Abstract
Aims: This study aimed to assess varietal differences of quinoa's tolerance to salinity and to investigate physiological mechanisms conferring these differences. Methods: Production of biomass in fourteen varieties grown under saline conditions was analysed in a pot experiment. For two contrasting varieties, the Danish variety Titicaca and the Bolivian variety Utusaya gas exchange, chlorophyll content index (CCI), fluorescence and ion relations were studied. Results: Responses to salinity differed greatly among the varieties; least affected were two varieties from the Bolivian altiplano and a variety from Peru. Titicaca and Utusaya both had substantially increased K+ concentrations in the leaf sap. But, Utusaya was much more efficient in restricting xylem Na+ loading. Xylem Na+ and K+ loading were found to be uncoupled. Utusaya maintained a relatively high stomatal conductance resulting in an only 25% NaCl-induced reduction in net CO 2 assimilation compared to a 67% reduction in salt treated Titicaca plants. Maximum photochemical efficiency of PSII was not affected by salinity. Conclusion: In addition to maintaining high gas exchange, tolerant varieties better control xylem Na+ loading. To what extent this control is related to radial root Na+ uptake or to the activity of Na+/H+-exchangers at the xylem parenchyma boundary remains to be studied.
Original language | English |
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Pages (from-to) | 117-129 |
Number of pages | 13 |
Journal | Plant and Soil |
Volume | 357 |
Issue number | 1 |
DOIs | |
Publication status | Published - Aug 2012 |
Externally published | Yes |