biologia plantarum

Biologia plantarum 70:11-17, 2026 | DOI: 10.32615/bp.2026.002

RT-qPCR analysis of genotype-specific beet yellows virus accumulation in sugar beet

Emad IBRAHIM¹, Dilara BOZDOĞAN^{1, 2}, Jiban KUMAR KUNDU^{1, *}

¹ Plant Virus and Vector Interactions, Czech Agrifood Research Center (CARC), Drnovská 507, 16106 Prague, Czech Republic

² Department of Plant Protection, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 16500 Prague, Czech Republic

Background: Rapid and objective characterisation of viral accumulation requires methods combining fast detection and temporal resolution.

Aims: Develop a two-phase approach for screening sugar beet genotypes for beet yellows virus (BYV) accumulation dynamics.

Methods: Phase 1 employed one-enzyme RTX-PCR for rapid BYV detection, followed by single-time-point RT-qPCR at 30 days post-inoculation (dpi) to screen ten genotypes. Phase 2 performed time-course RT-qPCR at six time points (10-60 dpi) on two contrasting genotypes selected from Phase 1, with assay performance validated by a standard curve.

Results: One-enzyme RTX-PCR confirmed BYV infection, enabling quantification; single-time-point RT-qPCR at 30 dpi showed a 5.7-fold titre range (5.6 × 10⁷ to 3.2 × 10⁸ copies), while time-course RT-qPCR revealed distinct trajectories, relatively resistant GZs1 increased gradually (~5.0 × 10⁵ at 10 dpi to 1.7 - 2.3 × 10⁷ at 40 - 60 dpi) whereas susceptible Masaryk rose rapidly early (~3.1 × 10⁶ at 10 dpi) and peaked at 3.7 × 10⁷ by 40 dpi, dynamics not captured by single-time-point measurements; standard curve metrics indicated high assay quality (R² = 0.9976; efficiency = 103%).

Conclusions: This two-phase method combines speed with precision for effective genotype comparison. It reveals BYV accumulation dynamics that are not captured by single‑point assays.

Keywords: Beet yellows virus, kinetics, RT-qPCR, RTX-PCR, sugar beet, viral quantification.

Received: December 22, 2025; Revised: February 2, 2026; Accepted: February 4, 2026; Published online: February 23, 2026  Show citation