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The plant species Sesbania tomentosa (‘ōhai; Fabaceae) is endemic to the Hawaiian Islands, federally listed as endangered in the USA and has been proposed for categorization as Vulnerable on the IUCN Red List. In 2021, c. 12,000 seeds from 12 seed lots collected during 1990–1992 from across the Hawaiian Islands were discovered in ambient herbarium conditions (55% relative humidity (RH) at 20 °C). International gene bank standards suggest drying seeds in equilibrium with 15% RH and stored at −18 °C. To investigate seed viability, we mechanically scarified then sowed 15 seeds from each accession at daily alternating regimes of 12 h light and 12 h dark at temperatures of 25/15 °C, respectively. Germination was observed after 7 days and ended after 34 days. Mean final germination was 88.9 ± SD 0.1% (range 73–100%). Each seed lot was accessioned into the National Tropical Botanical Garden's Seed Bank and Laboratory. In seeds with a water-impermeable seed coat (i.e. physical dormancy), such as S. tomentosa, seeds can desorb but not absorb water. Therefore, if the seeds were initially dried, although exposed to high RH for up to 32 years, seed equilibrium RH may have remained low, which may in part explain the observed high germinability. This study holds significance for managers who are working to conserve this endangered Hawaiian species and suggests that even suboptimal conditions may still yield highly viable seeds several decades into the future.

The plant species Sesbania tomentosa ('ōhai; Fabaceae) is endemic to the Hawaiian Islands, federally listed as endangered in the USA and has been proposed for categorization as Vulnerable on the IUCN Red List. In 2021, c. 12,000 seeds from 12 seed lots collected during 1990–1992 from across the Hawaiian Islands were discovered in ambient herbarium conditions (55% relative humidity (RH) at 20 °C). International gene bank standards suggest drying seeds in equilibrium with 15% RH and stored at −18 °C. To investigate seed viability, we mechanically scarified then sowed 15 seeds from each accession at daily alternating regimes of 12 h light and 12 h dark at temperatures of 25/15 °C, respectively. Germination was observed after 7 days and ended after 34 days. Mean final germination was 88.9 ± SD 0.1% (range 73–100%). Each seed lot was accessioned into the National Tropical Botanical Garden's Seed Bank and Laboratory. In seeds with a water-impermeable seed coat (i.e. physical dormancy), such as S. tomentosa , seeds can desorb but not absorb water. Therefore, if the seeds were initially dried, although exposed to high RH for up to 32 years, seed equilibrium RH may have remained low, which may in part explain the observed high germinability. This study holds significance for managers who are working to conserve this endangered Hawaiian species and suggests that even suboptimal conditions may still yield highly viable seeds several decades into the future. [ABSTRACT FROM AUTHOR]

Terap (Artocarpus elasticus Reinw. ex Blume) is a native Indonesian plant that can be a functional and medicinal food source. The conservation of terap has focused on implementing the field gene bank at botanical gardens. These methods presented risks, such as aging, pest and disease susceptibility, and weather-related threats; thus, diversifying conservation strategies, notably through seed banking, is imperative to mitigate these challenges. This study aimed to determine the physiological maturity level and critical moisture content crucial for effective terap seed banking. When harvested, physiological maturity determination used three fruit colors: green, orange, and orange-fall fruits. The critical moisture content identification of seeds had seeds dried for 0, 2, 4, 6, and 8 days in a room at 18 °C ± 2 °C and 55%-65% relative humidity, as predicted by regression analysis. The results indicated optimal quality and viability from physiologically mature orange fruits harvested 100-120 days after anthesis, with 35.31 g 100-seed dry weight and 75%-80% germination percentage. The germination evaluation revealed that the first count was 35 days after sowing, and the final count was 50 days after sowing. The seeds had 0.63% per 24 h germination rate, 64% germination uniformity, and more than 82% emergence ability. The critical moisture content was 36.93%, suggesting terap seeds are recalcitrant; hence, seed banking requires storage conditions to be moist. In addition, storing seeds can also proceed by in vitro techniques, using tissue culture and cryopreservation. [ABSTRACT FROM AUTHOR]

Background and aims – Gardenia species are ecologically, culturally, and economically significant but the three native species of Gardenia in Hawai‘i are assessed as Critically Endangered. Seed banking is the most cost effective and efficient means of conserving plant material ex situ. To better understand the conservation physiology of Hawaiian and South Pacific Gardenia spp. and support their conservation, we asked 1) How do seeds respond to different temperatures and light and dark regimes? 2) What class of dormancy, if any, do seeds exhibit? 3) How does seed germinability respond over time in a seed bank? and 4) What is the conservation status and level of ex situ representation of Gardenia globally? Material and methods – To answer these questions, we used 19 accessions of fresh seeds and seeds stored for varying periods of time in the National Tropical Botanical Garden’s Conservation Seed Bank and Laboratory of Hawaiian (G. brighamii, G. remyi), New Caledonian (G. aubryi, G. oudiepe), and Tahitian (G. taitensis) species. Seeds were incubated at varying temperatures and in light, and in dark. Key results – We found that (1) seeds of all species tested germinated slowly and only at higher temperatures in the light and dark, (2) seeds have non-deep physiological dormancy, (3) seeds of the Hawaiian species are short lived at conventional seed bank conditions, and (4) only 40% of Gardenia spp. are represented in ex situ facilities, and 66% of the species have not been evaluated for the IUCN Red List. Conclusion – Seeds of Hawaiian Gardenia spp. are short lived in storage. Since seeds germinate in darkness, they are unlikely to form a persistent soil seedbank. Although seeds of all species tested are physiologically dormant, they can be easily propagated from seed at warmer temperatures, giving some hope to the conservation and restoration of the Critically Endangered Hawaiian species. Since our dataset was limited by a lack of continuous viability monitoring, we emphasize the need for initial germination testing and ongoing viability tests to better understand seed longevity. Lastly, we discuss the ecological relevance of our results in the context of the Hawaiian archipelago. [ABSTRACT FROM AUTHOR]

Context: Globally, plant species are facing numerous threats; an issue particularly acute for island floras, which often exhibit high levels of endemism. Ex situ conservation in seed banks is an important tool for plant conservation. However not all species' seeds can be stored in conventional seed banks. Data on seed storage behaviour are therefore vital for conservation decision making. Aims: To review available seed storage information for the New Zealand (NZ) indigenous seed plant flora, 86% of which are endemic. Methods: We compiled seed storage information for the NZ flora from databases and existing literature, and used boosted regression trees models to investigate predictors of seed storage behaviour for NZ woody plants. We used existing global models to predict the likely storage behaviour for the NZ woody flora where this was unknown, to examine the overall contribution that conventional seed banking could make towards NZ plant conservation. Key results: Data were available for 412 of 1823 seed plants, of which 83% produced orthodox seeds that can be stored in a conventional seed bank. Of the woody flora, the incidence of non-orthodox seeds was positively correlated with seed mass, plant height, biotic dispersal, and habitat diurnal temperature range. Eighty-one percent of the woody flora are predicted to produce orthodox seeds. Conclusions and implications: Conventional seed banking is likely to be suitable for a high proportion of the NZ flora. However, work is required to gain further seed storage behaviour data for NZ species, and to develop protocols for alternative ex situ conservation strategies for non-orthodox species, especially those facing in situ conservation threats. Seed banks are an important tool for plant conservation. However not all species can be stored. We compiled information on seed storage for New Zealand plants, finding that 83% could be stored in a seed bank. Plants unable to be banked are generally bird-dispersed canopy trees, including some threatened species. [ABSTRACT FROM AUTHOR]

