盐胁迫下白杨无性系苗木体内离子分配及比较

Ion distribution and comparison in seedlings of white poplar clones under salt stress

以白杨杂种无性系及其亲本当年生苗木为材料 ,分析了盐胁迫下无性系的离子含量 ,及 Na+ 、K+ 、Ca+ +在植物体内运输和分配特点 ,并对无性系间差异进行了比较。研究表明 ,随盐浓度提高 ,植物体内Na+ 含量迅速提高 ,K+ 、Ca+ + 含量降低 ;盐分胁迫下 ,根部 Na+ 含量较高 ,叶片 Na+ 中含量最低 ,K+ 、Ca+ +含量则相反 ,特别是 Ca+ + ,其分布顺序为叶 >茎 >根。杂种无性系 B430及其亲本新疆杨对 K+ 和 Ca+ + 运输的选择性比毛白杨高 ,而对 Na+ 运输的选择性则比毛白杨低 ,从而导致根部存留的 Na+ 较多 ,叶片分配的 Na+ 数量较少 ,从而减轻 Na+ 对叶片的伤害。综合分析表明 B430和新疆杨耐盐能力最强 ,毛新杨其次 ,毛白杨最差。

A salt stress on seedlings of a white poplar hybrid clone B430, P. tomentosa, P. bolleana, and hybrid of P. tomentosa and P. bolleana was made in pots, with the NaCl solution concentration of 0.10%, 0.30%, 0.60%, 0.90% and a pure water control. Each pot was watered respectively with 2L corresponding salt solution every 10 day. The content of K+, Na+, Ca ++ in root, stem and leaf of the seedlings and the selectivity (RS K,Na, RS Ca, Na) to ions of transportation to above-ground part were determined and calculated after 28 days. Under the salt stress, the ion content of clone and the characteristics of transportation and distribution of K+, Na+, Ca ++ were analyzed and the differences between clones were compared. The result shows that the Na+ content in the plant increased as the solution concentration increased, but the increasing range was different in different tissues. Under the 0.90% treatment, the Na+ content in root is the highest with 7.48～8.01 mg/g FW, followed by the stem with 6.34～6.96mg/g FW. and the leaf with 4.03～5.65 mg/g FW. The variation was different among different clones. Under 0.60% treatment, differences between clones was the most obvious with Na+ content with the sequence of B430>P. bolleana > P. tomentosa in the root and stem. However the sequence in the leaf was in the contrary. As the salt stress increased, the K+ content decreased in the root and stem. The change of the K+ content in leaf was small. Only the K+ content in different tissues was about the same. The change of the Ca ++ content in leaf of all clones under the salt stress was identical, however, the decreasing range of the Ca ++ content in the root was smaller and under the 0.90% treatment the Ca ++ content falled to 36.6%～38.9%. The decreasing range of Ca ++ content in stem and leaf was larger. It falled to 43.9～79.4 in stem. There were differences between four clones. As the salt stress increased, the decreasing value of the Ca ++ content in different tissue of P. tomentosa was the largest and the change pattern of other three clones was about the same. As the salt solution concentration increased the ratio of Na+ to K+ and Na+ to Ca ++ was increasing and Na+ to Ca ++ of B430 and P.bolleana were bigger than that of P. tomentosa while their ratios in stem and leaf were lower than that of P. tomemtosa. The selectivity to transportation of Na+ and K+ in B430 and P. bolleana was higher than that of P. tomentosa while their selectivity to transportation of Na+ was lower than that of P. tomentosa. So the Na+ left in the root was more and Na+ distributed to the leaf was less. The damage of Na+ to leaf was reduced. All results showed that the sequence of the salinity tolerance ability was B430 and P. bolleana > P. tomentosa×P. bolleana > P. tomentosa.