Crop Wild Relatives Research Articles

A membrane associated tandem kinase from wild emmer wheat confers broad-spectrum resistance to powdery mildew

Crop wild relatives offer natural variations of disease resistance for crop improvement. Here, we report the isolation of broad-spectrum powdery mildew resistance gene Pm36, originated from wild emmer wheat, that encodes a tandem kinase with a transmembrane domain (WTK7-TM) through the combination of map-based cloning, PacBio SMRT long-read genome sequencing, mutagenesis, and transformation. Mutagenesis assay reveals that the two kinase domains and the transmembrane domain of WTK7-TM are critical for the powdery mildew resistance function. Consistently, in vitro phosphorylation assay shows that two kinase domains are indispensable for the kinase activity of WTK7-TM. Haplotype analysis uncovers that Pm36 is an orphan gene only present in a few wild emmer wheat, indicating its single ancient origin and potential contribution to the current wheat gene pool. Overall, our findings not only provide a powdery mildew resistance gene with great potential in wheat breeding but also sheds light into the mechanism underlying broad-spectrum resistance.

High levels of genetic variation and differentiation in wild tropical gourds provide a novel resource for cucurbit crop improvement

Social Impact StatementThe genetic variation of crop wild relatives will be key for our survival, as environmental change represents an increasing global threat for agriculture and food security. Cucurbita lundelliana and Cucurbita okeechobeensis subsp. martinezii are wild relatives of cultivated squashes and pumpkins that could be used for crop improvement. A genomic approach was used to characterize genetic resources in these taxa, that is, to identify candidate sites in the genome involved in responses to abiotic stress, and to understand the roles of gene flow and environmental differentiation in their divergence. This study highlights the importance of conserving these two species as phytogenetic resources for crop improvement.Summary Crop wild relatives (CWR) are reservoirs of genetic diversity and they are important for the maintenance of crop evolutionary potential. Mexico is the centre of domestication and diversity for many CWR. The genus Cucurbita originated in America, where at least six independent domestication events took place. Nonetheless, Cucurbita CWR have been seldom studied. In the present study, we test the role of incomplete lineage sorting (ILS) and secondary contact in the divergence of C. okeechobeensis subsp. martinezii and C. lundelliana. Additionally, we seek to understand the role of environmental differentiation in their divergence. We obtained 1,638 single nucleotide polymorphisms (SNPs) for 107 individuals from the most recently diverged wild species in this genus, encompassing 25 localities of C. lundelliana and nine localities of C. okeechobeensis subsp. martinezii in Mexico. We found higher genetic variation in C. lundelliana (HE = 0.227) than in C. okeechobeensis subsp. martinezii (HE = 0.187). Each taxon constitutes a well‐differentiated genetic group, with an area of introgression in Pantanos de Centla. We found candidate loci associated to hydric and thermal stress, which could be valuable for crop improvement. Our study supported a scenario of ILS followed by secondary contact, where divergence was probably driven by Pleistocene climate change. These CWR represent important phytogenetic resources for crop improvement given their high levels of genetic variation and differentiation and their SNPs associated to different climatic variables.

Nutritional value and functional properties of an underexploited Tunisian wild beet (Beta macrocarpa Guss.) in relation to soil characteristics

AbstractThe study centers on the valorization of Beta macrocarpa Guss., an endangered Mediterranean wild plant that grows in Tunisia. This plant is disappearing due to a reduction in marginal areas and a lack of awareness of this important crop wild relative (CWR). This prompted us to carry out work to assess the nutritional and functional value of its plant shoots in relation to physicochemical soil properties at three different Tunisian sites covering the north (Sijoumi), the center (Enfidha) and the south (Kerkennah) of the country. All soil samples showed an alkaline pH and high salinity. Sijoumi, Enfidha and Kerkennah soils were classified as loamy, silty clay loamy and sandy, respectively. Chemical analysis revealed that all soils, especially the sandy one, were low in total nitrogen, organic matter and microelements. Plant analysis showed that shoots harvested from the loamy soil presented the highest levels of carbohydrate (19.1 g/100 g FW) and fiber (6.1 g/100 g FW) and the greatest energetic value (94 kcal/100 g FW), whereas shoots collected from the sandy soil showed the highest contents of protein (4.1 g/100 g FW), ash (5.2 g/100 g FW), total polyphenols and flavonoids (39.01 mg GAE/g DW; 27.8 mg CE/g DW), and the greatest DPPH scavenging capacity (IC50 = 0.74 mg/ml). The results suggest that Beta macrocarpa, which naturally grows in poor and salt-affected soils, could play a crucial role in maintaining the biodiversity and sustainability of agro-ecosystems, particularly in marginal areas, and could also provide an alternative source of food with significant nutritional value and health benefits. Graphical abstract

