长春花(Catharanthus roseus)对热带珊瑚岛生理生态适应性研究

长春花(Catharanthus roseus)是夹竹桃科的一种亚灌木植物,具有重要的药用价值和观赏价值,在前期的试验性种植中,发现长春花对热带珊瑚岛环境有很强的适应性。为了探讨长春花对热带珊瑚岛环境的生理生态适应性,该文以移植到热带珊瑚岛的长春花和生长于海南省文昌市苗圃的长春花为研究对象,对其叶片的形态解剖结构、生理学特征、营养元素含量等进行了分析。结果表明:(1)与苗圃生长的长春花和其他耐胁迫的植物相比,移植到热带珊瑚岛上的长春花具有叶片厚、栅栏组织发达、比叶面积小等形态解剖特征,这些特征有利于其光能吸收、水分储存和对环境资源的利用。(2)长春花的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性较高,表现出较强的抗氧化性和抗胁迫能力。(3)长春花的叶绿素a和叶绿素b含量较低,可以减少过多的光能进入叶绿体光合系统,防止过剩的光能对光合系统产生伤害。(4)热带珊瑚岛土壤养分含量低,但生长在岛上的长春花叶片的营养元素含量高,表现出很强的养分吸收和利用能力。因此,长春花对干旱、贫瘠等恶劣生境具有很好的适应能力,可以作为热带珊瑚岛植被恢复工具种。

Ecological and physiological adaptabilities of Catharanthus roseus to tropical coral island

Catharanthus roseus(Apocynaceae)is a subshrub plant with important medicinal and ornamental values. In the previous experimental planting, we found that C. roseus had good adaptability to the environment on tropical coral islands. In order to explore the ecological and physiological adaptabilities of C. roseus to tropical coral island environment, we investigated the morphological and anatomical structures, physiological characteristics, and nutrient element contents of C. roseus were analyzed by taking samples from a nursery in Wenchang City, Hainan Province and those transplanted to tropical coral island as study objects. The results were as follows:(1)C. roseus transplanted to tropical coral island had thicker leaves, more developed palisade tissue, and lower specific leaf area than that growing in nursery and other stress-tolerant plants, which were beneficial to its light energy absorption, water storage and resource utilization.(2)Compared with C. roseus grown in the nursery, C. roseus transplanted to tropical coral island had higher level of superoxide dismutase(SOD), peroxidase(POD)and catalase(CAT)activities, indicating a strong antioxidant enzyme activity and anti-stress ability of this species.(3)However, C. roseus transplanted to tropical coral island had low chlorophyll a and chlorophyll b contents, which could reduce excessive light energy into the chloroplast photosynthetic system and prevent excess light energy from harming the photosynthetic system.(4)Though the coral sand soil that C. roseus growing has a low nutrient content, the nutrient content in C. roseus leaves was high, indicating a good capacity in absorbing and utilizing nutrients of this species. Therefore, C. roseus had a good adaptability to arid and barren habitats, and could be used as a tool species for revegetation restoration on tropical coral islands.