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Bergenia ciliata, a valuable medicinal perennial herb, belongs to the family Saxifragaceae. It bears very minute seeds which exhibit poor viability, germination potential and storability. Thus, the present study aimed to analyze the seed characters and germination biology of this medicinal herb. The study revealed that seeds were irregular shaped and dark brown coloured with average length ∼0.93 mm and width ∼0.31 mm. Test weight of seeds ranged between 42.6 and 56.4 mg, and moisture content varied from 7.05 to 10.46%. To standardize the conditions required for germination, the experiment was conducted under different regimes of temperature either in the light or in the dark. Results revealed that mean germination time was shortest and germination percentage highest (94%) when seeds were incubated at 20 °C with light. Seed imbibition pattern was studied at 24 h intervals starting from day zero, and it was found that changes in seed dimensions were small during the first 24 h but were greatest between 24 and 48 h. The experiment also revealed that average length of 8-day old seedling was 4.71 mm whereas it was 5.92 mm with better proportion of root length in 10-day old seedlings. [ABSTRACT FROM AUTHOR]

There is a need for robust methodological approaches to improve our capacity to automatically detect plant species from seed samples tohelp support plant management strategies. In this study, we tested different neural network techniques to automatically detect native species from seeds from the Andean páramo region based on optic RGB images. Specifically, we compared i) simple feed-forward networks (SNNs), consisting of feed-forward nets with error back-propagation, holding one hidden layer with different number of neurons; and ii) deep convolutional neural networks (CNNs), which have their convolutional layers-built form multiple 3x3 kernels. First, we sampled 50 seeds from four common plant species in the La Rusia Páramo (Colombia): Espeletia congestiflora, Bucquetia glutinosa, Calamagrostis effusa and Puya santosii. We took RGB images of individual seeds for each species on contrasted white and black backgrounds, and then classified all images under both SNNs and CNNs. Under a double cross-validation scheme, the SNN approach with 14 neurons approached 88% of test accuracy, while CNN achieved 93%. Moreover, when increasing the image sample in the training dataset fed to models, CNN performed with 100% accuracy when used on testing and validation datasets. Overall, the neural network approach explored here suggests a promising methodology for species prediction from seeds based on optical RGB images, with potential for automatic seed recognition and counting on the field. [ABSTRACT FROM AUTHOR]

This work stands for a modelling approach to identify the cardinal temperature of germination of Stipa tenacissima L., its capacity to recover and its adaptation potential considering dormancy and viability after exposure to salinity and drought. Seed traits characterised before germination were tested. The seeds were incubated at temperatures of 10 to 30 °C and low osmotic potentials were induced using sodium chloride (NaCl) or polyethylene glycol (PEG 6000) solutions of 0 to −1.6 MPa. The capacity of seeds to recover and remain viable under stress conditions was quantified. Our results proved that the seed yields and sizes were uniform. The analysis of cardinal temperature by thermal time model exhibited an optimal germination temperature (To) of about 19 °C, a base temperature (Tb) of 0.6 °C and a ceiling temperature (Tc) of 31 °C at 0 MPa. The base water potential Ψb (50) values ranged between −0.83 and −1.54 MPa and between −0.97 and −2.27 MPa for osmotic and salt stresses, at 30 °C and 20 °C, respectively. In conclusion, the species showed a lower seed recruitment related to a low drought tolerance (drought tolerance index = −0.5 MPa), To requirement and threshold sensitivity. Under salt stress, S. tenacissima used osmotic adjustment in order to germinate in a lower osmotic potential. [ABSTRACT FROM AUTHOR]

Bioindication of ecological variables such as humidity, temperature or pH by ecological indicator values of plants is a powerful tool for research in plant ecology, e.g. to detect early vegetation changes. Here, we provide a data set of ecological indicator values including niche width for an entire regional flora. We used an extensive data-base with floristic relevés from Southern France to recalibrate indicator values for light (L), temperature (T), continentality (K), air humidity (A), soil moisture (F), pH (R), productivity (N), soil texture (G), soil organic matter content (O) and salinity (S). Values were recalibrated using average values from co-occurring plants, enabling to develop indicator values for species not yet evaluated previously. Recalibrated values are on a continuous scale and we add standard deviation, median, first and third quartile for each indicator value. Linear regression of average indicator values against measured factors showed higher correlation with recalibrated values compared to original indicator values for temperature, pH and nitrogen, and comparable R2 for moisture. Individual indicator systems performed better than a combination and applying different weighting procedures demonstrated the usefulness of inverse variance. We further illustrate graphically how recalibrated values and niche width increase ecological knowledge on plants. [ABSTRACT FROM AUTHOR]

Fungal taxonomy is a fundamental discipline that aims to recognise all fungi and their kinships. Approximately 5% of a practical estimate of 2.2–3.8 million species globally are currently known, and consequently the Fungal Tree of Life (FTOL) is very incompletely reconstructed. With the advances of new technologies, mycology is marching into the interdisciplinary and globalisation era. To make fungal taxonomy relevant, innovative sampling methods and phylogenomics analyses should be performed to reconstruct a much more comprehensive FTOL. In association with this densely sampled FTOL, multiomics will reveal what drives fungal species diversification and how fungal traits evolve to adapt to various environments, while metagenomics will facilitate the understanding and protection of the ecological functions of fungi. A coordinated approach to pursuing these research agendas that includes conceiving of and costing a mission to describe all the fungi on the planet will unlock potential of fungi to support sustainable development of our society. [ABSTRACT FROM AUTHOR]

Reforestation projects are considered key climate change mitigation strategies, especially while considering native tree species as Ceratonia siliqua. The aims of this study were to evaluate the seed germination responses of three Tunisian accessions of Ceratonia siliqua, (Ichkeul (A1), Melloulech (A2), and Matmata (A3)), to temperature, water and salt stresses and their combination on germination aptitude. To overcome integumentary inhibition, we tested the different physical and chemical pre-treatments. Then, we subjected the seeds to different concentrations of NaCl and PEG (0 to −2 MPa), at different temperatures (from 10 to 35 °C). Results showed that the best pretreatment is soaking the seeds with 98% sulfuric acid for 20 minutes at 24 °C. The highest germination rate was observed at a temperature of 20 °C for A1 and 25 °C for A2 and A3. Using the hydrothermal time model, we found that the base water potential (Ψb), showed lower values in optimal range temperature (-2,19 MPa). All Ceratonia siliqua accessions showed a greater sensitivity to drought stress in germination and root growth in comparison with salt stress. The Ichkeul accession showed faster germination and better tolerance to stress. In conclusion, Ceratonia siliqua is thus recommended for restoration programs in arid and semi-arid ecosystems. [ABSTRACT FROM AUTHOR]

