Wild Relatives Research Articles

Integrated gene expression and network analysis identify drought-response genes and pathways in Solanum: a computational study

At times of rapid global climatic changes, refining drought tolerance in tomatoes is a demanding concern. Drought-resistant wild tomato relatives offer a valued resource for studying drought response mechanisms and leveraging them for breeding. To understand drought-response mechanisms in Solanum, we performed an integrated gene expression, transcription factor (TF), and network-based analysis in wild (Solanum pimpinellifolium L.) and cultivated (Solanum lycopersicum L.) tomato species with differing drought tolerance. This integrated analysis unveiled distinct gene expression patterns under drought stress in both species. Ethylene-responsive factors (ERFs) were notably the most significantly expressed transcription factors in both varieties. Additionally, species-specific TF expression was observed, such as Ethylene Insensitive3-like (EIL) and MIKC_MADS in the wild type, and Zinc Finger homeodomain (ZF-HD) in the cultivated variety. Differential expression pattern in ROS rummaging and heat shock proteins was observed in the top DEGs of both species. Network analysis highlighted shared genes involved in crucial pathways like jasmonic acid biosynthesis, the protein kinase pathway, and reactive oxygen species foraging in both species. Notably, the wild variety showed altered expression of genes associated with jasmonic acid/ethylene biosynthesis, antioxidant response, heat shock proteins, and cell wall remodeling. These observations offer insights into the differences in drought response in both species and suggest the role of jasmonic acid/ethylene biosynthesis, antioxidant response and ROS scavenging as significant factors contributing to improved drought tolerance in S. pimpinellifolium.

Wild Genetic Resource in Vegetable Improvement: Applications and Strategies

Domestication of feral types of the present-day cultivated types was in vogue in earlier days of farming followed by the selection and hybridization that led to many improved varieties. Expression of traits faded due to the development of homozygosity due to repeated interventions in the same set. Relying on wild relatives that are found to be the source of many target genes is found significant. While, this is not so easy, because of the barriers that reside in distant hybridization, consequences like failure in zygote and embryo formation, embryo death, linkage drags, and incompatibility within wild and cultivated groups, etc are need of concern. Strategies like bridge crosses, somatic hybridization, grafting, embryo rescue, etc., techniques are solely or in combination can combat these issues. Vegetables are the group of crops that are mainly cultivated for their high returns and quality aspects for the healthy food routine of the consumer. This review will spotlight the recent advances in vegetable improvement through their wild relatives and available strategies to overcome the barriers to the usage of wild relatives in vegetable improvement, meanwhile the conservation of these resources for the future utilization in vegetable improvement.

Rhizosphere Microbiome Co-Occurrence Network Analysis across a Tomato Domestication Gradient.

When plant-available phosphorus (P) is lost from a soil solution, it often accumulates in the soil as a pool of unavailable legacy P. To acquire legacy P, plants employ recovery strategies, such as forming associations with soil microbes. However, the degree to which plants rely on microbial associations for this purpose varies with crop domestication and subsequent breeding. Here, by generating microbial co-occurrence networks, we sought to explore rhizosphere bacterial interactions in low-P conditions and how they change with tomato domestication and breeding. We grew wild tomato, traditional tomato (developed circa 1900), and modern tomato (developed circa 2020) in high-P and low-P soil throughout their vegetative developmental stage. Co-occurrence network analysis revealed that as the tomatoes progressed along the stages of domestication, the rhizosphere microbiome increased in complexity in a P deficit. However, with the addition of P fertilizer, the wild tomato group became more complex, surpassing the complexity of traditional and modern tomato, suggesting a high degree of responsiveness in the rhizosphere microbiome to P fertilizer by wild tomato relatives. By illustrating these changing patterns of network complexity in the tomato rhizosphere microbiome, we can further understand how plant domestication and breeding have shaped plant-microbe interactions.

Irregular green netting of eggplant fruit peel: a domestication trait controlled by SmGLK2 with potential for fruit colour diversification.

