Abstract

Fifteen populations of Calotropis procera (Aiton) W.T. Aiton (milkweed) were collected from ecologically different regions of Punjab to evaluate anatomical traits that contribute to the ecological success of this plant in heterogeneous environmental regimes. Structural features relating to stems and leaves showed phenotypic variation. Xeromorphy was high in the desert population possessing thick cuticle and surface hairiness, enhanced xylem vessels, phloem area and deposition of storage parenchymatous tissues (cortex and pith) in the stem and leaves. The population from salt-affected areas showed increased inner phloem area and pubescence in stems, whereas lamina thickness and xylem vessels were greatly enlarged in leaves. The population from mountainous ranges showed the maximum stem area, outer phloem area, cuticle thickness and epidermal cell area. The population along riverbanks showed some prominent features like enlarged bundles of sclerenchyma fibers, and enhanced midrib thickness, cuticle thickness and inner phloem area. The population from the artificial forest plantation had a prominent layer of collenchyma developed under the epidermis, thick lamina and widened xylem vessels. The population from roadsides possessed thick cuticles and enlarged xylem vessels in leaves; in addition, a great proportion of trichomes/hairiness was found on the stem surface. Leaf succulence was the prominent feature of the population adapted to desert and dry mountains. All of these features possibly contribute to C. procera adaptability in a variety of habitats, i.e., desert and semi-desert, salt-affected areas, dry mountains, river/canal banks, roadside and forest plantations, and others.

摘要

Calotropis procera的 15 个种群(Aiton) WT Aiton（马利筋）是从旁遮普邦生态不同的地区收集的，以评估有助于这种植物在异质环境状况下的生态成功的解剖学特征。与茎和叶相关的结构特征表现出表型变异。荒漠种群的干形性高，具有厚的角质层和表面毛羽，增强的木质部血管，韧皮部区域以及茎和叶中的储存薄壁组织（皮质和髓）的沉积。受盐害地区的种群显示，茎的内部韧皮部面积和短柔毛增加，而叶片的叶片厚度和木质部血管大大扩大。山区种群表现出最大的茎面积、外韧皮部面积、角质层厚度和表皮细胞面积。沿河的种群表现出一些突出的特征，如厚壁组织纤维束增大，中脉厚度、角质层厚度和韧皮部内部区域增加。来自人工林的种群在表皮下发育了一层显着的厚壁组织、厚的叶片和加宽的木质部血管。来自路边的种群具有厚厚的角质层和扩大的叶木质部血管；此外，在茎表面发现了很大比例的毛状体/毛羽。叶肉质是适应沙漠和干旱山区的种群的显着特征。所有这些特征都可能有助于 来自人工林的种群在表皮下发育了一层显着的厚壁组织、厚的叶片和加宽的木质部血管。来自路边的种群具有厚厚的角质层和扩大的叶木质部血管；此外，在茎表面发现了很大比例的毛状体/毛羽。叶肉质是适应沙漠和干旱山区的种群的显着特征。所有这些特征都可能有助于 来自人工林的种群在表皮下发育了一层显着的厚壁组织、厚的叶片和加宽的木质部血管。来自路边的种群具有厚厚的角质层和扩大的叶木质部血管；此外，在茎表面发现了很大比例的毛状体/毛羽。叶肉质是适应沙漠和干旱山区的种群的显着特征。所有这些特征都可能有助于 叶肉质是适应沙漠和干旱山区的种群的显着特征。所有这些特征都可能有助于 叶肉质是适应沙漠和干旱山区的种群的显着特征。所有这些特征都可能有助于C. procera对各种生境的适应性，即沙漠和半沙漠、盐渍区、干旱山区、河流/运河岸边、路边和森林种植园等。