Molecular characterization of Ecuadorian quinoa (Chenopodium quinoa Willd.) diversity: implications for conservation and breeding

• Published in: Euphytica Vol. 215; no. 3; pp. 1 - 11
• Main Authors: Salazar, Juan, de Lourdes Torres, María, Gutierrez, Bernardo, Torres, Andrés Francisco
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.03.2019; Springer; Springer Nature B.V
• Subjects: Agronomy; alleles; Analysis; Andes region; Biodiversity; Biomedical and Life Sciences; Biotechnology; Breeding; breeding programs; Chenopodium quinoa; Divergence; Ecuador; Food security; Food supply; Genetic divergence; Genetic diversity; Genetic structure; genetic variation; Genotypes; Germplasm; Heterozygosity; Inbreeding; landraces; Life Sciences; microsatellite repeats; Nutritive value; plant breeding; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Quinoa; Seeds; Species; Species diversity; Subgroups; Ecuador; Andes region; Quinoa; Ecuador; Population structure; Genetic diversity; SSR; Breeding
• ISSN: 0014-2336; 1573-5060; 1573-5060
• DOI: 10.1007/s10681-019-2371-z

Quinoa ( Chenopodium quinoa Willd.) is recognized as an important crop to improve global food security. It has gained international recognition because of the nutritional value of its seeds and its broad agronomic resilience. Although several studies have attempted to characterize the genetic diversity of quinoa, none have focused on evaluating germplasm from Ecuador; the latter considered a relevant subcenter of diversity for the species. In this study, 84 accessions representing the species’ cultivated range in the Ecuadorian Andes were characterized using 15 species-specific SSR markers. The extent of allelic richness (196 alleles) and genetic heterozygosity ( H E  = 0.71) detected for these accessions demonstrate that Ecuadorian quinoa is highly diverse. Phenetic analyzes structured Ecuadorian germplasm into 3 subgroups; each containing genotypes from all surveyed provinces. Average expected heterozygosity was high for all 3 subgroups (0.53 ≤  H E  ≤ 0.72), and Nei-pairwise comparisons showed significant genetic divergence among them (0.31 ≤  Nei DST  ≤ 0.84). The lack of a clear geographic pattern in the genetic structure of Ecuadorian quinoa led us to believe that the 3 reported subgroups constitute independent genetic lineages representing ancestral landrace populations which have been disseminated throughout Ecuador via informal seed networks. Nevertheless, a Wilcoxon test showed that at least one subgroup had been subject to intensive inbreeding and selection; and possibly corresponds to the local commercial variety INIAP-Tunkahuan. Our results show that ancestral quinoa diversity in Ecuador has prevailed despite the introduction of commercial varieties, and should be preserved for future use in breeding programs.