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Water stress is one of the most important factors limiting the growth and yield of plants in many parts of the world. In order to evaluate the effects of water stress on some morphological, physiological and antioxidant enzyme activity traits of lentil, four lentil cultivars (i.e. Gachsaran, Kimia, Ziba and Robat) in four water deficit treatments including 25%, 50%, 75% and 100% of the field capacity (control) were studied in a factorial experiment, based on a completely randomized design with three replications. Water stress at 25 and 50% field capacity significantly decreased morpho-physiological traits and significantly increased antioxidant enzyme activity, proline and protein contents of all genotypes in comparison with the control group. Gachsaran and Robat cultivars were superior in most traits in comparison with the Kimia and Ziba cultivars. Under severe stress, the amounts of  proline and protein contents, CAT and SOD enzyme activity were significantly higher in Robat and Gachsaran cultivars than those of the Kimiya and Ziba cultivars. Results showed that Robat and Gachsaran cultivars were probably affected less by water stress due to more stress tolerance using various mechanisms such as more antioxidant enzyme activity, increased proline, proteins and photosynthetic pigments contents. Studied traits were introduced as suitable markers for identification of drought tolerant genotypes. Accordingly, Robat and Gachsaran cultivars were introduced as tolerant cultivars for cultivation under rainfed conditions.

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The purpose of this research was to identify the structural adaptations in three populations of Convolvulus persicus L. on coastal areas in Mazandaran Province, whose populations of which are severely reducing due to the intense environmental stresses of the coastal zone. In general, annular collenchyma, isobilateral mesophyll, amphiphloic siphonostele, abundant presence of laticiferous tubes, numerous druse crystals and the presence of periderm in rhizome can be introduced as the most important morpho-anatomical strategies utilized against harsh environmental conditions. Sari population was foud to have the most various structural toleration mechanisms in comparison with Babolsar and Nour populations. Few differences were observed in anatomical characteristics in the three populations of Convolvulus persicus as the evidence for high intra-specific phenotypic variability, leading to local adaptation and increase of the tolerability of plants against environmental changes.