Biochemical Parameters to Identify Shot-Hole Borer (Euwallacea fornicatus) Resistance in Tea Cultivars: Emphasis on Polyphenols, Catechins, and Caffeine

DOI

10.2991/978-94-6239-646-3_15How to use a DOI?

Keywords

Camellia sinensis; Shot-hole Borer; Secondary Metabolites; Pest Resistance; Screening

Abstract

Shot-hole borer (SHB) (Euwallacea fornicatus) is a major pest threatening tea (Camellia sinensis) plantations in Sri Lanka. Traditional methods for screening SHB resistance rely on variable levels of natural infestation, which can lead to inconsistent results. This study aimed to develop a screening protocol based on biochemical parameters to identify tea cultivars and accessions resistant to SHB. Resistance levels were evaluated through beetle-settling bioassays and biochemical analyses. The bioassay results demonstrated varying levels of resistance to SHB: Resistant (Accession 43, TRI 2023), Moderately Resistant (TRI 5006, TRI 5002, Accession 208), Moderately Susceptible (TRI 5005, TRI 2025), and Susceptible (Accession 88). Biochemical analysis of bark material revealed that the resistant cultivars, Accession 43 and TRI 2023, had significantly lower caffeine concentrations (p<0.05) of 2.46 mg/g and 2.85 mg/g, respectively, before infestation. However, these levels increased to 6.48 mg/g and 5.24 mg/g after infestation. In contrast, the susceptible cultivars (Accession 88, TRI 5005, and TRI 2025) exhibited higher caffeine levels before infestation (6.02 mg/g, 5.31 mg/g, and 5.08 mg/g, respectively), with further increases to 17.5 mg/g, 16.17 mg/g, and 15.75 mg/g, respectively, after infestation. There was a significant reduction (p<0.05) in total catechin concentration across all cultivars after infestation, while polyphenol levels varied among the cultivars. Cluster analysis classified the tested cultivars into two distinct groups. The findings indicate significant variation in the responses of secondary metabolites among tea cultivars and suggest that lower caffeine and specific catechin levels could serve as biochemical markers for identifying tea cultivars resistant to SHB infestation.

Copyright

© 2026 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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TY  - CONF
AU  - S. P. R. Wijewardhana
AU  - R. K. A. Amali
AU  - P. Edirisinghe
AU  - P. D. Senanayake
PY  - 2026
DA  - 2026/04/15
TI  - Biochemical Parameters to Identify Shot-Hole Borer (Euwallacea fornicatus) Resistance in Tea Cultivars: Emphasis on Polyphenols, Catechins, and Caffeine
BT  - Proceedings of the International Tea Symposium (InTSym100 2025)
PB  - Atlantis Press
SP  - 265
EP  - 279
SN  - 2468-5747
UR  - https://doi.org/10.2991/978-94-6239-646-3_15
DO  - 10.2991/978-94-6239-646-3_15
ID  - Wijewardhana2026
ER  -