Transcriptional Regulation of Quinoa Seed Quality: Identification of Novel Candidate Genetic Markers for Increased Protein Content

Genomic basis of seed colour in quinoa inferred from variant patterns using extreme gradient boosting

Quinoa is an agriculturally important crop species originally domesticated in the Andes of central South America. One of its most important phenotypic traits is seed colour. Seed colour variation is determined by contrasting abundance of betalains, a class of strong antioxidant and free radicals scavenging colour pigments only found in plants of the order Caryophyllales. However, the genetic basis for these pigments in seeds remains to be identified. Here we demonstrate the application of machine learning (extreme gradient boosting) to identify genetic variants predictive of seed colour. We show that extreme gradient boosting outperforms the classical genome-wide association approach. We provide re-sequencing and phenotypic data for 156 South American quinoa accessions and identify candidate genes potentially controlling betalain content in quinoa seeds. Genes identified include novel cytochrome P450 genes and known members of the betalain synthesis pathway, as well as genes annotated as being involved in seed development. Our work showcases the power of modern machine learning methods to extract biologically meaningful information from large sequencing data sets.

Current trends and prospects in quinoa research: An approach for strategic knowledge areas

Currently, the demand for healthy consumption and the use of alternatives to dairy proteins for the development of foods with good nutritional value are growing. Quinoa has received much attention because it contains a high content of proteins, essential amino acids, essential fatty acids, minerals, vitamins, dietary fibers, and bioactive compounds. Nevertheless, this content and the bioavailability of specific compounds of interest are related to the genotype, the agri-environmental conditions, and management practices where quinoa is grown and postharvest management. This article aimed to analyze the research trends for three knowledge areas: quinoa plant breeding for nutraceutical properties, plant-soil relations focused on abiotic stresses, and postharvest and value-added transformation activities. To this end, a specific methodological design based on bibliometrics and scientometrics methods was used. Through these analyses based on publications' keywords, titles, abstracts, and conclusions sections, for each knowledge area, the key research trends (scope and main topics), the classification of trends based on their development and relevance degree, and the core of knowledge were established. The trends comprise the current state of research. Finally, analyzing the conclusions, recommendations, and future research sections of key publications, a strong correlation among plant breeding research to obtain varieties with tolerance to biotic and abiotic stresses, nutritional and functional compounds of interest for food safety, and the development of products with higher added value established interest in further research on the potential bioactivity of quinoa and the verification of health benefits to humans.

Agro-morphological and nutritional assessment of chenopod and quinoa germplasm-Highly adaptable potential crops

Quinoa belongs to the family Chenopodiaceae, a pseudo-grain having high nutritional value and is considered an underexploited vegetable crop with the potential to improve the nutritional security of millions. Therefore, assessing genetic diversity in Chenopodium germplasm to untap nutritional and site-specific adaptation potential would be of prime importance for breeders/researchers. The present study used 10 accessions of two Chenopodium species, that is, C. quinoa and C. album. Quantitative and qualitative phenotypic traits, proximate composition, minerals, and amino acids profiles were studied to compare the differences in nutritional value and extent of genetic diversity between these two species. Our results showed significant variation existed in yield attributing agro-morphological traits. All the traits were considered for hierarchical clustering and principal components analysis. Large genetic variability was observed in traits of Chenopodium accessions. The protein, dietary fiber, oil, and sugar content ranged from 16.6% to 19.7%, 16.8% to 26%, 3.54% to 8.46%, and 3.74% to 5.64%, respectively. The results showed that C. album and C. quinoa seeds had good nutritional value and health-promoting benefits. The C. quinoa was slightly ahead of than C. album in terms of nutritional value, but C. album accession IC415477 was at par for higher test weight, seed yield (117.02 g/plant), and other nutritional parameters with C. quinoa accessions. IC415477 and other potential accessions observed in this study may be taken up by breeders/researchers in the near future to dissect nutritional value of Chenopodium and related species for dietary diversity, which is imperative for the nutritional security of the ever-growing world's population.

A comprehensive characterization of agronomic and end-use quality phenotypes across a quinoa world core collection

Quinoa (Chenopodium quinoa Willd.), a pseudocereal with high protein quality originating from the Andean region of South America, has broad genetic variation and adaptability to diverse agroecological conditions, contributing to the potential to serve as a global keystone protein crop in a changing climate. However, the germplasm resources currently available to facilitate quinoa expansion worldwide are restricted to a small portion of quinoa's total genetic diversity, in part because of day-length sensitivity and issues related to seed sovereignty. This study aimed to characterize phenotypic relationships and variation within a quinoa world core collection. The 360 accessions were planted in a randomized complete block design with four replicates in each of two greenhouses in Pullman, WA during the summer of 2018. Phenological stages, plant height, and inflorescence characteristics were recorded. Seed yield, composition, thousand seed weight, nutritional composition, shape, size, and color were measured using a high-throughput phenotyping pipeline. Considerable variation existed among the germplasm. Crude protein content ranged from 11.24% to 17.81% (fixed at 14% moisture). We found that protein content was negatively correlated with yield and positively correlated with total amino acid content and days to harvest. Mean essential amino acids values met adult daily requirements but not leucine and lysine infant requirements. Yield was positively correlated with thousand seed weight and seed area, and negatively correlated with ash content and days to harvest. The accessions clustered into four groups, with one-group representing useful accessions for long-day breeding programs. The results of this study establish a practical resource for plant breeders to leverage as they strategically develop germplasm in support of the global expansion of quinoa.

Diversity of quinoa genetic resources for sustainable production: A survey on nutritive characteristics as influenced by environmental conditions

Environmental extremes and climatic variability have enhanced the changes in numerous plant stressors. Researchers have been working to improve “major” crops for several decades to make them more adaptable and tolerant to environmental stresses. However, neglected and underutilized crop species that have the potential to ensure food and nutritional security for the ever-growing global population have received little or no research attention. Quinoa is one of these crops. It is a pseudocereal, considered a rich and balanced food resource due to its protein content and protein quality, high mineral content, and health benefits. This review provides currently available information on the genetic resources of quinoa and their quality in terms of variability of economically important traits such as yield, and the content of bioactive compounds, such as protein and amino acid composition. The influence of variety and environmental conditions on selected traits is also discussed. The various types of nutrients present in the different varieties form the basis and are key for future breeding efforts and for efficient, healthy, and sustainable food production.