One-year-old seedlings of ten provenances (KM, SY, LY, LQ, CX, NJ, GY, NC, GL and HS) of Camptotheca acuminata were used to study their responses to NaC1stress. The growth and physiological and biochemical parameters were measured under treatments 3 saline concentrations including 0% , 0. 2% and 0. 6% NaCl ( ( NaC1/dried soil weight) × 100% ). The results indicated that 1 ) seedling height, base diameter and biomass tended to decrease and a ratio of roots to crown tended to increase with the development of salt stress, and the decrease in growth of LQ and CX provenances were the most; 2) under the NaCl stress, SOD activity, contents of MDA, soluble sugar, soluble protein and Na + and Na + /K + value increased but RWC declined, and contents of K+ and POD activity increased initially, and then decreased; 3) based on the total biomass of the provenances under the stress of 0. 6% NaC1 concentratior, the salt-tolerating capacity of the ten provenances was in the following order; LY > NC > GL > HS > SY > GY > KM > NJ > LQ > CX; and 4) stepwise regression analysis showed that contents of soluble sugar and MDA and ratio of Na+/K+ in leaves had a most significant influence on the total biomass, which could be used as a reference parameter for evaluating of saline tolerance of Camptotheca acuminata.%以云南昆明(KM)、湖南邵阳(SY)、湖南浏阳(LY)、浙江龙泉(LQ)、浙江长兴(CX)、江苏南京(NJ)、贵州贵阳(GY)、江西南昌(NC)、广西桂林(GL)、安徽黄山(HS)10个种源的1年生喜树苗木为试验材料,设置3个盐含量梯度,即NaCl占土壤干质量的0,0.2％,0.6％,研究不同NaCl处理对喜树苗木生长及生理生化指标的影响.结果表明:1)随着NaCl胁迫程度增加,10个喜树种源苗高、地径和生物量均呈下降趋势,而根冠比呈上升趋势,LQ和CX种源的生长受到抑制最为明显.2)NaCl胁迫下喜树苗木的SOD活性,丙二醛、可溶性糖、可溶性蛋白、Na+含量和Na+/K+值上升,叶片相对含水量下降,K+含量和POD活性先上升后下降.3)根据0.6％浓度NaCl胁迫下各种源苗木总生物量大小,10个喜树种源的耐盐能力从大到小依次为LY＞NC＞GL＞HS＞SY＞GY＞KM＞NJ＞LQ ＞CX.4)逐步回归分析表明:喜树叶片中可溶性糖含量、MDA含量、Na+/K+比对总生物量有极显著的影响,因此可以用可溶性糖含量、MDA含量、Na +/K+比等作为评价喜树耐盐能力的参考指标.
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