No abstract

Water deficit is the largest limiting abiotic factor in agriculture and will increase in future. Evaluating the drought stress-induced changes in growth parameters as well as the leaves ethylene accumulation of medicinal plants to grow these in arid and semi-arid areas has particular importance. Chicory (Cichorium intybus L.) is a famous medicinal herbal plant which grows in most parts of Iran. A factorial greenhouse experiment was conducted to evaluate the effect of drought stress [100 (as a control), 80, 60 and 40% of field capacity (FC)] on morphophysiological parameters as well as the leaves ethylene accumulation of four chicory ecotypes. The results showed a significant effect of drought on plant height, leaf area, shoot moisture content and total dry matter production of chicory ecotypes which were reduced under drought stress. Under increasing drought level the Siyah Shiraz (Kh) ecotype performed better by maintaining more growth characters, thereby leading to more production of dry matter than the other ecotypes. Isfahan ecotype was the most affected by rising tensions and showed more reduction in growth traits. Drought stress also considerably changed leaf ethylene content, that made the leaf ethylene biosynthesis to be significantly higher under severe (60 and 40% FC) stress when compared to control (100% FC) and was significantly higher in drought-tolerant chicory ecotype (Kh). In general, it can be concluded that Kh was superior to other ecotypes in terms of growth and leaves ethylene accumulation, and can be suitable for cultivation in arid regions.

-Salinity is among the most common and severe abiotic stresses that drastically affects crop productivity all over the world. To evaluate the effect of salt stress on seed germination, early growth, antioxidant enzyme activity and ABA content of chicory ecotypes (Cichorium intybus), a factorial experiment was conducted at College of Agriculture, Shiraz University in 2014 based on completely randomized design with four replications. The treatments comprised five salinity levels (tap water, 3, 6, 9, 12 dS m -1 ) of sodium chloride on the ecotypes of Sefid Shiraz and Siyah Shiraz. The results showed that germination characteristics and primary seedling growth decreased in both ecotypes with increasing in salinity severity. The effects of salinity on radicle and plumule length as well as seedling weight were the same as its effects on seed germination. The effect of salt stress on antioxidant enzyme activity (especially catalase) and ABA content were significant which they were enhanced with increasing salinity level; the Siyah Shiraz ecotype performs better than the Sefid Shiraz under high salinity, as indicated by lower decrease in germination characteristics and primary growth and higher antioxidant enzyme activity as well as ABA content. These facts should be taken into consideration in the economic cultivation of this valuable horticultural and medicinal plant and this data would be useful for the crop breeding projects.Keywords: salt stress, chicory ecotypes, germination characteristics, antioxidant enzyme activity. RESUMO -