Effect of Water Stress during Grain Filling on Yield, Quality and Physiological Traits of Illpa and Rainbow Quinoa (Chenopodium quinoa Willd.) Cultivars

Abstract

The total area under quinoa (Chenopodium quinoa Willd.) cultivation and the consumption of its grain have increased in recent years because of its nutritional properties and ability to grow under adverse conditions, such as drought. Climate change scenarios predict extended periods of drought and this has emphasized the need for new crops that are tolerant to these conditions. The main goal of this work was to evaluate crop yield and quality parameters and to characterize the physiology of two varieties of quinoa grown under water deficit in greenhouse conditions. Two varieties of quinoa from the Chilean coast (Rainbow) and altiplano (Illpa) were used, grown under full irrigation or two different levels of water deficit applied during the grain filling period. There were no marked differences in yield and quality parameters between treatments, but the root biomass was higher in plants grown under severe water deficit conditions compared to control. Photosynthesis, transpiration and stomatal conductance decreased with increased water stress in both cultivars, but the coastal variety showed higher water use efficiency and less discrimination of 13C under water deficit. This response was associated with greater root development and a better stomatal opening adjustment, especially in the case of Rainbow. The capacity of Rainbow to increase its osmoregulant content (compounds such as proline, glutamine, glutamate, K and Na) could enable a potential osmotic adjustment in this variety. Moreover, the lower stomatal opening and transpiration rates were also associated with higher leaf ABA concentration values detected in Rainbow. We found negative logarithmic relationships between stomatal conductance and leaf ABA concentration in both varieties, with significant R2 values of 0.50 and 0.22 in Rainbow and Illpa, respectively. These moderate-to-medium values suggest that, in addition to ABA signaling, other causes for stomatal closure in quinoa under drought such as hydraulic regulation may play a role. In conclusion, this work showed that two quinoa cultivars use different strategies in the face of water deficit stress, and these prevent decreases in grain yield and quality under drought conditions.

Qualitative and Quantitative Differences in Osmolytes Accumulation and Antioxidant Activities in Response to Water Deficit in Four Mediterranean Limonium Species

“…This finding clearly suggests the presence of active transport systems of these ions to aerial plant parts, which was also found under salt stress in Limonium [18]. High leaf concentrations of K + and Na + also play an important role in osmotic adjustment under water stress in quinoa, as has been recently reported [25]. Secondly, significant differences were not found between the stressed and control plants in ion leaf contents for any ions or any species.…”

Morphological Response of Takka Plant (Tacca leontopetaloides L.) as Traditional Medicine for Drought Stress

“…Table 6 shows that the treatment of a 25% decrease in water content gave a significant effect on stem diameter and was lower than the 50%, 75% and 100% media moisture content. In accordance with research [19] that lack of water will interfere with physiological and morphological activities, resulting in the cessation of growth. This is presumably due to the lack of water available to plants causing a decrease in the rate of photosynthesis which results in at least asimilat scattered throughout the plant.…”

Future CO2, warming and water deficit impact white and red Tempranillo grapevine: Photosynthetic acclimation to elevated CO2 and biomass allocation

“…Leaf C/N ratio was determined, in five replications, at maturity (one leaf from five plants per treatment chosen randomly). C and N concentration (%) analyses were based on sample dynamic combustion, using an elemental analyser (ThermoFinnigan FlashEA1112, Thermo-Fisher Scientific) equipped with a MAS200R autosampler, as described in Gámez et al (2019). Briefly, oven-dried leaf samples 2A, E).…”