Quinoa Accessions Research Articles

Agronomical and analytical trait data assessed in a set of quinoa genotypes growing in the UAE under different irrigation salinity conditions.

The importance of quinoa has been emphasized considerably in the recent decades, as a highly nutritional crop seed that is tolerant to salinity and amenable to arid agronomical conditions. The focus of this paper is to provide raw and a supplemental data of the research article entitled "Agronomic performance of irrigated quinoa in desert areas: comparing different approaches for early assessment of salinity stress" [1], aiming to compare different approaches for early detection, at the genotypic and crop levels, of the effect of salinity caused by irrigation on the agronomic performance of this crop. A set of 20 genotypes was grown under drip irrigation in sandy soil, amended with manure, at the International Center for Biosaline Agriculture (UAE) for two weeks, after which half of the trial was submitted to irrigation with saline water and this was continued until crop maturity. After eight weeks of applying the two irrigation regimes, pigment contents were evaluated in fully expanded leaves. The same leaves were then harvested, dried and the stable carbon and nitrogen isotope compositions (δ13C and δ15N) and the total nitrogen and carbon contents of the dry matter analyzed, together with ion concentrations. At maturity yield components were assessed and yield harvested. Data analysis demonstrated significant differences in genotypes response under each treatment, within all assessed parameters. The significant level was provided using the Tukey-b test on independent samples. The present dataset highlights the potential use of different approaches to crop phenotyping and monitoring decision making.

Understanding the role of root-related traits in salinity tolerance of quinoa accessions with contrasting epidermal bladder cell patterning.

To compensate for the lack of capacity for external salt storage in the epidermal bladder cells, quinoa plants employ tissue-tolerance traits, to confer salinity stress tolerance. Our previous studies indicated that sequestration of toxic Na+ and Cl- ions into epidermal bladder cells (EBCs) is an efficient mechanism conferring salinity tolerance in quinoa. However, some halophytes do not develop EBCs but still possess superior salinity tolerance. To elucidate the possible compensation mechanism(s) underlying superior salinity tolerance in the absence of the external salt storage capacity, we have selected four quinoa accessions with contrasting patterns of EBC development. Whole-plant physiological and electrophysiological characteristics were assessed after 2days and 3weeks of 400mM NaCl stress. Both accessions with low EBC volume utilised Na+ exclusion at the root level and could maintain low Na+ concentration in leaves to compensate for the inability to sequester Na+ load in EBC. These conclusions were further confirmed by electrophysiological experiments showing higher Na+ efflux from roots of these varieties (measured by a non-invasive microelectrode MIFE technique) as compared to accessions with high EBC volume. Furthermore, accessions with low EBC volume had significantly higher K+ concentration in their leaves upon long-term salinity exposures compared to plants with high EBC sequestration ability, suggesting that the ability to maintain high K+ content in the leaf mesophyll was as another important compensation mechanism.

Growth, Biomass Production, and Yield Potential of Quinoa (Chenopodium quinoa Willd.) as Affected by Planting Techniques Under Irrigated Conditions

Quinoa is gaining importance globally owing to its nutritional quality and its adaptability under variety of conditions. However, limited information is available on the impact of planting techniques on growth, morphology, and yield and biomass accumulation under irrigation conditions. To the date, no ideal planting technique (sowing method) has been reported for the flat irrigated land for better adjustment of quinoa in a crop rotation. To test the hypothesis, a two-year field study (2013–14 and 2014–15) was carried out at University of Agriculture, Faisalabad, Pakistan. The experiment comprised of four planting technique bed sowing (BS), ridge sowing (RS), flat line sowing (FLS), and sowing in standing water (SSW) in main plots, and two quinoa accession (A7 and A9) in subplots. The results showed that BS method improved the morphological attributes viz. stem thickness, main panicle, main panicle, thousand grain weight, grain yield, and harvest index as compared to SSW. Regarding the quinoa accessions, A9 performed better than A7 for morphology, biomass, and yield. Panicle number per plant was positively correlated with harvest index and main panicle weight in 2013–14, while 1000-grain weight and harvest index had a stronger correlation during 2014–15. The average and maximum biomass production rate of A7 in BS plants were relatively higher than other sowing techniques either for A9 or A7. Our data suggest that the BS method is a relatively better planting technique and A9 quinoa accession is a suitable genotype to obtain a high targeted grain yield under irrigated conditions.

