Gametophyte Morphology Research Articles

Genus <I>Pronephrium</I> Presl in India

In the present communication four new combinations of Abacopteris species under the name Pronephrium are proposed as the generic name Abacopteris Fee has been antedated by Pronephrium Presl (Holttum, 1971 ; Holttum and Chandra, 1971). The morphology of sporophyte and gametophyte of five Indian species of Pronephrium viz. P. lakhimpurense, P. nudatum, P. penangianum, P. stenopodum and P. triphyllum is also described.

Arrival of the non-indigenous brown alga Mutimo cylindricus to the Atlantic Ocean

Every introduction of a non-indigenous species (NIS) in coastal environments poses a threat to the native species and communities, as its effects in the ecosystem are not readily predictable. Introduction rates have kept increasing in the last decades, and our finding of the brown alga Mutimo cylindricus in the Canary Islands is another example of this general trend. This work represents the first record of the species outside its native range (Japan, Korea and the Philippines) in half a century, since its report in 1973 in Baja California, and marks the first report of M. cylindricus in the Atlantic Ocean. We analyzed the morphology of a male gametophyte observed in the Canary Islands and its phylogenetic relationship with other known populations using rbcL and cox3 genes. The morphology of M. cylindricus in the Canary Islands is consistent with previous descriptions and the phylogenetic analyses revealed the close relationship with native populations from Japan. The finding of a male gametophyte is noteworthy, as introduced and some native populations of this species are composed exclusively by female gametophytes and thought to be parthenogenic, whereas androgenesis is considered rare in the field. Maritime traffic appears as the most apparent introduction vector of the species and it seems plausible that microscopic crustose sporophytes were present near the collecting site, highlighting the need of further monitoring of the invasive potential of this species in the Atlantic Ocean.

Impact of varying light spectral compositions on photosynthesis, morphology, chloroplast ultrastructure, and expression of light-responsive genes in Marchantia polymorpha

Marchantia polymorpha is a convenient model for studying light of different spectral compositions on various physiological and biochemical processes because its photoreceptor system is vastly simplified. The influence of red light (RL, 660 nm), far-red light (FRL, 730 nm), blue light (BL, 450 nm), and green light (GL, 525 nm) compared to white light (high-pressure sodium light (HPSL), white LEDs (WL 450 + 580 nm) and white fluorescent light (WFL) on photosynthetic and transpiration rates, photosystem II (PSII) activity, photomorphogenesis, and the expression of light and hormonal signaling genes was studied. The ultrastructure of the chloroplasts in different tissues of the gametophyte M. polymorpha was examined. FRL led to the formation of agranal chloroplasts (in the epidermis and the chlorenchyma) with a high starch content (in the parenchyma), which led to a reduced intensity of photosynthesis. BL increased the transcription of genes for the biosynthesis of secondary metabolites - chalcone synthase (CHS), cellulose synthase (CELL), and L-ascorbate peroxidase (APOX3), which is consistent with the increased activity of low-molecular weight antioxidants. FRL increased the expression of phytochrome apoprotein (PHY) and cytokinin oxidase (CYTox) genes, but the expression of the phytochrome interacting factor (PIF) gene decreased, which was accompanied by a significant change in gametophyte morphology. Analysis of crosstalk gene expression, and changes in morphology and photosynthetic activity was carried out.

Taxonomic study of Scytosiphon (Phaeophyceae) from temperate coasts of Argentina.

Scytosiphon is a common intertidal genus widely distributed on temperate coasts worldwide. Recently, eight species have been delimited with molecular tools. Although S. lomentaria is the only species that predominates in the macroalgal literature of the Southwestern Atlantic Ocean (SwAO), unpublished molecular data obtained for a population study of S. lomentaria revealed hidden species diversity of Scytosiphon among the individuals collected from four localities at the SwAO. The aim of this study was to revise the identity and phylogenetic relationships of Scytosiphon from temperate coasts of the SwAO using DNA data. Thalli were collected from the Argentinean coast between 39° S and 43° S, from which cox1 and rbcL gene sequences were obtained. Phylogenies and haplotype networks were inferred and morphology of gametophytes was studied. Four species were recognized, S. lomentaria, S. promiscuus, S. shibazakiorum, and one species that belongs to a complex of species known as "Scytosiphon Atlantic complex." This complex was known to occur only in the North Atlantic, however, the results found in this study revealed that it has an extended distribution range that includes the southern hemisphere, where its populations have high genetic diversity and unique haplotypes. The morphological differences among the four species were subtle; denoting that previous Scytosiphon records from the SwAO attributed to the renowned S. lomentaria could represent different species. In addition, sex ratio and genome-wide single nucleotide polymorphisms (SNPs) analyses were done for populations of S. promiscuus presumably introduced to the SwAO, and the results indicated that they included female-dominant parthenogenetic populations, which were probably introduced from Japan.

