Corrêa F F, Pereira M P, Madail R H, Santos B R, Barbosa S, Castro E M, Pereira F J
Departamento de Biologia, Universidade Federal de Lavras, Lavras, MG, Brazil.
Instituto Federal de Educação, Ciência e Tecnologia do Sul de Minas Gerais, Poços de Caldas, MG, Brazil.
Braz J Biol. 2017 Mar;77(1):52-59. doi: 10.1590/1519-6984.09715. Epub 2016 Jul 4.
Some macrophytes species show a high growth potential, colonizing large areas on aquatic environments. Cattail (Typha angustifolia L.) uncontrolled growth causes several problems to human activities and local biodiversity, but this also may lead to competition and further problems for this species itself. Thus, the objective of this study was to investigate anatomical modifications on T. angustifolia plants from different population densities, once it can help to understand its biology. Roots and leaves were collected from natural populations growing under high and low densities. These plant materials were fixed and submitted to usual plant microtechnique procedures. Slides were observed and photographed under light microscopy and images were analyzed in the UTHSCSA-Imagetool software. The experimental design was completely randomized with two treatments and ten replicates, data were submitted to one-way ANOVA and Scott-Knott test at p<0.05. Leaves from low density populations showed higher stomatal density and index. These modifications on stomatal characteristics were more evident on the leaf abaxial surface. Plants from low density populations showed thicker mesophyll and higher proportion of aerenchymal area. Roots from low density populations showed a higher proportion of the vascular cylinder. Whereas, plants from higher density populations showed greater thickness of the endodermis, exodermis, phloem and root cortex. Higher density populations showed a higher proportion of aerenchymal gaps in the root cortex. Therefore, cattail plants from populations growing under high density population show anatomical traits typical of plants under stress, which promotes the development of less functional anatomical modifications to aquatic environments.
一些大型植物物种具有很高的生长潜力，能在水生环境中占据大片区域。香蒲（狭叶香蒲）的无节制生长给人类活动和当地生物多样性带来了诸多问题，但这也可能导致该物种自身的竞争及其他问题。因此，本研究的目的是调查不同种群密度下狭叶香蒲植株的解剖结构变化，因为这有助于了解其生物学特性。从高密度和低密度生长的自然种群中采集根和叶。将这些植物材料固定并进行常规的植物显微技术处理。在光学显微镜下观察并拍摄玻片，图像在UTHSC SA-Imagetool软件中进行分析。实验设计完全随机，有两种处理，十个重复，数据进行单因素方差分析和p<0.05的斯科特-诺特检验。低密度种群的叶片气孔密度和指数较高。这些气孔特征的变化在叶片下表面更为明显。低密度种群的植株叶肉较厚，通气组织面积比例较高。低密度种群的根维管束比例较高。而高密度种群的植株内皮层、外皮层、韧皮部和根皮层更厚。高密度种群的根皮层通气组织间隙比例更高。因此，高密度种群生长的香蒲植株表现出受胁迫植物的典型解剖特征，这促进了对水生环境功能较差的解剖结构变化的发展。