Context: Knowledge of seed biology is imperative for effective curation and utilisation of seeds. Aims: We studied the seed biology and reproduction of Geijera parviflora , a species suitable for ecological restoration and ornamental horticulture that has largely been overlooked because of issues with unreliable germination and viability. Methods: Germination in response to dormancy-breaking treatments and soil seed burial, and variation in germination at an inter-population level were assessed for G. parviflora. Seed storability in a conventional seedbank was tested. Floral phenology was assessed. Key results: Germination of untreated and seed coat removed seeds were 0 ± 0.0% and 67 ± 5.5% respectively. Seed germination varied between 21.9 ± 1.8 and 66.6 ± 5.5% at an inter-population level. Seeds buried in soil for 6 months showed 11.7 ± 0.8% germination without any treatment. All seeds buried for 12 months were non-viable. Drying seeds from 11.4 ± 0.19% to 5.79 ± 0.17% moisture content resulted in 40% less germination. Visual observation of floral attributes confirmed the presence of orange-coloured pollen grains for 3.5 ± 0.48 days from floral opening. The stigmatic surface became shiny 3.5 ± 0.21 days after floral opening. Conclusion: Seeds of G. parviflora demonstrate physiological dormancy; treatments that remove seed coat resistance against embryo growth enable germination. Local environmental conditions may explain the inter-population variation in germination. Seeds are short-lived in soil and ex situ seedbank conditions. In soil, seeds release dormancy at the end of first winter, so seeds are available to germinate the following spring/summer with high rainfall. Floral phenology assessment indicated protandrous sequential hermaphroditism, which may reduce the probability of self-pollination in G. parviflora. Implications: This knowledge supports use of G. parviflora in ecological restoration and horticulture. Photograph of flowering Geijera parviflora. This study investigated seed biology and reproduction in the Geijera parviflora to inform conservation actions. Geijera parviflora is a species suitable for ecological restoration and ornamental horticulture, but has largely been overlooked because of issues with unreliable information on its seed biology and reproduction. The results of this study addressed several issues leading to poor seed germination and shed light on the previously unknown seed- storage behaviour of G. parviflora in both in situ and ex situ conditions. Photograph by Ganesha Liyanage. [ABSTRACT FROM AUTHOR]

Ex situ conservation involves the maintenance and reproduction of species in areas outside their natural habitats. Seed banking is a well-established ex situ approach used for plant conservation. Seed banking consists of collecting, drying, and storing seeds to preserve genetic diversity. The main limitation of this technique is that the seed must be desiccation tolerant. Seed storage behaviour can vary among species, and for some species, drying without loss of viability is not possible, meaning storage under conventional seed banking conditions (sub-zero temperatures and low relative humidity) is not possible. Understanding seed storage behaviour is an essential prerequisite for establishing whether conventional seed banking is an option for seed conservation. This study investigated the desiccation tolerance and sensitivity of mature seeds of two native New Zealand species of Pittosporum (P. eugenioides and P. crassifolium) from two geographic locations (Palmerston North and Wellington), with the aim of understanding their seed storage behaviour and thereby improving conservation outcomes. The variables measured were seed moisture content, viability, germination, and desiccation responses. We developed sorption isotherm for both species to support the future development of storage protocols. Our results show that both P. eugenioides and P. crassifolium display non-orthodox behaviour, i.e., are desiccation sensitive and cannot be stored under conventional seed banking conditions, but also suggest that seed desiccation responses vary with the geographical origin of the seeds. This study highlights the importance of exploring seed storage behaviour using different populations to optimize ex situ conservation strategies aimed at preserving the genetic diversity of New Zealand’s threatened and endangered species.

Context. Fifty per cent of Australian rainforest species produce orthodox seeds, but little is known about their longevity in storage. Aims. To (1) estimate the longevity of seeds of 33 rainforest species using artificial aging; (2) assess the influence of habit, habitat range (restricted to rainforest or more broadly distributed), seed characteristics (endospermy, dry weight), and collection environment (e.g. precipitation, elevation and average temperature) on longevity; (3) compare longevity of rainforest seeds to previously assessed species from non-rainforest habitats; (4) compare longevity in artificial aging to real-time longevity in storage. Methods. Seeds were aged at 60% relative humidity and 45°C, and tested at pre-determined intervals until germination was reduced to zero. The time taken for germination to decline to 50% (p50AA) was calculated by probit analysis. Ordinary least-squares regression was used to model p50AA for rainforest and non-rainforest species against predictor variables. Values for p50AA were then compared with the actual longevity in storage at -20°C (p50RT) using Pearson's correlation. Key results. Species restricted to rainforest exhibited a significantly lower p50AA than species with a wider distribution or those restricted to non-rainforest habitats. Collection elevation had a significant negative influence on p50AA. In all, 14 of 33 species showed a significant decline in viability after ≤12 years in storage. Values of p50AA were not correlated with p50RT. Conclusions. Rainforests contain a high proportion of potentially, and actually, short-lived species; however, p50AA is not a good predictor of their real-time longevity. Implications. Rainforest species should be managed as short-lived, with viability checked at least every 5 years, until real-time longevity data indicate otherwise. [ABSTRACT FROM AUTHOR]

Ex situ conservation involves the maintenance and reproduction of species in areas outside their natural habitats. Seed banking is a well-established ex situ approach used for plant conservation. Seed banking consists of collecting, drying, and storing seeds to preserve genetic diversity. The main limitation of this technique is that the seed must be desiccation tolerant. Seed storage behaviour can vary among species, and for some species, drying without loss of viability is not possible, meaning storage under conventional seed banking conditions (sub-zero temperatures and low relative humidity) is not possible. Understanding seed storage behaviour is an essential prerequisite for establishing whether conventional seed banking is an option for seed conservation. This study investigated the desiccation tolerance and sensitivity of mature seeds of two native New Zealand species of Pittosporum (P. eugenioides and P. crassifolium) from two geographic locations (Palmerston North and Wellington), with the aim of understanding their seed storage behaviour and thereby improving conservation outcomes. The variables measured were seed moisture content, viability, germination, and desiccation responses. We developed sorption isotherm for both species to support the future development of storage protocols. Our results show that both P. eugenioides and P. crassifolium display non-orthodox behaviour, i.e., are desiccation sensitive and cannot be stored under conventional seed banking conditions, but also suggest that seed desiccation responses vary with the geographical origin of the seeds. This study highlights the importance of exploring seed storage behaviour using different populations to optimize ex situ conservation strategies aimed at preserving the genetic diversity of New Zealand's threatened and endangered species. [ABSTRACT FROM AUTHOR]

The science is clear – significant reductions in tropical montane (TM) habitats are projected to occur by the end of this century. Urgent action is needed to build the resilience of TM flora and understand its adaptive capacity to climate change. Seed banking is the most widely employed ex situ conservation tool, providing insurance against plant species extinction and germplasm for associated research. However, tropical forest floras are grossly under-represented in seed banks due to historic assumptions and generalisations regarding collection, storage and germination of tropical forest seeds. In Australia, the Wet Tropics World Heritage Area of northeast Queensland contains tropical montane cloud forest (TMCF) in which > 70 endemic, seed-bearing species are at high risk of extinction. To mitigate this risk, we synthesised current seed science knowledge from TM plant communities around the world and examined what we know about collection, storage behaviour and germination of TM seeds. Included are our own preliminary investigations into seed banking of Australian TMCF flora. We argue that seed banking is applicable to more TM biodiversity than previously assumed and that a global effort to broaden ex situ conservation to include TM flora is needed. Making use of all the seed/gene banking tools available today, we call for a nationwide coordinated effort to establish a secure network of ex situ germplasm collections of Australian TMCF flora. Seed science research needed to inform and accelerate ex situ conservation of TMCF flora is also discussed.

A substantially rich diversity of the world's recorded useful plants (UPs) is captured within the Millennium Seed Bank collection hosted by the Royal Botanic Gardens, Kew, at Wakehurst, UK with 13,598 species (34%) belonging to 3696 genera and 325 families. This constitutes just over half of the total accessions and one third of the species and covers all 9 continents, 8 realms, 14 biomes, 34 biodiversity hotspots and 175 countries. The most common beneficial use category within the captured diversity is medicinal, then species with environmental, material, and human food value. About 86% of conserved UP species have a 'Least Concern' conservation status but 8% are identified as globally threatened. The advantages of mutual, continued, and long-term partnership (e.g., Mexico) are showcased when conserving plants important for local communities and addressing conservation challenges beyond seed banking. However, the geographic coverage suffers from a lack of partnerships with some parts of the world. Also, a low number of accessions contributed from many countries means that insufficient native range is yet to be captured for many species. This is particularly the case for restricted or narrow distribution species from families or genera with a high incidence of recalcitrant or short-lived seeds. Future planning must tailor better to cover the spatial distribution patterns for individual species, thereby improving the number of accessions and geographical coverage for those captured. Moreover, seed biology research should characterise desiccation tolerance and develop complementary, novel conservation methods, such as cryopreservation, to strengthen conservation options for UP species. [ABSTRACT FROM AUTHOR]

