Due to shared geological history and proximity, the flora of New Caledonia is closely linked to other Gondwanan land fragments such as Australia and New Zealand. Many predominant Australian groups are well represented within the New Caledonian flora, including the genera Hibbertia (23 species) and Scaevola (10 species). Previous studies have found that these two genera in particular have a marked positive germination response to smoke products, although all previous studies have centred on Australian species from fire-prone environments. In this present study, we test the hypothesis that two New Caledonian species of Hibbertia and Scaevola are smoke responsive even though the climate and ecological drivers in New Caledonia are in many respects fundamentally different from those of most of Australia. Preliminary results showed that germination of Hibbertia pancheri was significantly accelerated in response to smoke water while germination in Scaevola montana was also significantly enhanced. To the best of our knowledge, this is the first time that these trends have been illustrated for any New Caledonian species and these results will enhance restoration efforts of ultramafic scrublands impacted by mining activities in New Caledonia.

The strong mechanistic relationship between climatic factors and seed dormancy and germination suggests that forecast climatic changes will significantly affect seed bank persistence. This review focuses on the potential impact of changing temperature, rainfall and fire regimes on the longevity of long-term persistent seed-banks. Currently, there are few studies investigating the mechanistic responses of demographic processes, such as seed-bank dynamics, to forecast climate change. However, from the work that has been published, several key points have been highlighted. First, increased air temperatures will produce significantly higher soil temperatures in open and sparsely vegetated habitats. Some evidence shows that this could accelerate the decline of seed viability and compromise bet-hedging strategies of species in dryland regions. Second, changes to rainfall season may determine the relative success of recruitment, with lower levels of success producing net losses to seed bank longevity. Finally, higher temperatures are likely to produce increased fire frequency, compromising the persistence of plant populations dependent on long-lived seed banks. Improving our understanding of both the mechanistic response and adaptive capacity of seed banks to climate change will provide a solid basis for improved predictions of future species distributions and risk of extinction, particularly in ecosystems subjected to temporally stochastic disturbances. It is necessary to develop functional groups based on key life-history trait responses to changing environmental conditions, to enable broader-scale predictions of distribution and persistence in the future.

Methods of evaluation of seed quality providing accurate prediction of seed performance under field conditions are needed by the seed industry. Various physiological tests, i.e. germination tests in suboptimal conditions of temperature, oxygenation and water potential of the medium, or accelerated ageing and controlled deterioration allow sensitive differentiation between seed lots. A better understanding of the biochemical, cellular and molecular mechanisms involved in the acquisition of seed vigour during seed development, in the germination process and in seed deterioration during ageing could suggest various markers of seed quality. Among these markers, electrolyte leakage and ethylene production during imbibition, cell-cycle markers (DNA replication, β-tubulin), soluble sugar metabolism (in particular, changes in the raffinose family of oligosaccharides), proteins (11S globulin B-subunit, late embryogenesis abundant protein, heat-shock protein) and the efficiency of reactive oxygen species scavenging through antioxidant defence systems (e.g. catalase activity) have potential for the evaluation of the state of seed maturity, seed performance and effectiveness of seed priming treatments. Use of global approaches such as transcriptomic, proteomic or metabolomic analysis could also result in the identification of new markers.

Seed quality standards enable seed users to achieve their objectives in the establishment of uniform seedlings to a high and reliable level for a range of agricultural and horticultural crops, growing systems and market outlets. Quality standards of commercial seed lots are determined by their positions on the seed survival curves and the shape of their germination progress curves. Although comparative descriptions of germination curves can be achieved by the calculation of the mean germination time (MGT; delay to radicle emergence), single early counts of radicle emergence provide a convenient means of predicting MGT and differences between seed lots. Evidence is presented for an ageing and metabolic repair hypothesis as the overall physiological basis to explain the principles behind the standard germination and vigour tests (ageing, electrolyte leakage, cold test, germination rate and seedling size). The work of the International Seed Testing Association (ISTA) in developing convenient, inexpensive and internationally repeatable tests is illustrated.

