生境对紫茎泽兰叶片外部形态结构的影响

通过调查不同生境中紫茎泽兰植株叶片的外部形态结构，分析和探讨控制该植物植株叶片不同外部形态结构的关键环境因子。在云南玉溪师范学院校园内进行，选择10个当地常见生境，调查每个生境中紫茎泽兰植株叶片长、宽、长宽比、叶面积、叶缘两侧锯齿数目和比例等数据，分析不同环境因子及其组合对叶片外部形态结构的影响。结果表明，紫茎泽兰植株叶片长、宽和叶面积3组数据在10个生境间变化程度明显且变化规律一致，其排序从大到小为栽培（荫）>田间≈栽培（阳）≈池塘边（湿）>田埂≈林窗>林下>路基（荫）≈池塘边（干）>路基（阳）。叶片长宽比在10个生境间没有显著差异，为1.35左右；叶缘左右两侧锯齿数目在10个生境中均为12个左右，两侧锯齿数目比为1.00左右。调查数据分析结果也充分证明，光照强度、土壤水分和养分含量及三者交叉作用对紫茎泽兰植株叶片的长、宽和叶面积的影响均达到极显著水平，但对叶片的形状和叶缘两侧锯齿数目及比例的影响程度较弱。

Impacts of Varying Habitats on the External Morphological Structure of Ageratina adenophora Leaves

To investigate the external morphological structure of Ageratina adenophora leaves in various habitats, the key environmental factors controlling different external morphological structure of A. adenophora leaves were analyzed and discussed. This project was carried out in the campus of Yuxi Normal University of Yunnan Province. 10 local common habitats were selected to investigate the length, width, ratio of length to width, leaf area, number and proportion of serrations on both sides of the leaf edge of A. adenophora in each habitat, and to analyze the impacts of different environmental factors as well as their combinations on the external morphological structure of A. adenophora leaves. The study results showed that the three groups of data including leaf length, width and leaf area of A. adenophora obviously changed among the 10 selected habitats, and their change patterns were also consistent; the order from large to small was: artificial cultivation (shade) > farmland ≈ artificial cultivation (full light) ≈ pond side (wet) > farmland ridge ≈ forest gap > forest shade > road edge (shade) ≈ pond side (dry) > road edge (full light). There was no significant difference in the ratio of leaf length to width among the 10 selected habitats, which was about 1.35; the numbers of serrations on both sides of the leaf edge were both about 12 in the 10 habitats, and the ratio of serrations on both sides was about 1.00. The analysis results of the investigation data also fully proved that the impacts of light intensity, soil moisture and nutrient content as well as the interactions of the three environmental factors on the length, width and leaf area of A. adenophora reached an extremely significant level, but the effects on the shape of leaves and the number and proportion of serrations on both sides of the leaf edge were apparently weak.