Morphological and Physiological Traits Associated with Yield under Reduced Irrigation in Chilean Coastal Lowland Quinoa

Quinoa (Chenopodium quinoa Willd.) is a genetically diverse crop that has gained popularity in recent years due to its high nutritional content and ability to tolerate abiotic stresses such as salinity and drought. Varieties from the coastal lowland ecotype are of particular interest due to their insensitivity to photoperiod and their potential to be cultivated in higher latitudes. We performed a field experiment in the southern Atacama Desert in Chile to investigate the responses to reduced irrigation of nine previously selected coastal lowland self-pollinated (CLS) lines and the commercial cultivar Regalona. We found that several lines exhibited a yield and seed size superior to Regalona, also under reduced irrigation. Plant productivity data were analyzed together with morphological and physiological traits measured at the visible inflorescence stage to estimate the contribution of these traits to differences between the CLS lines and Regalona under full and reduced irrigation. We applied proximal sensing methods and found that thermal imaging provided a promising means to estimate variation in plant water use relating to yield, whereas hyperspectral imaging separated lines in a different way, potentially related to photosynthesis as well as water use.

Automated summary

Quinoa is a genetically diverse crop that can tolerate abiotic stresses and has gained popularity due to its high nutritional content. The coastal lowland ecotype of quinoa is of interest for cultivation in higher latitudes. A field experiment in Chile showed that some lines of coastal lowland self-pollinated (CLS) quinoa had higher yield and seed size than the commercial cultivar Regalona, even under reduced irrigation. Proximal sensing methods, such as thermal and hyperspectral imaging, were used to estimate plant water use and differences in photosynthesis among the lines.