Login | Request Account (DAF staff only)

Phenotypic and molecular analyses in rice weevil, Sitophilus oryzae (Linneaus) (Coleoptera: Curculionidae): identification of a super kdr mutation, T929I, conferring resistance to deltamethrin

View Altmetrics

Singh, S. K., Jagadeesan, R., Thangaraj, S. R., Selvapandian, U., Nayak, M. K. and Subbarayalu, M. (2021) Phenotypic and molecular analyses in rice weevil, Sitophilus oryzae (Linneaus) (Coleoptera: Curculionidae): identification of a super kdr mutation, T929I, conferring resistance to deltamethrin. Pest Management Science, 77 (7). pp. 3289-3299. ISSN 1526-498X

Full text not currently attached. Access may be available via the Publisher's website or OpenAccess link.

Article Link(s): https://doi.org/10.1002/ps.6373

Publisher URL: https://onlinelibrary.wiley.com/doi/abs/10.1002/ps.6373

Abstract

BACKGROUND The rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae) is a cosmopolitan pest of stored cereal grains and other commodities globally. Infestations caused by S. oryzae makes grains unsuitable for consumption, processing, and export. Deltamethrin, a synthetic pyrethroid insecticide, is widely used in major grain storages in India as a prophylactic treatment to control this pest. However, recurrent use of this insecticide had led to genetic resistance in S. oryzae, questioning its ongoing use at the current recommended concentration. RESULTS Dose response analysis of resistant (Delta-R) and susceptible (Lab-S) strains of S. oryzae collected from grain storages across southern India, revealed that Delta-R was 134-fold more resistant than the Lab-S at median lethal concentration (LC50). A concentration of 180 ppm over 48 h effectively discriminated 16 resistant field populations from Lab-S with per cent resistance ranging from 8.72% to 75.86%. Exposing all the resistant populations to 1000 ppm over 48 h identified 12 populations with strongly resistant individuals and confirmed the existence of two distinct resistance phenotypes, ‘weak’ and ‘strong’ in S. oryzae. Furthermore, sequence analysis of the voltage-gated sodium channel (vgsc) gene in Delta-R identified a single target site mutation, T929I conferring resistance in S. oryzae. CAPS (Cleaved Amplified Polymorphic Sequence) marker analysis of this allele confirmed that frequency of resistance is high (up to 0.96) supporting the results of phenotypic analysis. CONCLUSION Both phenotype and molecular marker analyses clearly demonstrated that deltamethrin at 180 and 1000 ppm can be used to discriminate weakly and strongly resistant populations in S. oryzae, respectively. Resistance diagnostics based on the mutation, T929I, supports our phenotypic data and indicates that resistance to deltamethrin in S. oryzae is prevalent in southern parts of India, stressing the need to identify a synergist or suitable alternatives.

Item Type:Article
Business groups:Crop and Food Science
Subjects:Science > Biology > Biochemistry
Plant pests and diseases
Plant pests and diseases > Individual or types of plants or trees > Rice
Deposited On:04 May 2021 05:24
Last Modified:12 Jul 2021 06:52

Repository Staff Only: item control page