Effects of different feeding time of Monolepta Signata on the composition and content of volatile in maize leaves
[Objective]To analyze the composition and content of maize leaf volatile before and after the damage caused by Monolepta signata in the hope of providing a scientific basis for further exploring the defense mechanism of maize leaf volatile against M.signata.[Methods]In this study,the volatile compounds of maize leaves and M.signata were detected and analyzed by GC-MS at different feeding induction time(6,24,36 and 48 h).[Results]The results showed that 29,30,33,36 and 26 volatile substances,mainly including aldehydes,terpenoids,alcohols and ketones,were detected after 0,6,24,36 and 48 h of feeding induction by the M.signata respectively.Twenty volatiles,including 1-stigmasterene,cis-11-hexadecanal,α-stig-masterene and hexanal,disappeared with the insect after feeding on the damage;42 compounds,such as 2-hexenal,(E)-2-hexenal,α-pinene and β-laurene,were newly collected.The results of principal compo-nent analysis showed that α-pinene,2-hexenal and β-pinene were the main compounds released under 6h and 24h of infestation;hexadecanal,tetradecanal,n-pentadecanal,β-pirolone and(E)-3-hexen-1-ol were the main compounds released at 36 h of infestation;β-red myrcene alcohol,nerolidol,(1R)-α-pi-nene,β-rolene,β-sandalene β-cineole,and humulene were the main compounds released at 48 h of in-sect infestation.[Conclusion]The composition and content of volatile compounds in maize leaves at different feeding times have a significant impact on the M.signata.Under 6 and 24 hours of pest infestation,it mainly releases olefins,while at 36 hours of pest infestation,it mainly releases aldehydes and ketones.After 48 hours of pest infestation,it mainly releases alcohols and olefins.