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Incarvillea sinensis var. przewalskii has attracted great attention because of the anticancer value of its alkaloids and the potential use of the species for ecological restoration. However, the scarcity of high-quality seeds has significantly hindered the cultivation and efficient utilization of this species. Understanding how seeds respond to maternal environmental conditions is crucial for developing high-yield and top-notch seed accessions, but the available knowledge in this area is limited. Here, we determined the effect of shading treatments on seed development, seed quality, and yield. Compared to the control, shade significantly increased the seed germination rate and 1000-seed weight by 29.2% and 25.6%, respectively. Regardless of light conditions, the seed germination rate and 1000-seed weight decreased by 7.13% and 37.5%, respectively, as the fruit positioned from base to apical. The seed yield per plant was 27.9% higher under shade than under the control treatment. The structural equation model showed that shade promoted seed yield through increasing flowers per reproductive branch and seed numbers per capsule. These findings suggest that adjusting shading conditions and optimizing inflorescence development can lead to high-yield and high-quality seeds. Additionally, prioritizing the number of flowers per reproductive branch and seeds per capsule in breeding programs can further enhance the seed yield of I. sinensis var. przewalskii. [ABSTRACT FROM AUTHOR]

Cacti have a wide distribution in the arid and semi-arid ecosystems of Mexico, with environmental variations affecting both physical and physiological seed traits. Herein, the physical and ecophysiological traits of Opuntia streptacantha seeds were evaluated to determine whether they are affected by sites. The seeds from eight sites of O. streptacantha from six Mexican states were studied, Sain Alto, Villa de Guadalupe, Villa González Ortega (Zacatecas), Zaragoza (San Luis Potosí), Lagos de Moreno (Jalisco), San Luis de La Paz (Guanajuato), Cardonal (Hidalgo) and Santiago Tepetitlán (Estado de México); being Lagos de Moreno and Santiago Tepetitlán the less dry sites and Villa González Ortega and Cardonal the drier ones. The longest seeds were from Zaragoza (3.81 mm), Villa González Ortega (3.72 mm) and Villa Guadalupe (3.70 mm); the widest and thickest seeds were from San Luis de La Paz (3.44 and 2.16 mm, respectively). The highest volumetric weight was found in seeds from Villa Guadalupe (9.92 kg hL-1 ), Lagos de Moreno (9.90 kg hL-1 ) and Santiago Tepetitlán (9.67 kg hL-1 ). The site San Luis de La Paz (1.31 g) had the highest weight of 1000 seeds and Cardonal (8874 seeds) the highest number of seeds per kilogram. The seeds with the highest moisture content were those from Villa González Ortega (9.81%), and the seeds with the lowest hardness were those from Santiago Tepetitlán (17.95 lbf), and Lagos de Moreno (16.55 lbf). The seeds from the western region of the country (Lagos de Moreno), where the species is less abundant and the environment is moister, showed the highest germination (26%). The seed hardness was negatively correlated with seed germination, with soft seeds having the highest germination. No correlation between seed weight and germination was found. The seed traits are related to environmental factors that influence the seed quality. The physical seed traits and seed germination from different sites for ecological restoration plans need to be considered. [ABSTRACT FROM AUTHOR]

The objective of ecological restoration and rehabilitation of grasslands is to recreate the original appearance of damaged or degraded vegetation. From previous research, the pneumatic spraying technology is now more commonly used in the world for vegetation restoration. Pneumatic spraying is relatively inexpensive and causes little damage to the original vegetation, making it one of the most effective techniques for restoring natural grassland vegetation under natural climatic conditions. In this paper, the effect of the spraying machine pipe working airflow on the quality of spraying was studied through simulation analysis and experimental tests. The seeding area of the spraying machine corresponding to different values of the pipe inlet airflow speed was determined. The conclusions show that: 1) the spray pipe inlet airflow velocity has a great influence on the uniformity of spraying. When the airflow velocity is higher than 55 m/s, the spraying is not uniform, while the airflow velocity is lower than 45 m/s, the spraying amplitude is smaller, the operational efficiency is low, which is not conducive to the restoration of degraded grasslands; 2) considering the uniformity of spraying and operational efficiency, the airflow velocity at the inlet of the spray pipe should be between 45 and 55 m/s when the spraying machine is in operation. The seed drop area is changed, by adjusting the airflow velocity of the spray pipe inlet, and the reseeding and leakage area of the seed drop area is reduced, so that the spraying performance of the spraying machine is optimized. [ABSTRACT FROM AUTHOR]