Biodiversity has been degraded all around the world due to anthropogenic factors. To counteract this worldwide tendency, ecological restoration programs are expanding. In these programs, the use of native herbaceous species, particularly those endemic or threatened, can be promoted by seeding them but germination requirements for most of these species are unknown. Our research meant to fill this gap of information for six Iberian endemic species suitable to use in restoration actions - Digitalis thapsi, Ferula communis subsp. catalaunica, Linaria amethystea subsp. amethystea, Pterocephalidium diandrum, Sanguisorba hybrida, and Silene scabriflora subsp. scabriflora. Their seed germination behaviour was analysed to establish germination protocols for conservation actions. Three germination conditions were used to simulate different sown seasons. Seeds of all species were tested without pre-treatment and subjected to a cold stratification. Seeds of S. hybrida and P. diandrum were additionally tested with a scarification treatment. All species reached their better germination performance under autumn conditions (15/10 °C; 8/16 hours). In conclusion, for all the six Iberian endemic species tested, germination speed and percentage were suitable for their use in native plants reinforcement. [ABSTRACT FROM AUTHOR]

The establishment of seed banks is essential for the conservation of cultivated and wild plant species. Cattleya species are economically important, but many of them are at risk of extinction. In this study, we aimed to evaluate the effects of storage temperature on the physiological quality of seeds of seven congeneric species of diverse biomes from the UNOESTE-OSSSU seed bank and the lipid composition. Seeds were split into sub samples, pre-conditioned to 0.03 g H2O g DW−1 for a week over a supersaturated solution of lithium chloride at 23 ± 2 °C and maintained in rubber-sealed vessels for nine months under four storage temperatures: room temperature (23 ± 2 °C), 5 °C, –18 °C and –196 °C. Germination, the germination speed index, and viability based on a tetrazolium test were evaluated at three-month intervals. Lipid profiles were determined by GC-MS in the original seed lots. Different lipid profiles were found among species. Orchid seeds with a low water content could be stored for a short period in all conditions studied and were considered orthodox short-lived seeds. Cattleya rupestris seeds were more tolerant than the congeners to deterioration under all the storage conditions. [ABSTRACT FROM AUTHOR]

We hypothesised that a prehydration period (exposure to humid air) should mitigate the damaging effects of short or long periods of desiccation in a desert moss, Syntrichia ruralis. Cultured uniclonal shoots of S. ruralis were dried rapidly, equilibrated at 42% relative humidity (RH), allowed to remain at this RH for 1–50 days, and either (1) prehydrated (24 h at 100% RH) then rehydrated with liquid water, or (2) rehydrated directly using liquid water without a prehydration treatment, and assessed using chlorophyll fluorescence and visual damage. At both 20 min and 24 h postrehydration, all chlorophyll fluorescence measures (Fm, Fv/Fm, ΦPSII, qP) were higher in shoots that were prehydrated. Prehydrated S. ruralis shoots also had less visual leaf damage 7 d postrehydration. Duration-dry (DD) had an overall negative effect for all fluorescence measures on shoots immediately after rehydration, an effect that dissipated at 24 h postrehydration in three of the four fluorescence measures (Fm, Fv/Fm, ΦPSII). Leaf damage was not influenced by Duration-dry. Although no interaction was detected between Prehydration and Duration-dry treatments, the benefits of prehydration were accentuated based on fluorescence metrics Fv/Fm and ΦPSII, when shoots are exposed to longer drying periods. A prehydration treatment implemented just prior to hydration with liquid water significantly mitigated shoot damage accrued from a prior rapid drying event and DDs of up to 50 d at 42% RH. Based on photosynthetic efficiency, prehydration conferred greater effects at longer DDs. Experiencing humid conditions prior to rainwater mitigates damage incurred during prolonged desiccation. [ABSTRACT FROM AUTHOR]

Syzygium maire is an endemic tree in New Zealand and classified as critically endangered. The in situ populations of this species are further threatened by the incursion of myrtle rust. The biology and ecology of S. maire have not been well documented and limited information on seed development, effective germination and seed storage behaviour of S. maire are hampering ex situ conservation and restoration. In this study, we investigated fruit and seed development on S. maire populations growing at four sites and in different seasons, and used short-term seed storage protocols to investigate the storage potential of harvested seeds. Fruit development took 8–11 months with three of the four identified stages occurring during the warmer spring and summer months. Embryos were found to be viable from stage two, but seedlings from final stage embryos were more robust. The moisture content of the fruit pulp varied between populations and within populations between seasons, but embryo moisture content remained more constant. S. maire seeds have high germinability when removed from the fruit pulp, and removal from the pulp is essential for germination. Seeds in fruits stored hydrated at 5°C remained viable for up to 12 weeks, although some germination was observed from eight weeks. This paper identifies optimal time for seed collection to ensure high quality seed for propagation and restoration while the short term storage provides an opportunity for further research into long term seed conservation through cryopreservation. [ABSTRACT FROM AUTHOR]

The current threat of myrtle rust (Austropuccinia psidii) to New Zealand Myrtaceae, including a number of indigenous and socio-economically important species, requires that ex situ conservation is used to complement in situ populations. New Zealand's Myrtaceae have received little attention in terms of ex situ conservation. In this study, we assessed the integrated ex situ conservation strategies for selected New Zealand Myrtaceae. We particularly investigated seed banking options by assessing seed desiccation tolerance, in vitro culture, pollen cryopreservation and zygotic embryo cryopreservation of the recalcitrant Syzygium maire. A desiccation trial was conducted on six Myrtaceae species: Lophomyrtus bullata, L. obcordata, Metrosideros diffusa, M. umbellata, M. bartlettii and Syzygium maire. S. maire seeds and embryos showed extreme sensitivity to desiccation confirming its recalcitrant behaviour. The seeds of the other species were desiccation tolerant i.e. orthodox. Zygotic embryos of S. maire were successfully cryopreserved using an encapsulation-dehydration technique. Pollen cryopreservation was successful for M. excelsa following desiccation to about 5% moisture content, rapid freezing and rapid thawing. For M. bartlettii, one of the most endangered and a nationally critical Myrtaceae species in New Zealand, we tested the efficacy of hand pollination in producing viable seeds. Our assessment confirmed that one of the M. bartlettii trees at Otari is self-incompatible, and successful hand pollination using pollen obtained from different genotypes growing in the gardens at the University of Auckland resulted in seed production with c. 20% germination. Tissue culture protocols were successfully developed for selected Myrtaceae. In addition, photoautotrophic micropropagation techniques were developed for the first time for L. scoparium. This paper highlights the importance of holistic conservation strategies to ensure future access to New Zealand's unique Myrtaceae germplasm as a key component of long-term management response to the threat posed by A. psidii. [ABSTRACT FROM AUTHOR]

