Combined effects of soil salinity and high temperature on photosynthesis and growth of quinoa plants (Chenopodium quinoa)

Abstract

The halophytic crop quinoa (Chenopodium quinoa Willd.) is adapted to soil salinity and cold climate, but recent investigations have shown that quinoa can be grown in significantly warmer latitudes, i.e. the Mediterranean region, where high temperature and soil salinity can occur in combination. In this greenhouse study, effects of saltwater irrigation and high temperature on growth and development of the Bolivian cultivar ‘Achachino’ were determined. Development was slightly delayed in response to saltwater treatment, but significantly faster at high temperature. Biomass and seed yield decreased in response to salt, but not to high temperature. Plants increased their number of stomata in response to salt stress, but reduced its size on both sides of the leaf, whereas high temperature treatment significantly increased the stomata size on the abaxial leaf surface. When salt and high temperature was combined, the size of stomata was reduced only on the abaxial side of the leaf, and the number of epidermal bladder cells significantly increased on the abaxial leaf surface, resulting in preservation of photosynthetic quantum yields. We hypothesise that this morphological plasticity improves the partition of water and CO2 resulting in maintenance of photosynthesis in quinoa under adverse environmental conditions. We present a GLM-model that predicts yield parameters of quinoa grown in regions affected by soil salinity, high temperature and the factors combined.

Effect of high temperature on pollen morphology, plant growth and seed yield in quinoa (Chenopodium quinoa Willd.)

“…The same results were reported in the quinoa cv. “Achachino” at day/night temperatures of 28/20°C (Becker et al., ). The number of branches in sorghum increased under a temperature of 36/26°C; however, when the temperature was increased to 40/30°C, the number of branches was reduced (Prasad, Boote, & Allen, ).…”

“…Interestingly, the seed yield of the quinoa cv. “Achachino” increased at high temperature (28/20°C) when the plants were watered with freshwater, but there were no differences observed when the plants were watered with saltwater (Becker et al., ).…”

“…Moreover, night temperatures between 20 and 22°C reduced grain yield between 23% and 31% when high temperatures occurred during the flowering stage (Lesjak & Calderini, ). However, experiments in controlled conditions showed that day/night temperatures of 25/20°C stimulated quinoa growth (Becker et al., ; Yang, Akhtar, Amjad, Iqbal, & Jacobsen, ).…”

The scope for adaptation of quinoa in Northern Latitudes of Europe

“…40 °S), and further improved in European material leading to European cultivars from the Netherlands and Denmark (Galwey, ; Jacobsen, , ; Jacobsen & Stølen, ). It is concluded that a strong, daylength sensitive, stay green reaction is the main cause of the late maturity of South American quinoa accessions in North Europe (Adolf, Shabala, Andersen, Razzaghi, & Jacobsen, ; Becker et al., ; Christiansen et al., ).…”

Effect of Individual and Combined Salinity and High Temperature Stress during Germination Stage of Different Wheat (Triticum aestivum L.) Genotypes

“…Among genotypes the reduction in SPAD Value due to the given combined stress was highest in genotypes HD-2985, HT-8 and HI-1563 (41.8, 29.0 and 41.6 respectively) and least reduction in genotypes KRL-19, HD-2733 and KRL-1-4 (13, 12.6 and 14.5% respectively). Becker et al, 2017 also studied the effects of combined soil salinity and high temperature on photosynthesis and growth of quinoa plants (Chenopodium quinoa). Thus wheat genotypes KRL-19, HD-2733 and KRL-1-4 were considered as tolerant as they were able to tolerate the different stress interactions and genotypes HD-2985, HT-8 and HI-1563 were considered as susceptible.…”