Investigating the Virulence of some Plasmopara halstedii Isolates in Hungary
Session
Agriculture, Food Science and Technology
Description
Downy mildew a major threat to sunflower cultivation globally, frequently leads to substantial reductions in sunflower yields. This disease is caused by the highly virulent and aggressive oomycete pathogen Plasmopara halstedii. Investigating the regional spread of the disease and the evolution of virulence in the downy mildew population is crucial for developing new sunflower inbred lines that are resistant to the current variants. This study aims to clarify the virulence phenotypes of Plasmopara halstedii isolates collect-ed in Hungary in 2021, particularly focusing on sunflower differential lines with the Pl6 and Plarg resistance genes. The aggressiveness of these isolates was also analyzed by evaluating the disease rate. Sunflower genotypes Iregi szürke csíkos, HA-335 (Pl6), and RHA-419 (Plarg) were tested against isolates I3 and I9. Seedlings were germinated at different temperatures (19°C and 24°C), inoculated with Plasmopara halstedii at a concentration of 50,000 sporangia/ml, and then incubated overnight at 16°C. Disease evaluation was based on the presence of sporangia on cotyledons and damping-off/chlorosis on 21-day-old leaves, with classifications of susceptible (S) or resistant (R) after the second assessment. Isolate I9 was not able to overcome Pl6 and the Plarg resistance gene. On the other hand, I3 was a more aggressive isolate, as it was able to cause disease on the plants carrying Pl6 resistance gene but not the Plarg resistance gene.
Keywords:
Sunflower Downy Mildew, Plasmopara halstedii, Resistance Genes Pl6, Plarg.
Proceedings Editor
Edmond Hajrizi
ISBN
978-9951-982-15-3
Location
UBT Kampus, Lipjan
Start Date
25-10-2024 9:00 AM
End Date
27-10-2024 6:00 PM
DOI
10.33107/ubt-ic.2024.254
Recommended Citation
Berisha, Arbnora; Bán, Rita; and Berisha, Kaltrina, "Investigating the Virulence of some Plasmopara halstedii Isolates in Hungary" (2024). UBT International Conference. 5.
https://knowledgecenter.ubt-uni.net/conference/2024UBTIC/AFCT/5
Investigating the Virulence of some Plasmopara halstedii Isolates in Hungary
UBT Kampus, Lipjan
Downy mildew a major threat to sunflower cultivation globally, frequently leads to substantial reductions in sunflower yields. This disease is caused by the highly virulent and aggressive oomycete pathogen Plasmopara halstedii. Investigating the regional spread of the disease and the evolution of virulence in the downy mildew population is crucial for developing new sunflower inbred lines that are resistant to the current variants. This study aims to clarify the virulence phenotypes of Plasmopara halstedii isolates collect-ed in Hungary in 2021, particularly focusing on sunflower differential lines with the Pl6 and Plarg resistance genes. The aggressiveness of these isolates was also analyzed by evaluating the disease rate. Sunflower genotypes Iregi szürke csíkos, HA-335 (Pl6), and RHA-419 (Plarg) were tested against isolates I3 and I9. Seedlings were germinated at different temperatures (19°C and 24°C), inoculated with Plasmopara halstedii at a concentration of 50,000 sporangia/ml, and then incubated overnight at 16°C. Disease evaluation was based on the presence of sporangia on cotyledons and damping-off/chlorosis on 21-day-old leaves, with classifications of susceptible (S) or resistant (R) after the second assessment. Isolate I9 was not able to overcome Pl6 and the Plarg resistance gene. On the other hand, I3 was a more aggressive isolate, as it was able to cause disease on the plants carrying Pl6 resistance gene but not the Plarg resistance gene.