Restoration seedbanks have become a key infrastructure resource in efforts to restore damaged and degraded environments across the globe. Large‐scale ecological restoration typically utilizes large volumes of valuable, usually wild‐collected seeds, but insufficient knowledge of seed biology (including storage requirements in some cases) and ecology for many species continues to hamper the utility of restoration seedbanks to meet this rising demand. Poor germination and establishment when seeds are deployed from seedbanks can stem from factors such as premature seed collection, low seed quality, poor processing, handling and storage, variable seed quality from year to year, and, critically, insufficient understanding of seed dormancy, seed germination traits, and the ecological requirements for germination stimulation. While these factors may impact the success of seed‐based ecological restoration both synergistically and idiosyncratically, they can be universally addressed by adopting best practice principles in seedbank management and operation and through an improved understanding of the seed biology and ecology of stored species. Drawing upon an industry case study in seedbanking for post‐mining ecological restoration, we outline how optimizing seed storage conditions and a focus on seed biology and ecology in the operation of a restoration seedbank can deliver broad and immediate benefit and cost‐efficiency to native seed use. Such improvements are crucial in developing more effective approaches for returning biodiverse plant communities to highly modified landscapes and are foundational for meeting the aspirations for ecological restoration at global scales in the coming decade. [ABSTRACT FROM AUTHOR]

Seeds are a critical and limited resource for restoring biodiversity and ecological function to degraded and fragmented ecosystems. Cleaning and quality testing are two key steps in the native seed supply chain. Optimizing the practices used in these steps can ensure seed quality. Post‐collection handling of seeds can have a profound impact on their viability, longevity in storage, and establishment potential. The first section of this article describes seed cleaning, outlines key considerations, and details traditional and novel approaches. Despite the growth of the native seed industry and the need for seed quality standards, existing equipment and standards largely target agricultural, horticultural, and commercial forestry species. Native plant species typically have complex seed traits, making it difficult to directly transfer existing cleaning and quality standards to these species. Furthermore, in ecological restoration projects, where diversity is valued over uniformity crop standards can be unsuitable. We provide an overview and recommendations for seed quality testing (sampling, purity, viability, germinability, vigor), identity reporting, and seed transfer as well as highlight the need to implement internationally recognized standards for certification for native seeds. Novel and improved cleaning and testing methods are needed for native species from a range of ecosystems to meet the challenges and goals of the United Nations Decade on Ecosystem Restoration. The guidelines outlined in this article along with others in the Special Issue of Restoration Ecology "Standards for Native Seeds in Ecological Restoration" can serve as a foundation for this critical work. [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]

The growing demand for native seeds in ecological restoration and rehabilitation, whether for mining, forest, or ecosystem restoration, has resulted in a major global industry in the sourcing, supply, and sale of native seeds. However, there are no international guidance documents for ensuring that native seeds have the same standards of quality assurance that are regular practice in the crop and horticultural industries. Using the International Principles and Standards for the Practice of Ecological Restoration as a foundation document, we provide for the first time a synthesis of general practices in the native seed supply chain to derive the Principles and Standards for Native Seeds in Ecological Restoration ("Standards"). These practices and the underpinning science provide the basis for developing quality measures and guidance statements that are adaptable at the local, biome, or national scale. Importantly, these Standards define what is considered native seed in ecological restoration and highlight the differences between native seeds versus seeds of improved genetics. Seed testing approaches are provided within a logical framework that outline the many different dormancy states in native seed that can confound restoration outcomes. A "pro‐forma" template for a production label is included as a practical tool that can be customized for local needs and to standardize reporting to end‐users on the level of seed quality and germinability to be expected in a native seed batch. These Standards are not intended to be mandatory; however, the guidance statements provide the foundation upon which regulatory approaches can be developed by constituencies and jurisdictions. [ABSTRACT FROM AUTHOR]

