Identification of 13 Spirogyra species (Zygnemataceae) by traits of sexual reproduction induced under laboratory culture conditions

Abstract

The genus Spirogyra is abundant in freshwater habitats worldwide, and comprises approximately 380 species. Species assignment is often difficult because identification is based on the characteristics of sexual reproduction in wild-collected samples and spores produced in the field or laboratory culture. We developed an identification procedure based on an improved methodology for inducing sexual conjugation in laboratory-cultivated filaments. We tested the modified procedure on 52 newly established and genetically different strains collected from diverse localities in Japan. We induced conjugation or aplanospore formation under controlled laboratory conditions in 15 of the 52 strains, which allowed us to identify 13 species. Two of the thirteen species were assignable to a related but taxonomically uncertain genus, Temnogyra , based on the unique characteristics of sexual reproduction. Our phylogenetic analysis demonstrated that the two Temnogyra species are included in a large clade comprising many species of Spirogyra . Thus, separation of Temnogyra from Spirogyra may be untenable, much as the separation of Sirogonium from Spirogyra is not supported by molecular analyses.

Recent bloom of filamentous algae in Lake Baikal is caused bySpirogyraLink., 1820 of local origin

“…Up to date, Spirogyra diversity is studied in four localities: California [19], Hawaii [20], Japan [21] and Lake Baikal (current study). Other sequences clustering within the genus and presented in the NCBI database were treated as being of unknown origin.…”

“…PCR amplification of the respectiv fragments was performed with the Biolabmix (Novosibirsk, Russia) HS180Taq k in 25 μ l of the reaction mixture in a Bio-Rad (USA) thermocycler Bio-Rad T10 After electrophoresis purification and extraction with the gel elution kit (Biosili Co., Novosibirsk, Russia) the direct sequencing of forward and reverse sequenc were performed in Research and Production Company SYNTOL (Russia) using a ABI 3130 automated sequencer. 21], the alignment was checked with mafft [22,23]. Three species of other Charales (Zygogonium ericetorium, Zygnema cylindricum, and Mougeoutia sp.)…”

Induction of sexual reproduction reveals the presence of heterothallic Spirogyra strains (Zygnematophyceae, Streptophyta)

“…Because the conjugated filaments were not observed in the field-collected samples, samples containing filaments of different individuals of Spirogyra were used to induce sexual reproduction. Sexual reproduction was induced on agar plates as described in our previous studies (Ikegaya et al 2012;......................................................................................... Takano et al 2019) with the following two modifications. First, samples on agar plates were incubated under continuous light.…”

“…Total DNA was extracted using DNeasy Plant Mini Kits (Qiagen, Hilden, Germany) according to the manufacturer's instructions. RuBisCO Large subunit (rbcL) and ATP synthase beta subunit (atpB) genes were amplified by polymerase chain reaction (PCR) with previously designed primers (Takano et al 2019). PCR products were then purified using a FastGene Gel/PCR Extraction Kit (Nippon Genetics, Tokyo, Japan).…”

Chemical Composition, Algicidal, Antimicrobial, and Antioxidant Activities of the Essential Oils of Taiwania flousiana Gaussen

“…Spirogyra (Zygnemataceae, Zygnematales) is a genus in the Class Zygnematophyceae (Conjugatophyceae), which is a member of the Infrakingdom Streptophyta. Spirogyra communis (Hassall) Kuetzing in the genus is widely distributed in freshwater habitats including flowing water, permanent ponds, and temporary pools and can cause great loss to farm produce [12,13]. Microbes such as Rhizoctonia solani, Fusarium moniliforme Sheld, and Fusariun oxysporun, etc., are common pathogens with a great diversity of host plants and can significantly reduce the quantity and quality of farm produce [14][15][16].…”