Universal dna isolation kit

The genomic DNA was extracted using a Axygen Universal DNA Isolation Kit (Axygen, Suzhou, China). Partial 18S rDNA was obtained as described in Zhu et al. (2017). The PCR products were purified and then sent to Tsingke Biotech Company, Inc. (Wuhan, China) for sequencing. Additional 18S rDNA and rbcL sequences from Trentepohliales species were downloaded from GenBank for analyses. Sequence matrices for phylogenetic analysis were initially aligned with MAFFT 7.0 and refined manually using Seaview [26 (link),27 (link)]. ModelFinder was utilized to select the best-fitting evolutionary models for each marker according to Bayesian information criterion calculations [28 (link)]. IQ-TREE and MrBayes3.2 were used to infer the phylogeny [29 (link),30 (link)]. We performed two phylogenetic analyses using the 18S rDNA matrix. First, Cladophorales was used as the outgroup to infer the topology of Trentepohliales. Based upon the results of the first phylogenetic analysis, we selected Cephaleuros as the outgroup to perform the second analysis. In the phylogenetic analysis using the rbcL matrix, Ulotricales was selected as the outgroup.

The strains described in this study were isolated from water or soil samples, and have been deposited to the Freshwater Algae Culture Collection at the Institute of Hydrobiology (FACHB collection), Wuhan, Hubei Province, China. Strain FACHB-3309 was collected from a paddy field in Hechuan (29°50′15″ N, 106°12′46″ E), Chongqing Province, China, in March 2019. Strain FACHB-3310 was collected from a pond in Lvliang (37°34′20″ N, 112°12′29.25″ E), Shanxi Province, China, in July 2018. Strain FACHB-3311 was collected from a pond in Wuhan (30°3′46″ N, 114°23′56″ E), Hubei Province, China, in June 2019. Strain FACHB-3312 was collected from a ditch in Wuhan (30°33′2″ N, 114°25′48″ E), Hubei Province, China, in April 2019. Strain FACHB-3313 was collected from damp soil in a park in Haikou (20°2′23″ N, 110°21′1″ E), Hainan Province, China, in December 2018. All the strains were grown at 25 °C in liquid BG11 medium under a 12/12-h light/dark cycle. The genomic DNA was extracted using a Universal DNA Isolation Kit (Axygen, Suzhou, China) [56 ]. An Olympus BX53 (Tokyo, Japan) light microscope equipped with an Olympus DP80 digital camera and CellSens standard image analysis software (Tokyo, Japan) were used for morphological examination. The characteristics of the five species were summarized in Table 1.