We argue that the need for a quality seed supply chain is a major bottleneck for the restoration of Chile's native ecosystems, thus supplementing the list of bottlenecks proposed by Bannister et al. in 2018. Specifically, there is a need for defining seed transfer zones, developing standards and capacities for properly collecting and storing seeds, reducing information gaps on seed physiology and longevity, and implementing an efficient seed supply chain with certification of seed origin and quality. Without such capacities, countries are unlikely to meet their restoration commitments. Although we focus on bottlenecks in Chile, the issues we raise are relevant to other countries and thus the global agenda for ecological restoration. [ABSTRACT FROM AUTHOR]

Direct native seed planting is a cost-effective and popular approach for restoring degraded terrestrial ecosystems. However, the handling and precision seeding of multispecies mixes with diverse seed sizes, and shapes is logistically complex, requires highly customised equipment and often results in poor seedling establishment. This issue is accentuated in small-seeded species, where handling difficulties and a lack of precision placement result in seed wastage. The agricultural seed sector relies on the application of external material to small seeds to improve handling via seed pelleting. Yet this method has been rarely tested on small-seeded native species for ecological restoration. We pelleted the seeds of 15 small-seeded Myrtaceae species commonly used for seed-based restoration programs and recorded a range of physical traits. Prior to pelleting, each seed batch was tested for purity and viability and processed to improve quality (Pure Live Seed, PLS%). Seedling emergence from pelleted and control seeds was tested in controlled laboratory conditions and at two field sites in Western Australia. We linked seedling's emergence outcomes to the degree of physical modification achieved via pelleting to understand which trait would be responsible for a potential decrease or delay in emergence. Seed processing improved the average quality (PLS%) across all species from 23.4 ± 4.8% to 83.6 ± 2.3%. Seed pelleting, on average, resulted in a 27-fold increase in volume, a 30-fold increase in weight, and a 26% increase in bulk density. Seedling emergence response to pelleting varied among species, but on average, emergence speed was 3.1 days faster (p < 0.001) for pelleted seeds, while final emergence was not significantly different (p = 0.217). The results show that a combination of seed processing and pelleting can be used to increase and standardise seed physical properties for improved handling and precision seeding, with limited consequences on seedling emergence and faster emergence. This novel approach could enable the use of large-scale agricultural seeding equipment for rapid and cost-effective delivery of multispecies native seed mixes in biodiverse global restoration programs. • Seed quality of small-seeded Myrtaceae species is improved by seed processing • Seed pelleting greatly increased the size and volume of individual seeds. • The physical properties of pelleted seeds are more homogenous across species, improving handling of multi-species mixes. • Seed pelleting had limited effect on final seedling emergence but increased emergence speed. [ABSTRACT FROM AUTHOR]

Large‐scale ecological restoration programs across the world involve a voluminous demand for native seeds of diverse native plant species. In this article, we explore how institutional systems have operated and impacted native seed supply in Brazil. Native seed supply for restoration is essentially a community‐based activity which faces broad barriers to operating within regulations because of requirements for excessive and costly technical documentation, scarcity of seed laboratories, and lack of instructions for native seed quality testing. Although decentralized seed networks have stimulated arrangements for local organizations to promote seed supply, policies constrain the development of local capacities and the ongoing sustainability of these organizations. These conditions have resulted in a vast network of informal collectors and producers who are largely "invisible" and unknown to the regulatory authorities. Policies have decentralized responsibilities from the state without devolving decision‐making power to the multiple stakeholders engaged in policy elaboration. The policies maintain the centralized regulation of native seed supply. After examining Brazilian seed networks' experiences and conducting discussions with stakeholders and experts, we suggest adapting the current regulations to more local level contexts, encompassing the following strategies: (1) ensuring native seed origin and identity; (2) relaxation of the laboratory accreditation process for native seed quality assurance; (3) fostering seed markets for restoration; (4) research to provide technological innovation; (5) supporting local, diverse, and small seed‐based businesses. [ABSTRACT FROM AUTHOR]

