effect of salinity and silicon on seed yield and yield components of purslane )portulaca oleracea l.(

abstract in order to study the effects on salinity and silicon application on yield and yield components of purslane (portulaca oleracea l.), an experiment was conducted in a completely randomized desgin with three replications and two factors consisted of four different levels of salinity using nacl (0, 7, 14, 21ds/m) and two levels of silicon (application of one mmol sodium silicate and not application). increasing salinity concentration significantly caused a negative effect on seed yield. but yield components such as number and weight of seed were more sensitive than number of capsul in main stem in final seed yield. application of silicon increased seed yield in control but was not significant in salinity levels and leaves and stem biomass. seed yield and total seed weight in branches was significantly decresed. weight of 1000 seed in main stem and branches was not significantly different in salinity levels. as a result, purslane could be extremely tolerated to saline conditions, so it seems that it can be cultivated in saline soils and arid regions. also applied silicon can be increase yield and plant tolerance to environmental stress.