Abstract: In Songnen Plain of northern China, salt marsh has been threatened by increasing flooding and soil salinity-alkalinity since the late 20th century. To explore how plants respond to such environmental changes, we examined the effect of flooding stress and saline stress on growth of Zizania latifolia under greenhouse conditions. We conducted a pot experiment with four water depths (5, 15, 30, and 60 cm) and four salinity levels (0, 15, 50, and 100 mmol·L^-1) and explored the tolerance and adaptive strategies of Z. latifolia, aiming to provide a reference for the protection and restoration of saline-alkali wetlands in this region. The results showed that: (1) Flooding had a significant effect on the growth and biomass allocation of Z. latifolia(P<0.05). As the water depth increased, plant height and aboveground biomass increased, while rhizome length, root length, total biomass, underground biomass and root-shoot ratio significantlydecreased. Leaf area showed a downward trend after a rise. (2) Salinity had significant effects on all the examined traits except root-shoot ratio. Plant height, leaf area, rhizome length, root length, total biomass, aboveground and underground biomass of Z. latifolia significantly decreased with increasing salinity (P<0.05). (3) Water depth and salinity significantly interacted in their effects on plant height, aboveground and underground biomass (P<0.05). In general, Z. latifolia survived in 60 cm water depth and 100 mmol·L^-1 salinity. However, the growth of Z. latifolia varied among different stress conditions. We concluded that Z. latifolia is highly tolerant to flooding and can resist flooding stress through elongating shoot and allocating more biomass to aboveground, while it shows poor tolerance to salt stress, which has negative effects on its morphological development and biomass accumulation.

Key words: quinclorac, bioremediation., corncob, bamboo charcoal and canola meal carrier, immobilization