Commercial sources of native seed are often unavailable for ecological restoration projects or do not have a suitable provenance. Local collection of wild seed is an option, but it can be challenging to collect seed for a variety of species and set fair seed prices. Our aim was to quantify the relative effort to collect, clean, store, and propagate seed to better prioritize species and assess the value of their seed. For 57 species native to the Canadian subarctic and typical of upland habitats, we evaluated 13 poorly correlated attributes in the field and lab or using the literature. For collection attributes, regional occurrence, local abundance, seed collection rate, and collection window were normally or log‐normally distributed. Most species were easy to identify and posed few collection obstacles. Cleaning effort was evenly distributed across species and the majority could be cleaned to more than 95% purity. We only encountered orthodox seed and most species had seed longevity exceeding a year. Seed viability mostly exceeded 80%, pre‐treatment requirements were evenly distributed and the majority of species could be germinated under standard conditions. We propose a standard worksheet, in which we assign relative effort scores to the distribution of each attribute. We illustrate this approach for the revegetation planning of a remote mine site. We also propose a seed lot certificate to ensure high seed quality. This tool can be applied to various restoration applications to assess relative effort, to plan and prioritize species for restoration projects and to help set fair seed pricing. [ABSTRACT FROM AUTHOR]

Restoration practitioners must increasingly incorporate seed procurement models and seed use planning early in project development, despite insufficient guidance about what are reasonable expectations for the sourcing and use of native seeds. This special issue presents a series of articles examining each key step in the native seed supply chain, and provides a framework for the "standards" that need to be applied to native seed batches if the native seed supply chain is to achieve the levels of reliability and transparency required. These Standards provide seed buyers, end users, and funding bodies with a level of confidence and reliability in the sourcing of quality native seeds, and a pathway toward global best practice in native seed use. [ABSTRACT FROM AUTHOR]

With the need to meet ambitious restoration targets, an improved native seed sector for the production of herbaceous species with a practical and supportive policy framework is recognized. We evaluated the current “ready‐made” policy frameworks in Europe regarding the native seed supply of herbaceous species and found them to be, generally, unsatisfactory for both producers and users. Initially, such policies were designed for fodder seed and relate to distinctness, uniformity, and stability, traits that do not reflect the genetic heterogeneity of native species required for ecological restoration. Until recently, more suitable certification standards were designed to multiply fodder seed for preservation of the natural environment; however, due to the disparateness of the seed market in Europe, this policy is rarely practical and fails to encompass all herbaceous native species often resulting in unregulated seed sales. We recommend a new or adapted native seed policy constructed through a participatory or bottom‐up approach and supported through the formation of widely based trade associations. Such a policy could stimulate the native seed trade with concomitant impacts on the speed of improving ecosystem services. [ABSTRACT FROM AUTHOR]

Abstract: Meeting the multimillion hectare commitments for forest and landscape restoration (FLR) will require billions of tree seed and seedlings. However, the adequacy of seed supply in terms of quantity, genetic diversity and quality has received scant attention in FLR planning. We surveyed 139 FLR projects worldwide and identified widespread problems in the availability and diversity of tree seed, with potentially deleterious consequences for the vigor, productivity and long‐term persistence of restored tree populations. Large projects and those focused on climate change mitigation were particularly associated with multiple problems in seed sourcing. To avoid large‐scale failure in FLR, we recommend: (1) national assessments of seed supply and demand for FLR, (2) reviewing FLR targets and funding cycles, (3) fostering sharing of knowledge and experiences regarding seed supply and selection, (4) enhancing seed exchange across landscapes, and (5) introducing regulations for seed quality and strengthening capacities for compliance. [ABSTRACT FROM AUTHOR]

