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• Powdery mildew poses severe threats to wheat production. The most sustainable way to control this disease is through planting resistant cultivars. • We report the map-based cloning of the powdery mildew resistance allele Pm5e from a Chinese wheat landrace. We applied a two-step bulked segregant RNA sequencing (BSR-Seq) approach in developing tightly linked or co-segregating markers to Pm5e. The first BSR-Seq used phenotypically contrasting bulks of recombinant inbred lines (RILs) to identify Pm5e-linked markers. The second BSR-Seq utilized bulks of genetic recombinants screened from a fine-mapping population to precisely quantify the associated genomic variation in the mapping interval, and identified the Pm5e candidate genes. • The function of Pm5e was validated by transgenic assay, loss-of-function mutants and haplotype association analysis. Pm5e encodes a nucleotide-binding domain leucine-rich-repeatcontaining (NLR) protein. A rare nonsynonymous single nucleotide variant (SNV) within the C-terminal leucine rich repeat (LRR) domain is responsible for the gain of powdery mildew resistance function of Pm5e, an allele endemic to wheat landraces of Shaanxi province of China. • Results from this study demonstrate the value of landraces in discovering useful genes for modern wheat breeding. The key SNV associated with powdery mildew resistance will be useful for marker-assisted selection of Pm5e in wheat breeding programs.

In the actual climate change scenario, in situ conservation of plant genetic resources for food and agriculture can significantly contribute broadening the diversity of our food system as well as increasing its resilience; nevertheless, landrace cultivation has been dramatically reduced in the last decades all over Europe. One of the most effective approaches to counteract the loss of landrace diversity in situ is facilitating its use. Aims of this study were to (i) describe how in situ maintenance of landraces occurs in different agro-environmental conditions in Europe and (ii) identify the main factors influencing landrace added values and accessibility as means to increase their adoption by new farmers. To the purpose, a collection of 95 case studies of both garden and open field landraces maintained in situ was analysed. A first description was obtained by classifying the information into 18 purposely defined categories. Data on landraces added values and accessibility were further transformed into weighted variables; the derived quantitative scores were then used as dependent variables in univariate and multivariate analyses. Results showed that farmers alone are still the main actors maintaining landraces in situ across different European biogeographical regions, mainly carrying out their activity under organic or low-input conditions, often in marginal areas. Results of the multivariate analysis showed that (i) type of actor involved in the multiplication, (ii) the main use of the product and (iii) presence of promotion actions significantly affect garden landraces added value and accessibility; presence of promotion actions was the only factor affecting added value of open field entries. Evidence arising from this work can contribute to the establishment of a fruitful ground of discussion for future European policies and strategies to protect and increase landrace use.

Aims Diversity of root systems among genetic resources can contribute to optimize water and nutrient uptake. Topsoil exploitation vs. deep soil exploration represent two contrasting ideotypes in relation to resource use. Our study reveals how rooting patterns changed between wheat wild progenitors and landraces in regard to these ideotypes. Methods Root (partitioning, morphology, distribution, elongation, anatomy) and shoot traits (dry-matter, leaf area, assimilation) of durum landraces, wild emmer and wild einkorn from Iran, Syria, Turkey and Lebanon were phenotyped using the GrowScreen-Rhizo platform. Distinctive rooting patterns were identified via principal component analysis and relations with collection site characteristics analyzed. Results Shoot trait differentiation was strongly driven by seed weight, leading to superior early vigor of landraces. Wild progenitors formed superficial root systems with a higher contribution of lateral and early-emerging nodal axes to total root length. Durum landraces had a root system dominated by seminal axes allocated evenly over depth. Xylem anatomy was the trait most affected by the environmental influence of the collection site. Conclusions The durum landrace root system approximated a deep soil exploration ideotype which would optimize subsoil water uptake, while monococcum -type wild einkorn was most similar to a topsoil exploiting strategy with potential competitive advantages for subsistence in natural vegetation.