Soil diversity metabarcoding from cacao crop wild relatives in a tropical biodiversity hot spot in Colombia

ABSTRACT Theobroma cacao, the source for chocolate fabrication, is a high-value crop that faces challenges such as the impact of climate change, pathogens, and cadmium accumulation. Soil associated with T. cacao has been extensively studied, looking for bio-controllers and microorganisms capable of Cd accumulation. However, there is no information about the microbial structure and interactions occurring in soil associated with cacao wild relatives, which represent a repository for biological diversity and its potential for biotechnological applications. We performed an extracellular DNA metabarcoding on soil samples associated with Theobroma spp. and Herrania sp. plants in two localities of the Biogeographic Chocó. We found microbial high diversity indexes and no correlation with plants or sampling locations. Potential cacao pathogens and bio-controllers and unexpected differences in the physicochemical soil properties from close locations were detected. Cadmium, an important economic factor for the commercialization of cacao products, showed significant differences between locations associated with a particular Theobroma species. We discuss some important relationships with soil physicochemical properties, the urgent need to complete the missing information on the diversity of bacterial, fungal and insect groups, and the potential of comprehensive analyses for decision-making regarding land-use and vocation. Also, we did not find the only T. hylaeum tree after three years, evincing the urgent need for conservation strategies in Colombia’s Chocó region.

Intensified Selection, Elevated Mutations, and Reduced Adaptation Potential in Wild Barley in Response to 28 Years of Global Warming

Many studies have investigated the threat of climate change on wild plants, but few have investigated the genetic responses of crop wild relative populations under threat. We characterized the genetic responses of 10 wild barley (Hordeum spontaneum K. Koch) populations in Israel, sampling them in 1980 and again in 2008, through exome capture and RNA-Seq analyses. Sequencing 48 wild barley samples of these populations representing two collection years generated six million SNPs, and SNP annotations identified 12,926 and 13,361 deleterious SNPs for 1980 and 2008 samples, respectively. The assayed wild barley samples displayed intensified selective sweeps and elevated deleterious mutations across seven chromosomes in response to 28 years of global warming. On average, the 2008 samples had lower individual and population mutational burdens, but the population adaptation potential was estimated to be lower in samples from 2008 than in 1980. These findings highlight the genetic risks of losing wild barley under global warming and support the need to conserve crop wild relatives.

Greater ecophysiological stress tolerance in the core environment than in extreme environments of wild chickpea (Cicer reticulatum)

Global climate change and land use change underlie a need to develop new crop breeding strategies, and crop wild relatives (CWR) have become an important potential source of new genetic material to improve breeding efforts. Many recent approaches assume adaptive trait variation increases towards the relative environmental extremes of a species range, potentially missing valuable trait variation in more moderate or typical climates. Here, we leveraged distinct genotypes of wild chickpea (Cicer reticulatum) that differ in their relative climates from moderate to more extreme and perform targeted assessments of drought and heat tolerance. We found significance variation in ecophysiological function and stress tolerance between genotypes but contrary to expectations and current paradigms, it was individuals from more moderate climates that exhibited greater capacity for stress tolerance than individuals from warmer and drier climates. These results indicate that wild germplasm collection efforts to identify adaptive variation should include the full range of environmental conditions and habitats instead of only environmental extremes, and that doing so may significantly enhance the success of breeding programs broadly.