Morphological characters and SNP markers suggest hybridization and introgression in sympatric populations of the pleurocarpous mosses Homalothecium lutescens and H. sericeum

Hybridization in bryophytes involves a fusion of gametes produced by haploid parental gametophytes of different species. The primary hybrid is thus the short-lived diploid sporophyte, which soon undergoes meiosis prior to the formation of large amounts of haploid spores. We compared morphology of gametophytes (branch leaves) and sporophytes (capsule inclination) from sympatric populations and allopatric populations of H. lutescens and H. sericeum. In addition, we used transcriptome data to select 85 nuclear SNP markers that were fixed for alternative alleles in the two species. The SNPs were used to estimate the degree of hybridization in diploid sporophytes. Our study shows that gametophytes from sympatric populations display intermediate morphology in a number of leaf characters, with exception for leaf sizes, which are markedly smaller than those in allopatric populations. None of the 100 sporophytes appeared to be primary hybrids, but 33 displayed admixing—heterozygotic expression of SNP markers or mismatch of occasional markers in homozygous condition—suggesting that extensive introgression takes place in the sympatric populations. Most sporophytes with intermediate capsule inclination, initially classed as putative hybrids, did not display admixture of nuclear SNP markers. Sixty-seven percent of admixed sporophytes have predominantly nuclear SNPs typical for H. lutescens. Our results suggest that interspecific hybridization and bidirectional introgression are relatively common in the studied sympatric populations, giving rise to viable recombinants, but not complete mixing of the parental genomes. Our study is one of the first detailed accounts of hybridization among pleurocarpous mosses, opening for future studies of gene transfer and introgression between bryophyte lineages and its role in local adaptation and long-term evolutionary diversification.

Fase gametofítica de tres taxones de Anemia (Anemiaceae)

Antecedentes y Objetivos: Anemiaceae presenta un único género, Anemia, con 115 especies que se distribuyen en el Neotrópico, África, India e islas en el Océano Índico. El objetivo de este trabajo es caracterizar las esporas vivas y la fase gametofítica de tres taxones de Anemia sudamericanas, poco estudiadas o con estudios fragmentados, A. herzogii, A. tomentosa var. anthriscifolia y A. tomentosa var. tomentosa.Métodos: Los gametofitos de los tres taxones han sido obtenidos a través de cultivos in vitro de las esporas. Las esporas y los gametofitos fueron estudiados a través del microscopio de luz y electrónico de barrido. Se describió el patrón de germinación de las esporas, evolución del desarrollo gametofítico y expresión sexual.Resultados clave: Los gametofitos filamentosos estaban formados por 4-20 células, los adultos fueron cordados simétricos o asimétricos, bisexuales y protándricos, en sus superficies y márgenes se observaron tricomas clavados. Los gametangios corresponden al tipo leptosporangiado. La dehiscencia de los anteridios se produjo mediante una perforación en la célula opercular. Los arquegonios tenían cuellos con cuatro a siete células y cuatro células triangulares en el extremo distal del cuello. Anemia herzogii mostró tricomas ramificados sobre los gametofitos y más tarde desarrolló esporofitos.Conclusiones: La germinación en todos los taxones corresponde al tipo Anemia y el desarrollo gametofítico al tipo Ceratopteris. Anemia herzogii se distingue de las dos variedades por la presencia de tricomas ramificados exclusivos de la fase gametofítica. Los taxones estudiados se caracterizan por la morfología del gametofito, tipo de tricomas y sexualidad.

