Studying the Impact of Different Field Environmental Conditions on Seed Quality of Quinoa: The Case of Three Different Years Changing Seed Nutritional Traits in Southern Europe

Abstract

Chenopodium quinoa Willd (quinoa) has acquired an increased agronomical and nutritional relevance due to the capacity of adaptation to different environments and the exceptional nutritional properties of their seeds. These include high mineral and protein contents, a balanced amino acid composition, an elevated antioxidant capacity related to the high phenol content, and the absence of gluten. Although it is known that these properties can be determined by the environment, limited efforts have been made to determine the exact changes occurring at a nutritional level under changing environmental conditions in this crop. To shed light on this, this study aimed at characterizing variations in nutritional-related parameters associated with the year of cultivation and different genotypes. Various nutritional and physiological traits were analyzed in seeds of different quinoa cultivars grown in the field during three consecutive years. We found differences among cultivars for most of the nutritional parameters analyzed. It was observed that the year of cultivation was a determinant factor in every parameter studied, being 2018 the year with lower yields, germination rates, and antioxidant capacity, but higher seed weights and seed protein contents. Overall, this work will greatly contribute to increase our knowledge of the impact of the environment and genotype on the nutritional properties of quinoa seeds, especially in areas that share climatic conditions to Southern Europe.

Genotype-Dependent Variation of Nutritional Quality-Related Traits in Quinoa Seeds

“…Both, the correlation and pathway analyses, showed a strong effect of the phenolic compounds and the P contents on the germination capacity of seeds (Supplementary Figure 3, Table 1). These results are in part supported by previous works, as it was already described a positive correlation between phenolic compounds and the germination capacity of quinoa seeds [25]. Furthermore, a stimulating effect of these compounds on the germination capacity has been reported as well in the close quinoa relative species Chenopodium album L. [54].…”

“…Yield was highly determined by different physiological traits including panicle size and plant biomass, but only correlated with two seed traits: the germination capacity and the phenolic content (Supplementary Figure 3). Intriguingly, previous works have observed correlations between yield and seed nutritional-related traits, like the positive correlation found between yield and the antioxidant capacity or the K content, or the negative correlation between yield and protein content or the amount of different amino acids [21,25,38]. However, these studies compared the nutritional profiles of quinoa seeds harvested from different cultivars but grown in different environmental conditions (with variations in the sowing date, the cultivation location, and/or the year of cultivation), and the variations on the nutritional traits of the seeds were mainly determined by differences in the environmental conditions at seed filling stage, which affect both, yield and seed-quality traits [25].…”

“…Intriguingly, previous works have observed correlations between yield and seed nutritional-related traits, like the positive correlation found between yield and the antioxidant capacity or the K content, or the negative correlation between yield and protein content or the amount of different amino acids [21,25,38]. However, these studies compared the nutritional profiles of quinoa seeds harvested from different cultivars but grown in different environmental conditions (with variations in the sowing date, the cultivation location, and/or the year of cultivation), and the variations on the nutritional traits of the seeds were mainly determined by differences in the environmental conditions at seed filling stage, which affect both, yield and seed-quality traits [25]. In the present study, only the genetic factor was evaluated, so the lack of correlations between yield and seed nutritional-related traits suggests that there might be no link between them, and those relations are only relevant when introducing the cultivars to new environments where they are not yet adapted.…”

“…In this study, most cultivars surpassed the 50% germination rate, but A-SE-13, A-SE-07, A-SE-01, and especially A-SE-03 and A-SE-06 (cluster 1), showed very low germination rates (Figures 5 and 9). Interestingly, a correlation between seed germination rates and the panicle's characteristics and seed yield of the mother plants was found [25] (Supplementary Figure 3), but germination rates were also influenced by nutritional traits of seeds. Both, the correlation and pathway analyses, showed a strong effect of the phenolic compounds and the P contents on the germination capacity of seeds (Supplementary Figure 3, Table 1).…”

“…What is still unclear is if the parameters that were evaluated are stable among cultivars at different locations or if steady correlations can be found between nutritional-related parameters. A recent work by Granado-Rodriguez et al [25] showed that some quinoa cultivars, Titicaca and Vikinga, present better qualityrelated traits (including higher protein contents) despite not being the most productive when growing in the Northwestern part of Spain. In line with this, it is key to better understand the genetic and environmental factors determining the nutritional characteristics of quinoa selecting the best adapted genotypes for a particular cultivation environment in terms of yield potential, biotic and abiotic stress tolerance but also considering the different nutritional traits.…”