Phylogeny and taxonomy of Meeboldia, Sinodielsia and their relatives (Apiaceae: Apioideae) inferred from nrDNA ITS, plastid DNA intron (rpl16 and rps16) sequences and morphological characters

Meeboldia H.Wolff, Sinodielsia H.Wolff and their relatives (Apiaceae: Apioideae) are similar in morphology, of which taxonomic treatments were controversial. In this study, the nuclear ribosomal DNA sequence (ITS) and two plastid DNA markers (rps16 and rpl16) were applied to reconstruct phylogenetic trees. The results demonstrated that Meeboldia and Sinodielsia formed a monophyletic group in phylogenetic trees and their highly similar morphological characteristics in taproot, basal leaves, calyx teeth, ribs, and vittae of fruits also confirmed their close relationships. Consequently, the following results were obtained: (1) Sinodielsia should be merged into Meeboldia; (2) Sinodielsia delavayi was confirmed conspecific with Meeboldia yunnanensis and renamed as Meeboldia delavayi (Franch.) W.Gou & X.J.He; (3) Sinodielsia thibetica was away from other Sinodielsia species; (4) Sinodielsia microloba was a member of Meeboldia and renamed as Meeboldia microloba (Kljuykov) W.Gou & X.J.He; (5) The name of Sinodielsia clade was suggested to be replaced by Hymenidium clade. We applied multiple approaches to explore the relationship of morphologically similar taxa, which will facilitate a deep understanding of taxonomy and species diversity of Apiaceae.

D-tartrate utilization correlates with phylogenetic subclade in Pseudomonas cichorii

ABSTRACT Pseudomonas cichorii is divided into two subclades based on the 16S ribosomal DNA sequence and core genome multilocus sequence typing. It was shown that subclade 2 strains utilize D-tartrate as a sole carbon source, whereas subclade 1 strains do not. Draft genome sequencing was performed with P. cichorii strains to identify D-tartrate utilization genes. By genome comparative and homology search studies, an approximately 7.1 kb region was identified to be involved in D-tartrate utilization. The region is subclade 2 specific, and contains tarD and dctA genes, which encode a putative enzyme and transporter of D-tartrate, respectively. When the region was introduced into subclade 1 strains, the transformants were able to utilize D-tartrate. Partial fragments of tarD and dctA were amplified from all subclade 2 strains tested in this study by PCR using gene specific primers, but not from subclade 1 strains. This is the first report on the genetic analysis of biochemical characteristics corresponding to a specific phylogenetic group in P. cichorii.

Isolation of the Parasite Enterocytospora artemiae From Chinese Grass Shrimp (Palaemonetes sinensis)—First Report in Asia

Chinese grass shrimp (Palaemonetes sinensis) is an economically important crustacean in Chinese aquaculture. Recently, we found that shrimp in Panjin city were infected with microsporidia, a group of fungi. The hepatopancreas of several infected shrimp showed white turbidity and pathological changes that negatively affected the health and appearance of the shrimp. Histopathology and transmission electron microscopy were used to examine the development of the parasite within its parasitophorous vacuole. Our results indicated that microsporidia developed asynchronously within the same parasitophorous vacuole. The spores were predominantly small, and rod or oval-shaped. The sizes of fresh spores were approximately 3.1 × 2.4 μm and fixed spores were 1.9 × 1.1 μm. The polar filament was isofilar with 5–6 coils and the thickness was 103.2 nm. Merogonial divisions occurred by binary fission and sporogonial division occurred by plasmotomy. The small subunit ribosomal DNA sequence (1295 bp) from the parasite was highly similar to the previously reported parasite Enterocytospora artemiae (99% nucleotide identity, JX915760). Using maximum likelihood to analyze the phylogenetic relationships, we found that this microsporidian should be grouped within Clade IV, an Enterocytospora-like clade, of the Microsporidia phylum. Based on this parasite’s life cycle characteristics, morphology, and small subunit ribosomal DNA sequence, the parasite described here is likely E. artemiae, which has previously only been described in Europe and North America. Thus, this is the first report of E. artemiae both in Asia and economically important shrimp.

Ultrastructures of Epibiotic Suctorian, Tokophrya huangmeiensis

Tokophrya species are either free-living or facultative ectosymbiotic suctorians associated with copepods, isopods, mysids, decapods and amphipods. Tokophrya huangmeiensis in particular is found to be epizoic with the redclaw crayfish Cherax quadricarinatus Von Martens, 1868, which has been observed as part of an ongoing investigation of freshwater ciliates biodiversity in Huanggang, Hubei, China (Tahir et al. 2017). This first study on T. huangmeiensis based on morphological features using light microscopy and small subunit ribosomal DNA sequence (Tahir et al. 2017), suggested that more detailed descriptions on the physiological and structural changes of this species should be done. Thus, in this study, we looked at the ultrastructures of T. huangmeiensis using electron microscopy, including both scanning (SEM) and transmission electron microscopy (TEM).