Neochrome (NEO) is a particular chimeric photoreceptor that can respond to red/far red as well as blue light. Using this photoreceptor, some cryptogams may enhance light sensitivity at low light environment. However, the NEO sequence information is extremely limited. Using inverse PCR and single oligonucleotide nested PCR genome-walking approaches, the full-length genomic sequences of NEO genes were determined for three fern species Coniogramme intermedia var. glabra, Plagiogyria distinctissima and Pronephrium lakhimpurnense. Sequence and structure analysis results indicate that they possess a conserved structure and organization. Introns are absent in three genes. They each contain an 4332, 4308 and 4317-bp ORF (Open reading frame), encoding a deduced protein with 1443, 1435 and 1438 amino acid residues. Their N-terminus consists of a putative functional phytochrome sensory module including PAS (Per / Arnt / Sim), GAF (cGMP specific phosphodiesterase / adenylate cyclases / formate hydrogen lyase transcription) and PHY (phytochrome) domains, whereas the C-terminus contains a nearly complete phototropin with two LOV (Light, Oxygen and Voltage-sensing) and one STKc (Serine/Threonine protein kinases, catalytic) domains. Phylogenetic analyses revealed that they are evolutionarily close to their homolog AcNEO found in Adiantum capillus-veneris. The 3D structures of the functional domains were computer-modeled, and the pivotal amino acid sites for each functional domain were also identified. This study represents the first comparative analysis of NEO nucleotide sequences and structures in ferns.

Arbuscular mycorrhizae (AM) influence the growth, morphology and fitness of the plant species they colonize. Despite the abundance and importance of epiphytes in forest dynamics, little is known about AM in these plants. Abundant epiphytes are present in the Valdivian temperate forests of South America, where ferns are one of the most important components of the epiphytic vascular flora. The aim of this work was to analyze the occurrence of AM in sporophytes of obligate and facultative epiphytic fern species in a Valdivian temperate forest of Patagonia, Argentina. We examined the roots of 10 epiphytic fern species. Roots of 66 sporophytes were collected from tree trunks and branches between 0.5 and 2 m height above the ground and were stained by using a modified Phillips and Hayman (1970) method. Of the 10 species examined in the present study two were found to be obligate epiphytes, six were facultative epiphytes and two could not be classified because few individuals were found. Most of them lacked AM structures, except for seven Hymenophyllum sporophytes which were rooted in soil and possessed scarce knobby hyphae and structures similar to coils and vesicles. Abundant dark septate fungi were observed within the cortex of all samples. The absence of AM in epiphytes may be explained by different ecological or taxonomic reasons, but in this study we suggest that root morphology may be an important factor influencing mycorrhizal behavior in ferns.

The surface of gametophytes of Tmesipteris sigmatifolia from axenic culture were examined with electron microscopy and histochemistry. A lipid layer, which gave a positive reaction with lipid stains, covers the surface of these gametophytes. In apical regions of the gametophyte the lipid coating, the cuticle, is less than half the thickness of the wall it covers. The wall was not stained with lipid stains, but did stain for cellulose and polyphenolic materials. A cuticle on the surface of Tmesipteris gametophytes indicates that a cuticle is characteristic of gametophytes in the Psilotaceae because gametophytes of both Psilotum and Tmesipteris are now known to have them.

The gametophytic generation of Cheilanthes pilosa (Pteridaceae), including spore germination, morphological development of the gametophytes, major vegetative features and sexual expression, was studied. In C. pilosa spore germination was of the Vittaria model and the developmental pattern was intermediate between Adiantum and Ceratopteris models. Adult gametophytes were cordate and hairy, with unicellular hairs located in the margins and both the ventral and dorsal surfaces of the prothalli. Gametangia were of the normal type described for leptosporangiate ferns. In C. pilosa populations the gametophytes produced at first instance a high proportion of female gametophytes, few male gametophytes developed and most of the female gametophytes became bisexual with time. Thus, although outbreeding is possible, this species seemed to be promoting intragametophytic selfing as the major reproductive strategy.

Cyathea srilankensis Ranil, a new endemic Sri Lankan tree fern species, is described. It is characterized by large pinnate-pinnatisect leaves, sparse narrowly triangular petiole scales and caducous membranous indusia.

An undescribed species of Isoëtes (Isoëtaceae) was found during a floristic survey in Lao PDR. This Laotian species is distinctive enough to identify it as a separate species from the related taxon I. coromandelina by its megaspore characteristics, polyhedral shape, large tubercules on proximal and distal surfaces, and the uniform size. We propose I. laosiensis as a new species from South East Asia (Laos).