Physiological response of <i>Miscanthus</i> genotypes to salinity stress under elevated <scp> CO ₂ </scp>

Abstract Miscanthus is a class of C 4 perennial grasses, which can be cultivated on marginal land even with high salinity. However, the future environment may altered by elevated atmospheric CO 2 concentration ([CO ]) and knowledge limited about interactive impacts enrichment salinity this bioenergy crop. In study, three genotypes ( M. sacchariflorus , × giganteus lutarioriparius ) were grown under either ambient (400 ppm) [CO ] or (800 e at five levels (0, 50, 100, 150, 200 m NaCl denoted as S0, S1, S2, S3, S4, respectively), plant physiological responses to salt stress investigated. Our results suggested that had no obvious effect net photosynthetic rate A n ), but significantly reduced stomatal conductance g s thus improving water use efficiency regardless levels. addition, could improve potential plants both control saline conditions, magnitude increase was highly genotypic dependent. The maximum quantum yield photosystem II F v / not ], which, however, alleviate negative . Furthermore, increased abscisic acid (ABA) in xylem sap leaves, while ABA level closely associated genotypes. Na + positive influences maintaining /K ratio, favoring ionic homeostasis, although such genotype Collectively, our data partially mitigate detrimental effects salinity, conferring higher tolerance