Elliott's lovegrass (Eragrostis elliottii S. Watson [Poaceae]) is an early successional perennial bunchgrass native to the southeastern US. It is a common species in several frequently restored ecosystems including flatwoods, dry prairies, and sandhills. The germination ecology of E. elliottii is largely unknown. Furthermore, practitioners seek reliable information on potential differences in vigor between seedlots. Knowledge of these factors may influence future use of this species in restoration projects. Germination ability of Elliott's lovegrass was tested with simulated seasonal alternating temperatures (33/24, 29/19, 27/15, 22/11 °C [91/75, 84/66, 81/59, 72/52 °F]) for 28 d. Final germination was high (> 80%) for seeds exposed to early spring/late fall (27/15 °C [81/59 °F]), summer (33/24 °C [91/75 °F]), or early fall/late spring (29/19 °C [84/66 °F]) temperatures. Seeds exposed to summer temperatures displayed more rapid and higher germination (89%) than did seeds exposed to cooler temperatures (P< 0.0001). Seeds exposed to winter (22/11 °C [72/52 °F]) temperatures germinated more slowly and with fewer total seeds germinating (P< 0.0001). The stressful conditions of 2 saturated salt accelerated aging (SSAA) treatments resulted in a maximum germination reduction of 7% in the 2012 seedlot when compared to controls. The 2013 seedlot responded to the same conditions with significantly fewer germination events per day and a reduction in total germination of 14 to 27%. In sum, these results suggest that germination of E. elliottii can occur throughout the year, but seed vigor differences are present between lots. [ABSTRACT FROM AUTHOR]

Madsen et al. (2016) reviewed several major limiting factors to establishment of seedlings in nonforest ecosystems ( NFE), and proposed seed enhancement technologies to overcome these restoration barriers. However, biodiverse nutrient-poor NFE present additional hurdles that preclude landscape-scale seed-based restoration and were not mentioned in their review. Here, we discuss issues related to native seed availability and provenance, and shortfalls in knowledge on seed quality testing and dormancy release that severely hamper restoration of degraded nutrient-impoverished NFE. We present alternatives for overcoming these challenges and highlight the need for investments to find more practical and cost-effective options for broad-scale restoration. [ABSTRACT FROM AUTHOR]

Reinstating dominant Triodia grassland communities following disturbance has been a focus of arid land restoration practitioners for decades in Australia. Yet, seed quality and variable seed germination have seriously hindered the reestablishment potential of Triodia species to date. This study set out to examine diaspore quality, germination requirements, and seed dormancy in seven Triodia species to identify first, then resolve, germination impediments. Freshly collected florets from all species were cleaned to ensure that each floret contained a viable seed and then evaluated for their initial germination capacity. Very low germination from florets (<10%) indicated the presence of physiological seed dormancy ( PD) in all species. However, germination was significantly improved (up to 57%) with the use of 0.67 µm karrikinolide ( KAR1), and to a lesser degree with 289 µm gibberellic acid ( GA3). When the covering floret structures (i.e. lemma and palea) were removed, germination increased up to 59%, which was further enhanced after exposure to GA3 (up to 66%) and KAR1 (up to 92%). Optimal germination temperatures varied from 20 to 35°C and were species specific. Dry after-ripening ( DAR −30°C and 50% relative humidity [ RH]) of florets and seeds promoted the progressive loss of PD over 12-24 months storage for most species. Germination, dormancy level, and response to incubation temperature differed amongst species, experimental units (florets and seeds), DAR treatments, and after exposure to germination stimulants ( GA3 and KAR1). For use in restoration seeding programs, careful consideration of seed pre-treatments is necessary to improve germination in Triodia species. [ABSTRACT FROM AUTHOR]

A thorough knowledge of soil functionality is critical to successful restoration of disturbed ecosystems, and its evaluation involves the assessment of soil properties and processes as a component of a healthy ecosystem. Here, we propose a set of soil quality indicators to assess the soil status in restored soils (topsoil and waste material) and test new methods that are easy to apply, interpret, and cost-effective for the analysis of soil biological indicators in restored ecosystems. We show that in addition to organic carbon and C:N ratio, biological indicators (microbial diversity and activity in particular) are the most sensitive indicators to detect differences among reconstructed soils and analogue undisturbed soils in semiarid areas. The use of the 1-day CO2 test is proven to be an alternative cost- and time-effective method to measure microbial activity and assess soil functionality of restored soils. Our results show a positive effect of vegetation on reconstructed soils and a recovery of soil functionality in waste material to levels similar to topsoil once vegetation is established. However, soil functionality in both restored waste materials and topsoils is still far from that in undisturbed native soils. We conclude that soil functionality is critical in the restoration process, particularly in semiarid areas, and the methods used here could be effectively applied in a broad range of restoration projects in arid and semiarid environments. [ABSTRACT FROM AUTHOR]

