Chlorophyll contents and photosynthetic characteristics of cassava seedlings in response to NaCl stress

To study the effect of severe salt stress on chlorophyll content and photosynthetic characteristics of cassava seedlings,four kinds of cassava seedlings were treated with NaCl solution,and the relative chlorophyll contents of leaves and photosynthetic parameters were measured. The results showed that relative chlorophyll contents,net photosynthetic rates,stomatal conductances,transpiration rates of four kinds of cassava subjected to 10 g / L NaCl stress were decreased and reached the lowest on day 5 of salt stress. Intercellular CO2 concentration showed an upward trend following initial decline,and reached the maximum on day 5 of salt stress. Stomatal limitation was replaced by non-stomatal limitation as a leading cause for decreased photosynthetic rate over the time of salt stress. Chlorophyll content and photosynthetic parameters were closely related to salt tolerance of cassava genotypes.