干果γ辐照杀虫最低有效剂量研究OA

This study aimed to clarify the lethal effect of γ-irradiation on pests in dried fruits and to optimize the treatment dosage.Five pest samples were collected from different dried food sources.Morphological identification and COⅠ gene sequencing followed by phylogenetic tree construction confirmed that the key pest in the dried fruit samples was Plodia interpunctella(Hübner).Then,Plodia interpunctella was propagated in bulk to generate sufficient population for testing.To investigate the insecticidal effects,nine irradiation doses(0,0.3,0.5,0.75,1.0,1.5,2.0,2.5 and 3.0 kGy)were applied to Plodia interpunctella larvae in dried fruits.In parallel,γ-irradiation doses 0,50,100,150,200,250,and 300 Gy were used to treat eggs of Corcyra cephalonica which belongs to the same family as Plodia interpunctella.The results indicate that Plodia interpunctella larvae irradiated with the dose of 0.3 kGy maintained normal feeding and crawling abilities in the early stage but all died around 60 days.After the exposure dose rose to 0.75 kGy,larvae only occasionally engaged in feeding in the early stage and all died within 56 days(harbored in raisins)and 49 days(harbored in red jujubes).After irradiated at 1.0 kGy,larvae exhibited no feeding activity during their survival period,and all died within 49 days(harbored in raisins)and 42 days(harbored in red jujubes).At high doses of 1.5 and 2.0 kGy,all larvae died after 28(for 1.5 kGy)and 21 days(for 2.0 kGy).At 2.5 kGy dose groups,all larvae died within 2 days post irradiation.A dose of 3.0 kGy was sufficiently high to cause instant larval death.Consequently,the minimum effective dose of irradiation required to kill Corcyra cephalonica eggs is 0.3 kGy.However,if the feeding damage during the survival period is used as the criterion,the minimum effective dose for Plodia interpunctella in dried fruits increases to 1.0 kGy.The minimum effective dose was determined as 2.5-3.0 kGy for the rapid control of larva.These findings provide a scientific basis for irradiation pest control in dried fruits and support the applications of irradiation technology for dried fruit storage.