One of the major challenges facing agricultural and food systems today is the loss of agrobiodiversity. Considering the current impasse of preventing the worldwide loss of crop diversity, this paper highlights the possibility for a radical reorientation of current legal seed frameworks that could provide more space for alternative seed systems to evolve which centre on norms that support on-farm agrobiodiversity. Understanding the underlying norms that shape seed commons are important, since norms both delimit and contribute to what ultimately will constitute the seeds and who will ultimately have access to the seeds and thus to the extent to which agrobiodiversity is upheld and supported. This paper applies a commoning approach to explore the underpinning norms of a Swedish seed commons initiative and discusses the potential for furthering agrobiodiversity in the context of wider legal and authoritative discourses on seed enclosure. The paper shows how the seed commoning system is shaped and protected by a particular set of farming norms, which allows for sharing seeds among those who adhere to the norms but excludes those who will not. The paper further illustrates how farmers have been able to navigate fragile legal and economic pathways to collectively organize around landrace seeds, which function as an epistemic farming community, that maintain landraces from the past and shape new landraces for the present, adapted to diverse agro-ecological environments for low-input agriculture. The paper reveals how the ascribed norms to the seed commons in combination with the current seed laws set a certain limit to the extent to which agrobiodiversity is upheld and supported and discusses why prescriptions of “getting institutions right” for seed governance are difficult at best, when considering the shifting socio-nature of seeds. To further increase agrobiodiversity, the paper suggests future seed laws are redirected to the sustenance of a proliferation of protected seed commoning systems that can supply locally adapted plant material for diverse groups of farmers and farming systems.

Parsimonious root phenotypes may benefit water capture under drought. Abstract I propose that reduced root development would be advantageous for drought resistance in high-input agroecosystems. Selection regimes for crop ancestors and landraces include multiple stresses, intense competition, and variable resource distribution, which favored prolific root production, developmental plasticity in response to resource availability, and maintenance of unspecialized root tissues. High-input agroecosystems have removed many of these constraints to root function. Therefore, root phenotypes that focus on water capture at the expense of ancestral adaptations would be better suited to high-input agroecosystems. Parsimonious architectural phenotypes include fewer axial roots, reduced density of lateral roots, reduced growth responsiveness to local resource availability, and greater loss of roots that do not contribute to water capture. Parsimonious anatomical phenotypes include a reduced number of cortical cell files, greater loss of cortical parenchyma to aerenchyma and senescence, and larger cortical cell size. Parsimonious root phenotypes may be less useful in low-input agroecosystems, which are characterized by multiple challenges and trade-offs for root function in addition to water capture. Analysis of the fitness landscape of root phenotypes is a complex challenge that will be aided by the development of robust functional-structural models capable of simulating the dynamics of root-soil interactions.

The valorization of plant genetic resources and their direct use in local markets can make a significant contribution to the preservation of agrobiodiversity, while also contributing to the sustainability of rural communities. Indeed, plant genetic resources are a precious source of genes, and they represent an important crop heritage for the quality and sensory characteristics that are required by both farmers and consumers. However, an efficient strategy of agrobiodiversity conservation is strictly connected to product marketability and to consumer preferences. In the present study, choice experiments that involved 920 consumers were carried out to determine their willingness to pay for ancient local tomato varieties (landraces) rather than commercial varieties based on their preferences, and to determine how much they valued these products. The results obtained indicate that consumers are willing to pay premium prices for ancient local tomato varieties (an additional €0.90 kg −1 ), thus demonstrating their increasing attention to sustainable food and the willingness to contribute to agrobiodiversity conservation and enhancement. These results provide the basis for planning strategies and programs to support the cultivation of these landraces and the development of regional and national markets to acknowledge their characteristics, which will considerably increase the effectiveness and efficiency of conservation strategies.

Assessment of photosynthetic traits and temperature tolerance was performed on field-grown modern genotype (MG), and the local landrace (LR) of wheat (Triticum aestivum L.) as well as the wild relative species (Aegilops cylindrica Host.). The comparison was based on measurements of the gas exchange (A/ci, light and temperature response curves), slow and fast chlorophyll fluorescence kinetics, and some growth and leaf parameters. In MG, we observed the highest CO2 assimilation rate ACO2, electron transport rate (Jmax) and maximum carboxylation rate VCmax. The Aegilops leaves had substantially lower values of all photosynthetic parameters; this fact correlated with its lower biomass production. The mesophyll conductance was almost the same in Aegilops and MG, despite the significant differences in leaf phenotype. In contrary, in LR with a higher dry mass per leaf area, the half mesophyll conductance (gm) values indicated more limited CO2 diffusion. In Aegilops, we found much lower carboxylation capacity; this can be attributed mainly to thin leaves and lower Rubisco activity. The difference in CO2 assimilation rate between MG and others was diminished because of its higher mitochondrial respiration activity indicating more intense metabolism. Assessment of temperature response showed lower temperature optimum and a narrow ecological valence (i.e., the range determining the tolerance limits of a species to an environmental factor) in Aegilops. In addition, analysis of photosynthetic thermostability identified the LR as the most sensitive. Our results support the idea that the selection for high yields was accompanied by the increase of photosynthetic productivity through unintentional improvement of leaf anatomical and biochemical traits including tolerance to non-optimal temperature conditions.

