Stress Resistance Characteristics of Calophyllum inophyllum, A Tropical Beach Plant

Abstract:

In order to understand the stress resistance of Calophyllum inophyllum, the morphological and anatomical, eco-physiological characteristics, element contents in leaves and soil of C. inophyllum growing in Xisha Islands were analyzed. The results showed that C. inophyllum was heliophyte plant with thick leaf, well-developed spongy tissue and tightly arranged palisade tissue with low stomata density (24.40 mm^-2), which was beneficial to its water retention and drought resistance of leaves. The contents of chlorophyll a and chlorophyll b were low (0.87 and 0.43 mg g^-1, respectively), indicating that C. inophyllum had good adaptability to the high irradiation environment. The low level of malondialdehyde content (13.46 nmol g^-1), the high level of proline content (127.89 µg g^-1), and superoxide dismutase activity (149.42 U g^-1) in leaves indicated that it had strong antioxidant capacity (388.60 U g^-1), so as to alleviate membrane lipid peroxidation under stress conditions. Though the nutrient in natural growing soil was poor, the content of nutrient elements in leaves of C. inophyllum was high, indicated that it had high utilization and good adaptability to poor soil. Overall, C. inophyllum had good adaptability to strong radiation, drought and poor soil, and could be used as a tool species for rehabilitation of tropical coral islands.

Key words:Calophyllum inophyllum;Nutrient element;Ecophysiology;Morphological anatomy;Xisha Islands