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The rehabilitation of mangroves depends on the availability of high-quality, sufficiently prominent seeds. Currently, a lot of mangrove nursery activities continue to employ traditional techniques, which results in low-quality and slowly growing seedlings. The mangroves of Jakarta were selected because they represent a heavily polluted mangrove ecosystem on Java's northern coast, whereas the mangroves in Kebumen, on Java's southern coast, are in the opposite situation. This study proposed to find an approach to supply Indonesia's mangrove restoration projects with adequate seeds. An experimental approach with a complete randomized design and a factorial pattern was used. The variables tested were planting media and three kinds of mangroves: Rhizophora mucronata, Ceriops tagal, and Bruguiera gymnorrhiza. Mangroves from Jakarta are treated with mud, soil media, or a mix of them. A mixture of mud, husk, and husk charcoal is used for six treatments planting media for mangroves from Kebumen. The mangrove seedlings' growth, biomass, and chlorophyll content are the dependent variables. ANOVA was used to evaluate the data with a 95% confidence level, and Duncan's comparison of means test followed. The growth of mangrove seedlings was discovered to be impacted by media type, while the chlorophyll content, dry biomass of roots, stems, and leaves were not affected by this factor. Three species of mangroves differ regarding growth rate, biomass of roots, stems, and leaves, and chlorophyll content. In order to support Indonesia's efforts to rehabilitate mangroves, this research can offer understanding regarding how to select and employ the best media to effectively produce high-quality seeds. [ABSTRACT FROM AUTHOR]

There is much controversy surrounding factors that affect the distribution of mangrove plants across the intertidal gradient. It was previously hypothesized that mangrove zonation was attributed to tidal sorting (TSH) of its propagules according to size (weight) or differential ability of propagules to establish in deep water. However, observational and experimental evidence have provided little support for the actual mechanism(s) of mangrove zonation. In general, species distribution pattern is the consequence of propagule dispersal. The specific gravity of water-borne mangrove propagules may affect their buoyancy, with inherent links to dispersal, thereby potentially influencing tree zonation. Propagule specific gravity can influence the distribution of mangroves in the context of global change, particularly in response to changes in seawater salinity. In this study, we measured the specific gravity and weight of 35 mangrove species propagules. There was no correlation between the weight of the propagule and its specific gravity. The specific gravity of propagules of true mangrove species was significantly greater than that of semi-mangrove. The results of the correlation between propagule specific gravity and the relative surface elevation of field distribution support the hypothesis that propagules are subject to tidal sorting and are not related to weight but to specific gravity. This newfound understanding of mangrove dispersal and distribution is critical in the context of mangrove protection and restoration, especially in projecting the effects of anthropogenic activities and global change on mangrove communities. [ABSTRACT FROM AUTHOR]

Abstract Background One issue in invasive plant ecology is identification of the factors related to the invasion process that increase number of non-native species. When invasion by non-native species increases, so does the probability that some non-native species will become harmful, or classified as invasive species, which disrupt natural ecosystems with attendant economic and social costs. I quantified patterns of how non-native species richness varied with vegetation types and human populations. To evaluate the relative importance of different predictor variables for invasion pathways in the conterminous United States, I modeled non-native plant species richness by county compared to current and historical human populations; greenhouses and nurseries; railroads, pipelines, transmission lines, and oil and gas wells; and land covers of impervious surface, development intensity categories, agriculture, and vegetation types. I also modeled these variables within vegetation types, excluding vegetation variables. Results To summarize patterns, non-native plant species richness increased from 72 to 200 with increasing human population density classes. Forests and forest land use mosaics had the greatest mean number of non-native plant species, ranging from 121 to 166, whereas grasslands and grassland mosaics had the least number of non-native plant species, about 70. For modeling variable importance, all combined variables had R 2 values of 56% (random forests regressor) and 54% (cubist regressor) for predictions of withheld observations of non-native plant species richness, with greenhouse density and percent forestlands as most influential variables. Single variables of greenhouses (R 2 = 29%), historical and current human populations (R 2 = 27% and 23%), impervious surface (25%), and medium intensity development (23%) were most associated with non-native plant species richness. For vegetation types, greenhouse and historical human population densities were influential variables particularly in forestlands, shrublands, and wetlands. Conclusions Based on these models, human population measures and horticultural locations of greenhouses and plant nurseries may have stronger relationships than measures of land use disturbance and transport with non-native plant species richness.

