Response of Lime Seedlings (Citrus aurantifolia L.) to Exogenous Spermidine Treatments under Drought Stress

Drought is one of the most important problems that restrict cultivation of crops in arid and semi-arid regions; Lime (Citrus aurantifolia L.) is one of the most important trees that grown in these restricts. In this greenhouse study, the effects of exogenous spermidine treatments and drought stress on growth of Lime evaluated. A factorial experiment in completely randomized design in 2008 in greenhouse were carried. For periodic irrigation 7, 15 and 21 respectively, each 7, 15 and 21 days one time and weight were given to the_FC. 4 repeat for each treatment were selected, total dry period lasted 180 days. Concentrations of spermidine treatments 0.1 and 2 ^M were used. The results show that polyamine spermidine treatment improved growth of root, shoot and total plant biomass in Lime seedlings. This treatments increased the proline concentration, and reduce cell membrane ion leakage. The results of this study show that increased periods of drought, reducing the rate of growth and total plant biomass is associated with. This research has shown that use of different degrees of exogenous polyamine can reduce the effects of stress on growth of Lime seedlings