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Volunteer canola (Brassica napus L.) is defined as canola germinating and emerging after the intended cropping season, and it continually ranks as a top occurring weed on the Canadian prairies. Seed dormancy is the physiological mechanism enabling the seed to remain viable in the soil seedbank for extended periods of time. Specifically, canola has a high likelihood of being induced into secondary seed dormancy under adverse environmental conditions not suitable for germination. A reduction of secondary seed dormancy in modern canola varieties may result in lower seedbank persistence; however, the effect of reducing dormancy on other seed traits is not known. This study examined a diverse collection of spring B. napus genotypes produced in differing maternal environments for secondary seed dormancy as well as seed germination, vigor, and seed quality traits. Genotype contributed the most to total variability (46%), the interactions between genotype and environment had a moderate contribution (28%), and very little contribution from maternal environment alone (4%) was observed for the secondary seed dormancy trait. The remaining variability (22%) was allocated to the residuals. No association was observed between secondary seed dormancy and germination time or seed vigor traits in genotypes examined. Significant associations with secondary seed dormancy were detected for primary dormancy, total protein, seed fiber components, glucosinolates content, seed geographical origin, and fatty acid composition. According to the results of this study, the reduction of secondary seed dormancy as a breeding objective in canola breeding programs is feasible as the trait is largely genetically controlled. Furthermore, direct selection against secondary seed dormancy is unlikely to have adverse effects on canola seed germination and vigor given no associations were detected in the current study. Core Ideas: Genetic reduction of secondary seed dormancy may help to reduce volunteer canola on the Canadian prairies.Genetics were the largest contributing factor to variability of the secondary seed dormancy trait.The current study was first to assess large number of spring Brassica napus genotypes across several environments.No associations were identified for seed germination or seed vigor traits and secondary seed dormancy.Increased seed fiber resulted in higher secondary seed dormancy, possibly due to mechanical restraint of seed coat. [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]

From 50 to 90% of wild plant species worldwide produce seeds that are dormant upon maturity, with specific dormancy traits driven by species' occurrence geography, growth form, and genetic factors. While dormancy is a beneficial adaptation for intact natural systems, it can limit plant recruitment in restoration scenarios because seeds may take several seasons to lose dormancy and consequently show low or erratic germination. During this time, seed predation, weed competition, soil erosion, and seed viability loss can lead to plant re‐establishment failure. Understanding and considering seed dormancy and germination traits in restoration planning are thus critical to ensuring effective seed management and seed use efficiency. There are five known dormancy classes (physiological, physical, combinational, morphological, and morphophysiological), each requiring specific cues to alleviate dormancy and enable germination. The dormancy status of a seed can be determined through a series of simple steps that account for initial seed quality and assess germination across a range of environmental conditions. In this article, we outline the steps of the dormancy classification process and the various corresponding methodologies for ex situ dormancy alleviation. We also highlight the importance of record‐keeping and reporting of seed accession information (e.g. geographic coordinates of the seed collection location, cleaning and quality information, storage conditions, and dormancy testing data) to ensure that these factors are adequately considered in restoration planning. [ABSTRACT FROM AUTHOR]

Abstract: Studying the seed production of herbaceous species can help to conserve grassland habitats and re‐create new high‐value grassland surfaces. Studies on grassland seed production have focused mainly on individual species and traits, without characterizing their relative importance at the plant community level. The aim of this study was to investigate the entire seed production process of the main species in a temperate grassland. Fertile shoots (FS) of twenty‐nine grasses and forbs were collected over 4 years and analysed for sixteen traits that determine inflorescence size, seed production and seed quality. The per cent viability played a predominant role in determining the total production of viable seeds. Forbs showed a range of reproductive strategies, including variable distribution of flowers among growth periods, number of inflorescences per FS and relationship between seed size and FS density in the grassland. The flower production for grasses was concentrated in the first growth period, but this limitation was mitigated by a higher seed dormancy. The number of viable seeds per FS and seed size were important components of the reproductive strategy of forbs, with heavy‐seeded species being characterised by high individual densities in the community, but producing few seeds per FS. Light‐seeded species showed an opposite pattern. The results suggest that when using seeds from semi‐natural grasslands for ecological restoration, special attention should be paid to the seed amount, germinability and viability of forbs, as they seem to depend more on seed reproduction and have a lower ovule to seed transformation efficiency. [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]

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]

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]

Seed quality for both germination in the next generation and for human consumption is adversely affected due to preharvest sprouting in peanut. It also makes seeds more vulnerable to infection by a number of pathogens. Therefore, it is desirable to have 2-3 weeks of fresh seed dormancy ( FSD) in the peanut varieties. In this context, one F2 population was developed from a cross between non-dormant ( ICGV 00350) and dormant ( ICGV 97045) genotypes. Phenotyping of this population showed control of the trait by two recessive genes. In parallel, genotyping of the population with Diversity Arrays Technology ( DArT) and DArT-seq markers provided a genetic map with 1152 loci covering a map distance of 2423.12 cM and map density of 2.96 cM/loci. Quantitative trait locus ( QTL) analysis identified two major QTLs, namely qfsd-1 and qfsd-2 explaining 22.14% and 71.21% of phenotypic variation, respectively. These QTLs, after validation in different genetic backgrounds, may be useful for molecular breeding for FSD in peanut. [ABSTRACT FROM AUTHOR]

Secondary seed dormancy in oilseed rape is a phenomenon that allows seeds to survive in the soil for many years without germination. Following soil cultivation, dormant seeds may germinate in subsequent years, and they are the main reason for the occurrence of volunteer oilseed rape plants in successive crops. Inheritance of secondary dormancy may be related to seed longevity ( SL) in the soil. Genetic reduction in secondary dormancy and SL could provide a mean to reduce the frequency of volunteer plants and especially the dispersal of transgenic oilseed rape. The aim of the present study was to analyse secondary dormancy, germination rate and SL of 28 black-seeded winter oilseed rape cultivars using in vitro laboratory tests. The material was tested in field experiments at six different locations in Germany in 2008/2009. Significant effects of the genotype and the location on all traits were found. Heritability was high for secondary dormancy (0.97) and moderate for germination rate (0.70) and SL (0.71). Results indicate that a selection for low secondary dormancy would be effective. [ABSTRACT FROM AUTHOR]

Focuses on the 5th Australian Workshop on Native Seed Biology conference held from June 21 to 23, 2004 in Brisbane, Australia. Discussion on seed production, quality and testing issues at the conference; Information on seed dormancy and germination; Investigation on the establishment and management of revegetation in soil seed ecology.