Morphometric analysis of wild potato leaves

AbstractTo catalog and promote the conservation and use of crop wild relatives, comprehensive phenotypic and genotypic information must be available. Plant genotyping has the power to resolve the phylogenetic relationships between crop wild relatives, quantify genetic diversity, and identify marker-trait associations for expedited molecular breeding. However, access to cost-effective genotyping strategies is often limited in underutilized crops and crop wild relatives. Potato landraces and wild species, distributed throughout Central and South America, exhibit remarkable phenotypic diversity and are an invaluable source of resistance to pests and pathogens. Unfortunately, very limited information is available for these germplasm resources, particularly regarding phenotypic diversity and potential use as trait donors. In this work, more than 150 accessions corresponding to 12 species of wild and cultivated potatoes, collected from different sites across the American continent, were analyzed using computer vision and morphometric methods to evaluate leaf size and shape. In total, more than 1100 leaves and leaflets were processed and analyzed for nine traits related to size, shape, and color. The results produced in this study provided a visual depiction of the extensive variability among potato wild species and enabled a precise quantification of leaf phenotypic differences, including shape, color, area, perimeter, length, width, aspect ratio, convexity, and circularity. We also discussed the application and utility of inexpensive but comprehensive morphometric approaches to catalog and study the diversity of crop wild relatives. Finally, this study provided insights for further experimental research looking into the potential role of leaf size and shape variation in plant–insect interactions, agronomic productivity, and adaptation.

Crop-to-wild gene flow in wild coffee species - the case of Coffea canephora in the Democratic Republic of the Congo.

Plant breeders are increasingly turning to crop wild relatives (CWRs) to ensure food security in a rapidly changing environment. However, CWR populations are confronted with various human-induced threats, including hybridisation with their nearby cultivated crops. This might be especially a problem for wild coffee species, which often occur near coffee cultivation areas. Here, we briefly review the evidence for wild Coffea arabica (cultivated as Arabica coffee) and Coffea canephora (cultivated as Robusta coffee) and then focussed on C. canephora in the Yangambi region in the Democratic Republic of the Congo. There, we examined the geographical distribution of cultivated C. canephora and the incidence of hybridisation between cultivated and wild individuals within the rainforest. We collected 71 C. canephora individuals from home gardens and 12 C. canephora individuals from the tropical rainforest in the Yangambi region and genotyped those with Genotyping-by-Sequencing (GBS). We compared those fingerprints with existing GBS data from 388 C. canephora individuals from natural tropical rainforests and the INERA Coffee Collection, a Robusta coffee field gene bank and the most likely source of cultivated genotypes in the area. We then established robust diagnostic fingerprints that genetically differentiate cultivated from wild coffee, identified cultivated-wild hybrids, and mapped their geographical position in the rainforest. We identified cultivated genotypes and cultivated-wild hybrids in zones with clear anthropogenic activity, and where cultivated C. canephora in the home gardens may serve as a source for crop-to-wild gene flow. We found relatively few hybrids and backcrosses in the rainforests. The cultivation of C. canephora in close proximity to its wild gene pool has led to cultivated genotypes and cultivated-wild hybrids appearing within the natural habitats of C. canephora. Yet, given the high genetic similarity between the cultivated and wild gene pool, together with the relatively low incidence of hybridisation, our results indicate that the overall impact in terms of risk of introgression remains limited so far.

Surveying and mapping cereals and legumes wild relatives in Mount Hermon (Bekaa, Lebanon).

Crop Wild Relatives (CWR) should be highly prioritized, monitored, and conserved as they have an immense effect on sustainability and livelihood. In this study we aim to survey and map cereal and legume wild relatives of Fabaceae and Poaceae families. Mount Hermon, Bekaa side, Lebanon. A set of 46 CWR species were targeted based on desk selection analysis and prioritization by the International Center for Agricultural Research in Dry Areas genebank for their potential importance in breeding programs. A botanical survey of 17 sites of the various habitats of Mount Hermon was performed during April-June 2021 using a systematic transect/quadrate sampling method. Recorded genera and species were accurately georeferenced and then mapped with the DIVA-GIS program. In total, 854 occurrences were observed belonging to 34 species of Fabaceae and 12 species of Poaceae. High H' Shannon diversity values were recorded in three sites (Al Fakiaa, Sham El Hafour and Ain Ata- al Berke) of the Mount with values ranking between 2.45 and 2.83. This was confirmed by the richness distribution maps of genera and species. Richness distribution maps provide relevant clues on candidate sites for high concentrations of each of the species under study. At least the three sites, hosting 87% of the surveyed CWR's species, can be considered for further insitu conservation actions.

