Preliminary Study On Allelopathy Of Solidago Canadensi L. On Prorocentrum Donghaiense

In order to explore the growth inhibition difference of extracts from different parts of Solidago canadensis on Prorocentrum donghaiense and to provide optimal red tide mitigation scheme based on allelopathy of Solidago canadensis, the paper study the growth inhibition effects of extracts of root, stem, leaves and flowers of Solidago canadensis on Prorocentrum donghaiense, and separate and identify the components of the strongest inhibitory effect of chloroform extract of the root of Solidago canadensis. Specific conclusions are as follows:(1) The growth inhibition ratios of Prorocentrum donghaiense by water extracts of the four organs of Solidago canadensis under the experimental concentration range were characteristic of significant dose effect relationship, growth inhibitory rate enhanced with the increase of the additive concentration. Allelopathic effects of water extracts from different parts of Solidago canadensis on Prorocentrum donghaiense are different. Under the same concentration, growth inhibition effect of water extract of the root of Solidago canadensis on Prorocentrum donghaiense was the strongest, when the concentration is 4g/L, inhibition rate can reach to 91.67%.(2) In the chloroform phase, one alllelopathic component can be obtained, which is present in the root of Solidago canadensis and its maximum inhibition rate is 97.08%. In the ethyl acetate phase, two alllelopathic components can be obtained, which are present in the root and leaves of Solidago canadensis and the maximum inhibition rates are 88.33% and 87.50% respectively. In the butanol phase, one alllelopathic component can be obtained, which is present in the root of Solidago canadensis and its maximum inhibition rate is 81.67%.(3) Among the three organic phases, the growth inhibition effect of Prorocentrum donghaiense by chloroform phase of the root of Solidago canadensis L. is obviously,which has nearly all been inhibited when7 days after co-cultivation,. Nearly half of the algal cells stopped their motion, many cells unshelled and cell division terminated when observed under the inverted microscope after 24 hours co-cultivation. Only few intact algal cells could be fond under the microscope, wheras most of the algal cells have been lysed when five days after co-cultivation,.The brown sediments were deposited at the bottom of the incubaiton bottle, while medium in the bottle was become clear and transparent.(4)The extracts of each organ of Solidago canadensis have an obvious growth inhibition effects on Prorocentrum donghaiense under the experimental concentration range, which showed a hormesis effect that promotion at low concentration and inhibition at high concentration.(5) The chloroform extract of the root of Solidago canadensis can be separated into five components by silica gel column chromatography,, each component has an obvious growth inhibition effects on Prorocentrum donghaiense. At the same concentration, B component has the strongest inhibition effect and the maximum inhibition rate is 98.75%.(6) Twenty compounds in B component were identified using FTIR, GC-MS and PY-GCMS, among which Palmitic acid, Triacontanol, Sterol, Phytol and Pentatriacontane were the primary constituents.