The distribution of chlorophylls in eggplant (Solanum melongena) peel exhibits either a uniform pattern or an irregular green netting. The latter, manifested as a gradient of dark green netting intensified in the proximal part of the fruit on a pale green background, is common in wild relatives and some eggplant landraces. Despite the selection of uniform chlorophylls during domestication, the netting pattern contributes to a greater diversity of fruit colours. Here, we have used over 2,300 individuals from different populations, including a multi-parental MAGIC population for candidate genomic region identification, an F2 population for BSA-Seq, and advanced backcrosses for edges-to-core fine-mapping, to identify SmGLK2 gene as responsible for the irregular netting in eggplant fruits. We have also analysed the gene sequence of 178 S. melongena accessions and 22 wild relative species for tracing the evolutionary changes that the gene has undergone during domestication. Three different mutations were identified leading to the absence of netting. The main causative indel induces a premature stop codon disrupting the protein conformation and function, which was confirmed by western blotting analysis and confocal microscopy observations. SmGLK2 has a major role in regulating chlorophyll biosynthesis in eggplant fruit peel.

Surveying and collecting Poaceae and Fabaceae crop wild relatives diversity in Lebanon

Surveying and collecting Poaceae and Fabaceae crop wild relatives diversity in Lebanon

In situ occurrence and conservation of Beta vulgaris subsp. maritima ((L.) Arcangeli) in Italy

IntroductionCrop Wild Relatives (CWR) have great socioeconomic importance for humans harbouring a broad spectrum of diversity and being important elements of different habitats. Beta vulgaris subsp. maritima ((L.) Arcangeli), also known as sea beet, is an important CWR of cultivated beets (GP-1). The high adaptability of this taxon to different environmental conditions, as well as its tolerance/resistance to different biotic and abiotic stresses, makes it a vital source for sugar beet improvement. Aim of this work was to analyse the in situ and ex situ status of sea beet population conservation in Italy, so as to guide protection activities and new collecting missions.MethodsGeographical distribution data of populations were that occur in the wild and conserved in genebanks were assembled from different databases and submitted to data quality control. Distribution, habitat characterization, land cover and use of the involved sites were then evaluated to provide insight into the current condition of areas hosting this CWR diversity. The presence of populations within vs. outside Italian protected areas was also evaluated. A density analysis of the records was performed and the adequateness of sea beet ex situ conservation, in terms of number of conserved accessions, was finally estimated.ResultsA collection of 138 B. vulgaris subsp. maritima high quality georeferenced records were obtained, mainly distributed into Mediterranean Biogeographic Region. About 22% of the considered populations occurs in protected sites of the Natura 2000 Network, while about 15% in areas recorded in the Official list of protected natural areas (EUAP). Occurrences within protected areas are founded primarily in natural environments, whereas those outside are mainly located in urban and cultivated areas. The comparison of distribution and density analysis results revealed the presence of several gaps between sites hosting in situ populations and sites where ex situ conserved accessions were originally collected.DiscussionHere presented data indicates that the protection status for sea beet in Italy can be considered only partially adequate; more proactive protection measures should be foreseen to increase the role of protected areas in safeguarding in situ conservation. “Out of reserve management” for populations outside protected areas should also be developed, as well as new collecting missions carried out.

Origin and evolution of the bread wheat D genome.

Bread wheat (Triticum aestivum) is a globally dominant crop and major source of calories and proteins for the human diet. Compared with its wild ancestors, modern bread wheat shows lower genetic diversity, caused by polyploidisation, domestication and breeding bottlenecks1,2. Wild wheat relatives represent genetic reservoirs, and harbour diversity and beneficial alleles that have not been incorporated into bread wheat. Here we establish and analyse extensive genome resources for Tausch's goatgrass (Aegilops tauschii), the donor of the bread wheat D genome. Our analysis of 46 Ae. tauschii genomes enabled us to clone a disease resistance gene and perform haplotype analysis across a complex disease resistance locus, allowing us to discern alleles from paralogous gene copies. We also reveal the complex genetic composition and history of the bread wheat D genome, which involves contributions from genetically and geographically discrete Ae. tauschii subpopulations. Together, our results reveal the complex history of the bread wheat D genome and demonstrate the potential of wild relatives in crop improvement.

