毛红椿凋落叶水浸液自毒作用研究

为探究毛红椿凋落叶水浸液的自毒作用,采用生物测试法研究毛红椿凋落叶水浸液对自身种子发芽和幼苗生长的影响,并结合气相色谱质谱联用(GC-MS)技术分析凋落叶水浸液石油醚、乙醚、氯仿、甲醇4种不同极性萃取组分中存在的自毒物质。结果表明,凋落叶水浸液对毛红椿种子发芽及幼苗生长、存活率等均有抑制作用,浓度越高抑制作用越强,中浓度溶液(100 g·L^-1)对种子发芽和茎长达到显著抑制水平,对种子发芽率、发芽势、发芽指数、茎长的抑制率分别为18%、31%、31%和17%;低浓度溶液(10 g·L^-1)对根长的抑制达到显著水平,抑制率为25%。毛红椿凋落叶水浸液4种不同极性萃取组分中共鉴定到22种化合物,总体含酰胺类、长链脂肪酸、酚类、苯甲酸衍生物、烷烃类、腈类、二甲苯、松油烯及谷甾醇等物质,其中酰胺类、长链脂肪酸、酚类、苯甲酸衍生物成分可能为毛红椿自毒物质。本研究结果为探索毛红椿的濒危机制,促进毛红椿的实生更新提供了理论依据。

Autotoxicity of Aqueous Extracts From Toona ciliata var. pubescens Leaf Litter

In order to investigate autotoxic effects of the aqueous extracts of leaf litter of Toona ciliata var. pubescens, the effects of leaf aqueous extracts on seed germination and seedling growth of the same species were investigated using biological test. Meanwhile, the autotoxic compounds in three different polar extracts of ether, ethyl acetate and n-butanol extracted from leaf aqueous extracts were analyzed by gas chromatography mass spectrometry (GC-MS). The results showed that the aqueous extract of T. ciliata var. pubescens has inhibitory effects on its seed germination, seedling growth and seedling survive rate. It was also found the higher concentration will result in a stronger inhibition. In addition, the inhibition effect of the medium concentration (100 g·L^-1) solution on seed germination and shoot length was significant, and the inhibition rates of seed germination rate, potential and index were 18%, 31%, 31% and 17%, respectively. Meanwhile, it was also found the extract with low concentration (10 g·L^-1) had significant inhibitory effect on root length, and the inhibition rate reached 25%. Finally, 22 compounds were identified from three different polar extracts of aqueous extracts of leaf litter, which may mainly contain amides, long chain fatty acids, phenols, benzoic acid derivatives, alkanes, nitriles, xylene, terpinene, sterols and other substances. Amongst these compounds, amides, long chain fatty acids, phenols, benzoic acid derivatives were regarded as the possible autotoxic substances of T. ciliata var. pubescens. In conclusion, the findings help to explore the endangered mechanism of the plant and provide reference for the promotion of seedling regeneration of T. ciliata var. pubescens.