Presowing seed treatment with glycine betaine confers NaCl tolerance in quinoa by modulating some physiological processes and antioxidant machinery

Soil salinity threatens the yield and food security worldwide and use of halophytes might be a valid option to cope with devastating salinity effects. The present investigation was accomplished to evaluate the role of glycine betaine (GB) as presowing seed treatment on growth parameters, photosynthetic pigments, gas exchange attributes, enzymatic antioxidants, lipid peroxidation (MDA), hydrogen peroxide (H2 O2 ), endogenous GB, total soluble proteins (TSP), and yield in quinoa (Chenopodium quinoa) under saline conditions. Ames-13737 (Q7) and PI-634919 (Q9) quinoa accessions were used for this trial. The plants were applied with two salt stress treatments (Control and 450 mM NaCl) after 45 days of sowing. Presowing seed treatments with GB (water, 10 and 20 mM) were given for 12 h. Each treatment replicated four times through completely randomized design. Imposition of salinity triggered a major decrease in growth, photosynthetic pigments, net CO2 assimilation rate (A), transpiration rate (E), and stomatal conductance (gs ), while the level of lipid peroxidation and activities of superoxide dismutase (SOD) and catalase (CAT) were enhanced. Slight increment in total soluble proteins was observed along with higher endogenous GB in quinoa under salinity. Both levels of GB increased the shoot length, shoot fresh, and dry weights in accession PI-634919 under saline regime. Photosynthetic attributes, E and gs were increased when 20 mM of GB was applied under saline conditions. Activities of antioxidant enzymes, TSP, endogenous glycine betaine and yield parameters were also increased when GB was applied. Presowing treatment with GB in quinoa plants prominently decreased the MDA and H2 O2 concentration. The concentration of 10 mM GB enhanced the panicle length while 20 mM GB showed same results for 1000 seed weight and TSP under saline conditions. Overall, quinoa accession Ames-13737 was better as compared to PI-634919 in terms of growth rate, photosynthetic properties, gas exchange parameters, enzymatic antioxidants, and yield.

A large-scale screening of quinoa accessions reveals an important role of epidermal bladder cells and stomatal patterning in salinity tolerance

The presence of epidermal bladder cells (EBCs) in halophytes allows considerable amount of Na+ being accumulated in these external structures, away from the metabolically active mesophile cells. Also, stomatal patterning may represent a primary mechanism by which plants can optimise its water-use efficiency under saline condition. This investigation was aimed to explore the varietal differences in a salinity tolerance of quinoa (Chenopodium quinoa) by evaluating a broad range of accessions and linking the overall salinity tolerance with changes in stomatal characteristics and EBC parameters. One hundred and fourteen accessions were grown under temperature-controlled glasshouse under non-saline and 400 mM NaCl conditions, and different physiological and anatomical characteristics were measured. Accessions were classified into three classes (sensitive, intermediate and tolerant) based on a relative dry weight defined as salinity tolerance index (STI). Results showed a large variability in STI indicating a strong genetic variation in salinity tolerance in quinoa. Bladders density was increased in a majority of accessions under saline condition while the bladder’s diameter remained unchanged; this resulted in a large variability in a bladder’s volume as a dependant variable. Stomata density remained unchanged between saline and non-saline conditions while the stomata length declined between 3% to 43% amongst accessions. Leaf Na+ concentration varied from 669 μmol/gDW to 3155 μmol/gDW under saline condition and, with an exception of a few accessions, leaf K+ concentration increased under saline conditions. Correlation analysis indicated a significant positive association between EBC diameter and STI on one hand and EBC volume and STI on the other hand, in a salt-tolerant group. These observations are consistent with the role of EBCs in sequestration of toxic Na+ in the external structures, away from the cytosol. A negative association was found between EBC density and diameter in salt-sensitive plants. A negative association between STI and stomata length was also found in a salt-tolerant group, suggesting that these plants were able to efficiently regulate stomatal patterning to balance water loss and CO2 assimilation under saline conditions. Both salt-sensitive and salt-tolerant groups had the same Na+ concentration in the shoot under saline conditions; however, a negative association between leaf Na+ concentration and STI in salt-sensitive plants indicated a more efficient Na+ sequestration process into the EBCs in salt-tolerant plants.

