蕨类生殖叶

… (sporophyll apical cell) near the original leaf apical cell. Through activity of the sporophyll apical cell most of the sporophyll … of the leaf of the leptosporangiate ferns, but a tetrahedral one …

… of the leptosporangiate ferns under experimental conditions, … and the vittarioid ferns together form the adiantoid fern clade of … , the fern plants produce many spores on the sporophylls. …

Platycerium bifurcatum is one of the most widely cultivated ornamental fern species worldwide and a valuable component of the biodiversity of pantropical forests. In addition to its photosynthetic function, the sporotrophophyll leaves of this species periodically develop a large, clearly demarcated sporangium at the leaf tips, enabling physiological and biochemical measurements both in the active sporulation part and in the non-sporulating leaf area. The aim of this study was to assess anatomical changes, determine thermal effects and the content of selected phytohormones, and analyze the spatial distribution of pigments in the sporophilic and trophophylic part of the same leaf during spore formation. The study utilized fluorescence microscopy, isothermal microcalorimetry, Raman mapping, and ultra-high-performance liquid chromatography coupled with a Triple Quad LC/MS analyzer. The results revealed significant physiological differences between the sporulating and non-sporulating leaf areas. For the first time, differences in thermogenesis within the two leaf regions accompanying sporulation and linked to the sporangium development stage have been demonstrated in ferns. Increases in gibberellins (GA3, GA4, and GA6), auxin (indole-3-butyric acid), (±)-cis, trans-abscisic acid, and abscisic acid glucose ester were observed in the sporophilic part of the leaf, as well as fluctuations in phytohormones in the trophophilic part, indicating internal metabolite relocation within the leaf. Raman analysis and 2D mapping revealed local lignin accumulation and fluctuations in carotenoid levels during spore maturation. The results of this study demonstrate physiological variation within a single leaf and the mechanisms accompanying sporulation, which provide a better understanding of fern adaptive strategies.

… structure as a fertile leaf or sporophyll, and will use the term … considers that “the anatomical characters of the Sphenophyllum … of the genera of Ferns. If we allow that the characters of the …

Recent advances in plant developmental genetics together with rapid accumulation of transcriptomic data on plants from divergent lineages provide an exciting opportunity to explore the evolution of plant morphology. To understand leaf origin in sporophytes of land plants, we have combined the available molecular and structural data on development of leaves with different morphologies in different plant lineages: clubmosses, spikemosses, leptosporangiate ferns, ophioglossioid ferns, marattioid ferns, whisk ferns, horsetails, and conifers. Specifically, we address the peculiarities of proximo-distal, ad/abaxial, and lateral development; presence/absence of mesophyll differentiation into palisade and spongy parenchyma; and type of leaf vascular bundles (collateral and bicollateral). Furthermore, taxon-specific and morphology-specific features of leaf development are considered in the context of the organization of shoot apical meristems (SAMs)—monoplex, simplex, or duplex—that produce leaf primordia. The data available imply that cellular patterns of leaf initiation correlate strongly with the structure of the SAMs but not with further leaf development or morphology. The later stages of leaf development are neither correlated with SAM structure nor with taxonomy. Occurrence and, if available, patterns of expression of homologs of the angiosperm genes responsible for the development of adaxial (ARP and C3HDZ) and abaxial (YABBY and KANADI) leaf domains, or establishment of the leaf marginal meristem (WOX) are discussed. We show that there is no correlation in the set of homologs of TFs that regulate abaxial and adaxial leaf domain development between leaves containing only spongy and no palisade mesophyll (of spikemosses, clubmosses, whisk ferns, horsetails, and most conifers), and leaves differentiated into palisade and spongy mesophyll (of leptosporangiate ferns, Ginkgo, Gnetum, and angiosperms). Expression of three out of four regulators of leaf development in primordia of both leaves and sporangia—C3HDZ in spikemosses and whisk ferns, YABBY in clubmosses and KANADI in spikemosses and horsetails—indicates that a sporangium developmental program could have been co-opted as a “precursor program” for the origin of microphylls and euphylls. Additionally, expression of leaf development regulators in SAMs of spikemosses (ARP, C3HDZ, and KANADI), clubmosses (YABBY), leptosporangiate ferns (C3HDZ), and horsetails (C3HDZ and KANADI) indicates that at least some mechanisms of SAM regulation were co-opted as well in the pre-program of leaf precursors.