Bacterial communities associated with plant propagules remain understudied, despite the opportunities that propagules represent as dispersal vectors for bacteria to new sites. These communities may be the product of a combination of environmental influence and inheritance from parent to offspring. The relative role of these mechanisms could have significant implications for our understanding of plant–microbe interactions. We studied the correlates of microbiome community similarities across an invasion front of red mangroves (Rhizophora mangle L.) in Florida, where the species is expanding northward. We collected georeferenced propagule samples from 110 individuals of red mangroves across 11 populations in Florida and used 16S rRNA gene (iTag) sequencing to describe their bacterial communities. We found no core community of bacterial amplicon sequence variants (ASVs) across the Florida range of red mangroves, though there were some ASVs shared among individuals within most populations. Populations differed significantly as measured by Bray–Curtis dissimilarity, but not Unifrac distance. We generated data from 6 microsatellite loci from 60 individuals across 9 of the 11 populations. Geographic distance was correlated with beta diversity, but genetic distance was not. We conclude that red mangrove propagule bacterial communities are likely influenced more by local environmental acquisition than by inheritance. [ABSTRACT FROM AUTHOR]

Background: One issue in invasive plant ecology is identification of the factors related to the invasion process that increase number of non-native species. When invasion by non-native species increases, so does the probability that some non-native species will become harmful, or classified as invasive species, which disrupt natural ecosystems with attendant economic and social costs. I quantified patterns of how non-native species richness varied with vegetation types and human populations. To evaluate the relative importance of different predictor variables for invasion pathways in the conterminous United States, I modeled non-native plant species richness by county compared to current and historical human populations; greenhouses and nurseries; railroads, pipelines, transmission lines, and oil and gas wells; and land covers of impervious surface, development intensity categories, agriculture, and vegetation types. I also modeled these variables within vegetation types, excluding vegetation variables. Results: To summarize patterns, non-native plant species richness increased from 72 to 200 with increasing human population density classes. Forests and forest land use mosaics had the greatest mean number of non-native plant species, ranging from 121 to 166, whereas grasslands and grassland mosaics had the least number of non-native plant species, about 70. For modeling variable importance, all combined variables had R2 values of 56% (random forests regressor) and 54% (cubist regressor) for predictions of withheld observations of non-native plant species richness, with greenhouse density and percent forestlands as most influential variables. Single variables of greenhouses (R2 = 29%), historical and current human populations (R2 = 27% and 23%), impervious surface (25%), and medium intensity development (23%) were most associated with non-native plant species richness. For vegetation types, greenhouse and historical human population densities were influential variables particularly in forestlands, shrublands, and wetlands. Conclusions: Based on these models, human population measures and horticultural locations of greenhouses and plant nurseries may have stronger relationships than measures of land use disturbance and transport with non-native plant species richness. [ABSTRACT FROM AUTHOR]

The American mink (Neovison vison) has been introduced for fur farming into several countries around the world. In southern South America, although invasive populations have established in Argentina and Chile, no feral minks have been recorded in the Pampas Biome to date. We report a potentially new biological invasion in Uruguay, presenting observations, pictures and a museum specimen of feral minks in the locality Melilla, Montevideo Department, which probably escaped or were released from a local fur farm. We obtained 35 mink records between 2010 and 2020, mostly close to the fur farm, within a 2.5 km radius. Our report provides the northernmost mink records in South America, being the first in the Pampas Biome. American mink is a feared invader in most of the sites where it has been introduced, and therefore these new records are important mainly to plan and apply management interventions. [ABSTRACT FROM AUTHOR]

The basic life cycle of Foraminifera has long been recognized as alternation between sexual and asexual generations; a common modification is several successive asexual generations. Production and release of flagellated gametes also has been documented as the basic sexual-reproductive mode in extant lineages. Research on population dynamics, local spatial distributions, and biogeography of Amphistegina spp. and Heterostegina depressa have been augmented by culture studies over the past 50 years, providing insights that have been widely used in paleoecological and paleoenvironmental interpretations. Hypotheses are proposed suggesting how stages in the life cycle might contribute to understanding biogeographic and evolutionary trends commonly observed in large benthic foraminifers. Recruitment of sexually-produced cryptobiotic propagules, followed by successive asexual generations (schizogeny), can potentially establish viable, locally-adapted populations within literally years, consistent with the concepts of both allopatric speciation and reticulate evolution associated with isolation and reconnection of local basins. The review concludes with the recommendation that future studies utilizing genomics, proteonomics, geochemistries, scanning technologies, and other approaches can promote greater understanding of both modern and fossil larger benthic foraminiferal lineages. [ABSTRACT FROM AUTHOR]

Agaricus bisporus var. bisporus, the button mushroom, has a predominantly pseudohomothallic life cycle. Most of its spores are heterokaryotic and give rise to fertile heterokaryons. However, previous studies have suggested that outcrossing should not be rare in wild populations. In order to discover how outcrossing occurs, we experimentally favored it between aerial propagules of a fruiting donor mycelium and a delayed receiver mycelium that only invaded culture trays. Two donor/receiver pairs were studied, and potentially hybrid basidiomata collected on the receiver trays were analyzed with a mitochondrial marker, two unlinked nuclear CAPS markers, then haplotype markers based on DNA sequences obtained after PCR cloning of the rDNA ITS region and the fruk gene. For one of the two pairs, most basidiomata were hybrids between the donor and the receiver. Genotyping of the hybrids revealed only two genotypes consistent with outcrossing involving airborne mycelium fragments rather than basidiospores. The resident receiver heterokaryon that provided its mitochondria to the hybrid basidiomata is suspected to have had a trophic contribution to their growth and successful fruiting. The high level of heterozygosity and the cultivar introgression previously revealed in wild populations of this pseudohomothallic species may result from outcrossing involving airborne pieces of mycelium. [ABSTRACT FROM AUTHOR]

