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

The Adapting Agriculture to Climate Change Project set out to improve the diversity, quantity, and accessibility of germplasm collections of crop wild relatives (CWR). Between 2013 and 2018, partners in 25 countries, heirs to the globetrotting legacy of Nikolai Vavilov, undertook seed collecting expeditions targeting CWR of 28 crops of global significance for agriculture. Here, we describe the implementation of the 25 national collecting programs and present the key results. A total of 4587 unique seed samples from at least 355 CWR taxa were collected, conserved ex situ, safety duplicated in national and international genebanks, and made available through the Multilateral System (MLS) of the International Treaty on Plant Genetic Resources for Food and Agriculture (Plant Treaty). Collections of CWR were made for all 28 targeted crops. Potato and eggplant were the most collected genepools, although the greatest number of primary genepool collections were made for rice. Overall, alfalfa, Bambara groundnut, grass pea and wheat were the genepools for which targets were best achieved. Several of the newly collected samples have already been used in pre-breeding programs to adapt crops to future challenges.

Wild Edible Plants (WEPs) still play a vital role in the subsistence of many traditional communities, while they are receiving increasing recognition in tackling food security and nutrition at the international level. This paper reviews the use patterns of native WEPs in Chile and discusses their role as future crops and sources of food products. We conducted an extensive literature review by assessing their taxonomic diversity, life forms, consumption and preparation methods, types of use (traditional and modern), and nutritional properties. We found that 330 native species were documented as food plants, which represent 7.8% of the total flora of Chile. These species belong to 196 genera and 84 families. The most diverse families are Asteraceae (34), Cactaceae (21), Fabaceae (21), Solanaceae (20) and Apiaceae (19), and the richest genera in terms of number of species are Solanum (9), Ribes (8), Berberis (7), Hypochaeris (7) and Oxalis (6). Perennial herbs are the predominant life form (40%), followed by shrubs (35%), trees (14%), and annual and biannual herbs (11%). Fruits (35.8%), roots (21.5%) and leaves (20.0%) are the parts of plants consumed the most. Nine different food preparation categories were identified, with ‘raw’ forming the largest group (43%), followed by ‘beverages’ (27%), ‘savoury preparations’ (27%), and ‘sweet’ (13%). Almost all native Chilean WEPs have reported traditional food uses, while only a few of them have contemporary uses, with food products mainly sold in local and specialised markets. Species’ richness, taxonomic diversity and family representation have similar patterns to those observed for the world flora and other countries where surveys have been carried out. Some Chilean native WEPs have the potential to become new crops and important sources of nutritious and healthy products in the food industry. However, there are still many gaps in knowledge about their nutritional, anti-nutritional and biochemical characteristics; future research is recommended to unveil their properties and potential uses in agriculture and the food industry.

Recalcitrant seeds are characterized by desiccation and freezing sensitivity, and short storage longevity. These physiological attributes obviate their ex situ conservation in conventional seed banks, where seeds are stored dry at sub-zero temperatures (typically, 15% relative humidity and –20°C) for extended periods of time. Propagation of plants for field collections (e.g., botanical gardens, nurseries, and arboretums) is a valuable ex situ conservation option. However, these collections are relatively costly, require high maintenance, preserve limited genetic diversity and/or are directly exposed to biotic (e.g., pests) and abiotic (e.g., climatic) threats. Therefore, recalcitrant-seeded (RS) species are dependent on cryopreservation for their safe and long-term ex situ conservation. Different explant sources such as whole seeds, zygotic embryos, dormant buds, shoot tips, and pollen, can be used for plant propagation of RS species in field collections as well as for their cryopreservation. The success of the propagation or the cryopreservation of these explants often depends on their developmental status, vigor, and/or tolerance to desiccation and chilling/freezing. These attributes are modulated by the environment where the donor plant grows and we hypothesize that climate change, by affecting these biological attributes, would impact the success of explant propagation and cryopreservation. To support this hypothesis, we have reviewed how temperature changes and drought, the two main climate change scenarios, affect the main biological attributes that are directly involved in the success of ex situ conservation of tropical and temperate RS species. In general, increases in temperature and drought will negatively affect plant development in field collections and the quality of the explants used in cryopreservation. Consequently, field collections of RS species may need to be moved to more suitable places (e.g., higher latitudes/altitudes). Additionally, we may find a reduction in the success of cryopreservation of RS species germplasm directly harvested from field collections. However, we cannot always generalize these effects for all species since they often depend on the origin of the species (e.g., tropical and temperate species tend to respond to climate change differently), the genotype, the adaptive genetic potential of each population, and the severity of the environmental change. On the other hand, the increase in temperatures and water stress in donor plants at high-latitude areas and also some tropical environments may favor the production of seeds and seedlings better adapted to drying, and hence, increase the success of plant propagation and zygotic embryo cryopreservation.

Positive interactions among plants, such as the nurse effect, can attenuate environmental stress (e.g., drought) or reduce the intensity of perturbations (e.g., herbivory), thus enhancing the possibility of regeneration in natural systems. This study analyses the potential use of nurse plants for restoring artificial environments, such as mine hard-rock dumps. We evaluated seedling recruitment and survival in open areas and beneath the canopy of nurse shrubs, with and without grazing exclusion, on an abandoned copper tailings storage facility in north-central Chile. The nurse species was Baccharis linearis (Asteraceae), and seedling species were B. linearis, Haplopappus parvifolius (Asteraceae), Schismus arabicus (Poaceae), and several forb/grass taxa. A field survey showed that seedlings of all species were more abundant beneath the Baccharis shrub canopy coverage than in the open spaces between shrubs. Only Baccharis seedlings produced a significant difference. We found a decreasing sequence of seedling survival under the following conditions: beneath the Baccharis canopy with herbivore exclusion, beneath the canopy without exclusion, in the open field with exclusion, and finally, in the open field without exclusion. Substrates beneath shrubs had higher P and K levels at depths < 10 cm than substrates in open areas. Water content, substrate compaction, and plant diversity did not differ between microenvironments. Our results demonstrate the importance of both the nurse effect and herbivore exclusion in enhancing seedling establishment on abandoned mine tailings storage facilities in semi-arid north-central Chile. Thus shedding light upon the ecological restoration possibilities in such disturbed environments.