盐胁迫对8种木本植物种子发芽的影响

Effect of Salt Stress on Seed Germination of Eight Woody Plants

摘要: 本文研究了柽柳(Tamarix chinensis Lour.)、沙枣(Elaeagnus angustifolia L.)、紫穗槐(Amorpha fru-ticosa L.)、杜梨(Pyrus betulifolia Bge.)、刺槐(Robinia pseudoacacia Linn.)、白腊(Fraxinus chinensis Roxb.)、白榆(Ulmus pumila L.)、荆条(Vitex negundo Linn. var. heterophylla (Franch.) Rehd.)等8种乔灌木在不同浓度梯度(0、0.3%、0.6%、0.9%、1.2%、1.5%、1.8%) NaCl胁迫下种子的萌发实验，观察了不同盐度下种子的发芽率、发芽势及发芽指数的变化。结果显示：低浓度的NaCl溶液有助于柽柳、白腊、荆条种子的萌发，但对沙枣、紫穗槐、杜梨、刺槐、白榆种子有轻微抑制作用；随着盐浓度的提高，8种植物种子的萌发能力均受到影响，发芽势、发芽率、发芽指数下降，尤其对荆条、白榆、白腊种子萌发的抑制作用最显著，柽柳种子在高盐浓度下表现出最强的忍耐能力，其次为沙枣和紫穗槐，杜梨、刺槐表现出中等耐盐能力。综合分析认为，8种植物可在不同盐渍化环境中生长，可作为沿海防护林体系建设的造林树种。在0.9% < 土壤盐浓度 < 1.2%时，可以选择柽柳为造林先锋树种；当0.6% < 土壤盐浓度 < 0.9%时，优先选种沙枣、紫穗槐；在0.3% < 土壤盐浓度 < 0.6%时，适合树种为杜梨和刺槐；在土壤盐浓度 < 0.3%时，最优选择树种为白腊、白榆和荆条。

Abstract: Eight woody plants including Tamarix chinensis Lour., Elaeagnus angustifolia Linn., Amorpha fruticosa Linn., Pyrus betulifolia Bge., Robinia pseudoacacia Linn., Fraxinus chinensis Roxb., Ulmus pumila Linn. and Vitex negundo Linn. var. heterophylla (Franch.) Rehd. were choosen to study their seed germination under different concentrations of NaCl (0, 0.3%, 0.6%, 0.9%, 1.2%, 1.5%, 1.8%) solution. The changes of germination rate, germination potential and germination index of seeds with different salinity were observed. The results showed that low salt concentration could promote the seed germination of T. chinensis, F. chinensis, V. negundo while had a slight inhibitory effect on E. angustifolia, A. fruticosa, P. betulifolia, R. pseudoacacia and U. pumila. The vigor, percentage and index of seed germination gradually descend along with the increasing NaCl concentration; espe-cially, the germination of seeds of F. chinensis, U. pumila as V. negundo showed the significant in-habitation while the seeds of T. chinensis had the strongest tolerance under high salt concentration followed by E. angustifolia and A. fruticosa, as well as P. betulifolia and R. pseudoacacia showed moderate salt tolerance. Comprehensive analysis considered that all the 8 plant species can grow in different salinization environments and could be used as afforestation tree species for coastal shelter forest system construction. T. chinensis was chose as optimal plants when above 0.9% and below 1.2% of salt concentration, the suitable plants were E.angustifolia and A. fruticosa when salt concentration is higher than 0.6% and lower than 0.9%, the optimum plants were P. betulifolia and R. pseudoacacia when above 0.9% and below 1.2% of salt concentration and the best trees were F. chinensis, U. pumila as V. negundo when the soil salt concentration is below 0.3%.