Plant selection and virological tests: Before effecting the collection procedure, heathy and infected plants of E. purpurea grown in the open field at the Herb Garden of Casola Valsenio were selected and labelled by visual inspection of their aerial parts. The infection by CMV was associated with symptoms on both leaves and flowers. The most characteristic symptoms are yellow mosaic, ring and line-patterns on crinkled and deformed leaves that drop prematurely. The flowers, which may be smaller than normal, show color breaking with white or pale stripes on red petals. Shortening of the internodes is also very common, giving the plant a bushy appearance known as stunting. In Italian environmental conditions, these symptoms are best visible in the summer. On the other hand, plants appeared symptom-free were collected as healthy material. Plant collection: About 3-4 Kg fresh aerial part materials (70% stems, 10% leaves and 20% flowers) of healthy E. purpurea plants were collected in June 2000 at almost the end of flowering. An equivalent quantity of CMV-infected plants (evaluated by DAS-ELISA) was also collected; the percentage of leaves in the infected infected was about 6.0% as due to CMV presence that caused the premature leaf drop.

The oil from healthy material was rich in germacrene D (57.8%) and was more abundant. The infected materials afforded a lower oil content and significant quantitative variations in the oil composition. In particular, the observed percentage of germacrene D (52.6%) was reduced as were other sesquiterpene hydrocarbons. These variations, tested to be significant for all the compound-class fractions and individual major components, were ascribed to the cucumber mosaic cucumovirus (CMV) infection, the only fixed-effect variable that might affect the oil composition.

To break the seed dormancy, they were soaked in boiling water for 10 min and were then placed in Petri dishes moistened with distilled water and kept in a refrigerator (4 ℃) for 7 days. Seeds were then sown in plastic pots containing sands and powdered leaves (1:2) and were allowed to grow in the greenhouse with the mean day/night temperature and relative humidity of 29 ℃ , 38 % and 17 ℃ , 50 % respectively. Sixty days after seed germination, uniform seedlings with two nodes and four opposite leaves were transplanted into big plastic pots (30 × 50 cm). Each pot was filled with 10 kg of air-dried soil and two seedlings were used per pot for all treatments.Eight weeks after transplanting, plants were subjected to different levels of salinity supplied with irrigation water. In order to prevent osmotic shock, salt solutions were added gradually at several stages and so, lasting for three weeks. To keep the levels of soil salt concentration constant, distilled water was used in subsequent irrigations. At the end of salt treatment, total soil electrical conductivities including control were determined by EC meter (0.40, 2.3, 4.5, 6.8 and 9.1 dS/m). Salt stress symptoms (leaf tip chlorosis and necrosis) in plants treated with high salt concentrations appeared after three weeks. At this time, seedlings were harvested. A total of 10 g of fresh leaf material was harvested per plant, 3.5 g of which was used for HGC-MS analysis and the rest was allowed to dry at room temperature.

Moderate salinity could induce S. mirzayanii to produce high amounts of some valuable volatile oils and total phenolic compounds.