ABSTRACT
Soil is a unique ecosystem with peculiar biodiversity that includes cyanobacteria and algae. Traditionally, cyanobacterial and algal cenoses were described mainly using the dominance approach, rarely based on the Braun-Blanquet method (floristic classification). More importantly, in both cases, the species of cyanobacteria and algae in communities were identified using classical methods (light microscopy) only. In this study, we present results of soil algal cenoses classification using the Braun-Blanquet approach based on species composition data obtained via an integrative approach. Characteristic tables include 19 out of 108 samples collected in the Jewish Autonomous Region, Primorsky Territory, and Sakhalin Region (Iturup Island) in 2018 and in 2020-2021. Twenty-five species of algae from four classes were identified in these sites. We described three new associations of algal communities-Coelastrelletum aeroterrestricae ass. nova, Vischerietum magnae ass. nova, Bracteacoccetum bullati ass. nova. PCA analysis corroborated the results of syntaxonomic analysis and revealed that Coelastrelletum aeroterrestricae inhabit soils with a high value of P; Vischerietum magnae inhabit soils with high value of soil organic carbon (SOC), N, and higher humidity; and Bracteacoccetum bullati inhabit soils with high K values.
ABSTRACT
A strain of oogamous biflagellate green alga was isolated during a study on soil algal diversity in the Russian Far East (Sakhalin Region, Iturup Island) and examined using an integrative approach. Phylogenetic analyses, based on the SSU rDNA gene, resolved the new strain as a part of the RL clade (sensu Watanabe and Nakada) within Oogamochlamydinia (Volvocales, Chlorophyceae). The strain was similar to members of the genus Oogamochlamys (parietal and massive cup-shaped chloroplasts; two apical contractile vacuoles), but was, however, distinguished from them based on the size and shape of the mature vegetative cells, the flagellar length, the presence of only one pyrenoid in both the mature vegetative cells and the zoospores, the anterior nucleus position, and the spermatozoids' shape. Although a concept of the genus Oogamochlamys has been compromised in recent phylogenetic analysis based on the SSU rDNA sequence data and its likely affinity to anisogamous Chlamydomonas allensworthii, we described the strain from Iturup Island as Oogamochlamys kurilensis sp. nov.
ABSTRACT
Diatoms inhabit different aquatic and non-aquatic environments, including soils. The naviculoid genus Luticola is widespread in various habitats and accounts for 264 species that are only based on morphological and morphometric characteristics. These parameters can greatly vary during the life cycle, making the species very similar to each other and complicating their unambiguous identification. During a study on soil algal diversity in the Russian Far East (Jewish Autonomous Region), we isolated a strain of naviculoid diatom and examined it using an integrative approach (phylogenetic, morphological, ultrastructural data, and life cycle). Phylogenetic analyses, based on chloroplast rbcL gene data, showed affinity of the new strain with the genus Luticola. Our alga shares morphological features typical of the genus members but differs from them by having valves with a larger width and hook-shaped external proximal raphe ends deflected to the side opposite the stigma. It was revealed that the strain reproduces via two types of sexual reproduction-isogamy and cis-anisogamy. Based on these phenotypic traits, we described the new isolate as Luticola tenera sp. nov.
ABSTRACT
Many filamentous and sarcinoid terrestrial or freshwater green algae that were previously assigned to the Chlorophyceae are members of lineages belonging to the class Ulvophyceae. One of these lineages is the Planophila-clade (Ulotrichales). Some genera in this clade share similar morphology: cell packages forming branched pseudofilaments, uniseriate or sometimes biseriate filaments, often embedded in common mucilage. During a study on soil algal diversity in the temperate monsoon climate zone in Russia (Primorsky Territory, Vladivostok), we isolated a strain of sarcinoid green alga and examined it using an integrative approach. SSU and ITS rDNA sequence data, morphological characteristics, and life cycle features differentiated this strain from closely related genera of the order Ulotrichales and led us to describe it as Ulosarcina terrestrica gen. et sp. nov.
ABSTRACT
Chlorella-like green algae that reproduce only asexually by immotile autospores or motile zoospores are the most typical inhabitants of non-aquatic environments. They have a simple morphology that hampers their differentiation, but algae of such habit represent a diverse array of lineages, which are mostly in the classes Chlorophyceae and Trebouxiophyceae. One of these lineages is the order Watanabeales (Watanabea clade; Trebouxiophyceae), which comprises 10 genera that share a distinct mode of reproduction through unequally sized autospores. Most of these genera account for a few species that are rarely recorded in nature. In contrast, the genus Chloroidium is one of the most species-rich and widely distributed members of the order. Three strains of coccoid green alga were isolated during a study of soil algae in the temperate monsoon climate zone of Asia. These strains are described here as a new species, Chloroidium orientalis. SSU and ITS rDNA sequence data, morphological characteristics, and life cycle features differentiate these strains from known members of the genus.
