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Compact blankets of free-floating plants generate stressful aquatic environments. The response of submerged macrophytes remains largely elusive. Will they rush toward the light or rather speed up reproductive efforts and escape using propagules—the macrophyte equivalent of lifeboats? We studied the effects of complete duckweed (Lemna minor) cover on growth and reproductive fitness of macroalga Chara globularis in a pond mesocosm experiment. C. globularis growing in Lemna-covered plots lost biomass and developed longer internodes, indicating an elongative reflex to escape stress. Densities of reproductive organs per biomass unit evolved positively in open plots and negatively in covered plots, suggesting a trade-off between reproductive effort and vegetative elongation. Reproductive potential correlated significantly with incident radiation. Lemna cover, however, did not affect oospore rain—at least within the limited time span of propagule trapping. C. globularis thus displayed an ability to modify phenology in response to floating plant stress, allocating resources to internodes instead of gametangia. Nevertheless, duckweed dominance clearly suppressed the overall reproductive performance of C. globularis. The regenerative capacity of many submerged macrophytes will likely suffer from increased floating plant dominance due to global warming—unless efforts are made to reduce nutrient levels in vulnerable waterbodies.

Riparian forests suffered from forest fragmentation, which in turn promote the change in the pattern of seed dispersion and modification of soil seed bank. The aim of this study is to indicate the main species that make up the seed bank of a stretch of riparian forest of the Mogi Guaçu River continued to a fragment of semidecidual forest, located in the Air Force Base of Pirassununga. It was delimited ten plots of 10 x 10 m. Four soil samples was collected by plot with a 25 x 25 cm template. Samples were packed in greenhouse for seed germination and monitored every 15 days for six months. Altogether, 494 individuals from 19 families were sampled, distributed in 30 genera and 40 morphospecies. Diversity and distribution of species in the fragment is homogeneous and can be used as source of propagules for forest restoration. RESUMO Florestas ripárias sofrem com a fragmentação florestal, que promove mudanças no padrão de dispersão de sementes e modificação do banco de sementes. O objetivo do presente estudo é indicar as principais espécies que compõem o banco de semntes de um trecho de floresta ripária do Rio Mogi Guaçu River contínuo a um fragmento de floresta estacional, localizada na Guarnição da Aeronáutica de Pirassununga. Foram delimitadas dez parcelas de 10 x 10 m. Quatro amostras de solo foram coletadas através de um molde de 25 x 25 cm. Amostras foram mantidas em estufa para germinação de sementes e monitoradas a cada 15 dias por seis meses. Ao todo, 494 indivíduos pertencentes a 19 famílias foram amostrados, distribuídos em 30 gêneros e 40 morfoespécies. A diversidade e a distribuição das espécies no fragmento é homogênea, podendo ser usado como uma fonte de propágulos para restauração florestal.

The purpose of this study was to determine the growth of mustard plant (Brassica junceaL.) responses to arbuscular mycorrhiza fungi under net house treatment. This research was conducted in net house of SindangKasih village, District of West Ranomeeto, South Konawe, and Laboratory of the Faculty Forestry and Environmental Science Halu Oleo University Kendari, Indonesia. This study used a Completely Randomized Design (CRD), which consists of 5 treatments i.e.: with out of mycorrhiza fungi propagules (M0), mycorrhiza fungi propagules as 25 g per polybag (M1), mycorrhiza fungi propagules as 50 g per polybag (M2), mycorrhiza fungi propagules as 75 g per polybag (M3), mycorrhiza fungi propagules as 100 g per polybag (M4). The variables observed were plant height, leaf number, total leaf area, specific leaves area and percentage of mycorrhiza fungi infection on rooting of mustard plant. The result of the research showed that application of the mycorrhiza fungi propagules at doses of 75 g per polybag given the highest of total leaves area as such as 1800.8 cm2, application the mycorrhiza fungi propagules at doses of 100 g per polybag given the highest specific of leaves area as such as 113.7 cm2, and application the mycorrhiza fungi at doses 25 g per polybag given the highest of percentage of mycorrhiza fungi infection to rooting of mustard plant as such as 14.90%.

This work aims to review the existing theoretical literature and experiments on plant species colonising gaps after soil disturbance. It attempts to evaluate the various mechanisms by which plants regenerate among the soil openings within the Mediterranean temporary ponds. Intensity and frequency of disturbances are key factors in the response of communities. Knowing the specificity of plant strategies and the species assembly process is important for a better understanding of the impact of soil disturbance on the structure of temporary ponds community, and their mechanisms of resilience. Under the scope of these mechanisms, we will assess the contribution of seed bank by regrowth of buried seeds, vegetative propagules growth via clonal propagation and dispersion of propagules. Soil disturbance has a biotic effect on competition giving a chance to competitively inferior species.

