As an ancient lineage of ferns, Ophioglossaceae are evolutionarily among the most fascinating because they have the highest chromosome count of any known organism as well as the presence of sporophores, subterranean gametophytes, eusporangiate sporangia without annuli, and endophytic fungi. Previous studies have produced conflicting results, identifyingsome lineages with unresolved relationships, and have paid much attention to the subfamily Botrychioideae. But the other species‐rich subfamily, Ophioglossoideae, has remained largely understudied and only up to 12 accessions of Ophioglossoideae have been sampled. In this study, DNA sequences of seven plastid markers of 149 accessions (75 in Ophioglossoideae) representing approximately 82 species (approximately 74% of estimated species diversity sensu J. Syst. Evol., 2016, 54, 563) in the family, and two Marattiaceae and two Psilotaceae, are used to infer a phylogeny. Our major results include: (1) Ophioglossaceae are resolved as monophyletic with strong support, and so are all four subfamilies and genera sensu PPG I except Botrypus and Ophioglossum; (2) a new genus Sahashia is segregated from Botrypus so that the monophyly of Botrypus can be retained; (3) the monophyly of Ophioglossum in its current circumscription is uncertain in spite of our large character sampling; (4) there is substantial cryptic speciation in Ophioderma detected by our molecular and morphological study; (5) the recognition of Holubiella is advocated based on its morphology and its sister relationship with Sceptridium; and (6) a novel sister relationship between Botrychium and the JHS clade (Japanobotrychium + (Holubiella + Sceptridium)) is discovered.

The main objective of the present study was to provide a comprehensive LCI

No abstract

Ophioderma redactophylla is described and illustrated as a new species from the Malay Peninsula. It is characterized by vermiform underground parts without tuberous rhizomes, the flat stalks, the linear trophophore, and the sporophore surpassing the trophophore. A taxonomic description and illustrations of the new species are presented. A key to species of Ophioderma is provided.

The relationships between Araceae diversity and altitude gradients in mountain ecosystem at Doi Suthep-Pui National Park, Chiang Mai Province in Thailand, were studied during January 2016-March 2018. The strip-plots, 10 m × 1,000 m along the five nature trails, were established from 300-500, 501-800, 801-1,100, 1,101-1,400, 1,401-1,685 m above mean sea level (amsl). Twenty species of 11 genera were found. Alocasia navicularis and Lemna sp. were found at 300-500 m amsl, wild taro (Colocasia esculenta) was at 300-800 m amsl, A. acuminata was at 300-1,400 m amsl, while Amorphophallus krausei, Hapaline benthamiana, Lasia spinosa, Rhaphidophora chevalieri and R. megaphylla were at 501-800 m amsl, but dwarf taro (C. affinis) was at 501-1,400 m amsl, Homalomena aromatica was at 801-1,100 m amsl, A. fuscus, A. thaiensis were at 801-1,685 m amsl, A. yunnanensis was at 1,101-1,685 m amsl, only five species, Arisaema consanguineum, A. kerrii, Remusatia hookeriana, R. peepla and Sauromatum horsfieldii were found at 1,401-1,685 m amsl. Species diversity in the rainy season was the highest (1.75), the top five dominant species were dwarf taro (C. affinis), wild taro (C. esculenta), A. fuscus, A. acuminata and A. thaiensis (importance value index (IVI%): 61. 54, 24.13, 17.12, 16.52 and 9.60, respectively). In dry season, the dominant species was wild taro. The altitude gradients showed the main effect on diversity and distribution of Araceae.

Microsorum species produce a high amount of phytoecdysteroids (PEs), which are widely used in traditional medicine in the Pacific islands. The PEs in two different Microsorum species, M. punctatum (MP) and M. scolopendria (MS), were examined using high-performance liquid chromatography (HPLC). In particular, MS produces a high amount of 20-hydroxyecdysone, which is the main active compound in PEs. To identify genes for PE biosynthesis, we generated reference transcriptomes from sterile frond tissues using the NovaSeq 6000 system. De novo transcriptome assembly after deleting contaminants resulted in 57,252 and 54,618 clean transcripts for MP and MS, respectively. The clean Microsorum transcripts for each species were annotated according to gene ontology terms, UniProt pathways, and the clusters of the orthologous group protein database using the MEGAN6 and Sma3s programs. In total, 1852 and 1980 transcription factors were identified for MP and MS, respectively. We obtained transcripts encoding for 38 and 32 enzymes for MP and MS, respectively, potentially involved in mevalonate and sterol biosynthetic pathways, which produce precursors for PE biosynthesis. Phylogenetic analyses revealed many redundant and unique enzymes between the two species. Overall, this study provides two Microsorum reference transcriptomes that might be useful for further studies regarding PE biosynthesis in Microsorum species.

Microsorum scolopendria is an important medicinal plant that belongs to the Polypodiaceae family. In this study, we analyzed the effects of foliar spraying of chitosan on growth promotion and 20-hydroxyecdysone (20E) production in M. scolopendria. Treatment with chitosan at a concentration of 50 mg/L in both young and mature sterile fronds induced the highest increase in the amount of accumulated 20E. Using RNA sequencing, we identified 3552 differentially expressed genes (DEGs) in response to chitosan treatment. The identified DEGs were associated with 236 metabolic pathways. We identified several DEGs involved in the terpenoid and steroid biosynthetic pathways that might be associated with secondary metabolite 20E biosynthesis. Eight upregulated genes involved in cholesterol and phytosterol biosynthetic pathway, five upregulated genes related to the methylerythritol 4-phosphate (MEP) and mevalonate (MVA) pathways, and several DEGs that are members of cytochrome P450s and ABC transporters were identified. Quantitative real-time RT-PCR confirmed the results of RNA-sequencing. Taken together, we showed that chitosan treatment increased plant dry weight and 20E accumulation in M. scolopendria. RNA-sequencing and DEG analyses revealed key enzymes that might be related to the production of the secondary metabolite 20E in M. scolopendria.

A new species of Ophioglossum, O. isanense, from Northeast Thailand is described and illustrated. It may be diagnosed from other congeners by a combination of morphological characters including: its smaller size, cylindrical rhizome, stoloniferous roots, brownish green common stalk and trophophylls, the presence of persistent leaf sheath at the top of the rhizome and by the unique structure of spores. Molecular study also supported it as a distinct species. A summary of the ecology and an IUCN conservation status of the new species are provided.