There is no published information on the seed germination or seed storage physiology of Lophomyrtus bullata, Lophomyrtus obcordata, and Neomyrtus pedunculata. This lack of information is hampering conservation efforts of these critically endangered species. This study investigated the seed morphology, seed germination requirements, and long-term seed storage methods for all three species. The impact of desiccation, desiccation and freezing, as well as desiccation plus storage at 5 °C, −18 °C, and −196 °C on seed viability (germination) and seedling vigour was assessed. Fatty acid profiles were compared between L. obcordata and L. bullata. Variability in storage behaviour between the three species was investigated through differential scanning calorimetry (DSC) by comparing thermal properties of lipids. L. obcordata seed were desiccation-tolerant and viability was retained when desiccated seed was stored for 24 months at 5 °C. L. bullata seed was both desiccation- and freezing-sensitive, while N. pedunculata was desiccation-sensitive. DSC analysis revealed that lipid crystallisation in L. bullata occurred between −18 °C and −49 °C and between −23 °C and −52 °C in L. obcordata and N. pedunculata. It is postulated that the metastable lipid phase, which coincides with the conventional seed banking temperature (i.e., storing seeds at −20 ± 4 °C and 15 ± 3% RH), could cause the seeds to age more rapidly through lipid peroxidation. Seeds of L. bullata, L. obcordata and N. pedunculata are best stored outside of their lipid metastable temperature ranges. [ABSTRACT FROM AUTHOR]

Abstract Background Seed viability testing is essential in plant conservation and research. Seed viability testing determines the success of ex-situ conservation efforts, such as seed banking but commonly testing protocols of orchids lack consistency and accuracy, therefore, there is a need to select an appropriate and reliable viability test, especially when conducting comparative studies. Here, we evaluated the suitability of three seed viability tests, Evans blue test (EB), Fluorescein diacetate test (FDA) and Tetrazolium test (TTC), with and without sterilization, on seeds of 20 orchid species, which included five epiphytes and fifteen terrestrials, using both fresh seeds and seeds stored at − 18 ºC for 6 to 8 years. Results We found that sterilization and lifeform of seeds affected seed viability across all tests but the storage time was not an influential factor. Sterilization negatively affected seed viability under EB and FDA test conditions but increased the detection of viable seeds in the TTC test in both epiphytic and terrestrial species. The EB test, when administered without sterilization provided the highest viability results. Being non-enzymatic unlike TTC and FDA tests, as expected, the EB test was the most reliable with similar results between sterilized and not sterilized seeds for most epiphytic and terrestrial species as well as when compared between groups. Conclusions The lifeform of the species and seed sterilization prior to testing are important influential factors in orchid seed viability testing. Since EB test was found to be reliable we recommend the EB test for seed viability assessment in orchids rather than the less reliable but commonly used TTC test, or the FDA test, which require more expensive and sophisticated instrumentation. Since storage time was not an influential factor in orchid seed viability testing, the recommendations of this study can be used for both fresh as well as long-term stored orchid seeds. This is helpful for research and especially for conservation measures such as seed banking. However, due to the species specificity of the bio-physiology of orchids, we call for comprehensive viability test assessment in the hyper diverse orchid family to be extended to a greater number of species to facilitate efficient conservation and research.

Conservation organizations with common missions can find strength and synergy in collaboration. Collaboration can also be challenging, especially finding the right partnerships or organizations to lead. Within the "ecosystem" of conservation organizations, botanical gardens have a unique array of resources and expertise which make them ideal candidates for leadership or partnership in collaborative conservation efforts. We will explore this idea by examining four conservation initiatives at Desert Botanical Garden (Phoenix, AZ, USA) that approach collaborative conservation on regional, state, and international scales. On a regional scale, Metro Phoenix EcoFlora and the Central Arizona Conservation Alliance lead landscape-level conservation by providing a structure for more than 60 official conservation partners, by generating data, and through public engagement needed in a rapidly developing region. On the state scale, Great Milkweed Grow Out is an initiative for pollinator conservation that provides expertise, materials, and opportunities for a wide range of partners across Arizona. Desert Botanical Garden's endangered plant species conservation efforts provide expertise and resources through horticulture and seed preservation for threatened and endangered plants across the US and internationally. We will share the structure of each program where applicable, how they came to fruition, and their successes. Through each case study, we will highlight the ways positioning within a botanical garden has benefitted the program and success in collaboration. We will also highlight unique challenges. Botanical gardens provide unique opportunities, and they should not be overlooked when seeking a conservation partner or leader. [ABSTRACT FROM AUTHOR]

Premise: To conserve native plants, many institutions are turning toward ex‐situ conservation methods, such as storage in seed banks; however, not all seeds are able to survive in seed bank conditions, or may not in the long term. Experimental aging has shown that alpine species lose viability more quickly than low‐elevation species. Furthermore, the germination requirements for rare species are largely unknown, but are a necessary first step in understanding storage behavior and viability decline. Methods: Five alpine species were subjected to germination and accelerated aging experiments to understand their longevity in storage. For the accelerated aging experiment, the seeds were rehydrated in a dark incubator and subsequently placed in a drying oven. Following the aging process, the seeds were placed into previously determined germination conditions. Results: All species had p50 values of <13.7 days, which is the threshold to consider a species short lived. These results suggest that we cannot haphazardly store seeds and assume that all species will survive for decades. Discussion: Accelerated aging experiments are not a perfect measure of seed longevity, and true longevity needs to be empirically determined. However, this experimental method allows us to predict which species may be short lived and whether alternative ex‐situ conservation methods might be needed beyond conventional seed banking. [ABSTRACT FROM AUTHOR]

Abstract Premise To conserve native plants, many institutions are turning toward ex‐situ conservation methods, such as storage in seed banks; however, not all seeds are able to survive in seed bank conditions, or may not in the long term. Experimental aging has shown that alpine species lose viability more quickly than low‐elevation species. Furthermore, the germination requirements for rare species are largely unknown, but are a necessary first step in understanding storage behavior and viability decline. Methods Five alpine species were subjected to germination and accelerated aging experiments to understand their longevity in storage. For the accelerated aging experiment, the seeds were rehydrated in a dark incubator and subsequently placed in a drying oven. Following the aging process, the seeds were placed into previously determined germination conditions. Results All species had p50 values of

Loss of sexual reproductive capacity has been proposed as a syndrome of domestication in vegetatively propagated crops, but there are relatively few examples from agricultural systems. In this study, we compare sexual reproductive capacity in wild (sexual) and domesticated (vegetative) populations of enset (Ensete ventricosum (Welw.) Cheesman), a tropical banana relative and Ethiopian food security crop.We examined floral and seed morphology and germination ecology across 35 wild and domesticated enset. We surveyed variation in floral and seed traits, including seed weight, viability and internal morphology, and germinated seeds across a range of constant and alternating temperature regimes to characterize optimum germination requirements.We report highly consistent floral allometry, seed viability, internal morphology and days to germination in wild and domesticated enset. However, seeds from domesticated plants responded to cooler temperatures with greater diurnal range. Shifts in germination behaviour appear concordant with a climatic envelope shift in the domesticated distribution.Our findings provide evidence that sexual reproductive capacity has been maintained despite long‐term near‐exclusive vegetative propagation in domesticated enset. Furthermore, certain traits such as germination behaviour and floral morphology may be under continued selection, presumably through rare sexually reproductive events. Compared to sexually propagated crops banked as seeds, vegetative crop diversity is typically conserved in living collections that are more costly and insecure. Improved understanding of sexual propagation in vegetative crops may have applications in germplasm conservation and plant breeding. [ABSTRACT FROM AUTHOR]

