al., 2021).
The description below is based on the specimen from Novaya Zemlya and the isotype from Svalbard. It is expanded by provided in square brackets characteristics, which were not observed in the specimens examined, but described and/or illustrated
by Kostantinova et al. (2022). The photomicrographs were made by camera Olympus Tough TG-5, using its macro- and stacking modes.
Results
The GenBank accession numbers for newly sequenced here specimen LE B-0026973 from Novaya Zemlya are OQ301636 for ITS1-2 nrDNA and OQ317923 for trreL-F cpDNA. The values of p-distances suggest divergence of tested specimen in 0-0.6% by ITS1-2 and in 0-0.5% by trreL-F from Svalbard's and Trans-Baikal Territory's accessions. This new record exceeds the level of molecular variability of Saccobasis polita var. arctica from previously published 0.3% in ITS1-2 and 0% in trreL-F and suggests this taxon as more variable than S. polita var. polita (Konstantinova et al., 2022).
Saccobasis polita (Nees) H. Buch var. arctica Konstant. et al., 2022, Arctoa 31: 177.
(Figs 1-3)
Plants procumbent to prostrate, 0.2-1.2[2] mm wide, 1-4 mm long, yellowish to dark brown and blackish, devoid purplish pigmentation, ± translucent and somewhat glistening. Stem fleshy, ± yellowish to fuscous brown with dark brown ventral part, 15-18 cells thick, with 1-stratose ± differentiated cortex of cells with hardly to strongly thickened outer walls, without mycorrhiza infection; dorsal cortical cells from x 2(3) as long as wide, 18-25 x 38-50 jm, to x (2)3 as long as wide, 25-37 to 37-50 x 50-90 |im. Rhizoids abundant, ± brown at the base, from the ventral side of stem and occasionally from the ventral leaf bases. Leaves succubous, ± oblique inserted, in mod. parvifolia with not developed or indistinct characteristic of Sacco-basis sinuous insertion, getting distinct in the larger plants, not decurrent dorsally and ventrally, 2-3(4)-lobed, 2-lobed x 0.95-1.25[1.3] as wide as long, 3-4-lobed x [0.85]1.0-1.5(2.2) as wide as long, with acute to shortly apiculate, to sometimes blunt and rounded lobes, and broad [to occasionally narrow and y-like] angulate to lunate sinuses, (0.1)0.15-0.25[0.3] of the leaf length; sinuses in 3-lobed leaves subequal or [ventral sinus shallower than dorsal, in 4-lobed leaves median sinus occasionally deeper than the lateral ones]; ventral leaf bases not differing in color or reddish brown to reddish, never purplish, once seen with solitary stalked slime papilla (Fig. 1E). Leaf cells in lobes and median part of leaves subisodiametric, from (20)25-30 x 25-37 |im to (25)30-37(40) x 30-45 jm; basal cells ± elongated, from 20-30 x 30-55(65) jm to 25-40 x 50-75 |im; cell walls thin, with ± coarse bulging to occasionally moderate acute translucent angular thickenings and usually remarkable middle lamellae (Figs. 1D-F, 3C, D), often with smaller angular thickenings in median basal cells, at least in separate leaves with characteristic solitary to ± numerous intermediate thickenings in basal cells (Fig. 3D, E); median part of leaves rare bistratose. Leaf surface smooth to ± finely striolate. [Gemmae green to brown, rounded, (1)2-celled, ca. 20 x 20-24 jim, according to Konstantinova et al., 2022: Fig. 4G, H]. Other unknown.
Distribution. Norway: Svalbard (Konstantinova et al., 2022); Russia: Arkhangelsk Region, Franz Josef Land Archipelago, Ziegler (Tsigler) Island (Konstantinova
Fig. 1. Saccobasis polita var. arctica (LE B-0026973). A-C, G-I — plants in mat and on slide; D, F — median leaf cells; E — ventral leaf base with stalked slime papilla. Scale bars: A-C — 800 |m; D — 35 |m; F — 27 |m; H, I — 600 |m; G — 400 |m.
et al., 2022); Novaya Zemlya Archipelago, Yuzhny Island (this report); Trans-Baikal Territory, Stanovoye Nagor'e Uplands, Kodar Range (Konstantinova et al., 2022).
The both localities in the Russian Arctic are situated nearly along 57th meridian; the locality in Yuzhny Island of Novaya Zemlya is 1170 km southwards from the locality in Franz Josef Land.
Fig. 2. Saccobasis polita var. arctica (LE B-0026973). A-D, F — plants in mat; E, G-I — leaves. Scale bars: A-D, F — 800 |m; E, G, H — 200 |m; I — 230 |m.
Ecology for previous collections is described by Konstantinova et al. (2022). Taking into account our collection, Saccobasis polita var. arctica occurs on bare, often frost-boil soils in tundra, and over rocks; associates with liverworts, growing on neutral and basic soils. In our collection, it growths among Blepharostoma trichophyl-lum (L.) Dumort. s. l. with admixture of hepatics Cephaloziella varians (Gotthche)
Fig. 3. Saccobasispolita var. arctica (LE B-0026973). A-B — leaves; C — median leaf base cells; D — median leaf cells; E — ventral leaf base cells. Scale bars: A, B — 275 ^m; C-E — 37 ^m.