In vitro Phytohormonal Regulation of Fern Gametophytes Growth and Development

Interest in ferns as objects of biotechnological research is determined by the characteristics of their development and reproduction, which is important for understanding the evolutionary pathways of seed plants. The previous published data on the phytohormones involvement in the regulation of fern gametophytes ontogenesis during in vitro cultivation are analyzed and summarized. The possibility of fern reproduction through spores application as explants using in vitro methods is considered. The effects of exogenous treatment with cytokinins, auxins, gibberellins, ethylene, jasmonic acid, and brassinosteroids on spore germination, gametophyte morphology and development are analyzed. The roles of gibberellins and antheridiogen in the formation of fern gametophytes’ sexual dimorphism are discussed. Data on disturbances of the sexual process in ferns and the phytohormones’ involvement in the formation of apogamic sporophytes are summarized.

Morphology and pigment content of sporophytes and gametophytes of ten fern species

The morphology and pigment contents of sporophytes and gametophytes of ten fern species were studied. In the morphological study, variations were found in stipe, texture, rachis, fronds and sori of these species. Photosynthestic pigment contents of sporophyte and gametophyte of ten species vary to a great extent. Even sporophyte and gametophyte of same species vary in pigment content. Sporophyte revealed higher chlorophyll content than gametophyte. The highest chlorophyll a and b were found in the gametophyte of Cetarach officinarum Gametophyte of Adiantum flabellatum produced maximum anthocyanin whereas minimum anthocyanin content was found in the sporophyte of Cetarach dalhousiae. The highest carotenoid content was obtained from the gametophyte of Cheilanthus albomarginata. Altitudinal variations were also found to affect morphology and pigment content of sporophytes and gametophytes of ten fern species.

Fluctuations in cell cycle, morphology and metabolism of Anemia phyllitidis gametophytes are the most important hallmarks of GA3-induced antheridiogenesis

The research object concerns partially explained mechanisms of plant hormone participation in male sex determination in plants, among them in A. phyllitidis gametophytes during GA3-induced antheridiogenesis.To provide an explanation of the mechanisms of fluorescence and white-light microscopy, cytophotometric, autoradiographic and spectrophotometic methods were used to study cell cycle, the number of nucleoli, the amount of DiOC6-stained IMN/ER, in which endoplasmic reticulum (ER) constitutes the main part, and its distribution as well as the amounts of proteins and chlorophylls and activities of acidic (Ac) and basic (Ba) phosphatases (Phases).It was revealed that antheridiogenesis was accompanied by cell cycle arrest at S-phase, changes of the number of nucleoli with simultaneous changes of the amount of IMN/ER and its distribution as well as fluctuations of protein amounts and of activities of acidic (Ac) and basic (Ba) phosphatases (Phases).The results indicated that initiation of antheridiogenesis in A. phyllitidis gametophytes by GA3 was related to the elevation of GAs/ANs in the culture media, during its induction phase, and the elevation of IMN/ER and GAs/ANs amounts, during expression phase of this process.

Developmental Evidence of Male and Female Gametophytes of Jatropha curcas L.: Pollen Capability and Stigma Receptivity

Physic nut (Jatropha curcas L.), a promising alternative resource for biodiesel production, produces restrictively a seed yield and has a low level of genetic variation, causing a barrier to improve the oil performance. Therefore, better understanding of reproductive biology is crucially important for breeding programs to achieve commercial viability in the future. The developmental features related to floral bud diameter and floral morphology of male and female gametophytes, by means of light and scanning electron microscopes, and their capability were investigated. It was found that bud diameter could be used as criteria for identification of pollen and embryo sac stages. Pollen capability and stigma receptivity showed an inverse S-shape with time after flowering. The highest pollen viability assessed by FCR (93.20 - 98.60 %), TTC (78.80 - 87.00 %), and germination test (43.40 %) were obtained at 0 - 8, 0 - 12, and 0 HAF, respectively. Moderately linear correlations were exhibited between viability and germination test (R2 = 0.57 - 0.62). Stigma receptivity was the highest (97.22 - 100 %) on the first three days.