Hormonal and epigenetic regulation of root responses to salinity stress

Salinity stress is a major environmental stress affecting crop productivity, and its negative impact on global food security is only going to increase, due to current climate trends. Salinity tolerance was present in wild crop relatives but significantly weakened during domestication. Regaining it back requires a good understanding of molecular mechanisms and traits involved in control of plant ionic and ROS homeostasis. This review summarizes our current knowledge on the role of major plant hormones (auxin, cytokinins, abscisic acid, salicylic acid, and jasmonate) in plants adaptation to soil salinity. We firstly discuss the role of hormones in controlling root tropisms, root growth and architecture (primary root elongation, meristematic activity, lateral root development, and root hairs formation). Hormone-mediated control of uptake and sequestration of key inorganic ions (sodium, potassium, and calcium) is then discussed followed by regulation of cell redox balance and ROS signaling in salt-stressed roots. Finally, the role of epigenetic alterations such as DNA methylation and histone modifications in control of plant ion and ROS homeostasis and signaling is discussed. This data may help develop novel strategies for breeding and cultivating salt-tolerant crops and improving agricultural productivity in saline regions.

Phylogenomic analysis reveals five independently evolved African forage grass clades in the genus Urochloa.

The grass genus Urochloa (Brachiaria) sensu lato includes forage crops that are important for beef and dairy industries in tropical and sub-tropical Africa, South America, and Oceania/Australia. Economically important species include U. brizantha, U. decumbens, U. humidicola, U. mutica, U. arrecta, U. trichopus, U. mosambicensis, and Megathyrsus maximus, all native to the African continent. Perennial growth habits, large, fast growing palatable leaves, intra- and interspecific morphological variability, apomictic reproductive systems, and frequent polyploidy are widely shared within the genus. The combination of these traits likely favoured the selection for forage domestication and weediness, but trait emergence across Urochloa cannot be modelled, as a robust phylogenetic assessment of the genus has not been conducted. We aim to produce a phylogeny for Urochloa that includes all important forage species, and identify their closest wild relatives (crop wild relatives). Finally, we will use our phylogeny and available trait data to infer the ancestral states of important forage traits across Urochloa s.l. and model the evolution of forage syndromes across the genus. Using a target enrichment sequencing approach (Angiosperms353), we inferred a species level phylogeny for Urochloa s.l., encompassing 54 species (~40% of the genus) and outgroups. Phylogenies were inferred using a multispecies coalescent model and maximum likelihood method. We determined the phylogenetic placement of agriculturally important species and identified their closest wild relatives, or crop wild relatives, based on well-supported monophyly. Further, we mapped key traits associated with Urochloa forage crops to the species tree and estimated ancestral states for forage traits along branch lengths for continuous traits and at ancestral nodes in discrete traits. Agricultural species belong to five independent clades, including U. brizantha and U. decumbens lying in a previously defined species complex. Crop wild relatives were identified for these clades supporting previous sub-generic groupings in Urochloa based on morphology. Using ancestral trait estimation models, we find that five morphological traits that correlate with forage potential (perennial growth habits, culm height, leaf size, a winged rachis, and large seeds) independently evolved in forage clades. Urochloa s.l. is a highly diverse genus that contains numerous species with agricultural potential, including crop wild relatives that are currently underexploited. All forage species and their crop wild relatives naturally occur on the African continent and their conservation across their native distributions is essential. Genomic and phenotypic diversity in forage clade species and their wild relatives needs to be better assessed both to develop conservation strategies, and exploit the diversity in the genus for improved sustainability in Urochloa cultivar production.