Global shipping facilitates the introduction of fouling organisms to new geographic areas. The increase in maritime transport in recent decades has led to unprecedented development, where marine coastal waters have become one of the most invaded habitats around the globe. Among the most successful invaders are ascidians. Despite the geographic and oceanographic isolation of Iceland, it is far from being excluded as a recipient region. Ascidians have successfully been able to establish stable populations in Iceland that are slowly expanding around the SW region. Here we report the first record of Ascidiella scabra in Icelandic waters, and the spread of seven non-indigenous ascidians across the S-SW Icelandic harbours. We compare their relative abundances to our survey from 2018. The bulk of these ascidians is not only present in the temperate Atlantic Ocean, but also in the Northwest Pacific and temperate Australasia, revealing that global homogenization of the ascidiofauna is emerging in anthropized coastal areas. The rising of sea surface temperature, driven by climate change, is likely to continue to support the development of this scenario leading to biodiversity loss, which could endanger living resources with severe economic impacts. [ABSTRACT FROM AUTHOR]

We provide the first documented case of the black mangrove, Avicennia germinans, producing multiple seedlings from a single propagule, a phenomenon called polyembryony, on several occasions. There is a lack of knowledge about polyembryony in mangroves, as it is an extremely rare phenomenon previously observed in only three other mangrove species. A higher weight of mature propagules may indicate polyembryony, thus enabling early detection. A. germinans may make use of mixed reproductive strategies to ensure the continued survival of the species, or to increase its expansion under favourable environmental conditions. Potential causes and implications of polyembryony in A. germinans are discussed. [ABSTRACT FROM AUTHOR]

Producing seedlings using the correct methods can aid in their better establishment in their habitats and help restore the fragile mangrove forests of southern Iran. This study aimed to investigate the effect of different methods of pericarp removal, irrigation regimes, and their interaction on germination percentage and some vegetative characteristics of Avicennia marina Forssk. Vierh. in the nursery. To achieve this goal, 30 healthy and mature trees were selected from the Sirik forest in Hormozgan province, Iran, and propagules were collected from them. The researchers used a completely randomized factorial design to study the effects of the treatments. Four pretreatments were tested for pericarp removal: pre-soaking propagules in 100% fresh water, 50% fresh water + 50% seawater, 100% sea water for 48 hours, and manually removing the pericarps. The propagules were then planted in plastic pots and irrigated twice a day, daily, every other day, or every three days. The seed germinations were measured for four weeks, and after two leaves appeared, collar diameter and height were recorded at the beginning and end of the six-month period. The results showed that seed germination and the vegetative characteristics of Avicennia marina Forssk. Vierh. seedlings were higher in the 50% fresh water + 50% seawater pretreatment. Additionally, germination, diameter growth, height growth, root length, and leaf number of the seedlings after six months were significantly higher with twice-a-day and daily irrigation regimes. Overall, the best conditions for producing Avicennia marina Forssk. Vierh. seedlings in the nursery were daily irrigation and pericarp removal using 50% fresh water + 50% seawater treatment. [ABSTRACT FROM AUTHOR]

Key message: Melatonin plays a crucial role in the mitigation of plant biotic stress through induced defense responses and pathogen attenuation. Utilizing the current knowledge of signaling and associated mechanism of this phytoprotectant will be invaluable in sustainable plant disease management. Biotic stress in plants involves complex regulatory networks of various sensory and signaling molecules. In this context, the polyfunctional, ubiquitous-signaling molecule melatonin has shown a regulatory role in biotic stress mitigation in plants. The present review conceptualized the current knowledge concerning the melatonin-mediated activation of the defense signaling network that leads to the resistant or tolerant phenotype of the infected plants. Fundamentals of signaling networks involved in melatonin-induced reactive oxygen species (ROS) or reactive nitrogen species (RNS) scavenging through enzymatic and non-enzymatic antioxidants have also been discussed. Increasing evidence has suggested that melatonin acts upstream of mitogen-activated proteinase kinases in activation of defense-related genes and heat shock proteins that provide immunity against pathogen attack. Besides, the direct application of melatonin on virulent fungi and bacteria showed disrupted spore morphology, destabilization of cell ultrastructure, reduced biofilm formation, and enhanced mortality that led to attenuate disease symptoms on melatonin-treated plants. The transcriptome analysis has revealed the down-regulation of pathogenicity genes, metabolism-related genes, and up-regulation of fungicide susceptibility genes in melatonin-treated pathogens. The activation of melatonin-mediated systemic acquired resistance (SAR) through cross-talk with salicylic acid (SA), jasmonic acid (JA) has been essential for viral disease management. The high endogenous melatonin concentration has also been correlated with the up-regulation of genes involved in pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI). The present review highlights the versatile functions of melatonin towards direct inhibition of pathogen propagule along with active participation in mediating oxidative burst and simulating PTI, ETI and SAR responses. The hormonal cross-talk involving melatonin mediated biotic stress tolerance through defense signaling network suggests its suitability in a sustainable plant protection system. [ABSTRACT FROM AUTHOR]