Floral Morphology and Development of Female and Male Gametophyte of Bambusa intermedia Hsueh et Yi

Floral Morphology and Development of Female and Male Gametophyte of Bambusa intermedia Hsueh et Yi

Morphological variations and sex expression in gametophytes of Cibotium barometz under in vitro conditions

Abstract. PraptosuwiryoTNg, Isnaini Y. 2017. Morphological variations and sex expression in gametophytes of Cibotium barometz under in vitro conditions. Biodiversitas 18: 312-320. Characteristics of gametophytes in ferns have been shown to be phylogenetically significant. Studies of fern gametophytes have become essential to fill the gaps in our knowledge of fern morphology, ecology, reproduction, evolution and distribution. The purposes of this study were: (i) to observe morphological variations and sex expression in gametophytes of Cibotium barometz (L.) J. Sm., and (ii) to understand how gametophyte densities affect sex expression in the species. Spores of five collection numbers of C. barometz from Sumatra, Indonesia, were sown on half-strength Murashige & Skoog (½MS) basal medium. Eleven weeks after germination of spores, prothalli were subcultured on ½MS medium along with sugar (30 g/L) and Naphthalene Acetic Acid (NAA, 0.5 mg/L). After eight months subculturing of prothalli (prothallus density: 100-150 individuals per cm2), 100 gametophytes were observed for each collection number to determine their shapes and sex expression. Between 9- 12 months after subculturing, gametophytes growing at different population densities (between 100-500 individuals per cm2) were sampled. One hundred prothalli were selected among the ten replicates for each collection number. The percentage of each identified gametophyte shape and their genders were recorded. Eight morphological types of adult gametophyte were recorded: (i) Branching filament (asexual), (ii) ribbon-like shape (male), (iii) spatulate shape (asexual, male, female), (iv) heart shape (male, female, bisexual), (v) gemmiferous heart shape (asexual, female, bisexual), (vi) long heart shape (male, bisexual); (vii) gemmiferous long heart shape (asexual, male, bisexual), and (viii) gemmiferous irregular shape (asexual, male, female, bisexual). We conclude that gametophyte morphology is simply “too plastic” to be used in suporting species delimitation in ferns if the prothalli is to be cultured in a high population density. There is a correlation between gametophyte size, shape and sex expression that is related to the population density. The presence of unisexual and bisexual gametophytes indicates that both intergametophytic and intragametophytic selfing occur in C. barometz.
 Keywords: Cibotium barometz, Environmental Sex Determination theory, gametophyte, morphology, sex expression

Growth, development and morphology of gametophytes of golden chicken fern (Cibotium barometz (L.) J. Sm.) in natural media

Praptosuwiryo TNg, Pribadi DO, Rugayah. 2015. Growth, development and morphology of gametophytes of golden chicken fern (Cibotium barometz (L.) J. Sm.) in natural media. Biodiversitas 16: 303-310. The golden chicken fern, Cibotium barometz (L.) J.Sm., is an important export commodity for both traditional and modern medicine. To understand the reproductive biology of thisspecies, spore germination, gametophyte development, morphological variation, and sex expression were studied by sowing spores onsterilized natural media consisting of the minced roots of Cyathea contaminans and charcoaled rice husks (1: 1) mix. Spores ofC. barometz are trilete, tri-radially symmetrical, non chlorophyllous, and golden-yellow with a perine. Six stages of gametophytedevelopment (rhizoid stage, rhizoid/protochorm stage, filament stage, spatulate stage, young heart stage, mature heart stage) wereobserved between 24-45 days after sowing. Spore germination of C. barometz is Vittaria-type. Prothallial development of C. barometz isDrynaria-type. Five morphological types of adult gametophyte were recorded: (i) irregular spatulate shape (male), (ii) fan shape (male),(iii) elongated heart-shape (male), (iv) short heart or butterfly shape (female), and (v) normal heart shape (bisexual). The presence ofmorphological variations is presumed to be related to the population density, which significantly affects the sexual expression ofgametophytes. The variation of sex expression in C. barometz also indicates that this species may has a mixed mating systems thatresulted in genetic diversity within population and among populations.