The orchids are in danger of extinction due to the destruction of their habitats and uncontrolled collection. The most effective way of protecting plants' gene resources against these gradually increasing threats is seed banks. A viability test was conducted with two different scarification methods for Anacamptis laxiflora (Lam.) seeds preserved at 4 °C since 1988. The seeds were exposed to 5% Ca(ClO)2 at different periods in the year they were collected (1988) and seed coats were scarified. They were washed with sterile water, incubated for 12 h in TZ in the dark at 28 °C. Seeds with red stained embryos were evaluated as viable. Since the highest live seed rate (62%) was obtained in 8 h of 5% Ca(ClO)2 application, this period was applied in 20th and 30th years. In addition, in the 30th year, the seeds were incubated in moisturized cocopeats for 5 days and then the viability test was conducted with TZ. The viability rate of embryo containing seeds was 81,63%. Seeds inoculated with Rhizoctonia solani AG A were germinated at a rate of 91.16%. Seed packages were buried in their habitats and it was found that the seeds died completely two years after they were buried. [ABSTRACT FROM AUTHOR]

Desert plant species commonly use seed dormancy to prevent germination during unfavorable environmental conditions and thus increase the probability of seedling survival. Seed dormancy presents a challenge for restoration ecology, particularly in desert species for which our knowledge of dormancy regulation is limited. In the present study the effect of gibberellic acid (GA3) and potassium nitrate (KNO3) on seed dormancy release was investigated on eight Arabian desert species. Both treatments significantly enhanced the germination of most species tested. GA3 was more effective than KNO3 in enhancing germination percentage, reducing mean germination time and synchronizing the germination in most of the studied species. Light requirement during germination was species-specific, but in general the presence of light promoted germination more effectively when combined with KNO3 and GA3. The wide variation in dormancy and germination requirements among the tested species is indicative of distinct germination niches, which might assist their co-existence in similar habitat/environmental conditions. Seed pre-treatments that optimize germination in this habitat must therefore be assessed for individual species to improve the outcomes of ecological restoration. [ABSTRACT FROM AUTHOR]

The effect of exogenous application of jasmonic acid (JA) on the concentration of main terpenes and density of glandular trichomes was investigated in the Mexican oregano, propagated from seeds from 3 localities. JA 1 mM was applied locally and to the whole plant. JA locally applied increased the number of trichomes, with a mean of 20 trichomes more with respect to the controls in plants from Tecomavaca and Zapotitlán Salinas, and significantly increased the thymol concentration by 185% systemically and 255% locally, compared to the control. JA applied to the whole plant decreased the number of trichomes and increased the concentration of caryophyllene from 0.79 to 1.7 mg g−1, and α-caryophyllene from 0.3 to 0.8 mg g−1 in plants from San Rafael with reference to water control. The results suggest a plasticity of morphologic and phytochemical responses, and a potential use of JA to improve phenolic monoterpenes and sesquiterpenes production. [ABSTRACT FROM AUTHOR]

In the absence of barriers to dispersal, species' range limits should arise when physiological processes are compromised by unfavorable ecological conditions. This study aims to fill the knowledge gap on the role of physiology in determining plant species range limits. We developed the Physiological Marginality Hypothesis (PMH), a theoretical framework predicting that individuals in ecologically marginal populations are less physiologically efficient than those occurring at the ecological optimum. According to PMH, the probability to reach the optimal physiological efficiency is best shaped by a Gaussian function and curvilinear relationships should exist between physiological traits and ecological gradients. We conducted an analysis on plant physiology studies along altitudinal/latitudinal gradients to investigate which models best describe the relationship between the performance of a given physiological trait and the considered ecological gradients. Data from 54 cases (29 species) concerning photosynthesis, stomatal conductance, carbon isotope composition and photosynthetic water use efficiency were used. Overall, results support PMH in about 70% of cases, suggesting that ecologically marginal individuals can be physiologically less efficient than individuals occurring at the species ecological optimum. Physiology has an important causal role in shaping plant species distribution and further studies should focus on physiological processes at the ecological range edge. [ABSTRACT FROM AUTHOR]

The need to optimize seed banking efforts has stimulated research for rapid methods to estimate quality in seed-lots. For terrestrial orchids, viability testing using tetrazolium (TTC) staining requires chemical scarification, as seeds have an impermeable testa. Different seed-coat permeability may affect TTC staining, thus affecting the results. The aim of this study was to perform a permeability test to assess the effectiveness of the used scarification method and its usefulness to correct TTC viability results. Mature seeds of Anacamptis laxiflora were subjected to eight scarification treatments with sodium hypochlorite solutions with different concentration and duration. Viability tests were performed using the basic TTC methodology, followed by a permeability test performed by means of trypan blue dye. The different scarification methods resulted in estimated TTC viability ranging from 0% and 94% for the same seed lot of A. laxiflora seeds. Our results proved that the used scarification protocol significantly affects both seed coat permeability and subsequent TTC staining (two-way ANOVA, p < 0.0001). We describe a new rapid protocol that can be used to test terrestrial orchid seed viability. This double-staining method, providing rapid information on seed coat permeability, can be useful to avoid under-estimation of TTC results. [ABSTRACT FROM AUTHOR]

Copper is an essential micronutrient for normal plant metabolism and it is involved in number of physiological processes in plants but at the same time, at concentrations above threshold level, it acts as a potential stress factor. In this study, the phytoremediation potential of Bruguiera cylindrica (L.) Blume with respect to Cu was evaluated for the first time. Various physiochemical and anatomical parameters were analyzed in three-month-old healthy plantlets of B. cylindrica on exposure to different concentrations of CuSO4 (0, 0.05, 0.15, and 0.25 mM)for 20 d. Higher uptake and accumulation of Cu in the roots indicates that the roots are the primary site of Cu accumulation and thus the plant perform as an excluder. Tolerance index values (TI > 60) reveals the phytoremediation potential of this plant. Metabolites are accumulated in plants to cope up with the oxidative damage due to Cu stress. Increased rate of proline and free amino acids content and soluble sugar content especially in leaves of B. cylindrica subjected to CuSO4 contributes toward higher osmolality so as to counter the reduced water transport from roots. Nonenzymatic antioxidants like ascorbic acid, glutathione, and phenolics are the ROS scavenging compounds in the Defense system of B. cylindrica toward higher concentrations of CuSO4, and of these, phenolics accumulation plays greater role in the antioxidative function in B. cylindrica in response to Cu stress. The histochemistry of B. cylindrica revealed the prominent occurrence of star-shaped calcium oxalate crystals when exposed to 0.25 mM CuSO4, and it seems to be a prominent defense mechanism under Cu stress. Also a remarkable finding was the accumulation of Cu in the xylem vessels of plants on exposure of 0.25 mM CuSO4 as compared to control. The infrared spectra were analyzed to compare the functional groups in the phenolics and carbohydrate constituents of control and CuSO4-treated B. cylindrica plantlets and it indicated that carboxyl and hydroxyl groups are involved in the Cu binding so as to achieve tolerance to Cu. Thus this study revealed the potential role of B. cylindrica as a promising candidate for phytostabilization of copper. [ABSTRACT FROM AUTHOR]