Enset ( Ensete ventricosum  [Welw.] Cheesman) is a multipurpose perennial crop widely grown and consumed in Ethiopia. Although it is a high-value crop for local farmers, essential information on indigenous knowledge of its farming system, cultural practices, and traditional utilization is still an under-researched domain. This study was designed to assess and record the wealth of indigenous knowledge on enset, covering the local identification, categorization, and nomenclatural system in tandem with traditional uses of the enset crop. A random sample of 240 enset farmers from seven districts and 12 subdistricts of the Hadiya Zone were interviewed, along with four to six key informants selected from each subdistrict. Direct on-farm observation, 12 focus group discussions, and secondary data were considered in the documentation of indigenous and local knowledge associated with the enset farming system and use culture. We identified with the farmers 99 local farmer-named enset landraces under cultivation. Farmers identify and categorize enset landraces informally using morphological features as the main criterion. The local names of some landraces indicate their uniqueness in morphological traits, place of origin, agronomic features, and quality attributes of their products. Based on farmers' perception, cultivated enset landraces are grouped into ‘soft’ ( qechalwesa ) and ‘hardy’ ( qoxalwesa), considering characteristics regarding the strength of harvesting and processing, rate of fermentation, and quality of the end products. The indigenous knowledge about the cultural, social, and economic values of enset and its production system practiced by local farmers is crucial for the availability of the present landrace diversity. To sustainably use and conserve enset genetic resources, it is necessary to integrate indigenous knowledge with modern formal science, including in a field gene bank in Hadiya and other key enset growing areas in Ethiopia as a climate-smart crop.

Genetic diversity is an essential resource for breeders to improve new cultivars with desirable characteristics. Recently, genotyping-by-sequencing (GBS), a next-generation sequencing (NGS) technology that can simplify complex genomes, has now be used as a high-throughput and cost-effective molecular tool for routine breeding and screening in many crop species, including the species with a large genome. We genotyped a diversity panel of 369 Iranian hexaploid wheat accessions including 270 landraces collected between 1931 and 1968 in different climate zones and 99 cultivars released between 1942 to 2014 using 16,506 GBS-based single nucleotide polymorphism (GBS-SNP) markers. The B genome had the highest number of mapped SNPs while the D genome had the lowest on both the Chinese Spring and W7984 references. Structure and cluster analyses divided the panel into three groups with two landrace groups and one cultivar group, suggesting a high differentiation between landraces and cultivars and between landraces. The cultivar group can be further divided into four subgroups with one subgroup was mostly derived from Iranian ancestor(s). Similarly, landrace groups can be further divided based on years of collection and climate zones where the accessions were collected. Molecular analysis of variance indicated that the genetic variation was larger between groups than within group. Obvious genetic diversity in Iranian wheat was revealed by analysis of GBS-SNPs and thus breeders can select genetically distant parents for crossing in breeding. The diverse Iranian landraces provide rich genetic sources of tolerance to biotic and abiotic stresses, and they can be useful resources for the improvement of wheat production in Iran and other countries.

Aims Milpas are traditional agroecosystems found in rural areas of Mexico, where low input practices favor the presence of microbial associates with greater abundance and diversity than modern crops. Milpas can be found in a wide range of climates, but the beneficial functions of microbes are yet to be explored across biotic and abiotic conditions. In semi-arid regions of Hidalgo, Mexico, maize landraces have been selected to grow in milpas despite low rainfall and we hypothesized that associated bacteria contribute to the drought tolerance of these plants. Methods We collected maize seeds from arid and tropical milpas , as well as hybrid varieties from modern crops to test their responses to drought during germination and early vegetative growth; next, we studied the role of seed endophytic bacteria for this trait. Results Landraces from arid milpas displayed decreased phenotypic responses to drought (i.e. increased tolerance), and elimination of seed-endophytic bacteria from these landraces reduced germination in drought. Next, 16 S amplicon sequencing revealed that drought-tolerant landraces harbor Pseudomonas spp., Brachybacterium spp., and strains from the Bacilli class that were not found in drought-sensitive varieties; likewise, culturing methods allowed the isolation of these bacterial groups. Finally, inoculation of Pseudomonas spp. and Brachybacterium sp. strains improved the germination of a drought-sensitive variety. Conclusions Our results indicate that seed-endophytic bacteria associated to maize landraces from arid milpas contribute to drought tolerance in early developmental stages and support that ancestral practices manifest in the microbial ecology of milpas , selecting beneficial microbes to cope with local conditions.