Genome‐wide microsatellite characterisation and marker development in Chenopodium quinoa

AbstractMicrosatellites, as the tracts of repetitive DNA, are an essential constituent of the plant genome that holds important evolutionary significance, and have been extensively used to develop molecular makers for genetic analysis. To understand the microsatellite dynamics of quinoa genome and its relatives, in this study we performed a genome‐wide analysis of microsatellites in five Amaranthaceae species using available genome sequences. The results demonstrated that the microsatellites of the five Amaranthaceae species were characterised by relatively high proportions of mono‐, di‐ and trinucleotide repeats with A/T rich motifs, implying conservative organisation and composition of microsatellites in this family. Furthermore, a significant negative correlation between microsatellite frequencies and GC contents (r = −.87) were observed. In total, 533,961 (89.57%) and 542,601 (89.86%) microsatellite loci could be used to develop simple sequence repeat (SSR) molecular markers, of which 7,178 were found to be polymorphic between the two sequenced quinoa cultivars, QQ74 and Real Blanca, through in silico PCR analysis. Finally, 15 SSR markers were randomly selected to validate their polymorphism across 12 quinoa accessions by wet‐lab PCR amplification. The newly developed genome‐wide SSR markers provide a useful resource for population genetics, gene mapping and molecular breeding studies in quinoa and beyond.

Deciphering species relationships and evolution in Chenopodium through sequence variations in nuclear internal transcribed spacer region and amplified fragment-length polymorphism in nuclear DNA

Evaluation of sequence variations in the internal transcribed spacer (ITS) region of 19 accessions, comprising of 11 accessions of Chenopodium quinoa, eight accessions of Chenopodium album and 165 retrieved sequences of different species of Chenopodium belonging to subfamily Chenopodioideae revealed a higher intraspecific genetic diversity in Himalayan C. album than that in C. quinoa. ITS and amplified fragment-length profiles of the accessions suggest the existence of accessions of Himalayan C. album as heteromorphs of the same species rather than a heterogenous assemblage of taxa. While the evolutionary relationship reconstructed from variations in 184 sequences of ITS region from species belonging to Chenopodiaceae, Amaranthaceae, Polygonaceae and Nelumbonaceae established a paraphyletic evolution of family Chenopodiaceae, it also revealed a monophyletic evolution of Chenopodieae I. The reconstruction also established five independent lineages of the subfamily Chenopodioideae with C. album as a sister clade of C. quinoa within the tribe Chenopodieae I. The results also indicate a much younger age for Himalayan chenopods (C. album) than the reported crown age of Chenopodieae I.

Biological and Molecular Characterization of Chenopodium quinoa Mitovirus 1 Reveals a Distinct Small RNA Response Compared to Those of Cytoplasmic RNA Viruses.

Indirect evidence of mitochondrial viruses in plants comes from discovery of genomic fragments integrated into the nuclear and mitochondrial DNA of a number of plant species. Here, we report the existence of replicating mitochondrial virus in plants: from transcriptome sequencing (RNA-seq) data of infected Chenopodium quinoa, a plant species commonly used as a test plant in virus host range experiments, among other virus contigs, we could assemble a 2.7-kb contig that had highest similarity to mitoviruses found in plant genomes. Northern blot analyses confirmed the existence of plus- and minus-strand RNA corresponding to the mitovirus genome. No DNA corresponding to the genomic RNA was detected, excluding the endogenization of such virus. We have tested a number of C. quinoa accessions, and the virus was present in a number of commercial varieties but absent from a large collection of Bolivian and Peruvian accessions. The virus could not be transmitted mechanically or by grafting, but it is transmitted vertically through seeds at a 100% rate. Small RNA analysis of a C. quinoa line carrying the mitovirus and infected by alfalfa mosaic virus showed that the typical antiviral silencing response active against cytoplasmic viruses (21- to 22-nucleotide [nt] vsRNA peaks) is not active against CqMV1, since in this specific case the longest accumulating vsRNA length is 16 nt, which is the same as that corresponding to RNA from mitochondrial genes. This is evidence of a distinct viral RNA degradation mechanism active inside mitochondria that also may have an antiviral effect.IMPORTANCE This paper reports the first biological characterization of a bona fide plant mitovirus in an important crop, Chenopodium quinoa, providing data supporting that mitoviruses have the typical features of cryptic (persistent) plant viruses. We, for the first time, demonstrate that plant mitoviruses are associated with mitochondria in plants. In contrast to fungal mitoviruses, plant mitoviruses are not substantially affected by the antiviral silencing pathway, and the most abundant mitovirus small RNA length is 16 nt.