Priority areas for the establishment of genetic reserves to actively protect key crop wild relative species in Italy

Crop Wild Relatives (CWR) are wild plant taxa genetically close to a crop. Being a precious source of genetic variability and of traits for crop improvement, CWR have a high socio-economic value and are identified among the main plant genetic resources. Alarming enough, the inter- and intraspecific diversity, as well as their habitat diversity, is under threat of irremediable loss. Italy is the second richest country in Europe in terms of plant species number; applying the taxon group concept 5712 have been recently identified as CWR. The aims of the present research are to identify the best sites for: i) the institution of genetic reserves to actively protect CWR species of the key crop genera as Allium, Brassica and Triticum and ii) performing new collection missions to reach adequate ex situ conservation of target species. Georeferenced data were retrieved from different online databases. CAPFITOGEN tools were initially used to develop an ecogeographic land characterisation map (ELC) of Italy. Geographical distribution data were assembled for 379 populations of 18 CWR taxa. Results of the complementarity analysis showed that 10 protected areas provide coverage of the 46.4% of the target conservation units and include 66.7% of the priority CWR taxa investigated. Alarming enough, only 7.4% of the 379 populations are currently conserved ex situ; among the 18 ecogeographic land characterisation categories only 3 are covered by ex situ conservation. This is the first study where most suitable protected areas for the institution of genetic reserves are proposed for Italy for the protection of multiple CWR taxa of key genera; this is relevant also considering the global value of many of the related crop such as different wheat species, cabbages, rape, garlic and onion. Being already dedicated to habitat and species conservation, the identified sites are optimal candidates for the institution of genetic reserves. Results will hopefully also guide new collecting missions that are urgently needed to strength ex situ conservation of such precious genetic resources.

Freezing stress response of wild and cultivated chickpeas.

Chickpea is an economically and nutritionally important grain legume globally, however, cold stress has adverse effects on its growth. In cold countries, like Canada where the growing season is short, having cold stress-tolerant varieties is crucial. Crop wild relatives of chickpea, especially Cicer reticulatum, can survive in suboptimal environments and are an important resource for crop improvement. In this study, we explored the performance of eleven C. reticulatum wild accessions and two chickpea cultivars, CDC Leader and CDC Consul, together with a cold sensitive check ILC533 under freezing stress. Freezing tolerance was scored based on a 1-9 scale. The wild relatives, particularly Kesen_075 and CudiA_152, had higher frost tolerance compared to the cultivars, which all died after frost treatment. We completed transcriptome analysis via mRNA sequencing to assess changes in gene expression in response to freezing stress and identified 6,184 differentially expressed genes (DEGs) in CDC Consul, and 7,842 DEGs in Kesen_075. GO (gene ontology) analysis of the DEGs revealed that those related to stress responses, endogenous and external stimuli responses, secondary metabolite processes, and photosynthesis were significantly over-represented in CDC Consul, while genes related to endogenous stimulus responses and photosynthesis were significantly over-represented in Kesen_075. These results are consistent with Kesen_075 being more tolerant to freezing stress than CDC Consul. Moreover, our data revealed that the expression of CBF pathway-related genes was impacted during freezing conditions in Kesen_075, and expression of these genes is believed to alleviate the damage caused by freezing stress. We identified genomic regions associated with tolerance to freezing stress in an F2 population derived from a cross between CDC Consul and Kesen_075 using QTL-seq analysis. Eight QTLs (P<0.05) on chromosomes Ca3, Ca4, Ca6, Ca7, Ca8, and two QTLs (P<0.01) on chromosomes Ca4 and Ca8, were associated with tolerance to freezing stress. Interestingly, 58 DEGs co-located within these QTLs. To our knowledge, this is the first study to explore the transcriptome and QTLs associated with freezing tolerance in wild relatives of chickpea under controlled conditions. Altogether, these findings provide comprehensive information that aids in understanding the molecular mechanism of chickpea adaptation to freezing stress and further provides functional candidate genes that can assist in breeding of freezing-stress tolerant varieties.

Genomics empowering conservation action and improvement of celery in the face of climate change.