Commercial seed mixes and various mechanical planting methods have been implemented to overcome barriers to successful restoration of degraded grasslands but their effectiveness in aiding the restoration process has been understudied. Harvested seed must be cleaned of chaff to allow mechanical planting, which can exclude small seeds. We propose that fluid seed drilling techniques (suspending uncleaned harvested seed in a cellulose-based gel matrix, which may then be injected into the soil with a mechanical planter) may overcome these challenges. As a preliminary investigation of the proposed method we designed a greenhouse pot trial experiment aimed at quantifying restoration success through the measurement of seedling recruitment, biomass production and composition responses of commercial and harvested seed mixes under simulated fluid seed drilling and smoke water priming (collectively termed application method). These data were analysed using generalised linear modelling and multivariate analyses. Commercial mixed seed resulted in greater recruitment, whereas harvested seed produced the greatest biomass production. There was large multivariate separation between seed types and seed type × application method centroids for recruitment responses and only seed type for biomass responses. Application method had minimal effects on restoration measurements whilst seed type greatly affected these measurements. Careful selection of the restoration seed mix is advised. [ABSTRACT FROM AUTHOR]

To elucidate biochemical mechanisms leading to seed deterioration, we studied 23 wheat genotypes after exposure to seed bank storage for 6–16 years compared to controlled deterioration (CD) at 45 °C and 14 (CD14) and 18% (CD18) moisture content (MC) for up to 32 days. Under two seed bank storage conditions, seed viability was maintained in cold storage (CS) at 0 °C and 9% seed MC, but significantly decreased in ambient storage (AS) at 20 °C and 9% MC. Under AS and CS, organic free radicals, most likely semiquinones, accumulated, detected by electron paramagnetic resonance, while the antioxidant glutathione (GSH) was partly lost and partly converted to glutathione disulphide (GSSG), detected by HPLC. Under AS the glutathione half-cell reduction potential (EGSSG/2GSH) shifted towards more oxidising conditions, from −186 to −141 mV. In seeds exposed to CD14 or CD18, no accumulation of organic free radicals was observed, GSH and seed viability declined within 32 and 7 days, respectively, GSSG hardly changed (CD14) or decreased (CD18) and EGSSG/2GSH shifted to −116 mV. The pH of extracts prepared from seeds subjected to CS, AS and CD14 decreased with viability, and remained high under CD18. Across all treatments, EGSSG/2GSH correlated significantly with seed viability (r = 0.8, p<.001). Data are discussed with a view that the cytoplasm is in a glassy state in CS and AS, but during the CD treatments, underwent transition to a liquid state. We suggest that enzymes can be active during CD but not under the seed bank conditions tested. However, upon CD, enzyme-based repair processes were apparently outweighed by deteriorative reactions. We conclude that seed ageing by CD and under seed bank conditions are accompanied by different biochemical reactions. [ABSTRACT FROM AUTHOR]

Limonium supinum, a perennial herb with interest for the restoration and gardening of arid zones, is widely distributed in saline areas from southeastern Iberian Peninsula. Laboratory experiments were carried out to assess the effects of temperature and salinity on seed germination and on germination recovery from the effects of saline conditions after transfer to distilled water. Seed germination responses were determined over a four temperature regimes (20/10, 25/15, 30/20 and 35/25 °C; 12 h light/12 h dark photoperiod) and six salinities (0, 100, 150, 200, 400 and 600 mM NaCl). The higher germination percentages were obtained in non-saline conditions, under all temperature regimes. An alternating temperature of 20 °C light and 10 °C dark yielded the maximum germination for any saline concentration. Increase in salinity delayed the beginning and end of germination and reduced the final percentage of germination, which becomes completely inhibited at 600 mM NaCl. The adverse effect of salinity is reinforced by high temperatures (30/20 and 35/25 °C). The germination rate was also negatively affected by the increase in salinity and temperature. The final recovery percentages in high salt treatments were near 100%, indicating that exposure to high concentration of NaCl did not inhibit germination permanently. [ABSTRACT FROM AUTHOR]

Background: Plant reproductive output is determined by a complex set of factors including resource availability, pollination success and pre-dispersal predation. Disentangling the relative contribution of each factor is critical to underpin the factors determining plant fitness. Aims: To unravel the relative contributions of initial reproductive effort, pollination success and pre-dispersal seed predation to plant reproductive success in the fleshy-fruited, wind-pollinated Juniperus thurifera. Methods: We conducted an experiment including pollen addition and pesticide application on 40 female juniper trees for 20 months. Flower production was used as a proxy for resource levels. Results: Main fruit loss occurs in early stages of fruit development. Initial flower number affected fruit and seed set by (a) increasing the rate of fruit formation and the number of viable seeds within fruits and (b) modifying the incidence of low-mobile predators through a satiation effect. Pollination did not limit fruit set, although hand pollinated fruits had more viable seeds. Pre-dispersal seed predation by different arthropods was critical in defining final fruit set. Conclusions: Fruit set in J. thurifera was determined by the interaction of initial reproductive effort and pre-dispersal seed predation. Pollination was not a limiting factor in this relatively dense juniper forests during a year of high flower production. [ABSTRACT FROM AUTHOR]

Phaius hainanensis C. Z. Tang et S. J. Cheng is a species with extremely small populations and is endemic to China. Genetic data of this orchid species is minimal. With the aim to identify appropriate chloroplast markers for the use in conservation biology studies, the plastome of P. hainanenisis was assembled. The plastome of P. hainanensis is 158,314bp in length and contains a large single copy region of 86,700bp in length, a small single copy region of 18,452bp, and a pair of inverted repeats of 26,581bp. The annotation predicted 114 unique genes, including 80 protein-coding, 30 tRNAs, and four rRNAs. Seventeen genes contained a single intron and two genes (clpP and ycf3) have two introns. The GC content of P. hainanensis is 36.9%. Phylogenetic analysis indicated P. hainanensis is closely related to P. tancarvilleae, and it also supported that Phaius and Calanthe are sister groups. The plastome data reported in this study will contribute to further studies of phylogeny and conservation of Phaius species. [ABSTRACT FROM AUTHOR]

Seed dormancy and germination characteristics are important factors determining plant reproductive success. In this study, we aimed to explore the characteristics of seed dormancy and germination of two endemic Labiatae species (Lamiophlomis rotata and Marmoritis complanatum) in the Himalaya-Hengduan Mountains. Germination was first tested in the light using freshly matured seeds at 25/15 and 15/5°C, and then again after dry after-ripening. Dried seeds were incubated in the light at a range of constant temperatures (1-35°C). The effects of dark and GA3 on germination were tested at several different temperatures. Base temperature (Tb) and thermal times for 50% final germination (θ50) were calculated. Seeds were also buried at the collection site to test seed persistence in the soil. Increased final germination after dry after-ripening indicated that the seeds of the two species exhibited non-deep physiological dormancy; however, they exhibited different germination characteristics and soil seed bank types. In L. rotata, GA3 only promoted germination at 5°C, producing no significant effect at other temperatures. Dark conditions decreased germination significantly at all temperatures. Tb and θ50 values were 0.6 and 82.7°C d. The soil seed bank of this species was classified as persistent. In M. complanatum, GA3 significantly promoted germination at all temperatures except 15°C. Dark conditions depressed germination significantly at warmer temperatures (20 and 25°C) but had no effect at lower temperatures. Tb and θ50 values were 0.1 and 92.3°C d. The soil seed bank was classified as transient. Our results suggest that the seed dormancy and germination of the two co-existing species share some commonalities but there are also species-specific adaptations to the harsh alpine environment. [ABSTRACT FROM AUTHOR]