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The growing global population size and the increasing mobility of people can make humans as a potentially super-effective dispersal vector of plant propagules. Therefore, human-vectored dispersal (HVD) on clothing and footwear can be an effective way of the dispersal of invasive alien species (IAS). This can be especially problematic in protected areas, which are not exposed to the mass invasions caused by vehicles, construction works, trade or agriculture, but still exposed to HVD by tourists. In this study, we collected those biosecurity measures which currently apply to the control of IAS dispersed on human clothing. We also extracted relevant findings from studies on HVD for giving recommendations in order to improve policy measures aiming the prevention and mitigation of the spread of propagules of IAS on clothing. Even though many peculiarities of HVD are already known, e.g., retention potential of different fabric and cloth types, traits of the species of the most successful IAS dispersed by HVD and potential dispersal efficiency of HVD, we found that current IAS control measures usually do not consider and do not address sufficiently the threats represented by HVD on cloths. We suggest a number of voluntary and institutional measures that could be easily applied to decrease the chance of dispersing IAS by HVD, including information, self-regulation, legislation, quarantine measures, monitoring, interception and visitor management.

Agaricus bisporus var. bisporus, the button mushroom, has a predominantly pseudohomothallic life cycle. Most of its spores are heterokaryotic and give rise to fertile heterokaryons. However, previous studies have suggested that outcrossing should not be rare in wild populations. In order to discover how outcrossing occurs, we experimentally favored it between aerial propagules of a fruiting donor mycelium and a delayed receiver mycelium that only invaded culture trays. Two donor/receiver pairs were studied, and potentially hybrid basidiomata collected on the receiver trays were analyzed with a mitochondrial marker, two unlinked nuclear CAPS markers, then haplotype markers based on DNA sequences obtained after PCR cloning of the rDNA ITS region and the fruk gene. For one of the two pairs, most basidiomata were hybrids between the donor and the receiver. Genotyping of the hybrids revealed only two genotypes consistent with outcrossing involving airborne mycelium fragments rather than basidiospores. The resident receiver heterokaryon that provided its mitochondria to the hybrid basidiomata is suspected to have had a trophic contribution to their growth and successful fruiting. The high level of heterozygosity and the cultivar introgression previously revealed in wild populations of this pseudohomothallic species may result from outcrossing involving airborne pieces of mycelium.

Dispersal and establishment dynamics are critical in understanding shifts in species' ranges. We seek to illuminate patch-level dispersal dynamics by examining the shifting salt marsh-mangrove ecotone. Specifically, we ask the following: (1) How are mangrove propagules dispersed, retained, and exported within a discrete patch? (2) How do differences across a flooding gradient influence propagule dispersal dynamics? (3) How does the distribution of established seedlings compare to propagule movements? Avicennia germinans is the most temperate mangrove species in the northern Gulf of Mexico forming an ecotone with Spartina alterniflora marshes in coastal Louisiana. Sets of 500 distinctively marked mangrove propagules were placed at five different elevations. After their release, we observed dispersal dynamics for 1 month. Retention was limited in the study area (< 10%) with ~ 70–80% of propagules exporting out of the system and ~ 20% propagule predation. Retained propagules largely remained at their original elevations and were generally found at the highest elevation. Seedling establishment was also studied and unlike propagule dispersal distributions, peak seedling density occurred at elevations flooded 20–40% of the time. Our study highlights the mass export of mangrove propagules, the disparity between dispersal and establishment dynamics, and the need to explore dispersal at biologically relevant temporal and patch-level spatial scales. By understanding dispersal and establishment dynamics within the ecotonal boundary, we provide one of the first studies on dispersal at a temperature-controlled latitudinal limit for mangroves and highlight some of the drivers needed to better connect plot-, patch-, and landscape-level dynamics at this and other range limits. [ABSTRACT FROM AUTHOR]

Dispersal is a critical ecological process that modulates gene flow and contributes to the maintenance of genetic and taxonomic diversity within ecosystems. Despite an increasing global understanding of the arbuscular mycorrhizal (AM) fungal diversity, distribution and prevalence in different biomes, we have largely ignored the main dispersal mechanisms of these organisms. To provide a geographical and scientific overview of the available data, we systematically searched for the direct evidence on the AM fungal dispersal agents (abiotic and biotic) and different propagule types (i.e. spores, extraradical hyphae or colonized root fragments). We show that the available data (37 articles) on AM fungal dispersal originates mostly from North America, from temperate ecosystems, from biotic dispersal agents (small mammals) and AM fungal spores as propagule type. Much lesser evidence exists from South American, Asian and African tropical systems and other dispersers such as large-bodied birds and mammals and non-spore propagule types. We did not find strong evidence that spore size varies across dispersal agents, but wind and large animals seem to be more efficient dispersers. However, the data is still too scarce to draw firm conclusions from this finding. We further discuss and propose critical research questions and potential approaches to advance the understanding of the ecology of AM fungi dispersal. [ABSTRACT FROM AUTHOR]