Integration of genomic approaches like whole genome sequencing, functional genomics, evolutionary genomics, and CRISPR/Cas9-based genome editing has accelerated the improvement of crop plants including leafy vegetables like celery in the face of climate change. The anthropogenic climate change is a real peril to the existence of life forms on our planet, including human and plant life. Climate change is predicted to be a significant threat to biodiversity and food security in the coming decades and is rapidly transforming global farming systems. To avoid the ghastly future in the face of climate change, the elucidation of shifts in the geographical range of plant species, species adaptation, and evolution is necessary for plant scientists to develop climate-resilient strategies. In the post-genomics era, the increasing availability of genomic resources and integration of multifaceted genomics elements is empowering biodiversity conservation action, restoration efforts, and identification of genomic regions adaptive to climate change. Genomics has accelerated the true characterization of crop wild relatives, genomic variations, and the development of climate-resilient varieties to ensure food security for 10 billion people by 2050. In this review, we have summarized the applications of multifaceted genomic tools, like conservation genomics, whole genome sequencing, functional genomics, genome editing, pangenomics, in the conservation and adaptation of plant species with a focus on celery, an aromatic and medicinal Apiaceae vegetable. We focus on how conservation scientists can utilize genomics and genomic data in conservation and improvement.

Replenishment of the VIR perennial forage crops collection with samples from a collecting mission in Tambov and Ryazan provinces in 2018

The purpose of the collecting mission was to replenish the collection of perennial forage crops with crop wild relatives (CWR) of interest for breeding purposes, as well as for the subsequent preservation of forage CWR diversity in natural populations. The mission was tasked to conduct a survey of the territory along the middle and lower Tsna river and collect seeds of wild perennial and annual forages. Coordinates of collecting sites were recorded and sites mapped together with the collecting mission route. Two districts of the Tambov and two districts of Ryazan provinces were explored. As a result, 93 seed samples were collected. Out of these, 47 samples were perennial forage grasses, 39 perennial and annual forage legumes, and 7 belonged to other families. The main part of legumes was represented by Medicago species (11 samples of Medicago falcata L., M. varia Mart., M. lupulina L.) and clover (11 samples of Trifolium hybridum L., T. incarnatum L., T. medium L., T. pratensis L., T. repens L.); among the grasses there were Bromopsis inermis (Leyss.) Holub, Poa angustifolia L., Dactylis glomerata L., and Phleum pratense L.

Genetic structure and ecological niche space of lentil's closest wild relative, Lens orientalis (Boiss.) Schmalh.

Crops arose from wild ancestors and to understand their domestication it is essential to compare the cultivated species with their crop wild relatives. These represent an important source of further crop improvement, in particular in relation to climate change. Although there are about 58,000 Lens accessions held in genebanks, only 1% are wild. We examined the geographic distribution and genetic diversity of the lentil's immediate progenitor L. orientalis. We used Genotyping by Sequencing (GBS) to identify and characterize differentiation among accessions held at germplasm collections. We then determined whether genetically distinct clusters of accessions had been collected from climatically distinct locations. Of the 195 genotyped accessions, 124 were genuine L. orientalis with four identified genetic groups. Although an environmental distance matrix was significantly correlated with geographic distance in a Mantel test, the four identified genetic clusters were not found to occupy significantly different environmental space. Maxent modelling gave a distinct predicted distribution pattern centred in the Fertile Crescent, with intermediate probabilities of occurrence in parts of Turkey, Greece, Cyprus, Morocco, and the south of the Iberian Peninsula with NW Africa. Future projections did not show any dramatic alterations in the distribution according to the climate change scenarios tested. We have found considerable diversity in L. orientalis, some of which track climatic variability. The results of the study showed the genetic diversity of wild lentil and indicate the importance of ongoing collections and in situ conservation for our future capacity to harness the genetic variation of the lentil progenitor.

