黄足黄守瓜（Aulcophora femoralis chinensis）取食和机械损伤对南瓜子叶中葫芦素B的诱导作用

采用高效液相色谱分析方法，通过测定葫芦素B含量的变化，探讨黄足黄守瓜与南瓜之间在时间上的化学诱导关系。虫害和机械损伤均能引起南瓜子叶中的葫芦素B含量围绕着对照水平上、下波动的变化。但是，这两种因素所引起的葫芦素B含量变化的规律有较大的不同。黄足黄守瓜的为害相对于机械损伤诱导葫芦素B合成的差异主要表现在3个方面：首先，反应速度比较快。如叶部处理中，虫害株在虫害后1h葫芦素B含量已有了显著升高，而机械损伤株葫芦素B含量此时不仅没有升高，反而有下降趋势，在1．5h才有所升高。其次，反应程度比较大，即虫害株葫芦素B的最大诱导量显著大于机械损伤株的。最后，诱导反应持续的时间比较长，即是说虫害株结束诱导反应的时间要明显长于机械损伤株的。另外，即使被处理的是南瓜茎部，其子叶中葫芦素B含量也发生了变化，而且变化趋势与叶部被处理的具有相似性，证明虫害和机械损伤都能系统诱导被害南瓜合成葫芦素B。此外，实验结果还显示虫害株未被害叶葫芦素B的含量比被害叶的高。

Comparing on the inducing Cucurbitacin B content in cotyledon of squash aroused by Aulcophora femoralis chinensis (Coleoptera:Chrysomelidae) and mechanical damage

High performance liquid chromatography was used to analyse the content of Cucurbitacin B(CuB)to study the chemical communication relationship between Aulacophora femoralis chinensis Weise and Cucurbita moschara(Duch.)Poir.Both pest damage and mechanical damage resulted in the change of CuB content in the cotyledons of squash fluctuated around the CuB content in the uninfested or undamaged plants,but the changing trends of CuB content resulted from the beetle damage and mechanical damage were quite different in three aspects.Firstly,the velocity of induction reaction by the beetle was faster,comparing with mechanical damage.For instance,the CuB content in the beetle-infested plants had already distinctly increased after 1 h foliage disposal,but it is 0.5 h later in the mechanically damaged plants.Secondly,the inducing CuB content in beetle-infested plants was much higher than that in the mechanically damaged plants.Lastly,the duration of induction reaction in beetle-infested plants persisted much longer than that of the mechanically damaged plants.The reaction could last 160 h in the beetle-infested plants,however,it was only 80 h in the mechanically damaged plants.Furthermore,even if we dealt the stems with the pest damage or mechanical damage,the CuB content in the cotyledons of squash changed similarly to that in the foliage disposal.That demonstrated the release of CuB in the beetle-infested plants or mechanically damaged plants was systemic.At the same time,the uninfested or undamaged cotyledons had higher CuB content than that in the infested or damaged cotyledons in the same individual plant.