Comparative studies of reproductive biology, seed morphology and anatomy of new salt tolerant accessions of Quinoa (Chenopodium quinoa Willd.) introduced in Kur-Araz lowland (Azerbaijan)

Investigated salt tolerant top-ranking accessions of Quinoa introduced on drought prone and salt affected soils with higher clay contents, water holding capacity, evapotranspiration and shallow water in Kur-Araz (Azerbaijan) undergone all ontogenetic reproductive (pollen grain productivity, embryo and fruit developmental stages) and produce viable seeds. The floral initiation stage varies between 66-77 days depending on genotype, plant height, days to flowering and to seed maturity, and dry weight biomass (p > 0.05). The interaction effect of location and genotypes was significant for days to flowering and seed maturity and dry weight, though not for plant height and seed yield. Three early-middle and late-flowering, and thus early-middle and late seed maturation clusters of quinoas was described. Quinoa is predominantly self-pollinating species, but pollination inside the inflorescence by means of wind (anemophilous) or with support of small insects (entomophilous) occurs. There was no significant difference in the fruit and seed morphology among investigated accessions of quinoa cultivated under new environments. Fruits of quinoa are simple, dry, indehiscent, achene, monosperm with white pericarp in the mature state and remainans of perigonium, albuminous white or yellowish seed 1.8-2.5 mm in diameter. In quinoa seeds the pericarp is very thin; as a result, the achene is also referred to as utricle.Viable seed contains a peripheral, curved embryo surrounding by perisperm and pericarp. Pronounced micropylar endosperm (a non-embryonic tissue) of one or two cell layers thick forms a cone surrounds the root apical meristem of the embryo. Anatomy of quinoa micropylar endosperm revealed similarities in structure with coleorhiza cells in cereals. Both tissues serve as store reserve and play vital role by protecting the root apical meris-tem in the quiescent seed and control dormancy during germination. Further investigation of micropylar cellular tissue of quinoa, where stores lipids, proteins and minerals should be considered to select better adapted genotypes with high seed yields and nutritional qua-lity combined with salt-and drought-tolerance. Freshly collected quinoa seeds have endogenous physiological type of dormancy. All investigated quinoa accessions, except Quinoa-Q2 showed high germination rate (78-85%) through 16 hours at room temperature (24-25 ºC). Identification of desirable genotypes needs to be followed by work on optimization of cultural practices and seed storage to maximize productivity under the drought-prone and salt affected of Kur-Araz farming areas. Early seed sowing in the field is required, thus early flowering and seed maturation occurs long before heat summer season starts.

Potencial germinativo en semillas de quinua (Chenopodium quinoa Willd.) almacenadas bajo condiciones de frío

Quinoa is a crop with high potential due to its nutritional properties, wide adaptation to edaphoclimatic conditions and genetic diversity. This research aimed at evaluating four accessions of quinoa (Chenopodium quinoa) seeds, as well as their viability and germination percentage after cold storage. Storage temperatures and time were 4-20, -80°C and 10 months, with evaluation every two months. Initial seed viability was lower than 71% for all accessions and moisture content 10%. After storage, all accessions showed an increase in germination percentage. The accession with the greatest increase in terms of germination and the lowest moisture level (10,66%) before treatments, was the Narino cultivar. Quinoa seed showed a secondary dormancy because of adverse storage conditions, this was inferred from the better response in germination after cold storage treatment. On the other hand, quinoa loses its germinative potential in short periods of time when stored under environmental conditions, therefore, regarding its storage, cool conditions and seed moisture content near 10% are recommended.