Yacon (Smallanthus sonchifolius) is a plant of Andean origin currently cultivated and consumed in several parts of the world for having numerous nutraceutical properties. An increasing interest in its cultivation demands advanced technical information on this crop, still scarce. Considering this, our study aimed to evaluate the propagation of yacon by rhizophores with different bud number. The experiment was conducted in two phases: the first phase was developed in a seedling nursery, using a completely randomized design with four treatments and 50 repetitions. The treatments consisted of rhizophores with: one to two buds (T1), three to four buds (T2), five to six buds (T3), and seven to eight buds (T4). The second phase was performed in the field with random blocks, four treatments, four repetitions, and the same treatments of the first phase. The following morphological and growth characteristics were assessed: plant height, stem diameter, number of leaves, number of stems per plant, Dickson quality index (DQI), leaf area, leaf dry mass, rhizophores, tuberous root, and productivity. The following physiological features were also analyzed: chlorophyll content (FCI – Falker chlorophyll index), net carbon assimilation rate, leaf transpiration, stomatal conductance, internal carbon concentration, water use efficiency and instantaneous carboxylation efficiency. Seedlings from rhizophores with three to four buds presented the best morphological and growth characteristics, DQI = 0.47 and good performance in the field. In addition, the plants originated from this material (rhizophores with three to four buds) showed greater accumulation of dry matter in the aerial part and tuberous roots, and consequently higher productivity in fresh tuberous roots, constituiting a suitable propagation form for the cultivation of yacon. Highlights: Seedlings from rhizophores with three to four buds presented the best morphological and growth characteristics. The results indicate differences in photosynthetic capacity among seedlings. Possibility of estimating the CO2 assimilation in yacon plants through chlorophyll contents, determined by "ClorofiLOG" (model FL1030, Falker), a device that has lower cost and simple handling than other photosynthesis analyzers, like IRGA Licor 6400XT, representing a significant methodological contribution. Study shows that the number of buds in the yacon propagule (rhizophores) has a direct influence, from seedling phase to final production and that their weight should not be a factor for selection.

Shrimp aquaculture has caused broadscale shifts in mangrove ecosystems worldwide, including changes in habitats and functional traits of mangroves, to the point of widespread destruction in some countries. The propagule is an important stage in mangrove life history, reflecting the resource investment of parents and the ability of offspring to build a population. However, the impacts of shrimp aquaculture effluent on propagule functional traits and stoichiometry are poorly understood. Here, we comparatively investigated the functional traits and stoichiometry of Aegiceras corniculatum propagules in different shrimp aquaculture effluent-affected habitats on the coast of the South China Sea, including a control plot with no effluent discharge, a direct discharge area, and a landfill restoration area. We found that shrimp aquaculture effluent was associated with substantial impacts on the functional traits and stoichiometry of A. corniculatum propagules. In functional traits, both propagule morphology and biomass traits decreased in habitats affected by shrimp aquaculture effluent; in stoichiometry, the discharge of shrimp aquaculture effluent increased N and P contents, and after stopping the discharge, N and P in propagules remained at high concentration; propagule C/N and C/P ratios in all habitats were consistent with those of soils in that both were reduced and exhibited consistent N limits. Our findings highlight the effects of shrimp aquaculture effluent on functional traits and stoichiometric characteristics of A. corniculatum propagules, which may help improve our understanding of the underlying mechanisms of mangrove propagule adaptability. It also provides a scientific basis for assessing its impact on mangrove reproduction potential and population renewal and applies to mangrove management and restoration. [ABSTRACT FROM AUTHOR]

Yacon (Smallanthus sonchifolius) is a plant of Andean origin currently cultivated and consumed in several parts of the world for having numerous nutraceutical properties. An increasing interest in its cultivation demands advanced technical information on this crop, still scarce. Considering this, our study aimed to evaluate the propagation of yacon by rhizophores with different bud number. The experiment was conducted in two phases: the first phase was developed in a seedling nursery, using a completely randomized design with four treatments and 50 repetitions. The treatments consisted of rhizophores with: one to two buds (T1), three to four buds (T2), five to six buds (T3), and seven to eight buds (T4). The second phase was performed in the field with random blocks, four treatments, four repetitions, and the same treatments of the first phase. The following morphological and growth characteristics were assessed: plant height, stem diameter, number of leaves, number of stems per plant, Dickson quality index (DQI), leaf area, leaf dry mass, rhizophores, tuberous root, and productivity. The following physiological features were also analyzed: chlorophyll content (FCI - Falker chlorophyll index), net carbon assimilation rate, leaf transpiration, stomatal conductance, internal carbon concentration, water use efficiency and instantaneous carboxylation efficiency. Seedlings from rhizophores with three to four buds presented the best morphological and growth characteristics, DQI = 0.47 and good performance in the field. In addition, the plants originated from this material (rhizophores with three to four buds) showed greater accumulation of dry matter in the aerial part and tuberous roots, and consequently higher productivity in fresh tuberous roots, constituiting a suitable propagation form for the cultivation of yacon. [ABSTRACT FROM AUTHOR]

