Virological survey of walk-in plastic tunnel grown pepper seedlings and forced pepper varieties in Western Hungary in 2023-2024

Peppers can be infected by approximately 50 plant viruses of which the most common species causing significant economic losses in Hungary are Potato virus Y (PVY) and Cucumber mosaic virus (CMV) in outdoor cultivation and Tomato spotted wilt virus (TSWV) and tobamoviruses in indoor cultivation. In addition to vectors’ activity, the infected propagating material also plays a very important role in the spread of pepper infecting viruses. Thus, besides the use of virus-free propagating material and effective protection against vectors, the cultivation of virus-resistant varieties and application of hygiene regulations are essential in the control of pepper viruses. Even with the most precise cultivation techniques, virus infections can occur during indoor cultivation, not only in plantations which are already producing but also in seedling nurseries, therefore monitoring these is crucial to achieve virus-free fruiting pepper stand. In 2023–2024, virological survey of pepper seedlings and fruiting plants collected from two horticultural farms in Zala county and grown in walk-in plastic tunnel was performed using RT-PCR technique to test leaf and fruit samples. During the analysis only the presence of TSWV was identified in 13 samples, while infection of CMV, PVY and tobamoviruses was not detected. It is interesting to highlight that TSWV was detected, despite the black necrosis that developed, in the fruits of the TSWV resistance gene carrying pepper cultivars Antal F1 and Zalkod F1.These results indicate that the use of TSWV resistant pepper varieties or hybrids does not provide complete protection against TSWV damage as symptoms may also appear on resistant individuals not only on susceptible ones due to the vectors’ activity. Therefore, monitoring the vectors that can transmit TSWV and timely control them are essential for indoor pepper cultivation. Without these even TSWV resistant plants will not be able to produce marketable crop.