Phallus ultraduplicatus in Tomsk Oblast

In 1936 a new-to-science species of the Phallaceae family Dictyophora sibirica Lavrov n. sp. was described by Tomsk State University professor N.N. Lavrov in West Siberia. However, this specific epithet is not used in the scientific literature, and the current modern database of the world diversity of mycobiota Index Fungorum lists it as a dubious species. N.N. Lavrov samples were found in the north of Altai in the valley of the river Katun in 1927 and in the city Tomsk in 1933 (currently the Ste-panovka district). The type specimen (LE 1582) is stored in the Botanical Institute named by V.L. Komarov in St. Petersburg. It has not yet been possible to obtain good quality sequences from it. Siberian stinkhorns have a complex taxonomic history. In this regard, an attempt was made, using morphological and molecular genetic methods, to find out the specific epithet of the Tomsk stinkhorns with a short indusium. In addition, when preparing the next regional edition of the Red Book, it was necessary to establish the current name of the species found in Tomsk Oblast. Collecting samples and registration of encounters was carried out in the south of the region from 1998 to 2022 (12 cases, See Fig. 1). When studying macro- and microfeatures, generally accepted methods were used. For this purpose, group findings and aggregations of the species with fruiting bodies at various stages of development were used (See Fig. 2). Basic descriptions of morphological features were carried out on two samples: CCTR 1120 and CCTR 6759 (See Table 1) which are stored in the Mycota collection fund at the museum complex of Tomsk State University. For molecular genetic analysis, a freshly harvested fruiting body of the fungus with a short indusium at the “egg” stage, collected 12 km from the city of Tomsk, was selected. The voucher specimen is stored in the collection fund Mycota (CCTR 6759). The duplicate was transferred to the Mycological Herbarium of the BIN RAS (LE F-348635). DNA isolation and purification was carried out using the Sorb-GMO-B kits Syntol (Russia). The material was taken in laminar from various parts of the receptacle and endoperidium. Samples ITS1 and ITS4B were used to amplify the 18S-ITS1-5.8S-ITS2-28S r-DNA region. Amplification and sequencing were carried out in a DNA amplifier T100 Thermal Cycler BioRad (USA). The PCR product was treated with a mixture of Exonuclease 1 and FastAP Thermosensitive Alkaline Phosphatase Thermo Scientific (USA) enzymes. The BigDye Sequencing kit v3.1 Thermo Fisher Scientific (USA) was used for the sequencing reaction, and the D-Pure DyeTerminator Cleanup kit Nimagen (Netherlands) was used for sample purification. Sequencing was performed on an ABI 3730xl 96-capillary DNA analyzer Applied Biosystems (USA). In 2015, Phallus ultraduplicatus X.D. Yu, W.Lv, S.X. Lv, Xu H. Chen & Qin Wang was described based on specimens found in north-eastern China and having a short indusium. Comparison of morphological features of stinkhorn specimens collected in Tomsk Oblast showed their similarity with D. sibirica and Chinese specimens of Ph. ultraduplicatus. Tomsk specimens of the species are also almost identical to similar data from other points of the range in Siberia (See Table 1) - Novosibirsk Oblast and Krasnoyarsk Krai. Small deviations in the strength of indusium, smell, color of a mature “egg” and the structure of its surface may depend on the characteristics of the individual perception of traits by collectors, the place of growth and intraspecific variability of the species. ITS region r-DNA sequence analysis using the Blast suit algorithm for comparison with annotated sequences in the GenBank database showed 98.6% similarity of our sample with the stinkhorn from the Novosibirsk Oblast, 97.9% - from the Ussuriysky Reserve, and 98.6% - with 3 Chinese accessions. Thus, the Tomsk specimens collected in 2022 belong to the species Ph. ultraduplicatus (deposit OP787980). The distribution of this species in Russia, apparently, covers the entire Asian part of the country in the south (West Siberia, Central Siberia, and the Far East). The question remains open: are Dictyophora sibirica and Phallus ultraduplicatus synonyms or independent species? The authors express their sincere gratitude to leading researcher of the Southern Scientific Center of the Russian Academy of Sciences Yu.A. Rebriev and to S.V. Volobuev, senior researcher of the Botanical Institute named after V.L. Komarov of the Russian Academy of Sciences for valuable advices and comments during the work on this manuscript. The Authors declare no conflict of interest.

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