Jaagichlorella roystonensis var. epilithica Darienko & Pröschold, 2019

Darienko, Tatyana & Pröschold, Thomas, 2019, The genus Jaagichlorella Reisigl (Trebouxiophyceae, Chlorophyta) and its close relatives: an evolutionary puzzle, Phytotaxa 388 (1), pp. 47-68 : 64

Jaagichlorella roystonensis var. epilithica Darienko & Pröschold var. nov. ( Fig. 5A–H )

Description: Young cells are spherical or sometimes irregular with relative thick cell wall, 6.4–7.3 μm in size. Chloroplast by young cells saucer-shaped, covers a little bit more than a half of the cell; with a single pyrenoid surrounded by many starch grains.

Mature vegetative cells are spherical 9.1–10.0 μm, sometimes 11.8 μm in diameter, with cup-shaped chloroplast, sometimes slightly removed from the cell wall in the bottom part of the cell and occupied the middle position of the cell; chloroplast relatively thick, green or yellowish-green. Cells with numerous, colorless vacuoles. Old cells are spherical, 10.9–13.6 μm in size, sometimes up to 17,3 μm, with reduced small chloroplast, cells contain several vacuoles and fill around 1/3 of the cell.

Reproduction is by 2-4-8 unequal autospores. Autosporangia are spherical or very often irregular, (8.2)–9.1–10.0 μm, sometimes they can reach 16.4–20.9 μm. Large autospores 6.4–7.3 μm, (up to 10.0 μm), small autospores 3.7–5.4 μm in size. SSU and ITS rDNA sequences (GenBank: MH780940) and ITS-2 Barcode BC-3a in Fig. 3 .

Type locality: Lithophytic on rocks in Germany.

Holotype (designated here): The authentic strain SAG 2133 is cryopreserved in a metabolic inactive state at the Culture Collection of Algae ( SAG), University of Göttingen, Germany.

Iconotype (designated here to support the holotype): Fig. 5C in this study.

Etymology: The epithet of this variety indicates its epilithic life style.

Comment: Differs from the type variety by ecology and differences in the variable regions of SSU and ITS rDNA sequences.

Figures

FIGURE 3. Comparison of the conserved region of ITS-2 among the species of Jaagichlorella and Kalinella. Extraction of this region and translation into a number code for its usage as barcode. The ‘/’ indicated the position of the site loop in Helix III, which we excluded from the barcode. Number code for each base pair: 1 = A-U; 2 = U-A; 3 = G-C; 4 = C-G; 5 = G•U; 6 = U•G; 7 = pyrimidine-pyrimidine mismatch; 8 = deletion, single or unpaired bases. The phylogenetic tree shown was calculated using the neighbor-joining method based on the data set (69 number-coded positions of 11 haplotypes) using PAUP 4.0b10.

FIGURE 5. Morphology and phenotypic plasticity of Jaagichlorella roystonensis var. epilithica (SAG 2133; A.–H.) and J. roystonensis var. handai (SAG 2198; I.–G‘.); scale bar = 10 μm.