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作 者 ：程立丽3,李德志1,2,3*,朱志玲4,何莹莹3,王 浩3,纪倩倩3,刘 微3,陈慧娟3,赖苏雯3

期 刊 ：西北植物学报 2013年 7期 页码：1442~1451

关键词：结缕草；水分；生理整合；H218O；

Keywords:Zoysia japonica, water, physiological integration, H218O,

摘 要 ：以克隆植物结缕草为研究对象，采用¹⁸O作为示踪元素，从克隆植株不同生长发育阶段的复合节根系引入H₂¹⁸O，在“异质高水”、“均质低水”两种环境条件下，探测和分析结缕草克隆植株复合节根、匍匐茎、A和B分株叶各构件组分系列内的水分生理整合格局特征及其生态效应。结果表明：（1）在两种水分环境条件下，H₂¹⁸O在克隆植株主匍匐茎内各构件组分系列中均表现出双向传输的趋势，但更倾向于向顶传输。（2）H₂¹⁸O向顶传输时，在“异质高水”生境内，基部复合节根系吸收的H₂¹⁸O呈先增加后降低的趋势，而中部复合节根系吸收的H₂¹⁸O呈先降低后增加的趋势；在“均质低水”生境内，中部复合节根系吸收的H₂¹⁸O呈持续增加趋势。（3）在两种生境的3种引入情况下，H₂¹⁸O均向顶传输到尖端生长点。其中在“异质高水”和“均质低水”生境内H₂¹⁸O在克隆植株中向基传输过程中，传输强度整体上呈下降趋势； H₂¹⁸O在主匍匐茎中传输时¹⁸O分配于分株叶片中的量较多；H₂¹⁸O在二级匍匐茎中的传输都呈现出明显的向顶趋势，传输距离都到达了二级匍匐茎的顶端生长点。（4）在绝大多数情况下，A分株叶系列的¹⁸O丰度均明显高于B分株叶系列，这与A、B分株系列的生长发育特征相一致；但在“异质高水”生境内，中部分株吸收的H₂¹⁸O在二级匍匐茎中传输时，分配于B分株叶系列的¹⁸O明显高于A分株叶系列，即A分株系列相对于B分株系列的比较优势并不是一成不变的，在某些情况下还可以发生逆转。

Abstract:Based on tracer method,the characteristics of water physiological integration pattern and the ecological effects in the series of roots,stolons and ramet leaves of clonal plant species Zoysia japonica were studied.H₂¹⁸O were introduced into the roots of multiple-nodes at different growing stages.The experimental habitats were heterogeneously high and homogeneously low.(1)H₂¹⁸O translocation in primary stolons showed both basal and distal directions with the later as the dominance.(2)In the former HH habitat,when H₂¹⁸O was initially absorbed by the roots of basal and middle multiple-nodes,the translocation of H₂¹⁸O at distal direction showed a trend of increasing-then-decreasing and decreasing-then-increasing pattern,respectively.In the latter HL habitat,when H₂¹⁸O was initially absorbed by the roots of middle multiple-nodes,the translocation of H₂¹⁸O at distal direction showed a trend of continuous increasing.In all these conditions,the translocation of H₂¹⁸O at distal direction reached the apexes of the clones.(3)In both HH and HL habitats,the translocation of H₂¹⁸O at basal direction mainly showed a decreasing trend.When analyzing the translocation of H₂¹⁸O in the primary stolons in both habitats,H₂¹⁸O was mainly allocated to the ramet leaves.The translocation of H₂¹⁸O in the secondary stolons showed acropetal tendency,and H₂¹⁸O reached apexes of the secondary stolons.(4)H₂¹⁸O in A ramet leaves were usually significantly higher than those in B ramet leaves,showing consistence with the growth and development pattern of Z.japonica clone;but in HH habitat,after H₂¹⁸O being absorbed by the roots of middle multiple-nodes,the allocation ¹⁸O in B ramet leaves were significantly higher than those in A ramet leaves,implying that the advantages of A ramets relative to B ramets were changeable sometimes.

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