Morphological features of different accessions of Chenopodium quinoa

Morphological features of different accessions of Chenopodium quinoa

Development of novel InDel markers and genetic diversity in Chenopodium quinoa through whole-genome re-sequencing

BackgroundQuinoa (Chenopodium quinoa Willd.) is a balanced nutritional crop, but its breeding improvement has been limited by the lack of information on its genetics and genomics. Therefore, it is necessary to obtain knowledge on genomic variation, population structure, and genetic diversity and to develop novel Insertion/Deletion (InDel) markers for quinoa by whole-genome re-sequencing.ResultsWe re-sequenced 11 quinoa accessions and obtained a coverage depth between approximately 7× to 23× the quinoa genome. Based on the 1453-megabase (Mb) assembly from the reference accession Riobamba, 8,441,022 filtered bi-allelic single nucleotide polymorphisms (SNPs) and 842,783 filtered InDels were identified, with an estimated SNP and InDel density of 5.81 and 0.58 per kilobase (kb). From the genomic InDel variations, 85 dimorphic InDel markers were newly developed and validated. Together with the 62 simple sequence repeat (SSR) markers reported, a total of 147 markers were used for genotyping the 129 quinoa accessions. Molecular grouping analysis showed classification into two major groups, the Andean highland (composed of the northern and southern highland subgroups) and Chilean coastal, based on combined STRUCTURE, phylogenetic tree and PCA (Principle Component Analysis) analyses. Further analysis of the genetic diversity exhibited a decreasing tendency from the Chilean coast group to the Andean highland group, and the gene flow between subgroups was more frequent than that between the two subgroups and the Chilean coastal group. The majority of the variations (approximately 70%) were found through an analysis of molecular variation (AMOVA) due to the diversity between the groups. This was congruent with the observation of a highly significant FST value (0.705) between the groups, demonstrating significant genetic differentiation between the Andean highland type of quinoa and the Chilean coastal type. Moreover, a core set of 16 quinoa germplasms that capture all 362 alleles was selected using a simulated annealing method.ConclusionsThe large number of SNPs and InDels identified in this study demonstrated that the quinoa genome is enriched with genomic variations. Genetic population structure, genetic core germplasms and dimorphic InDel markers are useful resources for genetic analysis and quinoa breeding.

COMPUESTOS BIOACTIVOS Y ACTIVIDAD ANTIOXIDANTE DE SEMILLAS DE QUINUA PERUANA (Chenopodium quinoa W.)

Se investigaron azúcares reductores, compuestos bioactivos y actividad antioxidante de 24 accesiones de quinua de la colección nacional del INIA Perú. Las semillas mostraron fenólicos totales entre 0,783 a 3,437 mg GAE/g, flavonoides totales entre 0,199 y 1,029 mg CE/g muestra, betacianinas y betaxantinas en cantidades no significativas, y azúcares reductores entre 30,973 y 88,278 equivalentes mg de glucosa/g muestra. La actividad antioxidante según DPPH y ABTS mostraron diferencias significativas entre las diferentes semillas de quinua estudiadas.

Yield and Dry Matter Simulation Using the Saltmed Model for Five Quinoa (Chenopodium Quinoa) Accessions Under Deficit Irrigation in South Morocco

AbstractThe frequent drought in the Mediterranean region requires better water and crop management. Selection of suitable drought‐tolerant crops and the application of water‐saving strategies are essential.For this reason, a drought‐tolerant crop, quinoa, was selected to test its suitability to be grown under Morocco's conditions. In 2012, five accessions of quinoa (Chenopodium quinoa Willd.) were studied in a field in Agadir, Morocco. Four irrigation levels were applied; the control treatment received 100% of the crop water requirement and three other treatments received 75, 50 and 25% of the crop water requirement.The SALTMED model was calibrated using yield and total dry matter data obtained from the control treatment for each accession. The accessions differed in plant height, growth stage duration, harvest date, harvest index, leaf area index and photosynthesis efficiency. The SALTMED model simulated the total dry matter and grain yield for the five quinoa accessions under the different deficit irrigation regimes with reasonable precision, as confirmed by the values of coefficient of determination, R2 of 0.96 and 0.92, respectively.The results indicate that deficit irrigation at 75% would only reduce the yield of accession L142 by 5%. Therefore, L142 was recommended to the growers in Morocco. Copyright © 2017 John Wiley & Sons, Ltd.

