Quinoa plant architecture: A key factor determining plant productivity and seed quality under long-term drought

• Published in: Environmental and experimental botany 2023-07, Vol.211, p.105350, Article 105350
• Main Authors: Maestro-Gaitán, Isaac, Granado-Rodríguez, Sara, Poza-Viejo, Laura, Matías, Javier, Márquez-López, José Carlos, Pedroche, Justo Javier, Cruz, Verónica, Bolaños, Luis, Reguera, Maria
• Format: Article
• Language: English
• Subjects: calcium; Chenopodium quinoa; copper; cultivars; Drought; food security; iron; irrigation rates; manganese; mineral content; nutritive value; plant architecture; Primary panicle; proximate composition; Quinoa; Secondary panicle; seed germination; Seed nutritional quality; seed quality; seed weight; Seed yield; viability; water shortages; water stress; zinc
• ISSN: 0098-8472; 1873-7307
• DOI: 10.1016/j.envexpbot.2023.105350

Chenopodium quinoa (quinoa) is an underutilized crop proposed as key to achieving food security within the current climatic context, where water scarcity in rainfed areas is becoming more frequent and severe, especially in Mediterranean regions. Thus, aiming at deepening our knowledge regarding the impact of water limitation on the quinoa seed nutritional quality, seeds obtained from primary and secondary panicles of four different European-adapted cultivars (F14, F15, F16, and Titicaca) growing under full irrigation and water-limiting conditions, were here analyzed. A set of parameters were evaluated in this work, including agronomical (such as yield, seed weight, seed area, and seed germination and viability rates) and nutritional (including the seed proximate composition, mineral content, and antioxidants) traits. Our results indicate that the morphological changes associated with drought stress affect secondary panicles’ seed yield. This phenomenon was generally associated with an improvement in the nutritional quality of those seeds. However, cultivars such as F16, despite keeping total seed yield under low water availability, showed drought's detrimental effect on the seed nutritional quality. In contrast, cultivars like F15 and Titicaca reduced their seed yield under water-limiting conditions but increased their protein, iron, copper, calcium, manganese, and zinc contents, especially in secondary panicles. Therefore, the dichotomy between seed quantity and quality has to be considered in this crop under water stress scenarios, highlighting differences in sink strength along the plant panicles determining seed nutritional quality. •Quinoa primary and secondary panicles show distinct nutritional quality.•The drought-sensitive genotypes showed larger yields in the secondary panicles.•Secondary panicle seeds stood out by their protein, fiber, iron, calcium, copper, manganese, and zinc contents.•Water stress reduced the fat content of primary panicles but increased the protein and iron contents.•The drought-tolerant genotype F16 yielded lower-quality seeds.