… the anatomy and development of the sporophyte. So far as we yet have a comparative treatment of the prothallus of Ferns, … how directly plastic the prothallus of Ferns really is, t and raise …

Abstract The morphology and anatomy of vegetative leaves and sporophylls of six isophyllous species of Mexican Selaginella (subgen. Rupestrae): S. arsenei, S. extensa, S. peruviana, S. rupincola, S. sellowii and S. wrightii are described. The six species show small size of vegetative leaves (1.82–3.22 mm long × 0.32–0.62 mm wide), and lanceolate shape. The sporophylls are ovate (1.77–2.30 mm long × 0.63–0.84 mm wide). All species have hypostomatic leaves, with a central longitudinal stomatal groove on the abaxial surface. The central area is longitudinally flanked by long epidermal cells, and these by two rows of papillate cells. Epicuticular waxes as thin films, crusts or folds are present on the abaxial epidermal cells. The mesophyll has two longitudinal rows of sclerenchyma beneath the abaxial epidermis. Thickened epidermal cell walls are also present. These features are consistent with the climatic characteristics of the xeric environments these species live in, and can be considered xeric adaptations.

… leaf structure of six species of heterosporous ferns. Bot. Gaz.… Sterilefertile leaf dimorphism very widespread and developed to … Reproductive biology and gametophyte morphology of the …

… of growth and reproduction in ferns may correlate with … Monomorphic ferns that have fertile and sterile leaves with … than dimorphic ferns where the sterile and fertile leaves are …

… Therefore, a fern common in some primary forests in Costa Rica was selected to obtain an initial understanding of some aspects ofsexual reproduction in the herbaceous layer. Danaea …

Background: Drynaria roosii is a typically epiphytic fern characterized by the intriguing phenomenon that nest leaves (NLs) and sporotrophophyll leaves (SLs) are metatypical, with NLs persisting in a hardened form. Few reports have concentrated on the physiological characteristics of these two leaf types and the metabolite differences in their associated rhizomes (NRs and ORs). Methods: A comparative analysis of the two leaf types and their connected rhizomes was conducted based on photosynthetic parameters, leaf ultrastructure, Illumina HiSeqTM 2000 transcriptome sequencing, widely targeted metabolomics, and the spatial distribution of flavonoid components. Results: The results indicated that SLs exhibited significant advantages in photosynthetic parameters, with a net photosynthetic rate exceeding that of NLs by 228%. A total of 7236 differentially expressed genes (DEGs) were identified between SLs and NLs, with the majority of DEGs involved in developmental processes (491 DEGs), stress response (420 DEGs), and responses to abiotic stimuli (337 DEGs). A total of 1409 components were detected and authenticated, revealing that ORs contained relatively high levels of flavonoids, quinones, tannins, alkaloids, terpenoids, and vitamins. Furthermore, the spatial distribution of flavonoid components indicated a dispersive distribution in both NRs and ORs. Conclusions: This comprehensive study of NLs and SLs, along with their connected rhizomes, provides vital reference for scientific cultivation management and rational harvesting prior to medicinal use.

Abstract Although ferns are an important group for understanding leaf evolution, their developmental processes are still few understood. To better understand the organization of meristems and ontogeny of leaves in ferns, we studied their development in Elaphoglossum vagans (Mett.) Hieron., Lastreopsis amplissima (C. Presl) Tindale, Lomariopsis marginata (Schrad.) Kuhn, Mickelia scandens (Aubl.) R.C. Moran et al., Polybotrya cylindrica Kaulf., and Rumohra adiantiformis (G. Forst.) Ching, by using anatomical techniques. In addition, we observed herbarium specimens of those species, plus Elaphoglossum lingua (C. Presl) Brack, searching for unusual morphologies that may occur, that could represent a deviation from developmental processes here described. We propose hypotheses to explain these “natural mutants” based on known mechanisms of development. Shoot apical meristems of these species bear the typical tetrahedral cell with three dividing faces and the leaf apical meristem has two dividing faces. The leaf forms marginal meristems with enlarged initial cells, each of them bearing similarities to the leaf apical cell geometry and size, except in the simple-leaved fern Elaphoglossum vagans. Pinnae and segments primordia have grouped apical cells that are contiguous with their own marginal cells. In multi-pinnate leaves, one of these grouped apical cells in pinnae may enlarge and become similar to the leaf apical cell, indicating a reiterative process. The observed plants with unusual morphologies include plants with mixed reproductive identity, differential marginal growth, compromised apical growth, and reduced determinacy, supporting previous studies for leptosporangiate ferns. Apical and marginal cells of ferns may be homologous between them. Their characteristic geometry may allow specific cell divisions and their interconvertibility may drive the balance between apical and marginal growth. Unusual activity of these cells or changes in transcription factors may generate the observed abnormalities. A reiterative development in fern leaves supports the homology with shoots and the identity-in-parallel of their divisions.