Background: Seed viability testing is essential in plant conservation and research. Seed viability testing determines the success of ex-situ conservation efforts, such as seed banking but commonly testing protocols of orchids lack consistency and accuracy, therefore, there is a need to select an appropriate and reliable viability test, especially when conducting comparative studies. Here, we evaluated the suitability of three seed viability tests, Evans blue test (EB), Fluorescein diacetate test (FDA) and Tetrazolium test (TTC), with and without sterilization, on seeds of 20 orchid species, which included five epiphytes and fifteen terrestrials, using both fresh seeds and seeds stored at − 18 ºC for 6 to 8 years. Results: We found that sterilization and lifeform of seeds affected seed viability across all tests but the storage time was not an influential factor. Sterilization negatively affected seed viability under EB and FDA test conditions but increased the detection of viable seeds in the TTC test in both epiphytic and terrestrial species. The EB test, when administered without sterilization provided the highest viability results. Being non-enzymatic unlike TTC and FDA tests, as expected, the EB test was the most reliable with similar results between sterilized and not sterilized seeds for most epiphytic and terrestrial species as well as when compared between groups. Conclusions: The lifeform of the species and seed sterilization prior to testing are important influential factors in orchid seed viability testing. Since EB test was found to be reliable we recommend the EB test for seed viability assessment in orchids rather than the less reliable but commonly used TTC test, or the FDA test, which require more expensive and sophisticated instrumentation. Since storage time was not an influential factor in orchid seed viability testing, the recommendations of this study can be used for both fresh as well as long-term stored orchid seeds. This is helpful for research and especially for conservation measures such as seed banking. However, due to the species specificity of the bio-physiology of orchids, we call for comprehensive viability test assessment in the hyper diverse orchid family to be extended to a greater number of species to facilitate efficient conservation and research. [ABSTRACT FROM AUTHOR]

Halting and reversing the current loss of biodiversity and habitats will be facilitated by a comprehensive valuation of all nature's contributions to people (NCPs), on which we rely. In this context, we explore the full natural capital value of seeds to reveal how this extends far beyond their economic value associated with mainstream agriculture and forestry. Seeds represent the main assets for nature-based solutions at species (i.e., unlocking neglected species properties and via seed banking) and ecosystem level (i.e., ecological restoration). Challenges remain to enhance their sustainable use in nature conservation and in supporting a sustainable development model. Such advances will depend on the comprehensive valuation of the natural capital value of seeds, which has so far been grossly underestimated. 'Nature's contributions to people' (NCPs), on which we rely, are declining substantially. Plants contribute to a large spectrum of 'regulating', 'material', and 'non-material' NCPs. The natural capital value (NCV) of seeds can be described using a 'total economic value' approach, distinguishing their existence value, direct use, indirect use, and option value. Biodiversity and their NCPs constitute the assets for nature-based solutions (NbS). Seeds represent the main assets for NbS at species and ecosystem level. [ABSTRACT FROM AUTHOR]

Storing seed collections of crop wild relatives, wild plant taxa genetically related to crops, is an essential component in global food security. Seed banking protects genetic resources from degradation and extinction and provides material for use by breeders. Despite being among the most important crops in the world, banana and plantain crop wild relatives are largely under‐represented in genebanks. Nevertheless, banana crop wild relative seed collections are in fact held in different countries, but these have not previously been part of reporting or analysis. To fill this gap, we firstly collated banana seed accession data from 13 institutions in 10 countries. These included 537 accessions containing an estimated 430,000 seeds of 56 species. We reviewed their taxonomic coverage and seed storage conditions including viability estimates. We found that seed accessions have low viability (25% mean) representing problems in seed storage and processing. Secondly, we surveyed 22 institutions involved in banana genetic resource conservation regarding the key constraints and knowledge gaps that institutions face related to banana seed conservation. Major constraints were identified including finding suitable material and populations to collect seeds from, lack of knowledge regarding optimal storage conditions and germination conditions. Thirdly, we carried out a conservation prioritization and gap analysis of Musaceae taxa, using established methods, to index representativeness. Overall, our conservation assessment showed that despite this extended data set banana crop wild relatives are inadequately conserved, with 51% of taxa not represented in seed collections at all; the average conservation assessment showing high priority for conservation according to the index. Finally, we provide recommendations for future collecting, research, and management, to conserve banana and plantain crop wild relatives in seed banks for future generations. [ABSTRACT FROM AUTHOR]

The conservation of endemic and endangered plant species is of great interest to the scientific and research community. In this frame, seed banks play a crucial role when biodiversity preservation and climate change are considered. The study of seed viability and germination during storage conditions provides basic and useful information to ensure successful ex situ conservation. The aim of this study was to evaluate whether storage time and conditions (i.e., base collection at -25°C and active collection at +5°C) affect seed germination in the long term. For these purposes, eight Tyrrhenian endemic vascular plant species (mostly endangered) with orthodox seeds were studied: Brassica insularis, Centranthus amazonum, Dianthus morisianus, Digitalis purpurea var. gyspergerae, Ferula arrigonii, Helicodiceros muscivorus, Iberis integerrima and Verbascum plantagineum. These species were stored in the Sardinian Germplasm Bank (BG-SAR) at -25°C and at +5°C for a time ranging from 2 to 12 years. Germination tests were carried out following the optimal conditions reported in the literature for each species. The results showed, in general terms, the high seed germination capacity of all species stored at both conditions; regarding the time of seed storage, germination in some tested species (such as B. insularis and C. amazonum) slightly decreased over time. We argued that seed dehydration, low seed moisture content during storage and the use of hermetic glass containers can be considered key factors for long-term conservation of these orthodox seeds. In conclusion, this study showed that the conservation of these endemic species is ensured by seed bank storage, according to the general assumption that seed longevity depends on seed lot quality, on well-sealed storage containers and conditions before and during storage. [ABSTRACT FROM AUTHOR]

Summary: Seeds can deteriorate rapidly under high heat and humidity, making it challenging and potentially costly to store orthodox seeds effectively in the tropics, thereby affecting agriculture development. This work explores the effectiveness of novel, low-cost technologies for storing seeds in warm, humid, resource-constrained environments, focusing on maintaining the viability of seeds already dry prior to storage. Seeds of okra (Abelmoschus esculentus (L.) Moench), sorghum (Sorghum bicolor (L.) Moench), and velvet bean (Mucuna pruriens (L.) DC) were kept for 12 months under roofed, outdoor screened porches. Seed moisture content prior to treatment was 6, 9, and 12% for okra, sorghum, and velvet bean, respectively. Treatments, replicated four times at each of two locations (USA [Florida] and Thailand), were technology suites involving vacuum drawn on glass jars with a modified bicycle pump, vacuum drawn on polyethylene bags with an electric vacuum sealing machine, desiccant (calcium oxide powder or zeolite Drying Beads® at a 2:1 ratio, by weight, of seeds to desiccant) in glass jars, and nontreated seeds in paper bags. Ambient temperature and humidity were variable and high, reaching over 35 °C and 83%, respectively, at both locations. Under these conditions, okra and sorghum germination percentages (across locations) without treatment declined from over 90% initially to 30 and 0%, respectively, by month 12. Both vacuum treatments and calcium oxide maintained high germination of okra (≈ 80%) and velvet bean seeds (nearly 100%) across locations. Glass, however, was superior to polyethylene in maintaining vacuum and stabilizing the moisture content of okra and sorghum seeds. Only zeolite reduced seed moisture below initial values, drying seeds to ultradry levels of <5%. With zeolite, sorghum germination stayed near 70% over time, while okra and velvet bean germination fell to <40 and <20%, respectively, by month 12, suggesting that, with the beads kept with dry seeds in storage rather than removing the beads after reaching a target level of seed moisture, the 2:1 ratio of seed-to-bead weight was too high for seeds that are sensitive to ultralow moisture. Findings have practical implications for inexpensive household- or community-level seed storage to deliver development impact. [ABSTRACT FROM AUTHOR]

Societal Impact Statement We rely on plants and fungi for most aspects of our lives. Yet plants and fungi are under threat, and we risk losing species before we know their identity, roles, and potential uses. Knowing names, distributions, and threats are first steps toward effective conservation action. Accessible products like field guides and online resources engage society, harnessing collective support for conservation. Here, we review current knowledge of the plants and fungi of the UK and UK Overseas Territories, highlighting gaps to help direct future research efforts toward conserving these vital elements of biodiversity. Summary This review summarizes current knowledge of the status and threats to the plants and fungi of Great Britain and the UK Overseas Territories (UKOTs). Although the body of knowledge is considerable, the distribution of information varies substantially, and we highlight knowledge gaps. The UK vascular flora is the most well studied and we have a relatively clear picture of its 9,001 native and alien taxa. We have seedbanked 72% of the native and archaeophyte angiosperm taxa and 78% of threatened taxa. Knowledge of the UKOTs flora varies across territories and we report a UKOTs flora comprising 4,093 native and alien taxa. We have conserved 27% of the native flora and 51% of the threatened vascular plants in Kew's Millennium Seed Bank, UK. We need a better understanding of the conservation status of plants in the wild, and progress toward completion or updating national red lists varies. Site‐based protection of key plant assemblages is outlined, and progress in identifying Important Plant Areas analyzed. Knowledge of the non‐vascular flora, especially seaweeds remains patchy, particularly in many UKOTs. The biggest gaps overall are in fungi, particularly non‐lichenized fungi. Considerable investment is needed to fill these knowledge gaps and instigate effective conservation strategies.