Aim: Biogeographical barriers restrict the movement of individuals, resulting in population divergence, genetic differentiation, endemism and speciation. Yet, some barriers demonstrate unequal effect across species depending on species dispersal, which manifests in varying genetic structure. We test the hypotheses that the genetic structure of four coastal mangrove species would reflect differences in dispersal potential across the Malay Peninsula, a major biogeographical barrier in the Indo‐West Pacific region. Location: East and west coasts of the Malay Peninsula. Taxon: Mangrove trees Avicennia alba, Sonneratia alba, Bruguiera gymnorhiza and Rhizophora mucronata. Methods: For each species, we characterized genetic structure and gene flow using 7–12 species‐specific nuclear microsatellite markers. We tested for east–west genetic differentiation across the peninsula, a stepping‐stone migration pattern, and assessed the proportion of recent dispersal and direction of historical migration along the Malacca Strait. Results: Significant east–west genetic differentiation across the peninsula was observed in A. alba, S. alba and B. gymnorhiza, and the effect was most pronounced for the two species with lower dispersal potential (A. alba, S. alba). In contrast, the two species with higher dispersal potential (B. gymnorhiza and R. mucronata) exhibited much higher proportion of recent inter‐population migration along the Malacca Strait. The signature of historical colonization from refugia in the Andaman Sea (north‐to‐south migration along the Malacca Strait) predominated for A. alba and S. alba. Historical south–north migration predominated for R. mucronata and B. gymnorhiza. Main conclusions: This study implicated dispersal potential as a cause of varying mangrove species genetic structure across a biogeographical barrier. The Malay Peninsula functions as a filter to gene flow rather than a barrier. The genetic structure in mangrove species with a higher dispersal potential is more congruent with contemporary gene flow while that of species with a lower dispersal potential reflects historical processes. Our findings hint at the role of dispersal potential as a predictor of gene flow in mangroves. [ABSTRACT FROM AUTHOR]

Over 90% of global commercial trade occurs between seaports, which are initial points-of-entry for nonnative, potentially invasive propagules. As such, there is a need to develop means to both rapidly intercept and identify propagules as they arrive. Here, we focus on plant propagules that are assumed to be non-native, in seed form. Because standard morphological techniques alone are laborious and require taxonomic expertise, we sought to address if identification through barcoding of the plastid DNA (rbcL + matK genes) of plant seeds could improve current processes in the early detection and rapid response to prevent entry/establishment of nonnative plant species. This research conducted a preliminary foray to evaluate the utility of widely accepted plant plastid DNA barcodes to identify plant propagules (seeds, hereafter) collected from the air-intake grilles of refrigerated shipping containers of a single agricultural commodity arriving at the Port of Savannah, Georgia, USA. We ask four questions: (1) Can DNA barcoding be used to detect seeds collected from shipping containers at the port? (2) What is the genetic composition of propagules entering the port? (3) How do morphological identifications compare to those based on genetic analysis? (4) Are nonnative invasive plant species present on shipping containers entering the Port of Savannah? This research collected 11,044 seeds from 628 refrigerated shipping containers between 2015 and 2017. Seeds were then morphologically sorted into Seed Types. Barcoding of the matK and rbcL gene regions of the plastid genomes directly isolated from seeds resulted in poor amplification. This is likely due to a host of potential confounding factors. Therefore, we germinated seeds and utilized leaf-tissues for sequencing of these two gene regions. From BLASTn analyses, results returned top hits for a variety of species, with up to 22 possible nonnative plant species and one definite Federal Noxious Weed. This work investigates the interception application of DNA barcoding to improve agro- and bio-security issues posed by nonnative and invasive species. Though this study required the germination of the seeds to obtain leaf-tissue suitable for our DNA barcoding method, we effectively demonstrated seed viability. Our seed identification process was lengthy and understandably not feasible for real-time application. Therefore, we seek to improve our methods for future applications by testing other approaches that may better complement morphological identification. Next reasonable steps include improved extraction protocols, metabarcoding to generate DNA barcode sequences directly from groups of seeds harvested from shipping containers and implementing other next-generation sequencing techniques. [ABSTRACT FROM AUTHOR]

In this overview, the authors have discussed the potential advantages of the association between mycorrhizae and plants, their mutual accelerated growth under favorable conditions and their role in nutrient supply. In addition, methods for isolating mycorrhizae are described and spore morphologies and their adaptation to various conditions are outlined. Further, the significant participation of controlled greenhouses and other supported physiological environments in propagating mycorrhizae is detailed. The reviewed information supports the lack of host- and niche-specificity by arbuscular mycorrhizae, indicating that these fungi are suitable for use in a wide range of ecological conditions and with propagules for direct reintroduction. Regarding their prospective uses, the extensive growth of endomycorrhizal fungi suggests it is suited for poor-quality and low-fertility soils. [ABSTRACT FROM AUTHOR]