Rapid Screening of Colorado Potato Beetle Resistance Derived from Solanum okadae

Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say) is a major insect pest of potato and development of resistant varieties is part of a strategy for management. Wild relatives of potato are resources for genetic improvement through breeding. Interspecies crosses to introgress CPB resistance will be facilitated with rapid and inexpensive selection methods. Solanum okadae is a novel source of feeding deterrence against the beetle and was associated with production of a naturally occurring leaf-specific lactone-containing metabolite in the foliage. The Baljet assay has been used for decades in pharmaceuticals for rapid screening of lactone-containing compounds. A modified Baljet assay was developed for potato foliar tissue to rapidly screen for lactone-containing compounds in plants from the field, greenhouse, and laboratory. Herein we report the screening of potato foliage for CPB resistance with a Baljet assay validated by CPB larval feeding studies. Foliage from wild accessions of S. okadae were tested using the Baljet assay and results showed that production of the leaf-specific lactones has a large range of variation in the species. In addition, tubers tested using the Baljet assay had negligible levels of lactone-containing metabolites, confirming leaf-specific production of lactones. This inexpensive method using leaf disk screening will allow potato breeders to quickly select for potential CPB resistant germplasms and advance the breeding of sustainable crops.

Wheat domestication alters root metabolic functions to drive the assembly of endophytic bacteria.

The domestication process progressively differentiated wild relatives from modern cultivars, thus impacting plant-associated microorganisms. Endophytic bacterial communities play vital roles in plant growth, development, and health, which contribute to the crop's sustainable development. However, how plant domestication impacts endophytic bacterial communities and relevant root exudates in wheat remains unclear. First, we have observed that the domestication process increased the root endophytic microbial community diversity of wheat while decreasing functional diversity. Second, domestication decreased the endophytic bacterial co-occurrence network stability, and it did significantly alter the abundances of core microorganisms or potential probiotics. Third, untargeted LC-MS metabolomics revealed that domestication significantly altered the metabolite profiles, and the abundances of various root exudates released were significantly correlated with keystone taxa including the Chryseobacterium, Massilia, and Lechevalieria. Moreover, we found that root exudates, especially L-tyrosine promote the growth of plant-beneficial bacteria, such as Chryseobacterium. Additionally, with L-tyrosine and Chryseobacterium colonized in the roots, the growth of wild wheat's roots was significantly promoted, while no notable effect could be found in the domesticated cultivars. Overall, this study suggested that wild wheat as a key germplasm material, and its native endophytic microbes may serve as a resource for engineering crop microbiomes to improve the morphological and physiological traits of crops in widely distributed poor soils.

Dataspace Integration for Agrobiodiversity Digital Twins with RO-Crate

A severe impact of human-induced climate change is the global decrease in crop yields, threatening the United Nations sustainable development goal (SDG) to end hunger, achieve food security, improve nutrition, and promote sustainable agriculture (SDG 2: “Zero Hunger Goal”). Decision-making on appropriate mitigation strategies requires data integration from heterogeneous data-rich contexts including Earth observation (EO), biodiversity monitoring, gene banks as well as socio-economic data. Accordingly, large-scale initiatives for thematic data spaces, such as the European projects Destination Earth (DestinE) and the Green Deal Data Space, have been launched. Underutilized crops and crop wild relatives (CWR) can contribute to mitigating the impacts of climate change since their greater genetic diversity allows adaptation of agro-food sources to extreme weather events such as flooding and drought or emerging crop pests. Within the framework of Biodiversity Digital Twin (BioDT), a prototype digital twin for crop genetic resources modeling is under development. This prototype combines the scanning of genetic resources of CWRs and traditional cultivars for promising pest resistance and abiotic tolerance traits with advanced species distribution modeling and actual climate scenarios from EO. The aim is to generate habitat suitability maps and identify potential areas where relevant populations are potentially growing (Chala et al. 2024). The talk gives an overview of data models used to facilitate the required interoperability of both Earth models and environmental data within and across different data spaces such as the DestinE Data Lake (Duatis Juarez et al. 2023). Based on our findings from the use case of agrobiodiversity digital twins, we will discuss approaches for processing machine-actionable digital objects (Fig. 1) containing workflow information (i.e., in the Common Workflow Language format, Crusoe et al. 2022), and for sharing resulting research data in a FAIR (Findable, Accessible, Interoperable, and Reusable) manner by leveraging on so-called webby FAIR Digital Objects involving Research Object Crate (RO-Crate, Soiland-Reyes et al. 2022), FAIR Signposting (Soiland-Reyes et al. 2024) and schema.org and its Bioschemas extension respectively (Castro et al. 2020),