Abstract Storing seed collections of crop wild relatives, wild plant taxa genetically related to crops, is an essential component in global food security. Seed banking protects genetic resources from degradation and extinction and provides material for use by breeders. Despite being among the most important crops in the world, banana and plantain crop wild relatives are largely under‐represented in genebanks. Nevertheless, banana crop wild relative seed collections are in fact held in different countries, but these have not previously been part of reporting or analysis. To fill this gap, we firstly collated banana seed accession data from 13 institutions in 10 countries. These included 537 accessions containing an estimated 430,000 seeds of 56 species. We reviewed their taxonomic coverage and seed storage conditions including viability estimates. We found that seed accessions have low viability (25% mean) representing problems in seed storage and processing. Secondly, we surveyed 22 institutions involved in banana genetic resource conservation regarding the key constraints and knowledge gaps that institutions face related to banana seed conservation. Major constraints were identified including finding suitable material and populations to collect seeds from, lack of knowledge regarding optimal storage conditions and germination conditions. Thirdly, we carried out a conservation prioritization and gap analysis of Musaceae taxa, using established methods, to index representativeness. Overall, our conservation assessment showed that despite this extended data set banana crop wild relatives are inadequately conserved, with 51% of taxa not represented in seed collections at all; the average conservation assessment showing high priority for conservation according to the index. Finally, we provide recommendations for future collecting, research, and management, to conserve banana and plantain crop wild relatives in seed banks for future generations.

There is no published information on the seed germination or seed storage physiology of Lophomyrtus bullata, Lophomyrtus obcordata, and Neomyrtus pedunculata. This lack of information is hampering conservation efforts of these critically endangered species. This study investigated the seed morphology, seed germination requirements, and long-term seed storage methods for all three species. The impact of desiccation, desiccation and freezing, as well as desiccation plus storage at 5 °C, −18 °C, and −196 °C on seed viability (germination) and seedling vigour was assessed. Fatty acid profiles were compared between L. obcordata and L. bullata. Variability in storage behaviour between the three species was investigated through differential scanning calorimetry (DSC) by comparing thermal properties of lipids. L. obcordata seed were desiccation-tolerant and viability was retained when desiccated seed was stored for 24 months at 5 °C. L. bullata seed was both desiccation- and freezing-sensitive, while N. pedunculata was desiccation-sensitive. DSC analysis revealed that lipid crystallisation in L. bullata occurred between −18 °C and −49 °C and between −23 °C and −52 °C in L. obcordata and N. pedunculata. It is postulated that the metastable lipid phase, which coincides with the conventional seed banking temperature (i.e., storing seeds at −20 ± 4 °C and 15 ± 3% RH), could cause the seeds to age more rapidly through lipid peroxidation. Seeds of L. bullata, L. obcordata and N. pedunculata are best stored outside of their lipid metastable temperature ranges.

Seed banking of rainforest species is hindered by lack of knowledge as to which species are tolerant of desiccation and freezing. We assessed 313 Australian rainforest species for seed banking suitability by comparing the germination percentage of fresh seeds to seeds dried at 15% RH and seeds stored at −20 °C after drying. We then compared desiccation responses to environmental, habit, fruit and seed characteristics to identify the most useful predictors of desiccation sensitivity. Of 162 species with ≥ 50% initial germination, 22% were sensitive to desiccation, 64% were tolerant and 10% were partially tolerant; the responses of 4% were uncertain. Of 107 desiccation tolerant species tested for response to freezing, 24% were freezing sensitive or short-lived in storage at −20 °C. Median values for fresh seed moisture content (SMC), oven dry weight (DW) and the likelihood of desiccation sensitivity (PD-S) were significantly greater for desiccation sensitive than desiccation tolerant seeds. Ninety-four to 97% of seeds with SMC < 29%, DW < 20 mg or PD-S < 0.01 were desiccation tolerant. Ordinal logistic regression of desiccation response against environmental, habit, fruit and seed characteristics indicated that the likelihood of desiccation sensitivity was significantly increased by a tree habit, fleshy fruit, increasing fresh SMC and increasing PD-S. The responses observed in this study were combined with earlier studies to develop a simple decision key to aid prediction of desiccation responses in untested rainforest species. [ABSTRACT FROM AUTHOR]

Owing to decreasing costs and increased efficiency, it is now conceivable that conservation genomic information can be used to improve the effectiveness of recovery programs for many, if not most, threatened plants. We suggest that a simple genomic study be viewed as an initial step in conservation decision-making, as it informs long-term recovery efforts in various ways. We present biodiversity managers and conservation biologists with a simple, standardized workflow for genomic research that can guide efficient collection, analysis and application of genomic information across disparate threatened plants. Using two case studies, ‘Banksia vincentia’ and Daphnandra johnsonii, we demonstrate how a single round of genotyping by sequencing – a one-time cost – produces multiple directly applicable benefits, and how generating genomic information as early as possible can enhance conservation outcomes. We argue for a shift away from asking whether genomic information is needed or justified, and a shift towards consideration of the questions that need to be addressed. Such questions should aimed at cost-effectively guiding multiple practical aspects of a threatened plant’s management plan. The workflow presented here should help relevant stakeholders design a sampling strategy that directly suits their questions and needs.

Seed banks were first established to conserve crop genetic diversity, but seed banking has more recently been extended to wild plants, particularly crop wild relatives (CWRs) (e.g., by the Millennium Seed Bank (MSB), Royal Botanic Gardens Kew). CWRs have been recognised as potential reservoirs of beneficial traits for our domesticated crops, and with mounting evidence of the importance of the microbiome to organismal health, it follows that the microbial communities of wild relatives could also be a valuable resource for crop resilience to environmental and pathogenic threats. Endophytic fungi reside asymptomatically inside all plant tissues and have been found to confer advantages to their plant host. Preserving the natural microbial diversity of plants could therefore represent an important secondary conservation role of seed banks. At the same time, species that are reported as endophytes may also be latent pathogens. We explored the potential of the MSB as an incidental fungal endophyte bank by assessing diversity of fungi inside stored seeds. Using banana CWRs in the genus Musa as a case-study, we sequenced an extended ITS-LSU fragment in order to delimit operational taxonomic units (OTUs) and used a similarity and phylogenetics approach for classification. Fungi were successfully detected inside just under one third of the seeds, with a few genera accounting for most of the OTUs–primarily Lasiodiplodia, Fusarium, and Aspergillus–while a large variety of rare OTUs from across the Ascomycota were isolated only once. Fusarium species were notably abundant–of significance in light of Fusarium wilt, a disease threatening global banana crops–and so were targeted for additional sequencing with the marker EF1α in order to delimit species and place them in a phylogeny of the genus. Endophyte community composition, diversity and abundance was significantly different across habitats, and we explored the relationship between community differences and seed germination/viability. Our results show that there is a previously neglected invisible fungal dimension to seed banking that could well have implications for the seed collection and storage procedures, and that collections such as the MSB are indeed a novel source of potentially useful fungal strains.