Steph., Lophozia sp. and Orthocaulis quadrilobus (Lindb.) H. Buch, and mosses Aongstroemia longipes (Sommerf.) Bruch et Schimp., Bryum sp., Campylium stellatum (Hedw.) Lange et C. E. O. Jensen, Roaldia revoluta (Mitt.) P. E. A. S. Camara et Carv.-Silva. This composition of associated species, which are distinguished as calciphilous, neutrophilous or having a broad amplitude in substrate preferences, supposes weakly basic soils.
Variation. As follows from the description and illustrations of Konstantinova et al. (2022), and our data, arctic and montane plants of Saccobasis polita var. arctica differ greatly in the plant sizes and leaf width/length ratios [cf.: Figs. 1-3; Konstantinova et al., 2022: Figs. 3H, L, N, O; 4A-E, I, J (arctic plants); Figs. 3A-G, I-K, M, P; 4: F (plants from the Trans-Baikal Territory)]. Moreover, characteristic of Saccobasis sinuous leaf insertion, being distinct in the plants from the Trans-Baikal Region (Konstantinova et al., 2022: Fig. 4F), is indistinct or lacking in the small arctic plants of this variety (Fig. 1B; Konstantinova et al, 2022: Fig. 4B, C). Despite that angular leaf sinuses, acute lobes and not differing in color ventral leaf bases were mentioned as the key characters of S. polita var. arctica, the leaves with lunate sinuses and rounded lobes, that characteristic of var. polita, occur in our specimen from Novaya Zemlaya
(Figs 2H, I; 3A, B), and the plants of var. polita occasionally possess not differing in color ventral leaf bases (Kostantinova et al, 2022: Fig. 2J, K). Our study of kept in the Bryological herbarium Komarov Botanical Institute (LE) specimens of S. polita (S. polymorpha (R. M. Schust.) Schljakov phenotypes) from Chukotka (LE B-0026974, LE B-0026975, LE B-0026976) has shown frequent absence of purple pigmentation of ventral leaf bases as well as moderately elongated dorsal cortical cells x 2.5-4 as long as wide. Similar variability of pigmentation of ventral leaf bases and dorsal cortical cells was reported by Konstantinova et al. (2022) for S. polita. However, in description of S. polita and its variability, there was no segregation of two varieties. It makes unclear variability of S. polita var. arctica. These facts may lead to problems in differentiation of arctic plants of S. polita var. arctica from S. polita var. polita. It should be stressed that the leaf cells and dorsal cortical cells of plants from Novaya Zemlaya are larger than described in the protologue (Konstantinova et al., 2022). The frequent occurrence of plants with chiefly bilobed leaves causes the resemblance with Lopho-zia s. l. The plants with 2-3(4) lobed leaves with occasional stalked slime papillae in ventral leaf bases may result in the confusion with Orthocaulis s. l.
Differentiation. The obtained data on variation of Saccobasispolita var. arctica and a result of its comparative study point at less stability of its distinctive characters. The specific sinuous leaf insertion could not be distinguished as a reliable character, whereas the shapes of leaf lobes and sinuses appear to be rather variable. Despite the ventral leaf bases are often devoid specific pigmentation, some leaves have reddish leaf bases, which may be confused by an inexperienced researcher with purplish leaf bases of S.polita var. polita. The following distinctions are apparently most reliable: frequent acute to acuminate lobes (vs. mostly obtuse to rounded), varying in number from 2 to 4 (vs. mostly 3); predominance of angular (vs. rounded) leaf sinuses; smaller size of plants (0.2-1.2[2] mm wide vs. (1.2)1.5-3 mm wide, respectively); harsh growth conditions on bare, not moist (vs. humus-rich moist) soils.
A possibility of confusion of Saccobasis polita var. arctica with Lophozioid hepat-ics require to define distinctions from Orthocaulis s. l. and Lophozia (Dumort.) Du-mort. s .l. Among distinctions of S. polita var. arctica from Lophozia s. l. and Orthocau-lis s. l. the specific leaf areolation with translucent thickennings and distinct middle lamellae (Figs. 1D-F, 3C, D; Konstantinova et al., 2022: Fig. 5D), particularly in large bulging and pigmented trigones, as well as sporadic occurrence of intermediate cell wall thickenings of basal cells (Fig. 3E) are remarkable. The lack of mycorrhiza and rounded gemmae, when present, may be used as additional distinctions of the plants with chiefly bilobed leaves from Lophozia s. l.
Acknowledgments
We are grateful to Sergey V. Sidorenko for collecting Saccobasis polita var. arctica. Nadezhda A. Konstantinova is deeply thanked for careful reading of the first version of the manuscript, valuable comments, and the gift of the isotype of Saccobasis polita var. arctica for LE. The work of A. D. Potemkin and I. V. Czernyadjeva was carried
out within the framework of the institutional research project of Komarov Botanical Institute of the Russian Academy of Sciences "Flora and taxonomy of algae, lichens and bryophytes in Russia and phytogeographically important regions of the world" (121021600184-6). The study of A. A. Vilnet was carried out in the framework of the state project of Polar-Alpine Botanic Garden-Institute no. 1021071612832-8-1.6.11.
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