oa Restoration of saltdegraded marginal lands through cultivation of nutrient enriched quinoa in UAE: impact on growth yield traits and carbon isotope fractionation

Quinoa is an important nutritive crop that can play a strategic role in the development of marginal and degraded lands. Our aim was to evaluate and select superior salt tolerant quinoa genotypes that are well adapted to the UAE climate. We evaluated the carbon isotope composition, seed yield and other agronomical attributes as indicative of the functional performance of quinoa. Field trial was conducted in the hyper dry arid climate in Dubai, UAE and irrigation treatments comprised of saline water with three different salt concentrations (0, 10, 20 dS m-1) during growth and reproductive phase of quinoa. Plant growth, agro-physiological and isotopic composition responses of 6 quinoa genotypes were measured. Significant variations occurred in dry biomass, seed yield, plant height, number of branches, number of panicles, panicle weight, harvest index, N and C content. The stable isotope composition of carbon values varied among quinoa genotypes. Some genotypes produced yields with values significantly greater than 2.04 t ha-1 (Q12), with average increasing to 2.58 t ha-1 (AMES22157). The present study indicated a large variation in Δ values (3.43‰) among quinoa genotypes for salinity treatments and small amplitude of variations was found among the genotypes (0.95‰). Results from the current study showed that Δ might be used as an important selection index for screening and selection the tolerant stable quinoa genotypes that have high iWUE. The data indicate that some genotypes showed higher photosynthetic accimilation traits (ci/ca, iWUE) and were more productive, stable and higher yielder at various salinities. This study provides a reliable measure of specific responses of quinoa cultivars to salinity and it may be valuable in breeding programs. The development of genotypes having both high yield performance and high WUE would be a very useful contribution for producers in the dry regions like Arabian Desert climate.