Species delimitation methods based on macromorphology are often limited by phenotypic plasticity in plants. Fourier Transform near-infrared spectroscopy (FT-NIR) provides a promising alternative as a non-destructive technique that measures molecular vibrations (overtone and combination bands of C–H, N–H, and O–H bonds) from plant tissue exposed to near-infrared light (780–2,500 nm). We applied FT-NIR to the taxonomically challenging Scaly clade of Microgramma ferns (94 samples, eight species), including dimorphic and monomorphic taxa, to evaluate its diagnostic potential. Using multivariate models and cross-validation, we achieved 81–100% average identification accuracy. Well-defined species (e.g., M. percussa) reached 100% accuracy, while morphologically overlapping taxa showed lower accuracy, likely due to hybridization, introgression, or cryptic variation. Dimorphic species exhibited higher intraspecific spectral variability and lower accuracy linked to differences between fertile/sterile fronds than monomorphic species. FT-NIR proves effective as a complementary tool for fern systematics, elucidating species limits and diversity patterns. Further studies should address how hybridization, introgression, and indumentum affect spectral data.

… Interestingly, the climbing habit has evolved multiple times in the ferns, and many climbing species exhibit complete fertile-sterile leaf dimorphism. Examples include Blechnum fragile (…

… ferns growing in large gaps and forest understories. In this analysis two components of plant fitness—survival and reproductive … 10–30 cm height, dimorphic leaves (vegetative and fertile …

… leaves are larger than the sterile leaves, and thus, more leaf tissue is produced. A high reproductive cost has also been reported for the dimorphic … reported for dimorphic ferns (Danaea …

… of terrestrial ferns, with distinct evolutionary histories, leaf morphology, and reproductive systems. … leaf functional traits (dimorphism—1: fertile holodimorphic, 0: fertile non-holodimorphic; …

… Leaf dimorphism is related to reproductive … leaves enables the wind passage, which is the dispersal agent of spores (Kramer et al. 1995). In this study, the presence of dimorphic ferns …

… Biology of Pteridophytes 185 6.1 Diversity of Sori In the majority of the homosporous ferns, the … In Marsileales and Salviniales the sporangia develop in sori that are borne within a …

… from a marginal to a superficial position (see Scholch 2000a), highly complex basipetal marginal sori develop into the arrangement of superficial singly-arranged sporangia. Such a …

… In order to understand bow superficial sori are formed he developed the concept of "shifting"… For the study of sorus development, parts of leaves and pinnae with soral primordia were …

… Amphiacrostichoid sori developed from a coenosoric ancestor by … In ferns, acrostichoid sori result from fusion in several … gave insight into various aspects of the biology of Polybotrya: Dr. …

… The possible developmental relationship of sorus initiation to the marginal meristem ofthe … ferns, which have sori ofmarginal origin, and with the cyatheoid tree ferns, with superficial sori. …

