西瓜化感作用及其化感物质成分分析

以早佳84-24为试材，研究了西瓜根、茎叶以及根系分泌物的化感效应，并对西瓜根、茎叶和根系分泌物中的化感物质进行了GC-MS检测。结果表明：西瓜根、茎叶水浸提液浓度为2.5 g?L-1时，促进西瓜种子发芽和幼苗生长|在浓度大于5.0 g?L-1时，表现为抑制作用，且随着浓度的增加，抑制作用增强|同一浓度时，西瓜茎叶水浸提液对西瓜种子发芽和幼苗生长的抑制作用大于根系水浸提液。西瓜根系分泌物浓度在2.5 μL?L-1时，促进西瓜种子发芽和幼苗生长|浓度为5.0 μL?L-1时，也开始表现为抑制作用。表明西瓜根、茎叶和根系分泌物对西瓜种子发芽和幼苗生长均呈现出低促高抑的规律。在西瓜根、茎叶和根系分泌物中共检测出32种化学物质，其中酯类化学物质最多，有14种|在西瓜根中检测到14种化学物质，茎叶中检测到19种，根系分泌物中检测到22种，其中一些曾被报道为化感物质，说明西瓜不同组织中化感物质的种类与含量不同，化感作用强度也不同。

Allelopathy of Watermelon and Analysis of Its Allelochemical

Watermelon〔Citrullus lanatus（Thunb.）Matsum. et Nakai〕allelopathy was studied by bioassay method，and allelochemical in root，stem-leaf and root exudates were detected by GC-MS．The results showed that watermelon seed germination and seedling growth were promoted at 2.5 g?L-1 concentration of the root and stem-leaf aqueous extracts，while they were restrained under condition of their 5.0 g?L-1 concentration．The inhibiting effect became stronger with the increasing of concentrations．The inhibiting effect of stem-leaf was more than that of root at the same concentration．The root exudates promoted the seed germination and seedling growth at 2.5 μL?L-1．It began to restrain the seed germination and seedling growth at the point of 5.0 μL?L-1．32 chemicals were detected from root，stem-leaf and root exudates，of which 14 were esters chemicals．There were 14 in root，19 in stem-leaf，and 22 in root exudates，some of these chemicals which were previously reported were allelochemicals．The results revealed that there were obvious differences in different tissues of watermelon，so allelopathy was different.