Paraphysoderma sedebokerense (P. sedebokerense) (Blastocladiomycota) is a facultative pathogenic chytrid that causes irreversible damage to some green microalgae. Specific attacks leading to culture collapse under different conditions have only been described in the lucrative microalga Haematococcus pluvialis (H. pluvialis), while generating biomass for ketocarotenoid astaxanthin production, both indoors and outdoors. In order to manage the infection, parasite propagules (zoospores/amoeboid swarmers), the initiators of the disease, must be studied. Until now, no report on isolated P. sedebokerense propagules has been published. Here, we report on a reproducible method for the stimulation of P. sedebokerense propagule release and their isolation from fungal cultures in synthetic media and infected H. pluvialis cultures, and we further studied their development under different conditions. The isolated propagules featured different spore morphotypes, with coatless spherical spores and amoeboid swarmers being the most dominant in the first pulse of propagule release in both cultures. Inoculating the pure propagules with the host, in both the presence and absence of nitrogen, resulted in epidemic development in both green and red cells; however, in red cells, the epidemic developed more quickly in the presence of nitrogen. Biologically non-active autoclaved host cells were used to distinguish the initial stages of recognition from more progressive stages of the epidemics; on these cells, propagules encysted but did not develop further. These results prove the existence of heat-stable recognition sites on the host and an obligatory signal transduction from the host to support fungal cyst development. The propagule isolation method described herein is a breakthrough that will enable researchers to study the influence of different substances on the propagules, specifically as the initiators of the infection, and thus assist in the management of chytrid diseases. Moreover, it will be useful in studying host-parasite recognition and, therefore, will increase our understanding of the multiple chytrid infections found in nature.

RESUMO O banco e chuva de sementes podem ser indicadores utilizados para avaliar o potencial de recuperação de uma área que sofre influência antrópica. Assim, os objetivos deste trabalho foram quantificar o número de sementes viáveis e estimar a diversidade de espécies do banco e chuva de sementes, a fim de conhecer o potencial de recuperação de uma área inserida em uma matriz agrícola. Foram instalados 40 coletores para avaliar a chuva de sementes, bem como coletadas amostras de solo, para caracterizar o banco de sementes. Na chuva de sementes, foram encontradas 2.079 sementes, pertencentes a 43 espécies, sendo as famílias Lauraceae e Fabaceae as mais representativas. No banco de sementes, germinaram 69 indivíduos pertencentes a 23 espécies, sendo a família Asteraceae a mais representativa. Observou-se elevada diversidade de espécies na chuva de sementes (H’= 2,34 nats ind-1), em que as sementes das espécies secundárias tardias foram as mais abundantes, enquanto no banco de sementes, as espécies pioneiras. Em conclusão, o fragmento florestal encontrava-se em estágio sucessional avançado, o que pode garantir estabilidade ao sistema diante da influência antrópica. ABSTRACT The seed bank and seed rain can be used as indicators to evaluate the recovery potential of an anthropic area. Our aims were quantify the number of viable seeds and estimate species diversity of bank and seed rain to assess the recovery potential of an area surrounded by agriculture. We installed 40 collectors to evaluate seed rain and collected soil samples for seed bank quantifications. We found 2,079 seeds in seed rain, comprising 43 species, being Lauraceae and Fabaceae the most abundant families. Seed bank was represented by 69 seeds of 23 species, predominating Asteraceae family. We observed high species diversity in seed rain (H’= 2.34 nats ind-1). Secondary species predominated in seed rain, while pioneer species in seed bank. In conclusion, forested area is in an advanced successional stage indicating a potential capacity of system under anthropogenic pressures.