Morphoagronomic response and protein quality of three accessions of quinoa (Chenopodium quinoa Willd.) in the northern sabana of Bogotá

La quinua Chenopodium quinoa Willd. es una planta dicotiledonea, considerada un pseudocereal, por las caracteristicas del cultivo y formas de consumo, que ha pasado a ser de interes mundial en los ultimos anos, debido a su alta calidad nutritiva y de amplia adaptacion ecologica. Con el objetivo de aportar al conocimiento del cultivo, se evaluaron caracteristicas de rendimiento, de calidad, de variacion morfologica y de desarrollo fenologico, de tres accesiones de quinua, denominadas Piartal, Narino y Bolivia. El estudio, se llevo a cabo en la sede El Remanso de la Universidad de Ciencias Aplicadas y Ambientales U.D.C.A, ubicada en el norte de Bogota, con coordenadas geograficas 4°35' latitud norte y 74°04' longitud oeste. La evaluacion fue realizada durante un ciclo de produccion. Los resultados indicaron diferencias en rendimiento por planta, contenido de proteina, caracteristicas morfologicas de la coloracion del tallo, forma de la panoja y madurez fisiologica. El rendimiento promedio vario entre 140,09 a 260,74g por planta; los mayores rendimientos se presentaron en la accesion Piartal que, a su vez, revelo el desarrollo fenologico mas corto, de seis meses. Las accesiones evaluadas mostraron alta homogeneidad fenotipica al interior de cada material, lo que permite su uso en cultivos comerciales directamente y tambien como parental, para hibridacion dentro de programas de mejoramiento genetico.

Adaptive responses of quinoa to diverse agro-ecological environments along an altitudinal gradient in North West Argentina

Quinoa is an important Andean grain crop grown in a wide range of tropical and temperate environments. Time to flowering is an important trait determining grain yield. This work aimed to understand how responses to photoperiod and temperature might alter plant leaf and floral development. To assess the likely degree of G×E interactions, eleven quinoa accessions from a wide range of environments of origin within Northwest Argentina were grown in several sowing dates over two seasons at a high altitude site. In a third season at a low altitude site, a subset of six accessions planted in pots in the field was exposed to two artificially extended and a control (natural) photoperiod. Time to the appearance of floral buds and anthesis were recorded as was leaf number. A photothermal model developed for quinoa was used to compare responses to photoperiod. Plant development rates to visible floral buds and anthesis stages and phyllochron varied widely amongst accessions and across environments within a short day response though phyllochron varied mostly during the reproductive phase. There was a very strong association between time to flowering and altitude of origin (r=−0.98), mean temperature of the wettest quarter (r=0.98) and Normalized Difference Vegetation Index values (r=0.73). Photoperiod sensitivity was higher for accessions from the lowlands (normally late flowering), while temperature sensitivity was greatest for accessions from the highlands (early flowering); most variation for these traits detected at the species level was found in North West Argentina. Genotype by environment interactions for yield were related to the traits examined in this study and considering their high heritability it is suggested that quinoa breeding programs targeted for specific adaptation to a wide range of environments can be developed from this germplasm.

Diversity and interrelationships in nutritional traits in cultivated quinoa (Chenopodium quinoa Willd.) from Northwest Argentina

Quinoa (Chenopodium quinoa Willd.) is one of the oldest crops in the American continent. It has been recognized as an extremely nutritious grain all over the world. The importance that quinoa could play in nutrition is being emphasized not only in developing countries but also in the developed world. This is the first study reporting the nutritional characterization of Argentinean quinoa germplasm and describing diversity and interrelationships among nutritional traits, less studied in quinoa, which could provide tools for breeding strategies. Nutritional properties of quinoa accessions collected in different eco-regions from Northwest Argentina but grown on the same environment show a wide range of variation with only subtle differences according to the population's region of origin. However, Argentinean quinoa germplasm did not show clear genetic structure across regions based on nutritional traits as is the case with phenotypic and genotypic traits evaluated on a similar set of accessions.

