Screening and Evaluation of Powdery Mildew Resistance in a Diverse set of Linseed (Linum usitatissimum L.) Germplasm

Aims: The study was conducted to evaluate 356 linseed (Linum usitatissimum L.) germplasm accessions for resistance to powdery mildew under natural field conditions during the Rabi seasons of 2022-23 and 2023-24. Place and Duration of Study: The field experiment was carried out in the experimental plot of AICRP on Linseed, Regional Research and Technology Transfer Station (RRTTS), Odisha University of Agriculture and Technology (OUAT), Keonjhar, situated under North Central Plateau Zone (NCPZ) of Odisha. Methodology: The germplasm lines were screened for reaction to powdery mildew disease under natural field condition during Rabi-2022-23 and Rabi-2023-24. The disease severity was assessed using 0-5 scale, where genotypes with scores below 2 were classified as resistant. Results: The results revealed a significant range of resistance, with 21 genotypes categorized as immune, 37 as resistant, and 36 as moderately resistant. Conversely, 144 genotypes were highly susceptible. Resistant genotypes, including promising lines like EC-41890 and BAU-1892, exhibited high yield potential, indicating their suitability as donor parents for future breeding programs. Conclusion: Environmental factors such as temperature and humidity significantly influenced disease expression, highlighting the need for artificial inoculation in future validation studies. The findings emphasize the potential for integrating genetic resistance into linseed breeding programs, addressing a critical biotic constraint to enhance sustainable production.