Correlation between the carbon isotope composition (δ13C) of Puccinellia ciliata and Balansa clover in duel stresses of waterlogging and salinity (NaCl)

Theoretically, plants growing under stress conditions, such as in saline or waterlogged conditions,should behave with 13CO2 discrimination and have different δ13C values. Therefore, thisexperiment was conducted to evaluate the effect of factors such as salinity and hypoxia inaffecting delta values of Puccinellia ciliata and Balansa clover (Trifolium michelianum Savi.Var balansae boiss). This study reveals that these two species (C3 plants) behave differently andB. clover has more positive δ13C values (7.6%) compared to P. ciliata. The overall average ofδ13C were -28.85 and -26.66 0/00, respectively, for P. ciliata and B. clover. The δ13C valuesfor the shoots and roots of the two species also have different values (more positive valuesin roots compared to shoots). Waterlogging and salinity have a significant affect on 13CO2discrimination and, statistically, these effects on δ13C values are significant (p <0:001). Thismeans that environmental factors, such as salinity and waterlogging, create a situation for plantsin which the discriminate rate against δ13C would be changed (less discrimination for hypoxia andmore for salinity conditions). The combined effects on species and plant parts of waterloggingand salinity are not statistically insignificant on δ13C values, however, each factor separatelyhas a significant effect on _13C values. P. ciliata was grown in different seasons (summer andwinter) and showed significant differences in δ13C values (by almost 4%). The carbon content(%) of the two species was different, but, were not related to δ13C, respectively.