In flowering plants many of the diverse characteristics utilized in systematics to determine phylogenetic relationships represent direct adaptations to specific methods of pollination or reproduction. In turn, each of these specific methods can determine to a large extent the total amount of inbreeding and outbreeding occurring and thus control population variability, evolutionary potential, and geographical distribution of the species. These phenomena and influences are well known and have been discussed extensively in the literature. In ferns many of the diverse characteristics utilized in systematics to determine phylogenetic relationships relate to the production of spores and include the size, shape, position and development of the sorus, the sporangia, and the spores contained within. The reproductive mechanisms, however, which determine genetic diversity and evolutionary potential, are held in a free-living independent gametophyte generation, a generation which, with the exception of its morphology, has been largely ignored. The initial modern studies on reproductive biology in ferns were done by Edward J. Klekowski, Jr., in the middle 1960's (Klekowski & Baker, 1966; Klekowski & Lloyd, 1968). Since that time numerous studies have appeared on a variety of species and phenomena by a limited number of workers (Cousens & Horner, 1970; Duckett, 1970, 1972; Ganders, 1972; Holbrook-Walker & Lloyd, 1973; Klekowski, 1969a, 1969b, 1970a, 1970b, 1970c, 1971a, 1971b, 1972a, 1972b, 1973a, 1973b, 1973c, 1973d; Lloyd, 1973a, 1973b, 1974; Lloyd & Klekowski, 1970; Saus, 1973; Schedlbauer & Klekowski, 1972). Homosporous ferns for the most part produce hermaphroditic haploid gametophytes, arising from a single haploid spore by a series of mitotic divisions. As a result, gametes from a single gametophyte will be identical genetically, barring mutation. Self-fertilization, i. e. fusion of sperm and egg from a single gametophyte (intragametophytic selfing) will produce a zygote which is completely homozygous. Thus, in ferns it is possible to produce completely homozygous individuals in a single generation, a condition rarely achieved in flowering plants even after many generations of inbreeding. Due to the complexities of the freeliving gametophyte and the genetic system of ferns, it has been necessary to utilize specific terminology to describe their mating systems. Those terms that will be used in this paper are: (1) intragametophytic selfing: fusion of sperm and egg from a single gametophyte, usually resulting in complete homozygosity of the resultant zygote; (2) intergametophytic selfing: fusion of sperm and egg from different gametophytes but both having arisen from a single sporophyte; this is analogous to inbreeding in flowering plants and results in a zygote with less heterozygosity than the parental sporophyte; (3) intergametophytic crossing: fusion of sperm and egg from different gametophytes, each originating from a

Abstract Resource allocation theory posits that organisms distribute limited resources across functions to maximize their overall fitness. In plants, the allocation of resources among maintenance, reproduction, and growth influences short‐term economics and long‐term evolutionary processes, especially during resource scarcity. The evolution of specialized structures to divide labor between reproduction and growth can create a feedback loop where selection can act on individual organs, further increasing specializaton and resource allocation. Ferns exhibit diverse reproductive strategies, including dimorphism, where leaves can either be sterile (only for photosynthesis) or fertile (for spore dispersal). This dimorphism is similar to processes in seed plants (e.g., the production of fertile flowers and sterile leaves), and presents an opportunity to investigate divergent resource allocation between reproductive and vegetative functions in specialized organs. Here, we conducted anatomical and hydraulic analyses on Onoclea sensibilis L., a widespread dimorphic fern species, to reveal significant structural and hydraulic divergences between fertile and sterile leaves. Fertile fronds invest less in hydraulic architecture, with nearly 1.5 times fewer water‐conducting cells and a nearly 0.5 times less drought‐resistant xylem compared to sterile fronds. This comes at the increased relative investment in structural support, which may help facilitate spore dispersal. These findings suggest that specialization in ferns—in the form of reproductive dimorphism—can enable independent selection pressures on each leaf type, potentially optimizing spore dispersal in fertile fronds and photosynthetic efficiency in sterile fronds. Overall, our study sheds light on the evolutionary implications of functional specialization and highlights the importance of reproductive strategies in shaping plant fitness and evolution.

A contemporary interpretation of Dollo's Law is that the evolution of specialized structures is irreversible. Among land plants, reproductive specialization shows a trend toward increasing complexity without reversion, raising questions about evolutionary steps and irreversibility of reproductive complexity. Ferns, exhibit varied reproductive strategies, some are dimorphic (producing separate leaves for photosynthesis and reproduction), while others are monomorphic (where one leaf is used for both photosynthesis and spore dispersal). This diversity provides an opportunity to examine the applicability of Dollo's Law in the evolution of reproductive leaf specialization across plants. We analyzed 118 species in Blechnaceae and Onocleaceae using quantitative morphometrics and phylogenetic comparative methods to test the pillars of Dollo's Law of irreversibility. The evolution of dimorphism in Blechnaceae is neither stepwise nor irreversible, with direct transitions from monomorphism to dimorphism, including several reversions. In contrast, Onocleaceae exhibit irreversibility to monomorphism upon further specialization of fertile leaves for spore dispersal, suggesting that additional specialization, not dimorphism alone, may facilitate irreversibility. These results provide insight into the canalization of fertile-sterile leaf dimorphism in seed plants, where traits like heterospory and ovules lead to further specialization and potential irreversibility. These findings suggest that as new specialized traits evolve alongside pre-existing ones, reversion may become increasingly unlikely.

