A Comparison of the Effects of Salinity on Photosynthetic Physiology of a Salt Sensitive Grass, Panicum obtusum, and a Salt Tolerant Grass, Distichlis Spicata
There have been numerous studies of the effects of substrate salinity on physiology, anatomy and growth of plants. Most studies have dealt with mechanisms of salt tolerance in native halophytes or agronomic plants which exhibit some degree of salt tolerance. Another approach to understanding mechanisms of salt tolerance is to examine the sensitivity of various aspects of structure in plants which are not salt tolerant. This approach has been used to some extent, mostly in studies of crop plants.
In order to broaden the understanding of salt tolerance, particularly in plants native to the southwest United States we have designed a comparative experiment encompassing both of the above approaches. This experiment focuses on examining the effects of substrate salinity on a grass which is tolerant of high salinity and a grass which is apparently intolerant of salt. Both species have the C4 dicarboxylic acid pathway of photosynthesis and both species occur in periodically flooded habitats. Thus, the greatest differences between these species appears to be in their tolerance of salt.