Mycorrhizas face unique anthropogenic stressors in urban environments, but the factors influencing their abundance in cities remains comparatively unstudied. Using green roofs as a model system, we built a conceptual model outlining the biotic and abiotic factors influencing arbuscular mycorrhizal (AM) fungal abundance in cities. We then tested this model and its multiple causal hypotheses with structural equation modeling using plant, soil, and AM fungal abundance measurements from 60 plots across 12 green roofs in Chicago, USA. The best direct predictor of AM fungal abundance was not plant cover, plant richness, or soil nutrients, but instead green roof age, suggesting temporal accumulation of AM fungal propagules in degraded urban environments. Soil P had the strongest total effect on AM fungal abundance both directly and via indirect promotion of plant cover. This study highlights knowledge gaps and challenges to studying the urban ecology of AM fungi. [ABSTRACT FROM AUTHOR]

Seed or samara terminal velocity is a key trait affecting the dispersal potential of wind‐dispersed plants. However, this trait is often represented in dispersal models by a single mean value per species. This is despite considerable variation in dispersal traits within species and individuals that may have implications for both phenotypic selection and rates of spread. Methodological constraints may have acted as a barrier for robust assessments of intraspecific variation in seed terminal velocity.To quantify intraspecific variation in wind dispersal traits, we develop a low‐cost, time‐efficient method to measure the terminal velocity of a large number of samaras. We made three separate terminal velocity measurements for each of 750 Pinus radiata samaras, allowing partitioning of variation among individual cones, trees and source populations. We use the mechanistic WALD model to assess the potential influence of observed variation in samara terminal velocity on predicted dispersal kernels under a variety of realistic conditions.We demonstrate a twofold range in samara terminal velocity within P. radiata, with the highest variation occurring within individual cones, and the lowest among cones within individual trees. We identify a potential influence of source population on terminal velocity. Our modelling results demonstrate that this within‐species variation is sufficient to affect the shape of the predicted dispersal kernels, particularly the kernel tails and therefore the likelihood of long‐distance dispersal events. The effect of samara terminal velocity on dispersal is especially pronounced under environmental conditions that enhance seed dispersal.Our findings illustrate the scale of within‐species variation in a key dispersal trait, and the likely effect of this variation on dispersal distance. We suggest that the high level of variation observed within individual cones of P. radiata is likely to reduce the potential for phenotypic selection, and may either be indicative of a "bet‐hedging" strategy, or simply the result of the constraints of cone morphology on samara development. To obtain accurate dispersal models for wind‐dispersed species we highlight the necessity of capturing this variation for inclusion in future modelling approaches, and describe a device that can achieve such measurements easily and at low cost. [ABSTRACT FROM AUTHOR]

Both biotic and abiotic factors can affect whether seagrass meadows establish as large, continuous features or as a mosaic of smaller patches, and these processes act across multiple spatial scales. Of these processes, sexual recruitment is considered vital for the recovery and resilience of seagrass meadows. Because numerous estuarine fauna can impact sexual recruitment by consuming seeds, it is important to understand variation in seed consumption throughout the seascape.We sought to determine how cross‐scale processes affected seed consumption of Zosteramarina, a widely distributed seagrass species. We deployed seed predation units (SPU) within patches ranging in size from 0.28 to 28.48 m2, and on unvegetated, sandy bottom. Seed consumption was analysed across patch sizes, at patch centres and edges and within the context of total seagrass cover within buffer zones surrounding SPU locations.Using structural equation modelling, we found that measured seascape parameters explained 34% of the observed variation in seed consumption. Specifically, we found that seagrass presence had the strongest effect on seed predation followed by a negative effect of patch size on seed consumption. Although there was no direct effect of percent seagrass cover (within a 4‐m buffer of the SPU) on seed predation, percent seagrass cover had a negative indirect effect through its positive correlation with patch size. However, we found that once variation due to patch size and areal cover were accounted for, seeds placed at patch interiors actually experienced greater consumption rates. We did not find similar relationships with our potential seed consumers, although our snapshot sampling likely obscured transient effects.We argue that seagrass recruitment could be affected by seed predation, which is influenced by multiple processes, including predator dispersal, behaviour and aggregation. Since seed‐based restoration is becoming more common, and the role of sexual recruitment in meadow maintenance appears to be increasingly important for seagrass resilience, our results demonstrate that for current management strategies to be successful, there is a need to better understand seed predation in seagrass‐dominated seascapes.Synthesis. Factors that influence propagule supply and recruitment success of seagrass operate and interact across multiple spatial scales, which can have implications for management. [ABSTRACT FROM AUTHOR]