Leaf trichome diversity, acylsugar concentration, and their relationships to leaf area in Solanum galapagense

Glandular trichomes are physical and chemical barriers used by some tomato wild relatives to confer resistance against insect pests and diseases transmitted by them. Solanum galapagense has been identified as one of the potential sources of insect pest resistance. The present study aimed to examine the trichome diversity and acylsugar concentration of 26 accessions of S. galapagense along with one cultivated tomato (S. lycopersicum) and one cherry tomato (S. l. cerasiforme) cultivar. The results revealed large phenotypic variation among S. galapagense accessions for all studied traits. The S. galapagense accessions had significantly higher trichome types IV density on the adaxial and abaxial surfaces of the leaf and greater acylsugar concentration but a smaller leaflet area than the cultivated tomato. The selected cherry tomato line represents greater trichome type IV density and acylsugar concentration than other groups. The acylsugar concentration was positively associated with trichome type IV but negatively associated with trichome type V on both leaf surfaces. DNA markers revealed the presence of two previously identified whitefly-resistance alleles in S. galapagense accessions. This study will support breeding programs aiming to improve insect pest resistance in tomato cultivars using crop wild relatives.

Disease Resistance-Based Management of Alternaria Black Spot in Cruciferous Crops

Alternaria black spots or blights in cruciferous crops have been devastating diseases worldwide and led to economic losses in broccoli, Chinese cabbage, kale, radish, rapeseed, etc. These diseases are caused by different &lt;i&gt;Alternaria&lt;/i&gt; spp., including &lt;i&gt;A. brassicae, A. brassicicola&lt;/i&gt; and &lt;i&gt;A. raphani&lt;/i&gt; transmitted from infected seeds or insect vectors. Efforts to excavate disease resistance traits of cruciferous crops against Alternaria black spots or blights have been demonstrated. Genetic resource of disease resistance was investigated in the wild relatives of cruciferous crops, and different cultivars were screened under different inoculation conditions. Development of the disease-resistant lines against Alternaria black spots or blights was also tried via genetic transformation of the cruciferous crops using diverse plant defence-associated genes. Plant immunity activated by pre-treatment with chemicals, i. e. β-amino-&lt;i&gt;n&lt;/i&gt;-butyric acid and melatonin, was suggested for reducing Alternaria black spots or blights in cruciferous crops. The disease resistance traits have also been evaluated in model plant Arabidopsis originating from different habitats. Various plant immunity-related mutants showing different disease responses from wild-type Arabidopsis provided valuable information for managing Alternaria black spots or blights in cruciferous crops. In particular, redox regulation and antioxidant responses altered in the &lt;i&gt;Alternaria&lt;/i&gt;-infected mutants were discussed in this review.

Genome editing to re-domesticate and accelerate use of barley crop wild relatives

Climate change threatens global food security, but the biggest impact will be in arid, low social-economic regions. To improve food security, new breeding technologies (NBTs) could be implemented for re-domestication of crop wild relatives (CWR). CWR harbor many beneficial traits, but it is difficult to incorporate these traits into conventional breeding programs. Thus, although genebanks hold significant collections of CWR, their potential has yet to be reached. Using barley as an example, we describe how using genebank collections, digital sequence information and NBTs, re-domesticated barley can be produced with improved characteristics, while retaining the resilience and adaptation of the original material. Lastly, we highlight some obstacles that need to be overcome for re-domesticates to be adopted.

Wild strawberry Fragaria vesca as potential source for phytonematode resistance

AbstractPhytonematode infections are a major constraint to agriculture and can cause pre-harvest losses of up to one-third of the crop in affected fields. With increasing restrictions on the use of chemical pesticides due to environmental and human hazards, and increasing nematode pressure due to climate change, soil degradation and agricultural intensification, more sustainable ways to manage such plant pests are needed to meet the growing demand for food. Therefore, the reproduction of thermophilic Meloidogyne spp. was evaluated in comparison with that of the northern root-knot nematode Meloidogyne hapla on the wild strawberry Fragaria vesca vs. semperflorens cv. Alexandria, a potential source of resistance to nematode infection. M. hapla showed a high reproductive rate in F. vesca, while the thermophilic Meloidogyne species tested showed significant lower reproductive rates. This suggests that F. vesca vs. semperflorens cv. Alexandria, although not resistant to the nematode species tested, could be used in a management system to down-regulate nematode pressure. In addition, this study helps to reinforce the importance of crop wild relatives in the search for resistance traits to support a more sustainable agriculture.