Dormancy Breaking Requirements and Germination Ecology of Descurainia sophia Under Variable Temperature and Light Conditions

Abstract

Dormancy breaking requirements and germination ecology of Descurainia sophia were investigated under variable temperature and light conditions to understand factors regulating seed germination and establishment potential in agricultural ecosystems. Laboratory experiments were conducted using seeds subjected to different pre-treatments and incubation regimes involving alternating and constant temperatures combined with varying photoperiods. Results indicated that fresh seeds exhibited strong primary dormancy, requiring specific environmental cues for successful germination. Cold stratification significantly enhanced germination percentage, suggesting physiological dormancy as a key limiting factor. Temperature regimes played a critical role, with moderate alternating temperatures promoting higher germination compared to constant extremes. Light exposure further influenced germination behavior, with some seed batches showing positive photoblastic responses, while others demonstrated partial insensitivity depending on dormancy status. The interaction between temperature and light conditions revealed that optimal germination occurred under combined favorable thermal fluctuations and light exposure. Dormancy release was found to be gradual, indicating a multi-phase germination ecology adapted to seasonal variability. The study highlights the ecological adaptability of D. sophia and its capacity to persist in disturbed agroecosystems through a persistent seed bank. These findings provide valuable insights for predicting emergence patterns and improving weed management strategies targeting early-season establishment in cropping systems.