Genetic Control of Effective Seedling Leaf Rust Resistance in Aegilops biuncialis Vis. Accessions from the VIR Collection.

Leaf rust (caused by Puccinia triticina Erikss., Pt) is a severe foliar disease of cultivated wheat worldwide. Severe development of the disease results in significant losses in seed yield and quality. Growing immune varieties is the most rational method for Pt control in terms of effectiveness and ecological safety. However, the gene pool of cultivated wheat is very narrow for seedling Pt effective resistance genes, which hampers breeding for this trait. One of the well-known methods to broaden genetic diversity for resistance is the introgression of highly effective genes from wild relatives into the genomes of cultivated wheat. The Aegilops L. species have been proven to be perfectly suited for this purpose. No gene for Pt resistance has been transferred to wheat from Aegilops biuncialis Vis. (Lorent's goatgrass) up to now. Previously, we selected eight accessions of the species from the VIR (N.I. Vavilov All-Russian Institute of Plant Genetic Resources) genebank that showed a perfect level of resistance to leaf rust. In this research, we studied the genetic control of resistance using hybridological, phytopathological, and molecular analyses. According to the F1-F3 hybrid evaluation results, each accession possesses one dominant gene for Pt resistance, and genes in different accessions are allelic or very tightly linked. Phytopathological test clone analysis showed that this gene is not identical to Lr9, Lr19, Lr24, Lr39, and Lr47, which are effective against Pt populations in some areas of Russia. This conclusion was partially supported by the results of the identification of DNA markers specific to these genes in bread wheat. Thus, we identified one dominant gene (temporarily symbolized as LrBi1) for effective seedling Pt resistance; it is recommended for introgression to cultivated wheat via interspecific hybridization.

Modeling the richness and spatial distribution of the wild relatives of Iranian pears (Pyrus L.) for conservation management

The preservation of the genetic resources of crop wild relatives (CWRs) is crucial for food production systems and is considered a vital measure for global agricultural health and food security. The identification of potential areas where CWRs can thrive is one of the first steps towards their conservation. In this study, we used a maximum entropy model (MaxEnt) to determine the habitat suitability of seven wild relatives of pears (Pyrus L.) for the first time. We aimed to identify high-priority areas for conservation and determine the hotspots for rich biodiversity in Iran. The study showed excellent predictive performance for all species studied (AUC value ≥ 90). The soil depth, solar radiation, minimum temperature of the coldest month (Bio6), and precipitation of the wettest quarter (Bio16) were the main environmental factors that influenced the habitat suitability of all seven species, according to permutation importance. The projected maps revealed that P. elaeagnifolia had the largest suitable habitat area, while P. glabra had the lowest. The results also showed that less than 5% of the suitable habitats for these seven species were in protected areas. This research highlights the need for national preservation policies and the development of cultivation and rehabilitation strategies for these threatened species.

Convergent evolution of plant prickles by repeated gene co-option over deep time.