Bubon macedonicum L. is a chasmophytic species of south-eastern Europe. In Italy, it has been detected only in Rocca Monforte (Campobasso, central Italy). This rare species is included in the IUCN Red Lists of Critically Endangered Italian Flora, and there are no studies relating to B. macedonicum biology. The seed germination dynamics of this species was studied with the aim of building up an appropriate germination protocol to be used in ex situ conservation. On the basis of an ISTA protocol, about 3,000 seeds were collected from Rocca Monforte in August 2013. Fifty seeds were measured. The considered parameters were seed length, width, thickness, seed surface, volume, density, surface/mass ratio and eccentricity index. The morphometric parameters examined showed morphological dormancy, where a short warm period is necessary for embryo growth and seed germination. The results showed high germination percentages under the different conditions of temperature, pH, GA3 and photoperiod. Only at 5 °C was there no germination. Finally, the seeds maintain high germination percentages from the seed storage process after 130 and 390 days. This factor can be considered of great importance for the conservation of B. macedonicum over the medium and long term. [ABSTRACT FROM AUTHOR]

Background: Seed mass and plant growth forms can affect dispersal syndrome that determines where seed is stored until germination, which can consequently determine germination requirements and the fate of emerged seedlings. Aims: This study aimed to assess the relationships between seed mass, germination rate and light and temperature requirements during germination of 23 desert plants with an aerial seed bank. Methods: Freshly collected seeds and those stored for 9 months at room temperature and enclosed within plant parts in the field were germinated in three growth chambers adjusted to three temperatures and two light regimes. Results: Trees and shrubs had significantly heavier seeds with greater dormancy compared to herbs. Germination at all storage conditions responded positively to light in herbs and germinated in both light and dark in shrubs and trees. Field storage enhanced light germination in trees, but not in shrubs and herbs. Germination rate index was greater for seeds of herbs and trees compared to those of shrubs. The relationships between seed mass and final germination in both light and dark regimes were positive in herbs but negative in shrubs. Conclusions: Growth form, seed size, storage condition can affect light, but not temperature, requirement of the studied plants. [ABSTRACT FROM AUTHOR]

Quercus roburL. was micropropagated by axillary bud proliferation testing two different shoot culture systems: (i) on gelled medium in Microbox (plastic vessel with a strip for ventilation) and (ii) in liquid culture in PlantformTMbioreactor (a temporary immersion system). Two different conditions of temporary immersion were assessed: 12 min/8 h (Plantform 1) and 8 min/16 h (Plantform 2). The effect of the two culture systems was evaluated also during subsequent rooting phase, carried out on gelled medium. Finally, the influence of the different culture conditions on leaf structure was considered, taking also into consideration the micromorphological characters of young leaves from in-field-grown oaks. Nodal segments, excised from establishedin vitroshoots and cultured on modified Woody Plant Medium, showed a higher Relative Growth Rate in Plantform than in Microbox, but culture conditions provided in Plantform 1 favored shoot and leaf hyperhydricity. Shoots cultured in Microbox or Plantform 2 presented the same percentage of rooting after their transfer on gelled rooting medium. Leaves developed in the two different microenvironments had large stomata with elliptical shape, which indicates good functionality, and formed hairs, and epicuticolar waxes. These leaf features are considered to provide a good adaptability toex vitroconditions. [ABSTRACT FROM PUBLISHER]

Seed-borne pathogens are a daily issue for ex situ collection managers who try to solve it using various chemicals more or less harmful to the staff and the plant material stored. The most common physical method for seed sterilisation is moist heat, in contrast to dry heat which is used much less frequently. Consequently, the efficiency of dry heat as disinfection method and the behaviour of seeds undergoing this treatment are currently poorly known, especially for wild species. In this study, seed viability was estimated by performing germination tests according to standard procedures. Germination tests were conducted on 13,200 seeds from 66 wild species of temperate regions belonging to 22 different families. Results indicate that dry seeds exposed to 60°C during 1hour were less infected by seed-borne pathogens in 14% of the cases, whereas no change has been registered in the other cases. For all 66 studied species, no decrease in germination percentage was detected after the heat treatment. Given its positive effect on infection control without affecting seed viability, dry heat treatment as proposed here opens opportunities for seed bank managers, but also for the disinfection of herbarium collections. [ABSTRACT FROM PUBLISHER]

In this study, we investigated the germination behavior, and the differences in desiccation sensitivity and water uptake (WU), of the acorns of the two subspecies ofQuercus ithaburensis, inhabiting different ecological niches. Sensitivity of acorns to drying was assessed by subjecting them to several desiccation treatments. The results showed that acorn water loss due to desiccation follows an almost linear pattern for the subspeciesmacrolepis, while in the case of subspeciesithaburensis, it follows a negative exponential model. Accordingly, the germination behavior was found highly dependent on water loss for both subspecies. The low acorn water content (15%) achieved after 15 days of drying was crucial for the ssp.macrolepis, while it had no effect on seed viability in sspithaburensis, that needed a subtle further water loss to reduce its germinability (i.e. <14.5% mc). Our results suggest that intraspecific differences in seed responses to drying may be due to different adaptation to survive drought after dispersal and contribute to explain the ability of ssp.ithaburensisto grow in the hottest and driest Mediterranean bioclimates. Despite being recalcitrant, the ssp.ithaburensiscan be considered as one of the most tolerant oaks to desiccation worldwide. [ABSTRACT FROM PUBLISHER]

The aim of this study was to determine the influence of selected halotolerant endophytic bacteria isolated from the roots ofSalicornia europaeaon the growth parameters ofBeta vulgarisunder different concentrations of salinity. Two endophytic strains were selected as inocula for the pot experiment:Pseudomonassp. ISE-12 (B1) andXanthomonadalessp. CSE-34 (B2). Surface-sterilised seeds were incubated in the bacterial inoculation suspensions before sowing and cultivated in a sterile mixture of sand and vermiculite (1:1). Six salinity treatments were taken into account: 0, 50, 100, 150, 200 and 300 mM NaCl. Inoculation of seeds with B1 and B2 positively affected germination percentage and germination index and shortened mean germination time, which led to a quickening of the growth stages of seedlings. After 42 days inoculated plants had, in general, a greater root length, higher dry biomass, lower tissue water content and lower specific leaf area compared with the control. While the positive effect of B2 bacteria was visible only at low salinity, strain B1 stimulated plant growth at higher salinities (200 and 300 mM NaCl). We suggest that the superior growth promotion observed for B1 may be related to the higher metabolic activity of these bacteria. [ABSTRACT FROM AUTHOR]

