Foliar stable carbon isotope compositions (δ13C) has been developed as an integrated indicator of water use strategy (WUS) for C3 plant, because it is related with the temporally averaged ratio of internal to ambient CO2 concentration (ci/ca), which is the result of both stomatal conductance and photosynthesis rate. Leymus chinensis has long been identified as a “euryhydric” species, occupying a large of area in eastern part of Euro-Asia steppe and thriving in diverse habitats. The spatial patter of foliar δ13C in it has been reported at several scales, showing that variance in foliar δ13C reflects moisture gradient. However, there is no evidence to unambiguously explain which is more important for driving its variance: phenotypic plasticity or local adaptation. L. chinensis growing in four locations along an aridity gradient are transplanted to a common garden and grown under controlled watering levels. Leaf δ13C changes in response to a moisture gradient are compared for the L. chinensis transplanted from different locations.
Results/Conclusions
Foliar δ13C value of all L. chinensis decreases with increasing watering levels. And Interactions between locations and watering also showed have significant effects on foliar δ13C of L.chinensis at α=0.104 level. Stable variation in foliar δ13C was observed between different locations’ L. chinensis. The results refer that local adaptation contributes to the difference in foliar δ13C of L. chinensis. And this is an evidence for functional divergence in L. chinensis.