Gametophyte Morphology and Development of Six Species of Pteris (Pteridaceae) from Java Island Indonesia

The morphology of sporophyte, the type of reproduction, and cytology of Pteris had been reported, while the gametophyte morphology of Pteris in Java island has not been studied yet. The objective of this study was to describe the gametophyte morphology and development of P. biaurita, P. ensiformis, P.exelsa, P.longipinnula, P. tripartita, and  P. vittata in Java island. Spores were obtained from fertile leaves of Pteris plants originated from several locations in Java island. The number of spores per sporangium were counted from fresh fertile leaves with mature sporangia. As much as 0.002 g spores was sown in transparent box with sterile medium contain of vermiculite, spaghnum moss, and perlite with ratio 2:2:1. The gametophyte development of each species was observed under a microscope every 7 days. The spores of P. ensiformis were germinated faster, 10 days after sowing, while the spores of P.longipinnula were germinated slower, 18 days after sowing. The pattern of spore germination is Vittaria-type. The development of gametophyte is Ceratopteris-type in common, but in a few cases is the Adiantum-type. The gametophyte development of observed Pteris spesies are varied in six characters including the number of filament cell, germinated time, formation time of notch and gametangia, margin shape, and development type.

Primary Hemiepiphytism inColysis ampla(Polypodiaceae) Provides New Insight into the Evolution of Growth Habit in Ferns

Premise of research. Epiphytes are prominent in many tropical floras; however, the evolution of epiphytism, especially among ferns, remains poorly understood. Transitions in habit have been proposed as evolutionary stepping stones in the radiation of ferns in the epiphytic niche, with hemiepiphytes playing an important role. However, few examples of hemiepiphytism have been conclusively documented in ferns, and evidence for this transition is limited. Because of this lack of information, the relationship between hemiepiphytism and epiphytism remains unclear. We fill this gap with new observations and analysis of habit evolution in the Polypodiaceae.Methodology. We document primary hemiepiphytism in Colysis ampla from field observations of both gametophytes and sporophytes, and we examine its sporophyte anatomy in relation to its growth habit. Using cpDNA sequence data, we place the species within a phylogenetic context and perform ancestral state reconstruction of growth habit to infer the evolution of hemiepiphytism in C. ampla.Pivotal results. Here we provide the first examination of gametophyte morphology and sporophyte growth habit in this species as well as the first conclusive documentation of primary hemiepiphytism in the Polypodiaceae. Phylogenetic analyses place C. ampla in a small clade of probable hemiepiphytes closely allied to the Old World ant-fern genus Lecanopteris. We infer a transition from epiphytism to hemiepiphytism in the clade consisting of C. ampla and closely related species, the first such transitional series reported for the polypod ferns. A hemiepiphyte syndrome consisting of gametophyte, rhizome, root, and leaf characteristics is presented to guide future investigation of this growth habit.Conclusions. Hemiepiphytes are likely underreported among climber- and epiphyte-rich groups of ferns. Primary hemiepiphytes may be more frequently derived from holoepiphytic ancestors because epiphytic gametophytes and sporophytes are preadapted to hemiepiphytic growth. We propose that hemiepiphytism provides a mechanism for acquisition of stable nutrient and water supplies by tree-dwelling plants.

Morphology and development of leaf papillae in the Pilotrichaceae

Sporophyte morphology has been traditionally used in taxonomic studies of pleurocarpous mosses. However, the gametophyte morphology of the Pilotrichaceae still holds interesting and under-investigated characters. Here, we conducted an in-depth investigation of the morphology and development of Pilotrichaceae leaf papillae and assessed their usefulness in inferring the evolutionary history of the family. Specimens were observed under scanning electron microscopy, and we identified seven morphological types of papillae, as well as two different pathways of development. Our results suggest that papilla morphology and development are phylogenetically informative in the Pilotrichaceae.

