热带滨海植物红厚壳的抗逆生物学特性

Stress Resistance Characteristics of Calophyllum inophyllum, A Tropical Beach Plant

摘要:

为了解红厚壳（Calophyllum inophyllum）的抗逆特性，对西沙群岛自然生长的红厚壳叶片的形态解剖、生理生态、以及叶片和适生土壤的元素含量进行了研究。结果表明，红厚壳是阳生性植物，其上表皮厚，海绵组织发达且栅栏组织排列紧密，气孔排列松散且密度小（24.40 mm^-2），有利于叶片保水抵御干旱。叶片的叶绿素a、b含量低（分别为0.87和0.43 mg g^-1），表明红厚壳具适应强光环境的能力。叶片的MDA含量低（13.46 nmol g^-1），PRO含量高（127.89 μg g^-1），SOD活性高（149.42 U g^-1），总抗氧化能力高（388.60 U g^-1），显示红厚壳能通过提高自身的抗氧化能力抵御膜脂过氧化伤害。红厚壳自然生长的珊瑚岛土壤较为贫瘠、营养元素含量低，但红厚壳植株体内具有较高的营养元素含量，表明红厚壳营养元素利用率高，对于贫瘠土壤具有很好的适应能力。因此，红厚壳具有较高的抗氧化胁迫能力和耐受干旱的能力，适宜生长在热带珊瑚岛等土壤贫瘠的生境，可以作为热带珊瑚岛防风固沙和植被恢复的工具种。

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.