The Brazilian literature on seed germination testing of tropical forest species, although still insufficient, is extensive for species with economical potential. However, this information is still fragmented and often reported in scientific communications of modest circulation. In this summary, we present the results of a validation process for germination tests on Brazilian forest species, which had as a starting point the ample reviewing of current methods, besides exhaustive pre-testing in certified laboratories. Specific protocols were created for each species, including substrate, temperature, seed disinfection, breaking of dormancy, seedling classification and other information. These protocols were sent to research laboratories and accredited by the Ministry of Agriculture, together with seed lots of three distinct qualities. The presuppositions of normality of the residuals and homoscedasticity of the variations were previously tested and the completely randomized factorial design statistical model was applied to the normal seedlings of each species. After this analysis, germination test methods for seeds of Astronium fraxinifolium, Ceiba speciosa, Cybistax antisyphilitica, Enterolobium contortisiliquum, Guazuma ulmifolia, Lafoensia pacari, Mimosa caesalpiniaefolia, Peltophorum dubium, Pseudobombax tomentosum and Pterogyne nitens, all forest species of different Brazilian biomes, were considered to be validated.

Winter rape has a life cycle which necessitates rapid testing of seed quality for the seed production sector, namely between July after harvest of the previous crop and August when the next crop establishment begins. As this crop is the fourth most important crop in France, and the most important oilseed crop, the French seed testing station GEVES has managed several research programmes to study seed quality in this species. These collaborative programmes have not only associated seed science with seed technology but also informatics and electronic engineering to provide seed testing tools that are already used by the seed sector, such as conductivity, or innovative tools, such as germination time courses monitored by computer imaging. Forthcoming tools have also been looked at in order to control seed storage potential, which is often used nowadays to anticipate the next season. Biochemical markers have been studied, including seed-specific biotinylated proteins or enzymes involved in free radical (reactive oxygen species) scavenging, such as catalase. Both are well correlated with seed ageing and have been tested to provide an ELISA-like assay for seed testing laboratories. Germination monitoring by computer imaging is now used by research and breeding institutes to phenotype varying seed material, including genotype or mutant collections, primed or ageing seed lots, etc. The next step in seed quality testing in oilseed rape is to characterize variation in germination and seed vigour in order to stabilize optimal yield. This aim constitutes a new international project involving high-throughput phenotyping and genotyping of a large collection of genetically diverse rapeseed genotypes (double haploid populations or diverse cultivars).

Seed treatments are used globally on a wide range of field, vegetable and ornamental seeds, for efficient early season control of insects and diseases. However, specific seed-treatment compounds may be phytotoxic and this phytotoxicity is most acute in laboratory germination tests. Several strategies have been developed to alleviate seed-treatment phytotoxicity that include spatial separation of the pesticide from the seed. This can be accomplished by the application of the active compounds at the end of pelleting or by using a two-pellet system, termed ‘smart-pill technology’. Another approach is to detoxify or adsorb the agrochemical in a standard germination test by applying a peat medium over the seeds in a roll towel or blotter test. Many new seed-treatment chemicals have systemic activity, and the efficacy of these systemic seed treatments depends on the ability of these applied chemical compounds to be absorbed, and then transported in the developing plant. The present article describes seed-coat permeability to systemic seed treatments, examined by monitoring the movement of fluorescent tracers into intact seeds during imbibition. Two moderately lipophilic, fluorescent tracers have been used – rhodamine (ionic) and coumarin (non-ionic) – which differ mainly in electrical charge. Seed-coat permeabilities of particular species have been grouped into three categories: (1) permeable to both tracers; (2) selectively permeable to only coumarin; and (3) non-permeable to both tracers. The ability of a particular compound to diffuse through the seed coat is related to the chemical nature of the seed-covering tissues and the physico-chemical properties of the compound applied.