ResumenLa dispersión de semillas es un proceso clave en el restablecimiento de la vegetación en áreas rehabilitadas. El objetivo de este trabajo fue determinar la contribución de las hormigas Ectatomma ruidum y Pheidole fallax en la dispersión y germinación de semillas en áreas rehabilitadas en la mina de carbón del Cerrejón, Colombia. En cada área se instalaron cuatro parcelas de 6 x 40 m, donde se contó el número de nidos por especie y se midió la distancia entre los nidos más próximo de cada especie. De los nidos contabilizados cinco nidos fueron seleccionados para la extracción de semillas, por cada nido extraído se tomó un control. Un total de 295 nidos fueron contabilizados, 59 para la época seca y 236 para la época de lluvia, 84 pertenecían a P. fallax y 211 a E. ruidum. Un total de 21 304 semillas fueron encontradas en los nidos y suelos control, 19 349 fueron obtenidas de los nidos y basureros de P. fallax y 318 en nidos de E. ruidum, en el suelo control se hallaron 597 semillas. El número de semillas extraídas en los nidos fue significativamente mayor a la de los controles. El número de semillas removidas por P. fallax presentó diferencias significativas respecto a las removidas por E. ruidum. El porcentaje de germinación en los nidos fue mayor que en los controles, en el caso de P. fallax, el porcentaje de germinación fue bajo en los controles y alto tanto en los basureros como los nidos. Nuestros resultados sugieren que E. ruidum y P. fallax podrían contribuir a la dispersión de las semillas y al restablecimiento de la vegetación en las áreas donde se encuentran, lo cual es un aporte significativo para la rehabilitación de las áreas degradas por la minería. AbstractSeed dispersal is a key process in the re-establishment of vegetation on reclaimed lands. The aim of this study was to determine the contributions of the ant species Ectatomma ruidum and Pheidole fallax to seed dispersal and germination on reclaimed lands in the Cerrejón coal mine, Colombia. Four 6 x 40 m plots were installed in each area, in which the number of nests by species was counted and distances between closest nests of each species were measured. Five of the nests counted were chosen for seed extraction, and a nearby control sample was taken from each nest. In total, 295 nests were counted: 59 nests during the dry season and 236 nests during the rainy season, of which 84 belonged to P. fallax and 211 belonged to E. ruidum. A total of 21 304 seeds were found in nests and control samples, of which 19 349 were obtained from P. fallax nest refuse, and 318 were obtained from E. ruidum nests; 597 seeds were found in control samples. The number of seeds extracted from nests was significantly higher than the number of seeds removed from control samples. There was a significant difference between the number of seeds removed by P. fallax and the number of seeds removed by E. ruidum. The seed germination percentage from nests was higher than the percentage from seeds in control samples. In the case of P. fallax, the germination percentage was lower in control samples and higher in nests and refuse. The results suggest that the ant species E. ruidum and P. fallax may contribute to seed dispersal and re-establishment of vegetation in areas where they were found. These ants may thus significantly contribute to restoration processes in areas degraded by mining.

Made available in DSpace on 2020-12-12T01:42:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-12-15 Ministério do Meio Ambiente Rising temperatures due to climate change are expected to drive shifts in species composition, phenological patterns and the productivity of mangrove trees. During early life history stages, such as dispersal and settlement, temperature may affect the survival of propagules and, consequently, drive the distribution of mangrove species. The aim of this work was to evaluate whether low water and air temperatures experienced by propagules during the dispersal and settlement stages, respectively, limit the latitudinal distribution of the white mangrove Laguncularia racemosa. Based on the distribution range of L. racemosa, we investigated four water and air temperatures: 10, 15, 20 and 25 °C. First, we evaluated the effect of seawater temperature on the buoyancy time of propagules. Then we tested the effect of seawater temperature and buoyancy time (24, 48, 72 and 96 h) on the germination rate of L. racemosa. Finally, we evaluated the effect of air temperature (10, 15, 20 and 25 °C) on the germination of propagules during the stranded stage. The propagules in higher water temperatures (20 and 25 °C) submerged faster than in lower temperatures (10 and 15 °C). The percentage germination of propagules in water temperatures of 20 and 15 °C was higher than those in 25 and 10 °C. However, the percentage germination was greater than 70%, regardless of the water temperature or buoyancy time tested. Furthermore, the percentage germination of propagules in air temperatures of 25 and 20 °C was higher (above 70%) than in air temperatures of 15 and 10 °C (below 50%). Lower water temperature increased the dispersal time of propagules, but it was not crucial to the germination rate of L. racemosa, regardless of the buoyancy time of propagules. In contrast, a lower air temperature reduced the germination of propagules during the stranded stage. Therefore, water temperature is not a limiting factor for the success of L. racemosa during the dispersal stage, however, we found that the mangrove tree is highly sensitive to air temperature during its stranded stage. We hypothesized that the increased buoyancy time of propagules during lower temperatures is an adaptive advantage, which allows L. racemosa to be transported to warmer areas or to tolerate cold temperatures for longer periods before settlement. Santa Cecilia University (UNISANTA) Postgraduate Program in Biological Sciences (Zoology) Botucatu Biosciences Institute São Paulo State University – UNESP Biosciences Institute São Paulo State University (UNESP) Coastal Campus, São Vicente Postgraduate Program in Biological Sciences (Zoology) Botucatu Biosciences Institute São Paulo State University – UNESP Biosciences Institute São Paulo State University (UNESP) Coastal Campus, São Vicente Ministério do Meio Ambiente: 65376-1

