Extraction And Analysis Of Phenolic Acids In Poplar Branches And Their Effect To Saperda Populnea L.

In this research syringic acid,protocatechuic acid,chlorogenic acid,vanillic acid,caffeic acid,syringic acid,coumaric acid,benzoic acid,ferulic acid,salicylic acid and cinnamic acid were extracted from xylem and phloem in branches of P. deltoides Marsh×P. suaveolens Fisch.,P.×euramericana'DN113',P. pseudo-simonii Kitag.×P. nigra L.×P. nigra L'A5',P. pseudo-cathayana xP. deltoides Barry'Shan Hai Guan',P. nigra L.,P. deltoides Marsh×P. simonii Carr.,P. deltoids Marsh×P nigra L. var. thevestina Bean.,P. pseudo-simonii Kitag.×P. nigra L.,P.davidiana DodexP. bolleana Lauche,P. deltoides Marsh×P. cathayana Rehd.,P. simonii Carr.×P. nigra L.,P. stalinetz Jabl.,P. simonii Carr.,P. alba L.×P. berolinensis Dipp. and P. simonii Carr.×P. nigra L.×P. popularis. The content of these elven kinds phenolic acids in xylem and phloem of poplar branches were analysized by HPLC in order to mensure the difference between different strains at different time. The relationship between the content of eleven phenolic acids in xylem and phloem of different poplar trains with the average population density Saperda populnea on each strains were also been analysized... The vitality of cellulase and carboxylesterase in S. populnea L. that fed on those fifteen poplar species mentioned above were also been tested. Based on those results, those eleven kinds of phenolic acid was added to artificial diet of S. populnea lavae, and the vitality of cellulose and carboxylesterase in those larvae after feeding those artifical diets were tested. Several components shown remarkable affected to enzyme activity in S. populnea L were found. Those studies have established the theorecical foundation for the control of S.populnea L.utilizing of the plant secondary metabolites.The content of phenolic acids in xylem and phloem from branches of fifteen poplars species changed following the growth period variation. The content difference of phenolic acids at growth period or dormant period of poplar were very significant. The results gotten at the same period shown that there was extremely significant difference between the phenolic acids level containing in xylem with that in phloem of different poplar strains. The content of those phenolic acids shown correlation between each other at various significant level. During the period of S. populnea L. adult oviposition, the content of phenolic acids in phloem and density of oviposition were quite correlation, which shown that during the S. populnea L. was selecting host to oviposit, the content of phenolic acids in phloem of poplar branches was one of key factors which influence the host slection S. populnea L.Different host poplar has a significant effect on the vitality of cellulase and esterase of S. populnea L. The vitality of those two enzyme in the larvae shown negative correlation with the degree of insect resistance ability of those fifteen poplars species fed by those larvae. In the selected fifteen poplars species, the activity of cellulase and esterase in S. populnea L. larvae fed on P. simonii Carr.,P. deltoides Marsh×P. cathayana Rehd.,P. simonii Carr.×P. nigra L.,P.×euramericana'DN113'and P. nigra L. is significantly higher than that in those larvae fed on the other poplar species. It showed that these poplar species were most suitable host in supplement vegetative period and oviposition period of S. populnea L.. These poplars are vulnerable to hazard. The activity of cellulase and esterase in S. populnea L. that fed on P. stalinetz Jabl.,P.davidiana DodexP. bolleana Lauche,P. pseudo-simonii Kitag.×P. nigra L×P. nigra L'A5',P. pseudo-cathayana xP. deltoides Barry'Shan Hai Guan'and P. alba L.×P. berolinensis Dipp. is significantly lower than that in those larvae fed on the other species. It shown that these poplar species could inhibit the activity of cellulase and esterase in S. populnea L.larvae, and shouwn resistance to S. populnea L. The experimental results and the results of field investigation was consistent. Therefore, The activity diversification of cellulase and esterase of S. populnea L. fed different species could be used as a kind of resistance indicator.The testing result of enzyme activity in larvae of S. populnea L. fed artificial diet shown that in the vitality testing of C1,Cx and CUSβ, gallic acid,vanillic acid,caffeic acid,benzoic acid,ferulic acid and cinnamic acid had different restrain effection to the activity of Cx and CUSB, gallic acid,vanillic acid,caffeic acid and benzoic acid had little restrain effection to C1. This result indicated that Cx and CUSB, were more sensitive to phenolic acids, and those phenolic acids could weaken the vitality of cellulase in the body of S. populnea L. larvae to restrain their abilty to digest cellulose, then could reduce the survival rate of S. populnea L. larvae. Excepted for protocatechuic acid and syringic acid, The other nine kinds of phenolic acids had more significant restrain effection to activity, which shown that the CarE in S. populnea L. larva was quite sensitive to phenolic acids, Those phenolic acids have significantly restricted the detoxifying ablity of CarE.