Analysis of physiological and biochemical traits associated with drought stress tolerance in Hevea brasiliensis under different seasonal and climatic conditions
摘要
The rubber tree (Hevea brasiliensis Muell Arg) is a major global source of natural rubber; however, its biochemical response to seasonal water deficit remains insufficiently studied. This study evaluated the biochemical responses of three rubber clones (IAN 873, FX 3864, and FX 4098) during three climatic seasons (rainy, transition to dry, and dry) in two distinct edaphoclimatic zones of the northwestern Colombian Amazon. Multivariate analysis revealed that drought severity in each edaphoclimatic zone influences the plant’s stress response mechanisms. In the semi-humid warm zone, characterized by lower average monthly rainfall (266 mm month−1), the response was predominantly driven by osmoregulation, with a significant increase in proline content (59.22 µg proline g−1 FW). Conversely, in the humid warm zone where monthly rainfall was higher (437.7 mm month−1), the response was primarily associated with enhanced enzymatic antioxidant activity, particularly catalase (204.20 UCAT mg−1 protein) and peroxidase (60.04 UPOD mg−1 protein). These findings highlight the adaptive biochemical strategies of H. brasiliensis in response to seasonal drought and identify key biochemical traits that could aid in selecting clones with improved resilience for sustainable cultivation under changing climatic conditions in the Amazon.