Quinoa's Potential in the Mediterranean Region

AbstractThe climate of Mediterranean region will become drier and hotter, with increased problems of soil salinity. A possible alternative to minimize the effects of climate change is to introduce species with better tolerance to salt and drought stresses. One of the options is quinoa (Chenopodium quinoa Willd.), which was grown in field trials in several Mediterranean countries, to study the effects of drought and salinity on yield and other characters. Drought stress during the vegetative growth stage leads to deep root development, and without stress conditions for the rest of the growing season allowed the plant to be able to optimize its photosynthesis and carbon translocation. Stress during seed filling recorded the lowest yields. The influence of organic matter on yield was more important under deficit irrigation than under full irrigation. The interaction between relative water content and leaf water potential indicated that regulating cellular water deficit and volume is a powerful mechanism for conserving cellular hydration under drought. In all climatic conditions, drought and use of irrigation water with salinity up to 30 dS m−1 caused slightly reduced yield as compared to full irrigation with fresh water. Highest values of water conductivity resulted in higher seed weight, and as a consequence, an increase in fibre and total saponin content, and a small decrease in free phenolic compounds in quinoa seeds. The yield increase in quinoa accessions was less at the highest level of nitrogen application, that is, 200 mg kg−1 soil, compared with other levels of nitrogen application, that is, 50, 100 and 150 mg kg−1 soil.

Single Nucleotide Polymorphism Identification, Characterization, and Linkage Mapping in Quinoa

Quinoa (Chenopodium quinoa Willd.) is an important seed crop throughout the Andean region of South America. It is important as a regional food security crop for millions of impoverished rural inhabitants of the Andean Altiplano (high plains). Efforts to improve the crop have led to an increased focus on genetic research. We report the identification of 14,178 putative single nucleotide polymorphisms (SNPs) using a genomic reduction protocol as well as the development of 511 functional SNP assays. The SNP assays are based on KASPar genotyping chemistry and were detected using the Fluidigm dynamic array platform. A diversity screen of 113 quinoa accessions showed that the minor allele frequency (MAF) of the SNPs ranged from 0.02 to 0.50, with an average MAF of 0.28. Structure analysis of the quinoa diversity panel uncovered the two major subgroups corresponding to the Andean and coastal quinoa ecotypes. Linkage mapping of the SNPs in two recombinant inbred line populations produced an integrated linkage map consisting of 29 linkage groups with 20 large linkage groups, spanning 1404 cM with a marker density of 3.1 cM per SNP marker. The SNPs identified here represent important genomic tools needed in emerging plant breeding programs for advanced genetic analysis of agronomic traits in quinoa.

Implications of farmers’ seed exchanges for on-farm conservation of quinoa, as revealed by its genetic diversity in Chile

SUMMARYQuinoa cultivation in Chile presents an ancient and active complex of geographic, climatic, social and cultural interactions that has determined its current biodiversity in the three main growing zones (north, central and south). Importantly, these interactions involve the participation of farmers, whose activities are at the base of seed exchange networks due to their knowledge andin situconservation of genetic diversity. The present study reports how a better understanding of farmers’ seed exchanges and local production practices could impact the genetic structure and diversity of quinoa at national scale in Chile. Using field interviews and characterization of 20 microsatellite genetic markers in a multi-origin set of 34 quinoa accessions representative of Chile and the South American region, the phenetic analysis of germplasm was consistent with the current classification of quinoa ecotypes present in Chile and Andean zone. This allowed the identification of five populations, which were represented by quinoa of Salares (northern Chile), Coastal/Lowlands (central and southern Chile), Highlands (Peru, Bolivia and Argentina) and Inter-Andean Valleys (Ecuador and Colombia). The highly informative quality of the markers used revealed a wide genetic diversity among main growing areas in Chile, which correlated well with natural geographical–edaphic–climatic and social–linguistic context to the expansion of quinoa biodiversity. Additionally, in addition to ancient seed exchanges, this process is still governed by the diverse agricultural practices of Andean farmers. Genetic erosion is considered an imminent risk due to small-scale farming, where the influence of increased migration of people to urban systems and export-driven changes to the agro-ecosystems may further reduce the diversity of quinoa plants in cultivation.