Ecological restoration of grasslands using wild-collected seeds is a major undertaking in many parts of the world. Impediments to effective seed use such as low seed quality, difficult-to-handle and bulky collections of seeds, and seed dormancy and germination constraints contribute to restoration failure. Native grass florets are typically irregular in shape, with appendages that impede efficient mechanized sowing and render agricultural technologies, such as the application of polymer seed coatings, impractical. Our goal was to investigate the application of a novel flaming device to remove floret appendages and improve geometry using Triodia wiseana (C.A. Gardner [Poaceae]), a key framework grass of arid ecosystems in north-western Australia, as a test species. Through the modification of a rotary seed coater with an engineered flaming apparatus, a flash flaming technique was developed. We demonstrate that flash flaming is a highly effective and efficient means of removing floret appendages and subsequently improving geometry. Once flamed, the bulk density of florets was significantly increased, the application of polymer coatings was more effective, and germination was enhanced. The improved floret geometry through flaming therefore shows promise for enhancing the mechanization of direct seeding of grasses. [ABSTRACT FROM AUTHOR]

A fundamental aspect of establishing native plant species in restorations is ensuring that the seed used is viable. We test whether seed viability estimates for wild-collected seed of 4 forb species native to prairie habitat differ when using 3 methods: 1) germination, 2) tetrazolium, and 3) X-ray. Study species include Eryngium yuccifolium Michx. (button eryngo [Apiaceae]), Lespedeza capitata Michx. (roundhead lespedeza [Fabaceae]), Liatris aspera Michx. (rough prairie blazing star [Asteraceae]), and Ratibida columnifera (Nutt.) Woot. & Standl. (upright prairie coneflower [Asteracae]); multiple populations of each species are used to compare seed collected in the same year from different populations. Additionally, we test whether seed pretreatment (gibberellic acid or scarification) could improve germination estimates of viability by overcoming seed dormancy. Results show that viability estimates do not significantly differ by testing method for 3 of our 4 study species, with the exception being E. yuccifolium. We suspect that E. yuccifolium may have yielded different results for each viability testing method because its pretreatment was not enough to break dormancy, among other factors. Pretreatment yielded significantly higher viability estimates in L. capitata and in one population of L. aspera and E. yuccifolium in the germination study. These results confirm that restoration practitioners should calculate seeding rates based on viability measures on a per-species and per-accession basis. For many species, the method used to calculate viability can be determined by available equipment and expertise, but for species with unknown dormancy requirements, or those that may lose viability when stored, multiple methods may be needed. [ABSTRACT FROM AUTHOR]

The considerable risk factors associated with ecological restoration make the reintroduction of appropriate species critical to restoration success. In seed-based restoration efforts, using high quality seed is central to good in-field yields; consequently, determining the physiological status of seed prior to large-scale collection and use is important. To gain insight into the suitability of species for use in large-scale seed-based restoration efforts, this study set out to determine the seed viability and seedling emergence of 31 little-studied renosterveld species through laboratory and glasshouse trials, respectively. The outcomes of these seed quality tests were assessed in conjunction with several additional criteria, suggested throughout the literature as relevant to species selection and seed collection, towards determining an overall score, a restoration species index, as a measure of how suitable each species is likely to be in future seed-based restoration efforts. Among the 31 selected species, seedling emergence and to a lesser extent seed viability were variable yet moderate to high for the majority of species. The restoration species index presented here, drawing several considerations into a single, novel approach to species selection, proved useful in this study where the vast majority of species exhibited moderate to high potential. [ABSTRACT FROM AUTHOR]

Wiregrass (Aristida stricta) is an important species for restoration of imperiled pine-grassland ecosystems. However, in situ and ex situ seedling establishment is problematic due to highly variable germination. I assessed seed lot quality with respect to the production of viable and non-viable seeds from seven remnant wiregrass populations occurring in xeric or mesic habitats throughout Alabama, Florida, Georgia, and South Carolina. Additionally, I investigated the incidence of contamination and germination following surface sterilization. Approximately 55 to 90% of seeds were non-viable due to lack of seed fill and fungal contamination. The number of empty seeds always outweighed that of infected seeds. Populations were similar for seed lot quality when grouped by habitat. Alternatively, populations were heterogeneous for seed lot quality when grouped by geographic region. Seeds from all populations were infected with Curvularia and most were infected with Sorosporium. Surface sterilization with up to a 10% bleach solution did not eliminate pathogens on otherwise viable, healthy seeds suggesting that internal seed tissues may have harbored infection. The high level of non-viable seeds implies that large quantities of seeds are required in order to meet restoration objectives and that caution should be exercised if inter-population seed movement is needed. [ABSTRACT FROM AUTHOR]