An enduring question in evolutionary biology concerns the degree to which episodes of convergent trait evolution depend on the same genetic programs, particularly over long timescales. In this work, we genetically dissected repeated origins and losses of prickles-sharp epidermal projections-that convergently evolved in numerous plant lineages. Mutations in a cytokinin hormone biosynthetic gene caused at least 16 independent losses of prickles in eggplants and wild relatives in the genus Solanum. Homologs underlie prickle formation across angiosperms that collectively diverged more than 150 million years ago, including rice and roses. By developing new Solanum genetic systems, we leveraged this discovery to eliminate prickles in a wild species and an indigenously foraged berry. Our findings implicate a shared hormone activation genetic program underlying evolutionarily widespread and recurrent instances of plant morphological innovation.

A kinase fusion protein from Aegilops longissima confers resistance to wheat powdery mildew

Many disease resistance genes have been introgressed into wheat from its wild relatives. However, reduced recombination within the introgressed segments hinders the cloning of the introgressed genes. Here, we have cloned the powdery mildew resistance gene Pm13, which is introgressed into wheat from Aegilops longissima, using a method that combines physical mapping with radiation-induced chromosomal aberrations and transcriptome sequencing analysis of ethyl methanesulfonate (EMS)-induced loss-of-function mutants. Pm13 encodes a kinase fusion protein, designated MLKL-K, with an N-terminal domain of mixed lineage kinase domain-like protein (MLKL_NTD domain) and a C-terminal serine/threonine kinase domain bridged by a brace. The resistance function of Pm13 is validated through transient and stable transgenic complementation assays. Transient over-expression analyses in Nicotiana benthamiana leaves and wheat protoplasts reveal that the fragment Brace-Kinase122-476 of MLKL-K is capable of inducing cell death, which is dependent on a functional kinase domain and the three α-helices in the brace region close to the N-terminus of the kinase domain.

Wheat genetic resources have avoided disease pandemics, improved food security, and reduced environmental footprints: A review of historical impacts and future opportunities.

The use of plant genetic resources (PGR)-wild relatives, landraces, and isolated breeding gene pools-has had substantial impacts on wheat breeding for resistance to biotic and abiotic stresses, while increasing nutritional value, end-use quality, and grain yield. In the Global South, post-Green Revolution genetic yield gains are generally achieved with minimal additional inputs. As a result, production has increased, and millions of hectares of natural ecosystems have been spared. Without PGR-derived disease resistance, fungicide use would have easily doubled, massively increasing selection pressure for fungicide resistance. It is estimated that in wheat, a billion liters of fungicide application have been avoided just since 2000. This review presents examples of successful use of PGR including the relentless battle against wheat rust epidemics/pandemics, defending against diseases that jump species barriers like blast, biofortification giving nutrient-dense varieties and the use of novel genetic variation for improving polygenic traits like climate resilience. Crop breeding genepools urgently need to be diversified to increase yields across a range of environments (>200 Mha globally), under less predictable weather and biotic stress pressure, while increasing input use efficiency. Given that the ~0.8 m PGR in wheat collections worldwide are relatively untapped and massive impacts of the tiny fraction studied, larger scale screenings and introgression promise solutions to emerging challenges, facilitated by advanced phenomic and genomic tools. The first translocations in wheat to modify rhizosphere microbiome interaction (reducing biological nitrification, reducing greenhouse gases, and increasing nitrogen use efficiency) is a landmark proof of concept. Phenomics and next-generation sequencing have already elucidated exotic haplotypes associated with biotic and complex abiotic traits now mainstreamed in breeding. Big data from decades of global yield trials can elucidate the benefits of PGR across environments. This kind of impact cannot be achieved without widescale sharing of germplasm and other breeding technologies through networks and public-private partnerships in a pre-competitive space.

