Absorption and Distribution of Na+,K+ and Chlorophyll Fluorescence in Castor under Salt Stress
ZHANG Jie et al (Halophyte Research Laboratory,Nanjing University,Nanjing,Jiangsu 210093)
[Objective] The aim of this study is to reveal the salt resistance of castor.[Method] Under salt stress,the growth,osmotic potential,chlorophyll fluorescence parameters,Na+ and K+ uptakes and transports in the seedlings of two Ricinus communis varieties(cultivar castor Zibi 6 and wild castor which grew naturally in coastal saline-alkali land) were comparatively studied.[Result] Wild castor preformed better in halophilism than that of cultivar castor Zibi 6 under the NaCl treatment.One of the salt tolerant mechanisms of castor is to improve K+ uptake and transport to overground portion,thus to maintain K+/Na+ homeostasis in leaves;on the other hand,the high stability of Photoreaction System Ⅱ(PS Ⅱ) plays a key role in maintaining the leaf photosynthetic rate under salt stress.[Conclusion] The results of this study provided theoretical basis for the extension and application of castor in saline beach.