If the field of regenerative medicine is to deliver therapies, rapid expansion and delivery over considerable distances to large numbers of patients is needed. This will demand efficient stabilization and shipment of cell products. However, cryopreservation science is poorly understood by life-scientists in general and in recent decades only limited progress has been made in the technology of preservation and storage of cells. Rapid translation of new developments to a broader range of cell types will be vital, as will assuring a deeper knowledge of the fundamental cell biology relating to successful preservation and recovery of cell cultures. This report presents expert consensus on these and other issues which need to be addressed for more efficient delivery of cell therapies. [ABSTRACT FROM AUTHOR]

Limodorumspecies are hard-to-cultivate, germinating with difficulty or not germinating at all on a number of media. The present work was focused on the effects of seed sterilization-scarification methods and of different nitrogen sources onin vitroseed germination and seedling development ofLimodorum abortivum, L. brulloiandL. trabutianum. Our results showed that sodium hypochlorite solution with a 1% concentration of available chlorine was ineffective for both sterilization and scarification ofLimodorumseeds, while a 5% concentration was found to be an effective sterilizing and scarifying solution forL. trabutianum. The positive effect of organic nitrogen in promoting asymbiotic germination in many terrestrial orchids was confirmed by this study forL. trabutianumandL. brulloi, which showed significantly higher germination percentages on Basal Medium modified than on Knudson C, which contains inorganic nitrogen. This is the first report ofin vitroasymbiotic germination of mature seeds ofL. brulloiandL. trabutianum, especially successful forL. trabutianumthat showed high germination percentages (>63%) and an active seedling development. These results may be useful for conservation purposes, sinceL. brulloiis a narrow Italian endemics andL. trabutianumis threatened with extinction both in Italy and in France. [ABSTRACT FROM AUTHOR]

The tripeptide antioxidant glutathione (γ-l-glutamyl-l-cysteinyl-glycine; GSH) essentially contributes to thiol-disulphide conversions, which are involved in the control of seed development, germination, and seedling establishment. However, the relative contribution of GSH metabolism in different seed structures is not fully understood. We studied the GSH/glutathione disulphide (GSSG) redox couple and associated low-molecular-weight (LMW) thiols and disulphides related to GSH metabolism in bread wheat (Triticum aestivumL.) seeds, focussing on redox changes in the embryo and endosperm during germination. In dry seeds, GSH was the predominant LMW thiol and, 15 h after the onset of imbibition, embryos of non-germinated seeds contained 12 times more LMW thiols than the endosperm. In germinated seeds, the embryo contained 17 and 11 times more LMW thiols than the endosperm after 15 and 48 h, respectively. This resulted in the embryo having significantly more reducing half-cell reduction potentials of GSH/GSSG and cysteine (Cys)/cystine (CySS) redox couples (EGSSG/2GSHand ECySS/2Cys, respectively). Upon seed germination and early seedling growth, Cys and CySS concentrations significantly increased in both embryo and endosperm, progressively contributing to the cellular LMW thiol-disulphide redox environment (Ethiol-disulphide). The changes in ECySS/2Cyscould be related to the mobilisation of storage proteins in the endosperm during early seedling growth. We suggest that EGSSG/2GSHand ECySS/2Cyscan be used as markers of the physiological and developmental stage of embryo and endosperm. We also present a model of interaction between LMW thiols and disulphides with hydrogen peroxide (H2O2) in redox regulation of bread wheat germination and early seedling growth. [ABSTRACT FROM PUBLISHER]

This study was the first to investigate the direct effects of anomalous concentrations of ozone mediated by summer heat waves on seed germination in alpine plants. During germination, the seeds were exposed to three peaks of O3concentration (125 ppb for 5 and 10 days; 185 ppb for 5 days), derived from measurements taken close to the species growing site. High O3concentration delayed the first germination time, increased the mean germination time, and reduced the germination percentage during and immediately after the treatment, but, in most cases, effects were weak and had almost vanished three weeks after the treatments. In few cases, chronic exposure to O3(125 for 10 days’ treatment) enhanced seed germination compared to the control, suggesting that ozone may induce antioxidant and DNA-repair mechanisms or dormancy-breaking effects in hydrated seeds. Although seed mortality increased during O3treatments in four species, the effect of O3on seed germination is mostly limited to the period of exposure, indicating that it is unlikely to produce permanent negative effects on seeds, during the germination phase. Our results show that the direct effect of O3on seeds of alpine plants may have minor impacts on plant reproductive performance during seed germination. [ABSTRACT FROM PUBLISHER]

The effects of seed pretreatment and harvest date on the germination of European rowan (Sorbus aucupariaL) seeds were examined. In one experiment, seeds were subjected to drying, storage, soaking, warm and chilling treatments after harvesting in mid- and late August. In another experiment, fully imbibed (FI) seeds were given warm treatment for six weeks and then various durations of chilling (4 ± 1°C) for up to 24 weeks. Thereafter, the seeds were adjusted to target moisture content of 35% and 30% or remained in the FI state and were then subjected to either subsequent chilling or freezing (−3°C) for up to 32 weeks. The treated seeds were allowed to germinate at a constant 15°C with 8 hours of lighting per day. Treatment effects were generally consistent for each harvest date. Seeds did not germinate unless they were chilled and germination rates were low unless the seeds were soaked. Warm treatment applied before chilling appeared to induce dormancy. The effect of storage varied with harvest date and storage treatment, with germination being highest for seeds harvested in late August. Mild freezing of ≥16 weeks duration following 16–24 weeks initial chilling resulted in >80% germination, more than could be achieved using chilling alone. [ABSTRACT FROM AUTHOR]

Fire products have been widely identified as germination cues for a number of species from both fire-prone and fire-free ecosystems. However, there is uncertainty about the effects of fire products on seed germination of semi-arid rangeland species. We examined the germination of seven dominant species from Central Zagros rangelands in the semi-arid region of Iran under various heat shock (60, 80 and 120 °C), aerosol smoke, ash and control treatments. Our findings showed that fire products could enhance, inhibit or not affect the seed germination of rangeland species in this area. The germination percentage ofAstragalus adscendensincreased following 60 °C heat treatment in comparison with the control. The germination ofAstragalus verus,Bromus tectorum,B. tomentellusandPhlomis olivieriwere increased significantly using smoke treatment (P<0.0001). The seed germination ofB. tomentellusandB. tectorumwas promoted by ash treatment, whereas the other species exhibited no response or were inhibited by fire products. In addition, smoke treatment shortened the overall germination time ofB. tectorum. These findings suggest that fire products affect the germination of several species and can serve as potential tools for understanding the vegetation dynamics and restoration of disturbed semi-arid rangelands. [ABSTRACT FROM PUBLISHER]