Cultivated plants and their wild relatives of Central Russia and the North Caucasus (results of a collecting mission of 2023)

In 2023, field explorations of cultivated plants and their wild relatives were carried out in the regions of the Volga Upland, the western part of the Caspian Lowland and the Stavropol Upland with the aim of further replenishing seed and herbarium collections of VIR.A total of 525 samples of CWR and cultivated plants were collected, including 200 are herbarium sheets, 323 seed samples of cultivated plants and CWR, and a couple of cuttings. The collected material encompasses 145 species, including 91 cultivars. Seeds of the cultivars were purchased at markets, in supermarket chains and from local residents. The following areas were examined in detail: the left bank of the Lower Volga (Peschany anabranch, Kigach anabranch, as well as the “Novaya Roshcha” protected area). In the Republic of Ingushetia the team collected samples of cherry plum, Caucasian pear, barberry, viburnum, Lonicera orientalis, sea buckthorn, raspberry, and Malus orientalis, which local residents use in their diet. Also, samples of spicy herbs such as savory, catnip, oregano, thyme, etc. were collected. Hops were sampled in the Tambov and Volgograd provinces, the Republics of Ingushetia, North Ossetia and Adygea, from abandoned household plots in Botanika village in Gulkevichi District (Krasnodar Territory). The exploration in vicinities of Derbent and of the wall of Naryn-Kala fortress in Derbent resulted in collecting a rare specimen of Secale sylvestre Host., which previously used to be a fairly common plant in the North Caucasus, but is very rare now. Vegetable crops were collected along the entire route of the collecting mission. It was not always possible to collect seeds, so a part of the material enriched the herbarium collection. The collected material reflects the use of a vast range of vegetable and spicy plant species by the local population.Collecting missions help to understand which species are of primary importance for the conservation of natural processes, biodiversity and the maintenance of local ecosystems. The genetic diversity of a region is a key object of research for geneticists and plant breeders. Landraces of vegetable, cereal and other crops may have unique properties, such as adaptation to local climate conditions or disease resistance. Work on the mobilization and conservation of the plant genetic diversity is the basis for modern breeding and genetic research.

Deciphering desiccation tolerance in wild eggplant species: insights from chlorophyll fluorescence dynamics

BackgroundClimate change exacerbates abiotic stresses, which are expected to intensify their impact on crop plants. Drought, the most prevalent abiotic stress, significantly affects agricultural production worldwide. Improving eggplant varieties to withstand abiotic stress is vital due to rising drought from climate change. Despite the diversity of wild eggplant species that thrive under harsh conditions, the understanding of their drought tolerance mechanisms remains limited. In the present study, we used chlorophyll fluorescence (ChlaF) imaging, which reveals a plant’s photosynthetic health, to investigate desiccation tolerance in eggplant and its wild relatives. Conventional fluorescence measurements lack spatial heterogeneity, whereas ChlaF imaging offers comprehensive insights into plant responses to environmental stresses. Hence, employing noninvasive imaging techniques is essential for understanding this heterogeneity.ResultsDesiccation significantly reduced the leaf tissue moisture content (TMC) across species. ChlaF and TMC displayed greater photosystem II (PSII) efficiency after 54 h of desiccation in S. macrocarpum, S. torvum, and S. indicum, with S. macrocarpum demonstrating superior efficiency due to sustained fluorescence. PSII functions declined gradually in S. macrocarpum and S. torvum, unlike those in other species, which exhibited abrupt declines after 54 h of desiccation. However, after 54 h, PSII efficiency remained above 50% of its initial quantum yield in S. macrocarpum at 35% leaf RWC (relative water content), while S. torvum and S. indicum displayed 50% decreases at 31% and 33% RWC, respectively. Conversely, the susceptible species S. gilo and S. sisymbriifolium exhibited a 50% reduction in PSII function at an early stage of 50% RWC, whereas in S. melongena, this reduction occurred at 40% RWC.ConclusionOverall, our study revealed notably greater leaf desiccation tolerance, especially in S. macrocarpum, S. torvum, and S. indicum, attributed to sustained PSII efficiency at low TMC levels, indicating that these species are promising sources of drought tolerance.