Seed banks were first established to conserve crop genetic diversity, but seed banking has more recently been extended to wild plants, particularly crop wild relatives (CWRs) (e.g., by the Millennium Seed Bank (MSB), Royal Botanic Gardens Kew). CWRs have been recognised as potential reservoirs of beneficial traits for our domesticated crops, and with mounting evidence of the importance of the microbiome to organismal health, it follows that the microbial communities of wild relatives could also be a valuable resource for crop resilience to environmental and pathogenic threats. Endophytic fungi reside asymptomatically inside all plant tissues and have been found to confer advantages to their plant host. Preserving the natural microbial diversity of plants could therefore represent an important secondary conservation role of seed banks. At the same time, species that are reported as endophytes may also be latent pathogens. We explored the potential of the MSB as an incidental fungal endophyte bank by assessing diversity of fungi inside stored seeds. Using banana CWRs in the genus Musa as a case-study, we sequenced an extended ITS-LSU fragment in order to delimit operational taxonomic units (OTUs) and used a similarity and phylogenetics approach for classification. Fungi were successfully detected inside just under one third of the seeds, with a few genera accounting for most of the OTUs–primarily Lasiodiplodia , Fusarium , and Aspergillus –while a large variety of rare OTUs from across the Ascomycota were isolated only once. Fusarium species were notably abundant–of significance in light of Fusarium wilt, a disease threatening global banana crops–and so were targeted for additional sequencing with the marker EF1α in order to delimit species and place them in a phylogeny of the genus. Endophyte community composition, diversity and abundance was significantly different across habitats, and we explored the relationship between community differences and seed germination/viability. Our results show that there is a previously neglected invisible fungal dimension to seed banking that could well have implications for the seed collection and storage procedures, and that collections such as the MSB are indeed a novel source of potentially useful fungal strains. [ABSTRACT FROM AUTHOR]

Since the mid-twentieth century global modernization of agriculture, seed banking has become a core technoscientific strategy to counteract agrobiodiversity loss and ensure future food security. This article develops a post-anthropocentric reading of the Svalbard Global Seed Vault as a nodal point of global ex situ conservation efforts. Based on qualitative expert interviews, I explore the rationality of crisis and salvation that underlies these efforts and discuss its roots in an anthropocentric relation to nature as a resource. By arguing that the latter produces the crises that conservation measures intend to counteract, I show how the Seed Vault conserves this resource-orientation. I then illustrate a concurrent unruliness of more-than-human worldly becoming the embracing of which, I argue, is a way for conservationism to cultivate different, non-crisic futures. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: We rely on plants and fungi for most aspects of our lives. Yet plants and fungi are under threat, and we risk losing species before we know their identity, roles, and potential uses. Knowing names, distributions, and threats are first steps toward effective conservation action. Accessible products like field guides and online resources engage society, harnessing collective support for conservation. Here, we review current knowledge of the plants and fungi of the UK and UK Overseas Territories, highlighting gaps to help direct future research efforts toward conserving these vital elements of biodiversity. Summary: This review summarizes current knowledge of the status and threats to the plants and fungi of Great Britain and the UK Overseas Territories (UKOTs). Although the body of knowledge is considerable, the distribution of information varies substantially, and we highlight knowledge gaps. The UK vascular flora is the most well studied and we have a relatively clear picture of its 9,001 native and alien taxa. We have seedbanked 72% of the native and archaeophyte angiosperm taxa and 78% of threatened taxa. Knowledge of the UKOTs flora varies across territories and we report a UKOTs flora comprising 4,093 native and alien taxa. We have conserved 56% of the native flora and 51% of the threatened vascular plants in Kew's Millennium Seed Bank, UK. We need a better understanding of the conservation status of plants in the wild, and progress toward completion or updating national red lists varies. Site‐based protection of key plant assemblages is outlined, and progress in identifying Important Plant Areas analyzed. Knowledge of the non‐vascular flora, especially seaweeds remains patchy, particularly in many UKOTs. The biggest gaps overall are in fungi, particularly non‐lichenized fungi. Considerable investment is needed to fill these knowledge gaps and instigate effective conservation strategies. [ABSTRACT FROM AUTHOR]

Effective seed storage after sourcing (harvesting or purchasing) is critical to restoration practitioners and native seed producers, as it is key to maintaining seed viability. Inadequate seed storage can lead to a waste of both natural and economic resources when seeds of poor quality are sown. When working with native species with unknown storage behavior, general assumptions can be made based on studies on related species, and standard practices may be applied with caution; however, an investigation should be conducted to understand if specific storage requirements are needed and for how long seeds can be stored before they lose significant viability. In this paper of the Special Issue Standards for Native Seeds in Ecological Restoration, we provide an overview of the key concepts in seed storage and the steps to take for effective storage of native seeds for restoration use. [ABSTRACT FROM AUTHOR]

We investigated ex situ conservation options for two Australian rainforest species severely affected by myrtle rust in the wild – Rhodamnia rubescens (Benth.) Miq. and Rhodomyrtus psidioides (G.Don) Benth. Both species were successfully initiated into tissue culture though the rate of contamination was high and not significantly improved by the disinfection techniques tested. Explants surviving initiation grew well on Murashige and Skoog medium (MS; pH 6.0) with 30 g L−1 sucrose, 1 µm benzyl adenine and 0.2 µm indole-3-butyric acid. Culture of R. rubescens for eight weeks on MS with 0, 5, 10 or 20 µm indole-3-butyric acid resulted in root production for some plantlets, and successful transfer to potting mix; no significant differences in root production among treatments were detected. Both species were successfully propagated by semi-hardwood cuttings with strike rates of 0–67% for R. rubescens and 0–75% for R. psidioides. For R. rubescens , pretreatment of cuttings with Zaleton® and incubation in Preforma® plugs reduced the time to root development and significantly improved the strike rate (P = 0.001). R. rubescens seed proved to be orthodox and suitable for standard seedbanking; R. psidioides seed proved to be freezing sensitive but suitable for storage at 4°C. As the two species now produce few viable seeds in the wild, however, conservation by seedbanking will first require the establishment of a seed orchard from vegetatively propagated plants. We recommend swift action to conserve species in the Pacific similarly affected by myrtle rust before their growth and reproductive capacity are seriously diminished. Myrtle rust is having a devastating impact on some plant species in the Pacific. Ex situ conservation is necessary to preserve those species but their reduced ability to produce viable seeds or healthy new growth is a hindrance. Protocols for conserving severely impacted species are presented; however, susceptible species should ideally be conserved before their growth and reproductive capacity are affected. [ABSTRACT FROM AUTHOR]

UK trees require increased conservation efforts due to sparse and fragmented populations. Ex situ conservation, including seed banking, can be used to better manage these issues. We conducted accelerated ageing tests on seeds of 22 UK native woody species, in order to assess their likely longevity and optimize their conservation in a seed bank. Germination at four ageing time points was determined to construct survival curves, and it was concluded that multiple samples within a species showed comparable responses for most species tested, except for Fraxinus excelsior. Of all species studied, one could be classified as very short-lived, four as short-lived and 17 as medium, with none exceeding the medium category. The most important finding of this manuscript is that although some taxonomic trends were observed, the results indicate the need for caution when making broad conclusions on potential seed storage life at a species, genus or family level. Longevity predictions were compared to actual performance of older collections held in long-term storage at the Millennium Seed Bank, Kew. Although most collections remain high in viability in storage after more than 20 years, for short-lived species at least, there is some indication that accelerated ageing predicts longevity in seed bank conditions. For species with reduced potential longevity, such as Fagus sylvatica and Ulmus glabra, additional storage options are recommended for long-term gene banking. [ABSTRACT FROM AUTHOR]

Seeds are increasingly being stored in seed banks for ex situ conservation, food security, and restoration reserves. Although it is hypothesized that seeds of many species can survive the dry, freezer conditions (−20°C) of seed banks for many years, shelf life is unknown for many species. In particular, changes to dormancy and germination requirements following freezer storage have not yet been studied extensively. To improve our understanding of how seed dormancy and germination respond to seed banking conditions, we evaluated seed of six restoration-priority species in the southwestern United States, which is a region of increasing restoration need. Germination tendencies of seeds that were and were not exposed to a −20°C treatment for 4–6 months were evaluated under 22 cold-moist stratification and incubation treatments to broadly assess changes to dormancy and germination requirements and speed. Direct or indirect (via interactions with stratification and/or incubation treatments) differences in dormancy breaking and germination were observed in seeds for four of the six species studied. Specifically, storage temperature accounted for differences in the final germination proportion, germination during stratification, and/or rate of germination in five of the six species. Notably, seeds of the one species that exhibit a combination of physiological and physical dormancy showed significant differences in all germination measures. However, while significant differences were found between seeds exposed to short-term seed bank storage and those that were not, these differences were small and may not be biologically meaningful, indicating that seed banking these species should not change how they are used for restoration or reintroduction purposes. [ABSTRACT FROM AUTHOR]

