Variation in quinoa roots growth responses to drought stresses

Abstract

Soil moisture stress has become a serious environmental limitation to crop productivity and quality. The root system is the first organ sensing the changes in soil moisture; therefore, root development under water deficit is an important indicator for plant's drought tolerance. Previous studies focused on quinoa varietal differences in morphological traits under water stress; however, variation in root development including both growth and diameter responses to drought remains largely unclear. We conducted a preliminary screening of a diverse set of 30 quinoa genotypes to evaluate genetic variation in growth and yield performance in response to drought stress.Variation in drought tolerance indices showed large variation across the quinoa collection. Based on these results, five genotypes representative of a range of drought tolerance levels including 2-Want, Atlas, NL-6, Pichamán and Sayaña were selected to evaluate root development under control and severe drought conditions. Inhibition of root development was found for all genotypes as compared to controls; however, significant variation in root growth response to drought stress was observed. Among genotypes, Atlas and 2-Want expressed drought-tolerant phenotypes. The analysis of the interrelations between genotypes root length, root diameter, root surface area, drought tolerance and geographical origins reveals interesting guidelines for further studies to explore the mechanisms behind quinoa roots adaptation to drought.

Salinity and exogenous H2O2 improve gas exchange, osmoregulation, and antioxidant metabolism in quinoa under drought stress

“…Consequently, a strenuous antioxidant system is required for the efficient scavenging of ROS, and some sensitive plant genotypes may lack this system. It may be postulated that the wellestablished drought-sensitive nature of the Pichaman genotype (Iqbal et al, 2018b;Nguyen et al, 2022) is responsible for its weak antioxidant system under individual stresses in the present work. However, plants grown under combined stress showed higher antioxidant enzymes' activity than plants grown under single drought and salinity (Figure 5).…”

“…Bar values are the means of four replications with ±SE and different letters indicating significant differences among treatments by employing the LSD test at p ≤ 0.05 negative effects on quinoa without causing severe injuries (Iqbal et al, 2017;Orsini et al, 2011;Terletskaya et al, 2022). Notably, Nguyen et al (2022) also reported "Pichaman" as drought-sensitive and found a significant reduction in root and shoot dry weights compared to other quinoa genotypes under drought conditions. Though the detrimental effects of drought and salinity on plant growth and photosynthetic performance have been widely reported, the combination of these two stresses does not always have a negative effect on photosynthesis in plants (Li et al, 2020).…”

“…Drought‐sensitive quinoa genotype cv. “Pichaman” (Iqbal et al, 2018b; Nguyen et al, 2022) was grown in 5‐L plastic pots filled with loam soil; the physio‐biochemical properties of experimental soil were analyzed and given in Table 2. Five seeds were sown, and when three pairs of leaves became visible (BBCH‐13; Sosa‐Zuniga et al, 2017), only one healthy seedling per pot was maintained.…”

Effect of Nitrogen and Potassium on Growth, Yield, and Seed Quality of Quinoa in Ferralsols and Acrisols under Rainfed Conditions

“…The quinoa variety Atlas introduced from the Netherlands was used in the performed research. This was recommended as drought tolerance (Nguyen et al, 2021) and the best adaptive variety in Central Highland (Nguyen et al, 2020).…”