Obtaining reliable and representative mushroom production data requires time-consuming sampling schemes. In this paper, we assessed a simple methodology to detect mushroom emergence by trapping the fungal spores of the fruiting body community in plots where mushroom production was determined weekly. We compared the performance of filter paper traps with that of funnel traps and combined these spore trapping methods with species-specific quantitative real-time PCR and Illumina MiSeq to determine the spore abundance. Significantly more MiSeq proportional reads were generated for both ectomycorrhizal and saprotrophic fungal species using filter traps than were obtained using funnel traps. The spores of 37 fungal species that produced fruiting bodies in the study plots were identified. Spore community composition changed considerably over time due to the emergence of ephemeral fruiting bodies and rapid spore deposition (lasting from 1 to 2 weeks), which occurred in the absence of rainfall events. For many species, the emergence of epigeous fruiting bodies was followed by a peak in the relative abundance of their airborne spores. There were significant positive relationships between fruiting body yields and spore abundance in time for five of seven fungal species. There was no relationship between fruiting body yields and their spore abundance at plot level, indicating that some of the spores captured in each plot were arriving from the surrounding areas. Differences in fungal detection capacity by spore trapping may indicate different dispersal ability between fungal species. Further research can help to identify the spore rain patterns for most common fungal species. IMPORTANCE Mushroom monitoring represents a serious challenge in economic and logistical terms because sampling approaches demand extensive field work at both the spatial and temporal scales. In addition, the identification of fungal taxa depends on the expertise of experienced fungal taxonomists. Similarly, the study of fungal dispersal has been constrained by technological limitations, especially because the morphological identification of spores is a challenging and time-consuming task. Here, we demonstrate that spores from ectomycorrhizal and saprotrophic fungal species can be identified using simple spore traps together with either MiSeq fungus-specific amplicon sequencing or species-specific quantitative real-time PCR. In addition, the proposed methodology can be used to characterize the airborne fungal community and to detect mushroom emergence in forest ecosystems. We are very grateful to the PNIN of Poblet for supporting the process of installing and maintaining the experimental plots. We also thank Katarina Ihrmark and Johanna Boberg for providing the protocol and for advice on how to process and analyze the spore trap samples. We thank Josep Miró and Francesc Bolaño for their assistance with collecting the spore trap and fruiting body samples. We thank Caroline Woods for linguistic revision and for helping to clarify the manuscript. This work was supported by an STSM grant from COST Action FP1203 and by the Spanish Ministry of Economy and Competitiveness (MINECO) through the projects MICOGEST AGL2012-40035-C03 and MYCOSYSTEMS AGL2015-66001-C3. Carles Castaño received the support of the Secretaria d’Universitats i Recerca del Departament d’Economia i Coneixement de la Generalitat de Catalunya through the program of Doctorats Industrials. José Antonio Bonet is supported by the Serra-Hunter fellowship, and Josu G. Alday is supported by the Juan de la Cierva fellowship (IJCI-2014-21393). The funders had no role in the study design, data collection, and interpretation, or in the decision to submit the work for publication.

O estudo da reprodução vegetativa de 33 táxons infragenéricos de Lejeuneaceae, ocorrentes no Estado da Bahia (Brasil), permitiu a identificação de seis padrões básicos de processos de reprodução vegetativa: (a) produção de cládios; (b) fragmentação de filídios; (c) produção de regenerantes; (d) filídios caducos; (e) produção de gemas; (f) anfigastros semi-caducos. O emprego do padrão de reprodução vegetativa para avaliar as relações filogenéticas dos táxons não é recomendado, uma vez que está presente em vários táxons não estreitamente relacionados. The study of the vegetative reproduction of 33 infrageneric taxa of Lejeuneaceae from the State of Bahia (Brazil) allowed the identification of six basic patterns of the vegetative reproduction process: (a) cladia; (b) leaves fragmentation; (c) regenerates; (d) caducous leaves; (e) gemmae; (f) semi-caducous underleaves. The employment of the vegetative reproduction patterns to evaluate phylogenetic relationships is not recommended, since it is present in various taxa not closely related.

