Effect of putrescine on some physiological and morphological parameters of pot marigold (calendula officinalis L.) under salinity stress

This study was carried out to investigate the effects of salinity and putrescine on pot marigold. Plants were treated with sodium chloride solotions which their electrical conductivity (EC) were adjusted at 1، 3، 6 and 9 ds/m and putrescine spray at 0، 1 and 2 mmol. The experiment was factorial based on a completely randomized design (CRD) in greenhouse condition Stomatal length average on abaxial and adaxial sides of leaf، chlorophyll index، minimum and maximum florescence (F0 and Fm respectively) and photosystem II quantum yield were measured during the experiment. Result showed that salinity had significant effects on all characteristics. Generally all characteristics were reduced by increasing salinity levels except F0 and Fm. Chlorophyll index، quantum yield and stomatal length average on both leaf sider were reduced up to 30%، 27. 3%، 5%، 23%، 22. 3% and respectively، while F0 and Fm increased by salinity. Moreover، putrescine reduced the negative effects of salinity on chlorophyll index، stomatal length average on both leaf and quantum yield. putrescine also reduced the length of stomatal.