Gametophytic phase of two Neotropical ferns, Dennstaedtia globulifera (Poir.) Hieron and Hypolepis poeppigii Mett. ex Maxon (Dennstaedtiaceae)

This study aimed to provide a detailed description of the gametophyte morphology of two Neotropical ferns, Dennstaedtia globulifera and Hypolepis poeppigii, including spore germination, gametophytic development, and mature gametophyte morphology. Spores were sown in Petri dishes with Dyer medium. Petri dishes were kept in environmental room with a light regime of eight light-hours per day. We document the described morphologies through scanning electron microscope photomicrographs and light microscopy. Germination of spores follows the Vittaria type and the gametophytic development follows the Adiantum type. The adult gametophytes are cordiform or ameristic, unisexual and glabrous. Archegonia emerge from below the notch, and have four rows of cells, each with four, rarely five, cells and necks bent toward the roots. Antheridia are found among the roots, on the abaxial surface and margin of the laminar gametophyte, and have three cells; dehiscence of the antheridia is produced through formation of a pore. D. globulifera has simple antheridia, whilst H. poeppigii has individual antheridia or antheridia grouped on a single or multi-celled antheridiophore. The antheridiophore is described for the first time.

Gametophyte Morphology and Development of Three Species ofCyrtogonellumChing (Dryopteridaceae)

Abstract Gametophyte morphology and development of three species of Cyrtogonellum Ching (Dryopteridaceae) were described with the aim to increase our knowledge on the gametophytic stage of this fern genus especially the occurrence of sexual structures. Spore germination followed the Vittaria-type development, whereas prothallus growth followed the Aspidium-type development. Unicellular glandular hairs were located on both margins and surface of the prothalli. The heart-shaped prothalli of C. caducum showed irregularly lobed margins with multicellular filamentous to wing-like extensions. One to several agamously formed embryos were found on a single mature gametophyte of C. inaequale but only one of these developed into a mature sporophyte. Young sporophytes possessed scales with one to several glandular cells. Antheridia were found in all three species, but archegonia were observed only on mature prothalli of C. fraxinellum, which were always located near the midrib of the cordate-thalloid prothallus. The...

New records, replacements, reinstatements and four new species in the Radula parvitexta and R. ventricosa species groups (Jungermanniopsida) in Australia: cases of mistaken identity

Various published hypotheses regarding circumscription and relationships of species within the Radula parvitexta and R. ventricosa species groups were tested using molecular data from three chloroplast markers. The phylogeny resolves five clades within the R. parvitexta species group in Australia, which proves polyphyletic across two subgenera, or three subgenera if R. madagascariensis is included. One clade represents an undescribed species, R. psychosis sp. nov., one corresponds to R. madagascariensis, a new record for Australia, the others to R. ratkowskiana, R. tasmanica and R. robinsonii. R. ratkowskiana is reinstated from synonymy of R. tasmanica, and R. parvitexta is placed into synonymy of R. robinsonii. A second new species belonging to the R. parvitexta species group, R. kilgourii sp. nov., is described; however, it was not included in the phylogeny. Three clades were resolved within the R. ventricosa species group in Australia, which is nested within subg. Metaradula. These clades corresponded to R. jovetiana, R. loriana, which is reinstated from synonymy of R. ventricosa, and two new species, namely, R. myriopoda sp. nov. and R. forficata sp. nov. R. ventricosa is excluded from the Australian flora, because all material is referrable to R. loriana. R. forficata and R. kilgourii had not been collected before the present study. R. myriopoda and R. jovetiana exhibit overlap in morphology of the sterile gametophyte and can be reliably separated only on characters associated with the perianth mouth. They can be considered semicryptic species, and would not have been recognised independent of fieldwork and molecular investigations conducted as part of the present study.

Cryptic speciation and species diversity among Australian and New Zealand hornwort taxa of Megaceros (Dendrocerotaceae)

Recent molecular studies have redefined families and genera within the anthocerotes, but species boundaries are only now being revised. Monophyly of Australian and New Zealand taxa within the genus Megaceros Campb., which share the same spore and similar gametophyte morphology, was assessed. On the basis of sequence data, mainland Australian lineages are not monophyletic but are interspersed with New Zealand lineages. There are three species present in Australia, including the common and widespread M. gracilis (Reichardt) Steph., the widespread tropical M. flagellaris (Mitt.) Steph., recognised by its tesselated spores, and a new species, M. austronesophilus, found only in Tasmania and Macquarie Island. None of the currently recognised New Zealand taxa is conspecific with any of the Australian taxa. However, New Zealand lineages were found to be genetically and morphologically more diverse than is currently recognised.