The balance of oxidant and antioxidant status plays an important role in the left ventricular diastolic dysfunction (LVDD) in patients with hypertension (HT). Thiol is an important part of antioxidant system in the body. The aim of this study was to investigate the relationship between plasma thiol levels and LVDD in patients with HT. A total of 138 patients with newly diagnosed essential hypertensive and 20 age-gender matched subjects as control group enrolled in the study. After echocardiographic assessment, the hypertensive patients were divided into three groups: Group 1: without LVDD (n= 41); group 2: with LVDD grade 1 (n= 57); and group 3: with LVDD grade 2 (n= 40). Plasma thiol, lipid and glucose levels were measured in all subjects. Plasma thiol levels were significantly different between the groups (all ofp< 0.05). While the lowest thiol level was in the group 3, the highest level was in the control group. The presence of LVDD was correlated with age, systolic and diastolic blood pressure, thiol levels, and history of coronary artery disease and hyperlipidemia (all ofp< 0.05). Age and thiol were however independent predictors of LVDD in multivariate analyses (β = 0.318,p< 0.001, and β = − 0.314,p< 0.001, respectively). ROC-curve analysis revealed that thiol levels over 163 μmol/L predict LVDD in hypertensive patients with 75% sensitivity and 70% specificity (AUC = 0.783; 95% CI: 0.714–0.852). Plasma thiol is an independent predictor for the presence of LVDD. This suggests that thiol plays a role in the pathogenesis of diastolic function. Increased thiol levels may provide protection against the development of diastolic dysfunction. [ABSTRACT FROM PUBLISHER]

Theex situconservation of biodiversity is an essential tool for environmental protection interventions. Germination studies of seeds that belong to endangered species are essential forex situconservation strategies. In this study, we investigate the germination responses of three high-altitude endemic and vulnerable species (Leontopodium nivale,Pinguicula fioriiandSoldanella minimasubsp.samnitica). Specifically we identified potential dormancy mechanisms by investigating the responses of germination percentage and rate to different concentrations of gibberellic acid (GA3), by performing a general linear model.L. nivalereached a germination percentage of 98.0 ± 2.0% (mean ± SE) under control conditions (20°C; 12/12 photoperiod; no GA3addition).P. fioriishowed the highest germination percentage (78.0 ± 2.0%) in the treatment with GA3500 ppm.S. minimasubsp. samniticadid not show sensitivity to GA3but responded positively to cold stratification (6 month at 5°C) with a germination percentage of 90 ± 6%. This study made it possible to acquire important information on the germination process of threatened and rare endemic taxa. [ABSTRACT FROM AUTHOR]

Background:The flora of serpentine/ultramafic soils provides an excellent model system for the study of natural selection in plant populations.Streptanthus polygaloidesis a nickel hyperaccumulator that is endemic to serpentine soils in the Sierra Nevada of California, and has four floral morphs (yellow, purple, yellow-to-purple and undulate). Aims:We investigate three hypotheses: (1) the purple morph occurs in colder, wetter climates than the yellow morph; (2) tissue–soil ionic relationships differ among morphs; and (3) morphs occur on soils with differing elemental concentrations. Methods:We queried herbarium records to investigate patterns of occurrence among the yellow and purple floral morphs, and analysed soil and tissue samples from wild populations of all four morphs. Results:The purple morph inhabited serpentine outcrops with colder temperatures and greater precipitation levels than the yellow morph. Concentrations of elements in leaf tissue and rhizosphere soil differed little among populations of the morphs, but showed substantial within-site variation. Conclusions:Our results suggest that a climatic gradient may be responsible for divergence in floral colour among populations ofS. polygaloides. Because of the large within-site variation in soil and tissue elemental concentrations, plants appear to have a varied physiological response to edaphic factors, regardless of morph membership. [ABSTRACT FROM PUBLISHER]

Storage of recalcitrant seeds remains an unsolved problem. The study of gaseous atmospheres could provide insights in understanding the metabolism of recalcitrant seeds and their potential in being used as means for storage. This study investigated the metabolism of the recalcitrantQuercus albaseeds when subjected under nitrous oxide (N2O) and air atmospheres. Seeds were placed in sealed atmospheric flasks of 98/2% N2O/O2. Three experiments were conducted to determine N2O uptake in relation to oxygen (O2) and carbon dioxide (CO2) levels. For the first experiment, “non-renewed” closed atmospheric systems with 98/2% N2O/O2and air were used. Two more experiments were also conducted for the 98/2% N2O/O2atmosphere to determine how rate of gas renewal (two and seven days) affects the N2O, O2, and CO2gases quantitatively. Cumulative results on non-renewed flasks with 98/2% N2O/O2showed that as time progressed, N2O uptake increased with variation in the magnitude of N2O utilization throughout the 37 experimental days, while seeds ceased O2utilization by the 11th day. However, CO2levels did not decrease, suggesting a shift toward fermentation processes. Finally, the two experiments for the 98/2% N2O/O2indicated that the O2levels did not deplete under a two-day gas renewal, suggesting a frequent gas renewal under low O2storage conditions. [ABSTRACT FROM AUTHOR]

Using the example of Madagascar Fauna and Flora Group (MFG), we look at the factors which contribute to the successful maintenance of an international consortium dedicated to the conservation of Malagasy biodiversity. We discuss the philosophy, mission and set-up of the MFG and how, over its 25-year history, it has enabled the productive collaboration of its diverse international members to achieve the common goal of helping to protect Madagascar's unique biodiversity. We explore the benefits of pooling resources to fund a stable base of personnel and infrastructure to maximise the conservation impact of contributions from organisations that might not otherwise be able to fund viable independent programmes and consider the benefits that accrue to partners in the consortium. We highlight specific examples of plant conservation projects set up as a result of the productive working relationship between MFG and Missouri Botanical Garden to reinforce the argument that like-minded organisations working in successful partnership can far exceed the conservation capacity of individual institutions. [ABSTRACT FROM AUTHOR]

With the increased loss of plant biodiversity, theex situseed conservation has become of strategic importance. International treaties and conventions encourage more developed countries to cooperate in providing financial and other supports for the establishment and maintenance ofex situconservation facilities in developing countries. In this regard, the Nepal Academy of Science and Technology (Nepal) and the Ev-K2-CNR (Italy) set up the Himalayan Seed Bank, with the goal of establishingex situseed conservation facility of rare, endemic and endangered plants in Nepal. Here, we discuss the importance of training on seed curation, management and research for the seed bank operators in developing countries. Particular attention is given to the procedures for providing power supply and for optimizing seed longevity in dry storage. Finally, the importance of duplicates in high-standard international seed banks is also discussed. [ABSTRACT FROM AUTHOR]