… reproduction in ferns and … evolution, and the long-term implications of apomixis in ferns. Finally, I touch on notable gaps in our understanding of this reproductive approach in ferns, …

… Reduced reproduction of only the marsileaceous fern trajectories shown in Figure 7, with representative leaf shape outlines along the ontogenetic trajectories that were mathematically …

… Conversely, in an ironic vindication of the historical emphasis on reproductive characters, our results suggest that sorus position requires a simpler explanation under the 2012 topology …

Haploid gametophytes of bryophytes spread by clonal growth but mate locally, within an area defined by the range of sperm movement. Rarity of establishment from spores or vegetative competition can result in unisexual populations unable to reproduce sexually. Females typically outcompete males, probably because females expend fewer resources than males on the production of gametes. Extreme sexual dimorphism—tiny males growing as epiphytes on much larger females—has evolved many times. Haploid selfing is common in bryophytes with bisexual gametophytes, and results in completely homozygous sporophytes. Spores from these sporophytes recapitulate the genotype of their single haploid parent. This process can be considered analogous to ‘asexual’ reproduction with ‘sexual’ reproduction occurring after rare outcrossing between haploid parents. Ferns also produce bisexual haploid gametophytes but, unlike bryophytes, haploid outcrossing predominates over haploid selfing. This difference is probably related to clonal growth and vegetative competition occurring in the haploid but not the diploid phase in bryophytes, but the reverse in ferns. Ferns are thereby subject to stronger inbreeding depression than bryophytes. This article is part of the themed issue ‘Weird sex: the underappreciated diversity of sexual reproduction’.

Females tend to be smaller than males in woody dioecious plant species, but they tend to be larger in herbs. The smaller size of females in woody species has been attributed to higher reproductive costs, yet no satisfactory explanation has been provided for their larger size in herbs. Because herbs have higher nitrogen concentrations in their tissues than woody plants, and because pollen is particularly rich in nitrogen, we predicted that male growth would be more compromised by reproduction than female growth. To test this hypothesis, we conducted three experiments on the annual dioecious herb Mercurialis annua . First, we compared the timing of reproduction between males and females and found that males started flowering earlier than females; early flowering is expected to compromise growth more than later flowering. Second, we compared plants allowed to flower with those prevented from flowering by experimental debudding and found that males incurred a higher reproductive cost than females in terms of both biomass and, particularly, nitrogen. Third, we grew plants under varying levels of nitrogen availability and found that although sexual size dimorphism was unaffected by nitrogen, females, but not males, decreased their relative allocation to both roots and reproduction under high nitrogen availability. We propose that males deal with the high cost of pollen production in terms of nitrogen by allocating biomass to nitrogen-harvesting roots, whereas females pay for carbon-rich seeds and fruits by investing in photosynthetic organs. Sexual dimorphism would thus seem to be the outcome of allocation to above- versus below-ground sinks that supply resources (carbon versus nitrogen) limiting the female and male reproduction differentially.

Floret fertility is a key determinant of grain number per spike and an important factor in cereal crop yield. However, the mechanisms by which phytohormone signalling and transcription factors coordinately regulate floret fertility and spikelet development are not well understood, especially in wheat. In this study, we identified the role of jasmonic acid (JA) in the regulation of floret fertility in wheat. TaSPL13‐2B, a JA‐responsive regulator, directly represses the gene expression of the key JA signalling factor TaJAZ1 to improve floret fertility and increase the number of florets and grains per spikelet. The TaSPL13‐2B‐regulated JA signalling module (TaJAZ1–TaMYC2) contributes to floret fertility by inducing the expression of TaMADS1, an E‐class gene critical for floral organ identity and floret meristem activity, and increasing the content of jasmonoyl‐isoleucine (JA‐Ile) by upregulating the expression of genes involved in JA biosynthesis. We further demonstrated that TaSPL13‐2B is a potential target for yield improvement through field trials. Our work provides mechanistic insights into floret fertility and demonstrates that improving floret fertility could be a promising strategy to increase yield.

… in genome structure, gene expression, and developmental traits such as fertility, inbreeding, … , more leaves, longer and wider leaves, and taller plants than the parents. The fertility rate of …