【作者】 吴耿；

【导师】 余龙江； 李为；

【作者基本信息】 华中科技大学 ， 生物化工， 2007， 硕士

【摘要】 不同的地质环境造就了植物不同的适生机制。本文从植物生理生化以及结构解剖学角度,对西南岩溶地区不同地貌部位以及不同地质背景条件下生长的典型植物黄荆(Vitex negundo)的叶片特征进行了比较研究。结果表明:(1)黄荆具有较强的渗透调节能力。叶片的脯氨酸和可溶性蛋白含量具有明显的季节特征,如桂林毛村石灰岩区黄荆叶片的脯氨酸含量和可溶性蛋白含量都是旱季(10月)较高,分别为雨季(7月)的2.3倍和3.35倍。(2)岩溶区生长的黄荆叶片具有旱生植物叶片特征,其叶片厚度、上下表皮厚度、栅栏组织的厚度以及栅栏组织的致密程度均大于非岩溶区,这些特征有利于减少水分蒸腾,而且也与野外观测岩溶区黄荆的日平均蒸腾速率小于非岩溶区相对应。而且,岩溶区黄荆叶片的维管组织发达程度高于非岩溶区,有利于在蒸腾减小的情况下促进水分运输和营养元素的迁移。(3)同一岩溶地区不同地貌部位生长的黄荆的叶片形态结构具有明显差异。垭口黄荆相比于坡地黄荆有较厚的叶片、较浓密的表皮毛和较发达的栅栏组织,这些特征同样有利于减少水分散失,从而减少岩溶干旱带来的伤害。上述叶片特征体现出该种植物对岩溶干旱环境的适应。本文研究结果为进一步深入探索典型植物对岩溶环境的适应机制提供了一定的科学依据,并为岩溶地区适生植物的选择和栽种及岩溶石漠化治理提供了有价值的参考依据。更多还原

【Abstract】 Different site conditions lead to different mechanisms of plant ecological adaptations. In this paper, comparative studies on the foliar characteristics of Vitex negundo grown in different geomorphological locations and different geological background were investigated from the angles of plant physio-chemistry and structural anatomy. Major results were obtained as follows. (1) Vitex negundo had strong ability of osmoregulation. The contents of proline and soluble proteins in the leaves of Vitex negundo had obvious seasonal characteristics. For example, the contents of proline and soluble proteins were higher in the leaves of Vitex negundo grown in limestone area of Maocun of Guilin in dry season (October), which were respectively 2.3 times and 3.35 times higher than that in rainy season. (2) The leaves of Vitex negundo grown in the karst areas had the characteristics of leaves of xerophytes. The thickness of the leaves, the epidermis of both upside and downside, and the compact degree of palisade tissue of Vitex negundo were much greater in the karst areas than that in the non-karst areas. These characteristics were helpful to decrease water transpiration, which was consistent with the field observation results of daily average transpiration rate in karst areas being lower than that in non-karst areas. Moreover, the vascular tissue of the leaves was more developed in the karst areas than that in the non-karst areas, which make it advantageous to promote water transportation and migration of nutrient elements under the condition of decrease of transpiration. (3) There were obvious differences in the morphological structure of the leaves of Vitex negundo among different geomorphological locations. Compared to the Vitex negundo grown in Slope, the Vitex negundo grown in Saddle had more thickness leaves, more bushy epidermic hairs, and more developed palisade tissue, which make it advantageous to decrease water losses so that decrease damage caused by karst drought. Above characteristics of leaves of Vitex negundo reflected the ecological adaptation to the karst drought environments. These results would provide a scientific basis on further deep exploration of adaptation mechanisms of typical plants to karst environments, and provide valuable reference foundation for choice and planting of the suitable plants, and management of rock desertification in karst areas.更多还原