The stimulation of seed germination by smoke and aqueous smoke extracts from the combustion of plant material has recently received a great deal of attention. This study was conducted to assess the effects of smoke on the weed speciesEchinochloa crus-galli(barnyard grass). Plant-derived smoke was produced fromBauhinia variegatausing a newly designed furnace and then applied to the weed species. The results showed that plant-derived smoke solution significantly increased the germination rate (70–92.3%), germination percentage (31–47%), fresh weight (30–69%), shoot and root length (10–14.9%, 35–44%), germination index (50–100%) and vigour index (114–157%) of barnyard grass relative to the control. Treatment with plant-derived smoke solution also significantly reduced the endogenous abscisic acid of seeds, whileα-amylase activity increased significantly compared to the control. Overall, these findings indicate that stimulation and quick emergence from a dormant soil seed bank of barnyard grass can be induced by plant-derived smoke solution followed by chemical control through known weedicide/herbicide treatments as an eco-friendly alternative method of weed control. [ABSTRACT FROM AUTHOR]

This study investigated the variations in the carbon (C), nitrogen (N), and C/N ratios in the seeds of the Mediterranean Cypress (Cupressus sempervirensL.), a typical forest tree of the Mediterranean Region. The data were gathered from populations distributed across Turkey. We also evaluated the relationship between these variations and germination parameters such as the germination percentage (GP) and mean germination time (MGT). All of the evaluated characteristics demonstrated statistically significant variations among the populations. The GPs were generally low and varied between 14% in Datça and 51% in the Köprülü Kanyon. The MGTs ranged from 14.9 in the Köprülü Kanyon to 18.9 in Marmaris. In addition, the C ratios varied between 46% in Marmaris and 52% in the Köprülü Kanyon, while the N ratios ranged from 1.1% in Beycik and Göksu to 1.8% in the Köprülü Kanyon. Furthermore, we observed a positive correlation between the GP and the C and N contents (R2= 0.51 andR2= 0.49, respectively) but found a negative correlation between the MGT and the C and N contents (R2= 0.56 andR2= 0.32, respectively). Moreover, with regard to the combined C and N seed ratios of the regression models,R2= 0.95 for the GP andR2= 0.87 for the MGT, and the populations with higher quantities of C and N in their seeds had shorter MGTs and higher GPs. [ABSTRACT FROM AUTHOR]

Brassica rupestris Raf. is a chasmophyte species that includes two subspecies, both endemic to Central-Western Sicily (Italy). Inter-Simple Sequence Repeat (ISSR) markers were used to detect genetic diversity within and among eight populations representative of the species' distribution range. High levels of genetic diversity were revealed both at the population (PPB = 53.88%, H S = 0.212, Sh = 0.309) and at the species level (PPB = 96.55%, H T = 0.307, Sh = 0.464). The correlation between genetic and geographical distances was negative (Mantel test, r = −0.06, P < 0.95). The two subspecies of B. rupestris, subsp. rupestris and subsp. hispida, showed remarkable genetic similarity and molecular data did not unequivocally support their distinctness. The pattern of genetic variation revealed by our study bears important consequences for conservation management: It is desirable to preserve B. rupestris populations in situ with a “dynamic” strategy, while, ex situ conservation programmes might be improved to safeguard maximum genetic diversity. [ABSTRACT FROM PUBLISHER]

The collections stored at the Sardinian Germplasm Bank (BG-SAR) were analysed to verify if setting conservation priorities on the exclusive endemic flora of Sardinia (Italy) would make it possible to reach the 2010 GSPC Target 8. By 2010, 39.9% of the exclusive-endemics of Sardinia, 43.1% of the BGCI European threatened species and 65.0% of the taxa listed in Annex II of DIR 92/43/EEC present on the island had been stored in BG-SAR. Of the stored plants, 40% of those listed in the DIR 92/43/EEC, and only 25.69% of the BGCI threatened plants are represented by an adequate number of populations. For a few of the stored threatened plants (ca. 36%), and for 60% of the DIR 92/43/EEC ones, at least one seedlot with more than 5000 seeds is available. These data indicate that focusing on exclusive endemics gave a substantial, although not decisive, contribution towards the achievement of the 2010 GSPC Target 8 in Sardinia, and that more efforts are needed to guarantee the effective long-term conservation of these threatened taxa with the aim of reaching the 2020 GSPC target. [ABSTRACT FROM PUBLISHER]

Background: Over half of the world's primary forest and a quarter of the world's plant species are found in Latin America. As a result of the limited protected areas and significant degradation of terrestrial ecosystems, seed banks provide an efficient component of integrated plant conservation strategies, chiefly due to their relatively low cost and massive storage capacity for genetic resources. Aims: We analyse the role that ex situ seed banks play in the conservation and reintroduction of threatened species, and in supporting ecological restoration programmes in the region. Methods: An analysis of the second National Reports on the state of the World's Plant Genetic Resources for Food and Agriculture showed that most countries in the region had the capacity for seed conservation. Using three case studies from seed conservation programmes in Mexico, Brazilian Amazonia and Chile, together with the global Millennium Seed Bank Partnership, we review the status and potential of these initiatives for conservation of plant diversity. Conclusion: The collection, conservation and use of seeds from arid and semi-arid biomes is highly effective; however the higher frequency of recalcitrant seeds in humid tropical forests requires a greater investment in research to underpin large-scale seed banking. In order to safeguard native species and provide adequate diversity of seeds for habitat restoration programmes, we anticipate the need to strengthen the capacity of the region's seed banks for preservation, research and propagation of native species. [ABSTRACT FROM PUBLISHER]

The tripeptide antioxidant γ- L-glutamyl- L-cysteinyl-glycine, or glutathione (GSH), serves a central role in ROS scavenging and oxidative signalling. Here, GSH, glutathione disulphide (GSSG), and other low-molecular-weight (LMW) thiols and their corresponding disulphides were studied in embryogenic suspension cultures of Dactylis glomerata L. subjected to moderate (0.085 M NaCl) or severe (0.17 M NaCl) salt stress. Total glutathione (GSH ++ GSSG) concentrations and redox state were associated with growth and development in control cultures and in moderately salt-stressed cultures and were affected by severe salt stress. The redox state of the cystine (CySS)/2 cysteine (Cys) redox couple was also affected by developmental stage and salt stress. The glutathione half-cell reduction potential (EGSSG/2 GSH) increased with the duration of culturing and peaked when somatic embryos were formed, as did the half-cell reduction potential of the CySS/2 Cys redox couple (ECySS/2 Cys). The most noticeable relationship between cellular redox state and developmental state was found when all LMW thiols and disulphides present were mathematically combined into a 'thiol-disulphide redox environment' (Ethiol-disulphide), whereby reducing conditions accompanied proliferation, resulting in the formation of pro-embryogenic masses (PEMs), and oxidizing conditions accompanied differentiation, resulting in the formation of somatic embryos. The comparatively high contribution of ECySS/2 Cys to Ethiol-disulphide in cultures exposed to severe salt stress suggests that Cys and CySS may be important intracellular redox regulators with a potential role in stress signalling. [ABSTRACT FROM AUTHOR]