Study On The Effect Of Chemical Pesticides On The Release Of C₆-volatile In Tea Plant （Camellia Sinensis）

C6-green leaves volatiles (GLVs), including C6aldehydes, alcohols and theirester,et al., are important secondary metabolites, which plays key roles in indirectdefence against pests. Chemical control is still an indispensable means to managementof tea plantation but there is little literatures about effect of chemical pesticides onsecondary metabolites related to defensing pests in tea plants. In this study, thechanges of GLVs content among different cultivars, different seasons and diffenrentsampling time were measured by GC-MS after the GLVs were collected throughdynamic headspace adsorption device with the leaves treated by spraying pesticideswhilst the expressinon level of some key genes related to GLVs synthetic pathways,such as CsLOX3and CsHPL, were investigated via real-time PCR. The main resultsare as following:(1)Referring to some literatures, the dynamic headspace adsorption device wassuccessfully constructed and the main volatiles released from damaged leaves of teaplant were (Z)-3-hexenol,(Z)-3-hexenal,(Z)-3-hexenyl acetate and hexanal aftercollecting and identifying these substances.(2) After spraying imidacloprid at recommended concentration, the release amountof GLVs from potted “Longjing43” and “Shuchazao” seedlings was influenced. As for“Longjing43”, the release amount of (Z)-3-hexenol,(Z)-3-hexenal,(Z)-3-hexenylacetate and hexanal was less than the controls from3d to5d after spraying and onthe third day, the declining rate of (Z)-3-hexenol and hexanal was maximum and thecontent were45.8%and53.5%, respectively. Considering “Shuchazao”, thedeclining rate of (Z)-3-hexenol,(Z)-3-hexenyl acetate and hexanal was less than thecontrols from1d and the content of (Z)-3-hexenal decreased on the second day butsubsequently the amount of four components all increased.(3) The release amount of GLVs from potted “Shuchazao” seedlings decreasedafter spraying imidacloprid at recommended concentration in May and September. InMay, the declining rate of (Z)-3-hexenol and (Z)-3-hexenyl acetate was maximun andthe content were9.7%and54.2%, respectively, but the amount of the twocomponents increased in July.(4) The releasing amount of different components among C6-volatiles, collectedfrom “Longjing43” grown in filed, were affected after2d by spraying imidaclopridand cypermethrin at recommend concentration. The amount of (Z)-3-hexenol, (Z)-3-hexenal and hexanal were decreased59.3%,23.4%and33.1%, respectively,after spraying imidacloprid, which didn’t influenced the amount of (Z)-3-hexenylacetate. However, the amount of (Z)-3-hexenol,(Z)-3-hexenyl acetate and hexanalwere decreased12.1%,60.6%and18.5%, respectively, after spraying imidacloprid,which caused the amount of (Z)-3-hexenal increased, comparing with controls.(5) The expression level of CsLOX3in potted “Longjing43” and “Shuchazao”seedlings, analysised by qRT-PCR, were less than the controls after1d to5d byspraying imidacloprid at recommended concentration and the declining rate of“Shuchazao” was much more than “Longjing43” and the maximun decling rate were73.7%and52.1%, respectively. But the expression level of CsHPL increased after1d to4d by spraying imidacloprid and decreased on the fifth day. However, as for thetwo cultivars grown in the field, the expression level of CsLOX3of “Longjing43” wasless than the controls on the third and fifth day after spraying and on the third, fourthand fifth day for “Shuchazao”. The expression of CsHPL of “Longjing43” was lessthan controls from1d to4d and the declining rate,36.7%, is maximun on the thirdday but the level of “Shuchazao” was less than controls only on the third day and therate is16.4%.