The reproductive phenology of Gracilaria gracilis has been followed closely in a brackish water lake in Sicily. The life history of this red alga deviated from the typical Polysiphonia-type cycle and was characterized by the predominance of the tetrasporophytic phase over gametophytes, in situ development of germinated gametophytes and the presence of sterile pleustophytic thalli. Release of spherical agglomerates of cells produced by young tetrasporophytes was observed as well. Their ability to germinate forming new thalli appears to represent an alternative reproductive strategy of this organism. The population structure appears to reflect a predominance of the diploid phase except during the warmer summer season when only vegetative juveniles were found in the lake. Release and early stages of development of carpospores and tetraspores were critically observed in culture. A Dumontia type pattern of germination was observed for both types of spores, showing an erect thallus arising from a multicellular basal disk. Compared to tetraspores, carpospores are less readily released resulting in a subsequent delay in the development of new gametophytes.

The effect of density on the growth, recruitment of new ramets, biomass allocation, rhizome spacer length and rhizome branching of the submersed macrophyte Potamogeton perfoliatus L. was experimentally evaluated in a mesocosm with three different initial shoot densities. The findings suggest that the number of primary shoots available in the beginning of the season can strongly influence patterns of growth and clonal reproduction. In contrast to many studies that found decreasing production parameters with plant density, ramet and biomass production of Potamogeton perfoliatus plants were highest at medium plant density. This is probably due to negative feed-back through crowding at high density and unclear negative effects at low density. Shoot allocation tended to increase with density, rhizome allocation tended to decrease with density and root biomass remained unchanged. At low density Potamogeton perfoliatus produced longer rhizome spacers and more branchings than at higher densities. Shorter rhizome spacers at high plant density probably restrict patch expansion and cause discrete patch shapes. A likely mechanism for plastic changes in clonal architecture is increasing competition for light at increasing density, but other density-dependent factors may also contribute. Investigations on propagule numbers of tubers and turions show that self-regulation of ramet number was associated with self-regulation of propagule number in both Potamogeton perfoliatus and Potamogeton pectinatus , with higher densities producing less propagules per plant.

The photosynthetic activity of both the thallus and the typical propagules of Hypnea cornuta (Rhodophyta, Gigartinales), a non-indigenous seaweed from the Mar Piccolo of Taranto, was measured in order to assess both the adaptation and the possible ecological effect of this new introduction in the basin. The preliminary results indicate that this species is well adapted to the local conditions and it is likely to become a dominant seaweed in the basin

Alsidium corallinum C. Agardh from the Mar Grande of Taranto (Ionian Sea, Mediterranean Sea) reproduced primarily by propagules. These were starch- filled branchlets subtended by little-pigmented axes, which reached the maximum length of 6 mm with a diameter of about 300 ƒÝm. Propagules could both be branched up to three orders and form other propagules in their turn. On mature plants propagules originated by the transformation of the ultimate order branch whereas on overwintering plants they derived from the transformation of lower order branches. On some individuals, some tetrasporangial branchlets grew as propagules after having formed a variable number of tetrasporangia. Some propagules also formed tetrasporangia. Generally, propagules detached above the little-pigmented axis which successively regenerated a new propagule. In the field, propagules settled on various substrata and propagule-derived plantlets were often observed. As the other species of Alsidium do not form propagules, propagule production by A. corallinum may be considered as a specific character.

Acanthophora nayadiformis is a perennial species of red alga that overwinters by means of a rhizomatous prostrate system; both reproductive and vegetative plants are also able to spread by means of specialized vegetative propagules that have never been reported in other Acanthophora species. A detailed study of thallus morphology has highlighted four kinds of primordia in this species, distinct in shape, size and origin, that develop into as many different types of branches. Thallus growth is at first monopodial, shifting to ramisympodial in most plants. Even the morphological variation observed among tetrasporiferous branches is caused by the type and development of their parent primordia, which confirms the extreme inadequacy of this feature for taxonomic or diagnostic use at species level.

Propagules of A. marina (Forssk.) Vierh. were shown to be either ‘sinkers’, i.e. sink on shedding their pericarp, or ‘floaters’ i.e. remain buoyant after shedding their pericarp. While propagules from different estuaries showed big variations in buoyancy, generally mangroves in the north produced a high proportion of ‘floaters’ while those in the south produced mainly ‘sinkers’. The buoyancy of propagules appeared to be determined by the relative densities of the different parts of the cotyledons. Anatomical sections revealed that there was little difference between the different parts of ‘sinkers’, whereas in ‘floaters’ parts which were buoyant had a high proportion of intercellular air spaces and those which sank had closely- packed cells high in reserves. Some of the ‘sinkers’ were found to become buoyant after a period of submersion, although propagules from all estuaries did not behave in this way. Apparently those propagules which had a density close to that of sea water tended to become buoyant later and it was suggested that utilization of reserves reduced the original density to a level which enabled these propagules to float. The implications of variations in buoyancy of A. marina propagules for the further distribution of this mangrove along the southeast Cape coast are discussed.