Long distance dispersal (LDD) contributes to the replenishment and recovery of tropical seagrass habitats exposed to disturbance, such as cyclones and infrastructure development. However, our current knowledge regarding the physical attributes of seagrass fragments that influence LDD predominantly stems from temperate species and regions. The goal of this paper is to measure seagrass fragment density and viability in two tropical species, assessing various factors influencing their distribution. We measured the density and viability of floating seagrass fragments for two tropical seagrass species (Zostera muelleri and Halodule uninervis) in two coastal seagrass meadows in the central Great Barrier Reef World Heritage Area, Australia. We assessed the effect of wind speed, wind direction, seagrass growing/senescent season, seagrass meadow density, meadow location and dugong foraging intensity on fragment density. We also measured seagrass fragment structure and fragment viability; i.e., potential to establish into a new plant. We found that seagrass meadow density, season, wind direction and wind speed influenced total fragment density, while season and wind speed influenced the density of viable fragments. Dugong foraging intensity did not influence fragment density. Our results indicate that wave action from winds combined with high seagrass meadow density increases seagrass fragment creation, and that more fragments are produced during the growing than the senescent season. Seagrass fragments classified as viable for Z. muelleri and H. uninervis had significantly more shoots and leaves than non-viable fragments. We collected 0.63 (±0.08 SE) floating viable fragments 100 m−2 in the growing season, and 0.13 (±0.03 SE) viable fragments 100 m−2 in the senescent season. Over a third (38%) of all fragments collected were viable. There is likely to be a large number of viable seagrass fragments available for long distance dispersal. This study's outputs can inform dispersal and connectivity models that are used to direct seagrass ecosystem management and conservation strategies. • There are large numbers of viable seagrass fragments available for dispersal. • Moderate winds with high seagrass density increases seagrass fragment creation. • More seagrass fragments are produced during the growing than the senescent season. • Seagrass fragments have more shoots and leaves than non-viable fragments. • Over a third (38%) of all floating fragments are viable. [ABSTRACT FROM AUTHOR]

Large-scale production of Arbuscular Mycorrhizal Fungi (AMF) consortia is a crucial stride in harnessing their potential for sustainable agriculture and plant growth enhancement. However, establishing optimal production conditions is challenging due to their obligate nature, variability, lack of standardized protocols, and limited understanding of their specific requirements. Previous attempts to standardize Root Organ Cultures (ROC) for AMF overlooked challenges related to viable inoculum production for field applications. This current investigation reported, for the first time, the optimization of various factors during large-scale production of AMF using ROC. By optimizing factors like gelling agents, media preparation, medium-to-inoculum ratios, incubation conditions, age, harvesting method and drying temperatures, we achieved significant yields of viable propagules. The standardized protocol outlined in this study will greatly influence commercial-scale AMF production. These standardized protocols are poised to contribute to larger-scale AMF production worldwide, with the potential to support sustainable agriculture and ecosystem management., (© 2013-2023 The Journal of Biological Methods, All rights reserved.)

The success of biological control of insect pests depends not only on the isolation, characterization, and pathogenicity, but also on the success of the mass production of the microbial agents. The biological control strategy using entomopathogenic fungi like B. bassiana and M. anisopliae can only be useful if practical and economic methods of mass multiplication are available. Rice by-products like broken rice grains, rice hulls and their combination was evaluated for solid state multiplication of B. bassiana and M. anisopliae. The influence of photoperiod and incubation time in the production of conidia was also evaluated. This study showed that, broken rice was the most productive substrate for conidial production of both fungal genera, with a yield of 4.62 x 107 and 2.22 x 106 conidia g-1 respectively. Also, under the evaluated solid state multiplication conditions, the best conidia production was achieved with a photoperiod of 24 h of light for B. bassiana (with 4.43 x 107 conidia g-1) and M. anisopliae (with 1.35 x 106 conidia g-1). The results here demonstrated that these two fungal species could viably be multiplied with good yields of conidia on agro-industrial by-products using solid-state culture and regulating some culture conditions. [ABSTRACT FROM AUTHOR]

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Abstract: Propagule pressure plays a key role in the successful establishment of introduced species. Explaining invasion patterns, predicting future invasions and reducing invasion rates are priority areas of research and management, especially in marine systems, which need more detailed correlates and invasion predictors. The commercial maritime shipping fleet is the most prolific long distance anthropogenic transfer mechanism (vector) of marine non‐indigenous species on a global scale, causing invasions of coasts by a wide diversity of organisms. Although most vessel arrivals provide an opportunity for organism introductions, there are often substantial differences among ship types—in both their “morphological traits” (structural design) and “behavioural ecology” (cargo delivery model and operational tempo)—that influence propagule delivery by ballast water and biofouling, the two dominant sources or sub‐vectors for ship‐mediated species transfers. We reviewed ship specialization and its implications for marine invasion and vector management. First, we identified factors that affect ship‐mediated propagule delivery characteristics (number, identity, diversity and quality/condition), classifying these as ship type independent or dependent factors. Second, we compared the relevance of these factors for both ballast water and biofouling. Third, we estimated and compared the magnitude of several key factors affecting propagule delivery among seven major ship types. Typical voyage speed varies by 74% and port residence time varies sixfold among ship types. Similarly, typical ballast water discharge varies by an order of magnitude among ship types. These and other ship type dependent factors affect propagule delivery characteristics, resulting in uneven magnitude of species transfer among ship types. Policy implications. Variation among commercial ship types is rarely integrated into analyses of marine bioinvasions and proxy measures of propagule delivery. Their inclusion may lead to more robust explanation, prediction and management of marine invasions. Risk analyses that account for differences among ship types and prevailing traffic directionality will likely offer greater insight than null models, which treat ships equally. Furthermore, ballast treatment technologies and hull husbandry may advance to reduce species transfers more effectively when tailored for different ship types, recognizing the variation and operational constraints (that affect propagule delivery) among the diverse range of ship types. [ABSTRACT FROM AUTHOR]