Xylopia aromatica is a native species from Brazil's "Cerrado", recommended for restoration ecology and also as a medicine. Its seeds have embryos with morphophysiological dormancy, making nursery propagation difficult. The objective of this study was to verify the efficiency of X-ray and tetrazolium tests for evaluating the viability of three seed lots, stored for different periods. All seeds were X-rayed (13 kV, 350 seconds) and samples used for tetrazolium and germination tests. In the tetrazolium test, seeds were submitted to six treatments at two temperatures (25 and 30 °C) with imbibition in distilled water and immersion in three concentrations of tetrazolium solution (0.5, 0.75 and 1%) at the two imbibition temperatures. Seeds for the germination test were placed for imbibition in distilled water and a 500 ppm Promalin® (6-Benzyladenine + GA4 + GA7) solution and later sown in sterilized sand. The embryo could not be observed with the X-ray test. However, those seeds observed with an undamaged endosperm did not differ in the percentages of seeds with firm and stained endosperms observed in the tetrazolium test for all the lots. The tetrazolium test is efficient for evaluating seed viability, principally if imbibed at 30 °C and immersed in a 0.5% solution at 30 °C. [ABSTRACT FROM AUTHOR]

Restoring degraded land to combat environmental degradation requires the collection of vast quantities of germplasm (seed). Sourcing this material raises questions related to provenance selection, seed quality and harvest sustainability. Restoration guidelines strongly recommend using local sources to maximize local adaptation and prevent outbreeding depression, but in highly modified landscapes this restricts collection to small remnants where limited, poor quality seed is available, and where harvesting impacts may be high. We review three principles guiding the sourcing of restoration germplasm: (i) the appropriateness of using ‘local’ seed, (ii) sample sizes and population characteristics required to capture sufficient genetic diversity to establish self-sustaining populations and (iii) the impact of over-harvesting source populations. We review these topics by examining current collection guidelines and the evidence supporting these, then we consider if the guidelines can be improved and the consequences of not doing so. We find that the emphasis on local seed sourcing will, in many cases, lead to poor restoration outcomes, particularly at broad geographic scales. We suggest that seed sourcing should concentrate less on local collection and more on capturing high quality and genetically diverse seed to maximize the adaptive potential of restoration efforts to current and future environmental change. [ABSTRACT FROM AUTHOR]

A challenge for land managers restoring degraded agricultural landscapes across southern Australia will be to ensure the viability of remnant vegetation while simultaneously supplying the quantities of appropriate seed required for revegetation. To ensure such revegetation programs have the best chance of success, seed that is both genetically diverse and locally adapted will be required. Identifying suitable seed sources can be particularly difficult in regions where local seed sources are restricted to small and isolated remnants. Gold-dust Wattle ( Acacia acinacea Lindl.) is a key revegetation species in the Deniliquin region of New South Wales; however, broadscale land clearing in the area has limited local seed sources to a few remnant stands. Field-based experience suggests that revegetation success may depend upon the source of seed used, raising the question of whether differences in the germination and survival of seed reflect functional problems within these source populations. To test this possibility, seed was collected from 15 mothers in each of three seed sources regularly used for local restoration programs. Seed quality for each mother was assessed in terms of seed production and seedling fitness. In addition, genetic diversity and mating system parameters were determined to assess whether these explained the seed quality responses observed. Differences among the seed sources with respect to seed quality were generally congruent with field-based predictions. High levels of correlated paternity in the two poorly performing seed sources probably reflect limited mating availability due to smaller population sizes and genetic incompatibility being mediated by a self-incompatible reproductive strategy. Further research is now required to determine whether observed variability in the quality of seed from remnant vegetation in degraded landscapes is compromising revegetation efforts, and to help practitioners develop strategies to critically evaluate their seed sources. [ABSTRACT FROM AUTHOR]