Effective conservation of biodiversity should build on a strong basis of taxonomic and spatial distribution knowledge. The Carpathian Mountains, an iconic centre of biodiversity in temperate Europe, harbour a remarkable number of endemic vascular plants. Current knowledge on their taxonomic status, spatial distribution and genetic diversity is, however, incomplete. Research and conservation efforts have mostly been country specific, resulting in contrasting chorological knowledge and taxonomic acceptance between neighbouring countries, and differing conservation policies. Urgent synchronisation of cross-border conservation measures is required. Here, we present an overview of a new international project that will address these issues, outlining the current state of knowledge and theoretical background concerning Carpathian subendemics and endemics in order to improve their conservation status. The project involves partners from eight countries, working collaboratively in conservation, research and sharing of standardised data for the Carpathian flora. Long-term seed conservation of 500 species, with a focus on endemics, regionally endangered species and range-margin populations from the Carpathians, will be used as an effective measure for the conservation of Carpathian endemics and endangered species. Research focused on the biosystematics of selected taxa will increase our knowledge of the evolutionary processes involved in the origin of the Carpathian flora. Finally, the establishment of the Carpathian Research Network (CRN) provides an official framework for pooling, sharing and standardising scientific data on Carpathian endemics from different countries. The CRN is developing an online database of the distribution of selected species (The Carpathian Endemics Distribution Database, CEDD) including their intrinsic and extrinsic traits and current opinion on their taxonomic status. This will be used to produce a monograph on the Carpathians’ endemic flora. [ABSTRACT FROM AUTHOR]

Key message: Malus sylvestris(L.) Mill.,Pyrus communis(L.),Sorbus aucuparia(L.),Prunus avium(L.),Prunus padus(L.), andCornus sanguinea(L.) are related, co-occurring species producingorthodoxseeds. However, we observed differences in their response to storage conditions, such as storage at different seed moisture contents (5%, 8%, and 11%) and/or temperatures (− 3 °C, − 18 °C, and − 196 °C). Severe desiccation to ca. 5% of MC negatively affected seeds ofM. sylvestris. Seeds ofP. aviumwere sensitive to storage in LN or at − 18 °C.S. aucupariaseeds are best stored at − 3 °C, whereasC. sanguineaseeds tolerate desiccation and storage in LN. In general, species with deeper physiological dormancy (S. aucuparia,P. padus, andC. sanguinea) tended to be more tolerant to desiccation and low temperatures. For all species, storage conditions did not affect seedling growth. Context: Wild fruit woody species face many threats such as genetic loss, population fragmentation, and alien species; thus, their genetic variability should be preserved. Aims: To examine the effect of storage conditions on seed viability and the initial growth of seedlings of six European wild fruit species: Malus sylvestris (L.) Mill., Pyrus communis (L.), Sorbus aucuparia (L.), Prunus avium (L.), Prunus padus (L.), and Cornus sanguinea (L.). Methods: Seeds were desiccated to three different levels of moisture content (ca. 5, 8, or 11%) and stored at three different temperatures (− 3°, − 18°, or − 196 °C; liquid nitrogen, LN) for up to 3 years. Germination and seedling emergence tests were performed as well as measurement of seedling growth. Results: Desiccation of M. sylvestris seeds from 10.7 to 4.9% significantly lowered germination from 91 to 77% and seedling emergence from 88 to 74%. In P. avium, LN storage significantly inhibited seedling emergence, both in the laboratory and the greenhouse, but did not affect total seed germination. In P. communis, P. padus, and C. sanguinea, neither germination nor seedling emergence was affected by seed storage conditions. There were small or no differences in stem height and root collar diameter in the first year of seedling growth of stored seeds. Conclusion: Species with deeper physiological dormancy (S. aucuparia, P. padus, C. sanguinea) tended to be more tolerant of various storage conditions. Seeds of P. padus and C. sanguinea can be stored long term at − 18 °C or in LN at 5–8% MC without losing viability. M. sylvestris and P. avium seeds are sensitive to desiccation below 6% MC or low temperature of storage at − 18 °C or − 196 °C, respectively. We observed that storage conditions had significant influence on germination and seedling emergence but had no effect on seedling growth after the first growing season. [ABSTRACT FROM AUTHOR]

Organismal biology has undergone a dramatic paradigm shift in the last decade. The realization that host cells and genes are outnumbered by symbiotic microbial cells and their genes has forced us to rethink our focus on 'individuals'. It is also becoming increasingly clear that the ecology and biology of animals and plants are intimately connected with their microbial partners. In the context of conserving functioning species, such revelatory insights beg the question—what exactly should we be trying to conserve?Here, we review how an understanding of host–microbe interactions can benefit conservation biology. We propose a way forward for conservation biologists, to gather evidence of the potential effects of changes to plant and animal microbiomes, and to incorporate the holobiont concept into applied conservation practice.In humans, microbes influence physiology, health, behaviour and psychology. In animals and plants, microbes similarly influence critically important components of health, communication and (in animals) behaviour. Together, the animal or plant and all of its associated micro‐organisms are termed the holobiont.At the same time, humans are now the strongest evolutionary force on the planet, causing global change at unprecedented scale. We know that microbial diversity in humans has been compromised in urban societies, with a growing list of consequences for health and function. While we still have limited evidence for similar effects in plants and animals, anthropogenic factors that affect diversity are also likely to affect animal and plant microbiomes, with similar associated effects on host function and health.Microbiome research is still in its relative infancy, particularly in its application to plants and animals, yet the tools are becoming more widely available and affordable. Forward‐looking conservation biologists could harness such tools and apply them to the study of plant and animal microbiomes with the goal of understanding which microbiota might be required to ensure future viability of conserved host populations.For now, the precautionary principle applies. We suggest that, to meaningfully and effectively conserve a species, we must also consider how to conserve the bacteria, viruses, fungi and other symbionts intimately associated with that macro‐organism. A free Plain Language Summary can be found within the Supporting Information of this article. [ABSTRACT FROM AUTHOR]

Conserving wild plant seeds at the Millennium Seed Bank Partnership (MSBP) provides insurance by facilitating the reintroduction of threatened species. However, seed bank collections also provide an easily accessible resource for research into innovative conservation approaches and the adaptive management of natural resources and landscapes. In this regard, the MSBP corresponds with an emerging body of practice dubbed "New Conservation" that responds to the environmental implications of the Anthropocene and introduces the prospect of "gardening" nature. By examining the attitudes expressed by seed bank staff in the UK and United States. This article illustrates their awareness of the tension between the need to mitigate species extinction and the anthropocentrically governed, or gardened, form that the species' survival might subsequently take. Those within the MSBP were often thoughtfully engaged with the ideological questions their practice raises. However, external expectations of what seed bank collections facilitate, such as those of funders, will also impact how these collections are used. These expectations present selective pressures that risk limiting and thus filtering which species are reintroduced from the bank and the form in which their place in the world is forged. [ABSTRACT FROM AUTHOR]

Premise: Ex situ seed banking is critical for plant conservation globally, especially for threatened floras in tropical ecosystems like Hawai'i. Seed bank managers must maximize longevity, and species managers must plan restoration before seeds lose viability. Previous observations suggested some native Hawaiian seeds lost viability in frozen storage (−18°C). We investigated seed storage behavior in the Hawaiian flora to optimize storage conditions and recommend re‐collection intervals (RCI) to maximize viability of stored seeds. Methods: Using 20+ years of real‐time seed storage viability data, we tested freeze sensitivity for 197 species and calculated RCIs for 295 species. Using paired tests of accessions stored >2 yr at 5°C and −18°C, we developed an index of relative performance to determine freeze sensitivity. We calculated RCIs at 70% of highest germination (P70). Results: We identified four families (Campanulaceae, Cyperaceae, Rubiaceae, and Urticaceae) and four genera with seed freeze sensitivity and six additional genera with likely freeze sensitivity. Storage longevity was variable, but 195 species had viability >70% at the most recent tests (1 to 20+ yr), 123 species had RCIs >10 yr, and 45 species had RCIs <5 yr. Conclusions: Freeze sensitive storage behavior is more widely observed in Hawai'i than any other regional flora, perhaps due to insufficient testing elsewhere. We present a new protocol to test seed freeze sensitivity, which is often not evident until 2–5 years of storage. Re‐collection intervals will guide restoration practices in Hawai'i, and results inform seed conservation efforts globally, especially tropical and subtropical regions. [ABSTRACT FROM AUTHOR]

Understanding seed viability under long-term storage conditions provides basic and useful information to investigate the effectiveness of seed banking. Besides the germination success, seedling establishment is also an important requirement, and a decisive step to ensure plant propagation. We used comparative data of germination, seedling growth, and survival percentage between fresh and 10-years-stored seeds of Senecio morisii, a narrow endemic and vulnerable species of Sardinia (Italy), in order to evaluate if differences exist in these traits between fresh and 10-years-stored seeds. Stored seeds showed higher germination percentages than fresh ones, whereas seedling growth and survival did not present significant differences between them, except for seedling growth in plants produced from seeds germinated at 25 °C. This study allowed us to assess if seeds of S. morisii were able to germinate under controlled conditions, and if they maintained their viability and germination capacity for at least 10 years of long-term storage in the seed bank. In addition, the high seedling survival detected in both fresh and stored seeds suggests that stored seeds of S. morisii can be used to support reinforcement or reintroduction actions when fresh materials are not available.