The Impact of Pre-Breeding on Vegetable Crop Improvement: A Review

Pre-breeding begins with the finding of beneficial genes from wild relatives, native species, and various other unadapted materials. These advantageous qualities are subsequently transferred to a moderate pool of resources so that breeders can create new varieties for farmers. With the process of discovering useful characteristics, preserving their genetic diversity, and incorporating these genes into a form that can be used, crop improvement innovation is generated. Connecting genetic diversity from wild relatives along with other uncontrolled sources is the main goal. Pre-breeding strategies aim to introduce genes for tolerance to environmental difficulties and resistance to major diseases and pests from wild relatives into cultivated crops using the application of introgression and integration procedures. Pre-breeding provides the base for commercially important techniques for plant breeding by broadening the diversity of germplasm and providing breeders with easily accessible resources to breeding beneficial characteristics, while adhering to the basic concepts of the field. The comprehensive discussion of pre-breeding is a valuable resource for scientists and researchers alike, addressing all aspects of this crucial phase in improving vegetable crops.

Chía and its wild relatives: A superfood Salvia (Lamiaceae)

Societal Impact StatementAlternative crops are a promising approach to address the global food shortage that is exacerbated by climate change and wealth disparities. Some of these alternative crops are traditional food plants that have been widely traded for centuries, whereas others have only recently become more popular. Chía is a traditional native “superfood” that is the fruit of three distinct mint species. Chía (Salvia hispanica) is commercially cultivated and shares nutritional properties with California thistle sage (Salvia carduacea) and desert chía (Salvia columbariae). These wild relatives of S. hispanica are adapted to arid conditions and have potentially valuable genetic variation for the development of chía agricultural varieties. The development of nutritious, drought‐tolerant crops such as chía will increase the resilience of people to the impact of climate upheaval.SummaryIn the Spanish language, the word chía refers to the nutlet fruits of several Salvia species native to Mesoamerica. The process of domestication of S. hispanica altered several traits, including the absence of shattering fruits, which makes harvest easier and mechanizable. S. hispanica is commercially cultivated in Mexico, South America, Australia, and less so in Europe and Africa. Other edible chía species are not commercially cultivated, including S. carduacea, and S. columbariae. These Californian chías are traditionally harvested by hand since the fruiting calices shatter and release the nutlets. Here we compare these three edible chía species, review their uses by native peoples, describe their morphology, summarize their natural distributions and cultivation, and provide an identification key. Native peoples in North America have traditionally used chías for food, medicine, and oil. S. hispanica naturally occurs throughout areas of Mexico that receive summer monsoonal rains. As such, it is a summer annual with an erect habit and cauline, simple leaves. In contrast, the Californian chía species are distributed through areas of the Mojave and Sonoran deserts that receive winter rains. They are winter annuals and their rosettes of lobed, pubescent leaves are typical adaptations to arid conditions. Nutlets in these chía species are similar when dry, but cultivated S. hispanica nutlets produce extensive mucilage when wetted, while the other chía produce mucilage to a lesser extent. As consumer interest grows in superfoods like chía, crop breeders may use wild chía to breed varieties appropriate for areas affected by drought or in desert agroecological systems.

Cold tolerance of woodland strawberry (Fragaria vesca) is linked to Cold Box Factor 4 and the dehydrin Xero2.

Domesticated strawberry is susceptible to sudden frost episodes, limiting the productivity of this cash crop in regions where they are grown during early spring. In contrast, the ancestral woodland strawberry (Fragaria vesca) has successfully colonized many habitats of the Northern Hemisphere. Thus, this species seems to harbour genetic factors promoting cold tolerance. Screening a germplasm established in the frame of the German Gene Bank for Crop Wild Relatives, we identified, among 70 wild accessions, a pair with contrasting cold tolerance. By following the physiological, biochemical, molecular, and metabolic responses of this contrasting pair, we identified the transcription factor Cold Box Factor 4 and the dehydrin Xero2 as molecular markers associated with superior tolerance to cold stress. Overexpression of green fluorescent protein fusions with Xero2 in tobacco BY-2 cells conferred cold tolerance to these recipient cells. A detailed analysis of the metabolome for the two contrasting genotypes allows the definition of metabolic signatures correlated with cold tolerance versus cold stress. This work provides a proof-of-concept for the value of crop wild relatives as genetic resources to identify genetic factors suitable to increase the stress resilience of crop plants.