Edaphochloris, gen. nov.: a new genus of soil green algae (Trebouxiophyceae, Chlorophyta) with simple morphology

Abstract

Nannochloris-like green microalgae have evidently evolved by convergent evolution and are often unidentifiable by microscopy, including transmission electron microscopy (TEM). Their relatively simple morphology conceals an extremely high phylogenetic, physiological, and ecological diversity. The use of molecular tools has revolutionized algal diversity research, including the discovery of numerous new taxa. Strains ACSSI 104 and ACSSI 144 were isolated from solonetz and chestnut non-alkali soil, respectively (Volgograd region, Russia), in August 2014. Morphological and ultrastructural characteristics, a comparison of reproduction types and habitats, and the difference of the 18S rRNA gene and ITS2 secondary structure of the studied strains allowed us to propose a new genus—Edaphochloris A.Temraleeva, E.Krivina & O.Boldina, gen. nov. with type species—E. andreyevii A.Temraleeva, E.Krivina & O.Boldina, sp. nov. The new genus differed from the closely related Nannochloris-like genera through cell shape and size, chloroplast type, reproduction type, habitat, and value of genetic distances.