五爪金龙化感效应研究

 为探讨攀援与匍匐生长五爪金龙（Ipomoea cairica）化感作用差异，利用生物检测法研究了攀援与匍匐生长五爪金龙不同地上部分水提液对莴苣种子萌发率和根长生长的影响，结果表明：与对照相比，攀援与匍匐生长五爪金龙不同地上部分水浸提液化感效应存在不同程度的差异。攀援与匍匐生长五爪金龙茎尖均具有较强的化感抑制潜力，显著高于叶片和茎，这对五爪金龙搜寻支持物，提高种群的入侵能力具有重要意义。攀援生长五爪金龙地上不同部分高质量浓度水浸提液的化感抑制效应均高于匍匐生长五爪金龙，低质量浓度水浸提液的化感促进效应均小于匍匐生长五爪金龙。在0.002 5~0.02 g/mL质量浓度范围内，五爪金龙地上部分水浸提液质量浓度和化感综合效应指数均为负相关；攀援生长五爪金龙茎尖、成熟叶和茎的拟合直线斜率均大于匍匐生长五爪金龙，但落叶斜率相差较小；攀援生长五爪金龙不同处理质量浓度的“高抑低促”现象比匍匐生长五爪金龙明显。

Allelopathy Effects of Ipomoea cairica I. Comparison of Allelopathy Potentialsbetween Climbing Growth and Sprawl Growth

The effects were determined of aqueous extracts of different above ground parts of climbing and sprawl growth of Icairica on germination ratio and root lengths of lettuce (Lactuca sativa).The results showed that there were different extent diversities of allelopathy of aqueous extracts of different above ground parts of climbing and sprawl growth of Icairica. The stem apexes had stronger allelopathic inhibitory than leaves or stems of climbing and sprawl growth of Icairica, which was important significance on hunting trellis, promoting invasion capacity. Within concentrations of aqueous extracts, allelopathic inhibitory effects of different parts of climbing growth were higher than that of sprawl growth of Icairica at high concentration of aqueous extracts, but allelopathic anxoactions were lower at low concentration of aqueous extracts. With concentrations that ranges from 0.002 5 g·mL^-1 to 002 g·mL^-1, there were negative correlations between concentration of aqueous extracts and allelopathic synthesis effects of different parts of climbing and sprawl growth of Icairica. The linear fitting slopes of stem apexes, climax leaves and stems of climbing growth were greater than that of sprawl growth of Icairica. But egression coefficients variations or fluctuations of deciduous leaves didnt show obvious difference of allelopathic potentials between two growth patterns. Therefore the phenomenon about allelopathic inhibitory effects at higher concentrations and promotion effects at lower concentrations of climbing growth were more obvious than that of sprawl growth of Icairica.