Viral diseases of garlic

Increasing doctoral research focused on the molecular-level analysis of viruses occurring in garlic (Allium sativumwith particular emphasis on species belonging to the genera Potyvirus, Carlavirus and Allexivirus In Hungary, only limited research has been conducted on these viruses, despite their potential to severely affect crop yield. The aim of my work was to identify the virus species present in Hungary and to assess the impact of mixed infections.

I began with nucleic acid extraction and reverse transcription PCR (RT-PCR), through which I successfully detected several viruses in different garlic samples. Among the primer sets used were both my own designs and primers optimised based on literature sources. Using these primer sets, I was able to map the genetic profile of a Leek yellow stripe virus LYSV) isolate obtained from Hungarian samples. This isolate showed significant genetic similarity to Asian and European LYSV sequences in global databases, suggesting that the virus may spread through imported planting material.

Regarding mixed infections, I identified the simultaneous presence of viruses from the Potyvirus and Carlavirus genera, which act synergistically to weaken plants and may reduce yields by as much as 20–30%. Based on PCR and sequence analysis, the Shallot latent virus (SLV) and Garlic virus B (GarV-B) strains detected in Hungarian garlic samples proved particularly concerning, as they actively contribute to the development of mixed infections, thereby increasing disease severity.

At the end of the research, I performed phylogenetic analyses to understand the relationships between Hungarian viruses and international isolates. The genetic proximity observed on the phylogenetic trees suggests that several of the examined viruses may originate from Asian and European commercial garlic plantations. These findings support the theory that infections can easily be introduced into Hungary via imported planting material, highlighting the importance of regular virus testing of domestic propagation stocks.

Based on my results, I proposed developing a comprehensive plant protection protocol that combines the use of virus-free planting material with targeted diagnostic methods suitable for detecting mixed infections. I believe that my research can contribute to the competitiveness of Hungarian garlic production and improve the effectiveness of defence against viral diseases.