Effect of Salt Stress on Seed and Oil Yield, Chlorophyll and Proline Content in Three Local Populations of Castor Bean (Ricinus communis L.) in Controlled Environment

The experiment was conducted in 2012 to evaluate the effect of salinity stress on oil percent, oil yield, seed yield and some physiological charactristics on three local populations of castor bean (Ricinus communis L.), at the University of Shahrekord, Iran. Experiment was carried out with three replications in a completely randomized design including five levels of salinity (1.2, 2, 2.6, 3.8 and 4.8 dS/m in soil saturation paste) as the first factor and castor populations (Shiraz, Kerman and Urumieh) as the second factor. The effect of salinity was statistically significant (α>0.01) on seed yield, oil percent and oil yield, chlorophyl a, chlorophyll b and proline, while a significant effect (α>0.05) was observed for total chlorophyl. The results also showed that different populations had a significant difference (α>0.01) with regard to all studied factors. The highest and the lowest proline content were observed for Kerman and Shiraz populations, respectively. Increasing salinity increased the leaf proline content while it decreased the chlorophyll content was decreased. At low salinity levels, Shiraz population resulted to the highest seed and oil yield. However, with increasing salinity, seed yield and oil content of Shiraz population was less than other populations. Although more research is needed in this respect, but it seems that in castor been Shiraz population for soils with a low salinity and Kerman population for more saline conditions can be recommended.