Salinity threshold value of Quinoa (<i>Chenopodium Quinoa</i>‎Willd.) at ‎various growth stages and the appropriate ‎irrigation method by saline ‎water

2020

BMC Plant Biol

Background: Chenopodium quinoa Willd., a halophytic crop, shows great variability among different genotypes in response to salt. To investigate the salinity tolerance mechanisms, five contrasting quinoa cultivars belonging to highland ecotype were compared for their seed germination (under 0, 100 and 400 mM NaCl) and seedling's responses under five salinity levels (0, 100, 200, 300 and 400 mM NaCl).Results: Substantial variations were found in plant size (biomass) and overall salinity tolerance (plant biomass in salt treatment as % of control) among the different quinoa cultivars. Plant salinity tolerance was negatively associated with plant size, especially at lower salinity levels (< 300 mM NaCl), but salt tolerance between seed germination and seedling growth was not closely correlated. Except for shoot/root ratio, all measured plant traits responded to salt in a genotype-specific way. Salt stress resulted in decreased plant height, leaf area, root length, and root/shoot ratio in each cultivar. With increasing salinity levels, leaf superoxide dismutase (SOD) activity and lipid peroxidation generally increased, but catalase (CAT) and peroxidase (POD) activities showed non-linear patterns. Organic solutes (soluble sugar, proline and protein) accumulated in leaves, whereas inorganic ion (Na + and K + ) increased but K + / Na + decreased in both leaves and roots. Across different salinity levels and cultivars, without close relationships with antioxidant enzyme activities (SOD, POD, or CAT), salinity tolerance was significantly negatively correlated with organic solute and malondialdehyde contents in leaves and inorganic ion contents in leaves or roots (except for root K + content), but positively correlated with K + /Na + ratio in leaves or roots. Conclusion:Our results indicate that leaf osmoregulation, K + retention, Na + exclusion, and ion homeostasis are the main physiological mechanisms conferring salinity tolerance of these cultivars, rather than the regulations of leaf antioxidative ability. As an index of salinity tolerance, K + /Na + ratio in leaves or roots can be used for the selective breeding of highland quinoa cultivars.

Section: Accumulation Of Organic Osmolytes May Be Adaptivesupporting

confidence: 80%

Section: Plant Materials and Experimental Designmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Comparative physiological and biochemical mechanisms of salt tolerance in five contrasting highland quinoa cultivars

2020

BMC Plant Biol

Section: Introductionmentioning

confidence: 99%

Comparative physiological and biochemical mechanisms of salt tolerance in five contrasting highland quinoa cultivars

2020

Preprint

Background: Chenopodium quinoa Willd., a halophytic crop, shows great variability among different genotypesin response to salt. To investigate the salinitytolerance mechanisms, five contrasting quinoa cultivars belonging to highland ecotype were compared for their seed germination (under 0, 100 and 400 mM NaCl) and seedling’s responses under five salinity levels (0, 100, 200, 300 and 400 mM NaCl). Results: Substantial variations were found in plant size (biomass) and overall salinity tolerance (plant biomass in salt treatment as % of control) among the different quinoa cultivars. Plant salinity tolerance was negatively associated with plant size, especially at lower salinity levels (<300 mM NaCl), but salt tolerance between seed germination and seedling growth is was not closely correlated. Except for shoot/root ratio, all measured plant traits responded to salt in a genotype-specific way. Salt stress resulted in decreased plant height, leaf area, root length, and root/shoot ratio in each cultivar. With increasing salinity levels, leaf superoxide dismutase (SOD) activity and lipid peroxidation generally increased, but catalase (CAT) and peroxidase (POD) activities showed non-linear patterns. Organic solutes (soluble sugar, proline and protein) accumulated in leaves, whereas inorganic ion (Na + and K + )increased but K + /Na + decreased in both leaves and roots. Across different salinity levels and cultivars, without close relationships with antioxidant enzyme activities (SOD, POD, or CAT), salinity tolerance was significantly negatively correlated with leaf organic solute and malondialdehyde contents in leaves and inorganic ion contents in leaves or roots ( not except for root K + content), but positively correlated with K + /Na + ratio in leaves or roots. Conclusion: Our results establish indicate ed that leaf osmoregulation, K + retention, Na + exclusion, and ion homeostasis are the main physiological mechanisms conferring salinity tolerance of these cultivars, rather than the regulations of leaf antioxidative ability.As an index of salinity tolerance, K + /Na + ratio in leaves or roots can be used for the selective breeding of highland quinoa cultivars.

“…Among plants in 56 families of Douglas-fir, a trade-off between plant growth rate and cold hardiness, but not for drought, occurred [22]. As for salinity, it was hypothesized that the osmotic effect mostly limits the growth of salt-stressed plants, irrespective of the plant's capacity of excluding salt, resulting in decreased growth rate (biomass) [2].…”

Section: Introductionmentioning

confidence: 99%

Comparative physiological and biochemical mechanisms of salt tolerance in five contrasting highland quinoa cultivars

2019

Preprint

Background Chenopodium quinoa Willd., a halophytic crop, shows great variability among different genotypes in response to salt. To investigate the salinity tolerance mechanisms, five quinoa cultivars belonging to highland ecotype were compared for their seed germination (under 0, 100 and 400 mM NaCl) and seedling’s responses under five salinity levels (0, 100, 200, 300 and 400 mM NaCl).Results Substantial variations were found in plant size (biomass) and overall salinity tolerance (plant biomass in salt treatment as % of control) among the quinoa cultivars. Plant salinity tolerance was negatively associated with plant size, especially at lower salinity levels (<300 mM NaCl), but salt tolerance between seed germination and seedling growth is not closely correlated. Except for shoot/root ratio, all measured plant traits responded to salt in a genotype-specific way. Salt stress resulted in decreased plant height, leaf area, root length, and root/shoot ratio in each cultivar. With increasing salinity levels, leaf superoxide dismutase (SOD) activity and lipid peroxidation generally increased, but catalase (CAT) and peroxidase (POD) activities showed non-linear patterns. Organic solutes (soluble sugar, proline and protein) accumulated in leaves, whereas inorganic ion (Na + and K + ) increased but K + /Na + decreased in both leaves and roots. Across different salinity levels and cultivars, without close relationships with antioxidant enzyme activities (SOD, POD, or CAT), salinity tolerance was significantly negatively correlated with leaf organic solute and malondialdehyde contents and inorganic ion contents in leaves or roots (not root K + content), but positively correlated with K + /Na + ratio in leaves or roots.Conclusion Our results established that leaf osmoregulation, K + retention, Na + exclusion, and ion homeostasis are the main physiological mechanisms conferring salinity tolerance of these cultivars, rather than the regulations of leaf antioxidative ability. As an index of salinity tolerance, K + /Na + ratio in leaves or roots can be used for the selective breeding of highland quinoa cultivars.