Evaluating the combined effects of elevated ozone and carbon dioxide on seed-related traits in Indian mustard (Brassica juncea)

An experiment was conducted during winter (rabi) seasons 2020–21 and 2021–22 at ICAR-Indian Agricultural Research Institute, New Delhi, aimed to evaluate the influence of elevated conditions on seed germination in Indian mustard. Three winter Indian mustard (Brassica juncea) varieties (PDZM 31, Pusa Bold, and PM 30) to study the effects of elevated ozone (65 ± 10 ppb), elevated carbon dioxide (550 ± 10 ppm), and their interaction under FAOE, FACE, and FAOCE treatments. The impact of elevated ozone, carbon dioxide, and their interaction on seed-related traits remains scarce and underexplored. The results showed that seed germination traits (germination percentage, speed of germination, uniformity in germination, seedling shoot length, and seedling shoot width) and seed size parameters (seed length and seed width) were negatively affected by elevated ozone at different growth stages of Indian mustard. Additionally, significant changes were observed under elevated CO2. Notably, under interaction treatments, elevated CO2 was found to mitigate the detrimental effects of elevated ozone, providing insights into potential adaptation strategies for mustard cultivation under future climatic conditions.