The Antifungal And Insecticidal Activity Of Salt-tolerant Plants Kosteletzkya Virginica

Kosteletzkya virginica is known as the Malvaceae mallow.As a kind of economic salt-tolerant plant,K virginica has great application in fuel,fodder,medicine and the ornamental.So far,the plant has been planted extensively in China During cultivation,K.virginica are rarely found to be damaged by vermin while other plants in neighbor are badly attacked by pathogenic fungi and pests.According to this,there are presumably some active substances that kill pathogenic fungi and pests inside K.virginica.It is important to explore the antifungal and insecticidal active substances from this plant.Firstly,the components of volatile components extracted from leaves and seeds,were analyzed by GC-MS.19 constituents have been identified in the leaves and 22 constituents in the seed,accounting for 79.975%and 89.134%of the total peak area respectively.Both of the volatile components have multi constituents like olefins,esters,ketones,alcohols,polyphenol etc.,and specially 2,2 ’-methylene bis-(4-methyl-6-tert butyl phenol)takes high content in two volatile components.Meanwhile,the inhibitory effect of two volatile components on 6 different kinds of plant pathogen had been measured by the method of mycelial growth rates.And the insecticidal activity against the P.xylostella and N.Lugens had been measured by the method of drop and rice stem dipping respectively.Results showed that leaf volatile components have certain antifungal and insecticidal activity.Secondly,the antifungal and insecticidal activity of main components in K.virginica leaves was measured,which was extracted by reflux extraction and impregnation extraction.Antifungal test showed that the crude extracts by reflux method had certain antifungal activity against Rhizoctonia solani with the relative inhibition of petroleum ether and n-butanol reached 45.1%and 42.1%at the concentration of 100μg/mL respectively.Insecticidal test showed that methylene chloride phase in two extraction method had moderate contact activity against P.xylostella.The ethyl acetate phase of reflux condensation and the petroleum ether phase in cold soaking extraction had significant insecticidal activity for N.lugens,which reached 91.67%for the former and 100%for the latter.Finally,guided by bioassays,separation and purification of crude extracts which were extracted by EtOA.And for the first time three kinds of chemical compounds have been isolated from this species:tiliroside(1),2,5-dimethyl-cinnamic acid(2)and 5-hydroxy-2-methoxy cinnamic acid(3).Antifungal activity test showed that tiliroside has moderate antifungal activity against Rhizoctonia solan、Sclerotinia sclerotiorum、Botrytis cinerea and Fusarium graminearum.Insecticidal test showed that tiliroside has low contact activity against P.xylostella.But the correction mortality rate of stomach poison activity test reached 77.78%after 72 hours with a high stomach poisoning action against N.Lugens.