Jaagichlorella luteoviridis (Chodat) 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 : 63

Jaagichlorella luteoviridis (Chodat) Darienko & Pröschold comb. nov. ( Fig. 4A–I )

Basionym: Chlorella luteoviridis Chodat in Conrad & Kufferath, 1912, Bull. Soc. Roy. Bot. Belg. 49: 322; Chodat, 1913, Matériaux Flore cryptogam. Suisse 4: fig. 101 (lectotype, designated here) .

Synonyms: Chlorella aureoviridis Meyer, 1932 , Beih. Bot. Centralbl. 49: 510–511, fig.5 (lectotype, designated here); Chlorella luteoviridis Chodat var. lutescens Chodat in Conrad & Kufferath, 1912, Bull. Soc. Roy. Bot. Belg. 49: 322; Chodat 1913, Matériaux Flore cryptogam. Suisse 4: fig. 108 (lectotype, designated here); Chlorella mutabilis Shihira & Krauss 1965 , Chlorella : 18, fig. 7,8; Chlorella nocturna Shihira & Krauss 1965 , Chlorella : 19, fig. 9,10; Chlorella vulgaris var. luteoviridis (Chodat) Shihira & Krauss 1965 , Chlorella : 22, fig. 15,16.

Emended description: Young cells are spherical 4.6–6.4 μm or sometimes slightly ellipsoidal 5.5 x 4.6 μm or 6.4 x 5.5 μm with relative thick cell wall. Chloroplast of young cells is saucer-shaped to band-shaped, removed from cell wall in some places, very often pleated, with a single pyrenoid surrounded by many starch grains. Often in young cells many colorless vacuoles are present.

Size by mature vegetative cells depends on the strain, but in average was 7.3–9.1 μm. Old cells by some investigated strains were up to 20.5 μm in diameter, but on average 10.0–12.7 μm.

Reproduction is by 2-4-8 unequal autospores, producing in even or odd quantity (3 autospores per sporangia were observed). Autospores have saucer-shaped or band-shaped chloroplasts and some large vacuoles. Liberation of autospores by rupture of the sporangial cell wall. Remains of cell wall are usually bag-shaped. Often one autospore remains in the sporangial cell wall and develops to a mature vegetative cell or to a new autosporangia. Autosporangia are spherical (8.2–9.1 μm) or mostly irregular, because of unequal size of autospores and also varied in size (between 16.4 x 19.1 μm), but were in average 10.0 x 10.9 μm to 10.0 x 12.7 μm. Large autospores are often 6.4 μm in diameter, but sometimes up to 10.0 μm; small autospores around 3.7–4.6 μm in size. SSU and ITS rDNA sequences (GenBank: MH780927) and ITS-2 Barcode BC- 1 in Fig. 3 .

Epitype (designated here to support the lectotype): The authentic strain (SAG 211-2a) is cryopreserved in a metabolic inactive state at the Culture Collection of Algae (SAG), University of Göttingen, Germany.

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 4. Morphology and phenotypic plasticity of Jaagichlorella luteoviridis (SAG 211-2a; A.–I.) and J. africana (SAG 2213; H.–T.); scale bar = 10 μm.