Originating in Europe in the 16th century, botanic gardens are found in nearly every country in the world. Botanic gardens have had various roles during this time, including as physic gardens, as adaptation centers for commercial crops, as pleasure gardens, and more recently as conservation institutions. The role of botanic gardens in the conservation of Crop Wild Relatives is becoming increasingly important. At least 6000 taxa related to 68 crop genera are maintained by the world's botanic gardens with several gardens having specialist collections. The extent of infra-specific genetic diversity of these Plant Genetic Resources for Food and Agriculture (PGRFA) being conserved is currently unknown, although based on existing evidence it is likely to be low. However, these PGRFA collections, through display and education, play a significant role in linking the public to important issues, including food security and the need to conserve crop diversity. Today there are some 2700 botanic gardens in existence, and they are visited by over 500 million people every year. The majority of these gardens are found in temperate regions. At least 30% of all known plant species are found in botanic garden collections, including 41% of threatened species. These ex situ collections are conserved in a variety of ways, including as seed bank collections. Around 350 botanic gardens together maintain seed collections of 57,000 taxa. These seed bank collections have a variety of uses, including for research and reintroduction. [ABSTRACT FROM AUTHOR]

The Millennium Seed Bank (MSB) Partnership, developed and managed by the Royal Botanic Gardens, Kew (RBG Kew), conserves propagules primarily from orthodox seed-bearing wild vascular plants. It is the largest ex situ conservation programme in the world, currently involving 96 countries and territories. Where possible, seeds are collected and conserved in the country of origin with duplicates being sent to RBG Kew’s MSB for storage. In this paper we assess the conservation value of the germplasm stored at the MSB using both quantitative and qualitative methods. The MSB holdings represent a high quality, rich biological resource. Substantial and unique taxonomic diversity exists amongst the collections, representing 365 families, 5813 genera, 36,975 species and 39,669 taxa conserved. The collections cover a wide geographic range, originating from 189 countries and territories, representing all nine bio-geographic regions and all 35 biodiversity hotspots. The collections possess significant natural capital and population value: 32% of taxa, representing 49% of collections, have at least one identified use to humans; and 74% of taxa, representing 78% of collections, are either endemic, endangered (nationally or globally) and/or have an economic, ecological, social, cultural or scientific value. While 10% of taxa, representing > 8% of collections, are either extinct, rare or vulnerable to extinction at the global and/or national level, 20% of taxa, representing 13% collections, are endemic at the country or territory scale. Over the 17-year period since 2000 at least 11,182 seed samples, representing 12% of taxa and 8% of collections, have been distributed globally for conservation, research, education and display. This analysis highlighted collection gaps in MSB holdings in relation to their geographic representativeness, the taxonomic diversity of large families and genera of angiosperms, and coverage of threatened taxa. Further analysis across the entire MSB Partnership is required to underpin future collection activities and maximize the usefulness of collections. [ABSTRACT FROM AUTHOR]

Rainforests in the South Pacific hold a considerable amount of plant diversity, with rates of species endemism >80% in some countries. This diversity is rapidly disappearing under pressure from logging, clearing for agriculture or mining, introduced pests and diseases and other anthropogenic sources. Ex situ conservation techniques offer a means to limit the loss of plant diversity. Seed banking is considered the most efficient and cost effective of these techniques but is applicable only to seed capable of tolerating desiccation and cold storage. Data on the degree of tolerance of these conditions was lacking for more than half of the 1503 South Pacific rainforest genera examined for this review. Of the 710 genera for which data were available, the storage behaviour of 324 was based on an assessment of only one or two species, although 76% of those genera contained at least 10 species. Many of the unstudied or poorly studied genera are shared across several South Pacific nations, providing an excellent opportunity for collaboration on future ex situ research and conservation. Of the 386 genera for which three or more species have been studied, 343 have a very high proportion of species (>95% of those tested) that are suitable for seed banking. Seed banking could therefore provide a suitable means for preserving a large proportion of the rainforest flora before it becomes extinct in the wild. Alternatives for preserving species that are not suitable for seed banking are also discussed. [ABSTRACT FROM AUTHOR]

Thermal fingerprints for seeds of 20 crop wild relatives of Brassicaceae stored for 8 to 44 years at the Plant Germplasm Bank—Universidad Politécnica de Madrid and the Royal Botanic Gardens, Kew’s Millennium Seed Bank—were generated using differential scanning calorimetry (DSC) and analyzed in relation to storage stability. Relatively poor storing oily seeds at −20 °C tended to have lipids with crystallization and melting transitions spread over a wide temperature range (c. 40 °C) that spanned the storage temperature, plus a melting end temperature of around 15 °C. We postulated that in dry storage, the variable longevity in Brassicaceae seeds could be associated with the presence of a metastable lipid phase at the temperature at which they are being stored. Consistent with that, when high-quality seed samples of various species were assessed after banking at −5 to −10 °C for c. 40 years, melting end temperatures were observed to be much lower (c. 0 to −30 °C) and multiple lipid phases did not occur at the storage temperature. We conclude that multiple features of the seed lipid thermal fingerprint could be used as biophysical markers to predict potential poor performance of oily seeds during long-term, decadal storage.

The efficient storage and germination of seeds underpin the effective use of plants for livelihoods and sustainable development. A total of 204 wild species useful for local communities of the Tehuacán-Cuicatlán Valley were collected and stored in seed banks in country for long term conservation, and 66 % (i.e., 134) duplicated in the U.K., as an effective means of ex situ conservation. Of the 204 species, 147 (122 of which also duplicated in the U.K.) were previously listed as useful plants in the ethnofloristic inventory of the Valley. Based on literature surveys, we found that one of the major impediments to the use of stored seeds of wild species is the lack of knowledge of how to germinate the seed. In detailed studies, we found that seeds of 18 useful plant species from 10 different families germinated readily and could be propagated. In contrast, four species ( Actinocheita filicina, Bursera submoniliformis, Karwinskia mollis and Lippia graveolens) produced dormant seeds and therefore further studies are needed before their use can be maximised in large scale propagation programmes in support of conservation and livelihoods. Overall, this large-scale study on useful wild plant species in Mexico confirms that conventional seed banking can effectively support sustainable development and livelihood programmes. [ABSTRACT FROM AUTHOR]

Protocols for the conservation of threatened plants are often constrained by the absence of data on germination ecology. However, seed bank managers periodically monitor the viability of stored seed collections using germination tests. Here, we argue that data from those tests can and should be used to provide information on germination requirements of threatened species. Twelve taxa endemic to Portugal were used as a test case to determine the effect of incubation temperature and pretreatments upon germination and to identify major factors eliciting germination and releasing dormancy. We achieved maximum germination percentages >95% for nine taxa. Temperature significantly affected the final germination and mean germination time in most taxa. Maximum and faster germination at cool temperatures (15 °C or alternate 20/10 °C) was the prevailing trend. Cold stratification improved germination in one species, suggesting physiological dormancy. Scarification increased the germination percentage of one species among those expected to exhibit physical dormancy. Seed bank data provided valuable information on germination ecology, which can be used in in-situ conservation and as a baseline for further germination studies. Given the increasing threats to plant diversity, accessibility to seed bank data are paramount. [ABSTRACT FROM AUTHOR]