Mysterious Mycorrhizae? A Field Trip & Classroom Experiment to Demystify the Symbioses Formed between Plants & Fungi.
Mysterious Mycorrhizae? A Field Trip & Classroom Experiment to Demystify the Symbioses Formed between Plants & Fungi.
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神秘的菌根？
DOI：
10.2307/20565346
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发表时间：
2009
影响因子：
0.5
通讯作者：
G. Wilson
中科院分区：
文献类型：
--
作者：
N. Johnson;V. Chaudhary;Jason D. Hoeksema;J. Moore;A. Pringle;J. Umbanhowar;G. Wilson
人类每天都在食物、药物和环境中与真菌及其产物相互作用。酵母被用来制作面包和啤酒。青霉素和头孢菌素等挽救生命的抗生素是真菌的产物，添加到洗涤剂中的酶也是真菌的产物，以提高洗涤剂的清洁能力。当霉菌和霉菌在我们的建筑物、食物或栽培的植物中生长时，真菌会引起问题。运动员的脚真菌会引起不适，而谷热真菌（球孢子虫）和组织浆菌病（荚膜组织浆菌）会导致危及生命的疾病。尽管真菌在我们的日常生活中扮演着许多角色，但它们往往显得晦涩而神秘，在很大程度上被美国公众所知和忽视。生物课程在细菌、原生生物和原始植物单元中涵盖了真菌，但真菌与动物的关系比与细菌或植物的关系更密切（Wainwright et al., 1993）。像动物一样，真菌是异养生物，不能自己制造食物；但是，和植物一样，真菌也有细胞壁，而且大部分是不能动的。大多数种类的真菌都有一个生长不确定的丝状体：单个真菌可以无限期地生长，直到它们变得巨大而古老。学生们惊讶地发现，地球上最大、最古老的生物是真菌，而不是鲸鱼和树木（Smith et al., 1992）。真菌非常多样化，但这种生物多样性的大部分尚未被描述，因为估计150万种真菌物种中只有5%有名称（Hawksworth, 2001）。教师可以通过开展涉及真菌的课堂活动，帮助真菌王国变得不那么神秘和晦涩。我们鼓励教师阅读Flannery(2004)，并访问一些优秀的网站（表1），以获得更多关于真菌的背景知识。在这里，我们描述了一系列的实地和实验室活动，以帮助教师向学生介绍在大多数根和土壤中普遍存在的共生真菌。这些活动的主要目标如下：了解看不见的土壤生物对植物生长的影响。2. 了解共生现象及其在自然界中的一系列结果。3. 进行一个实验，在几个星期内收集数据，分析数据，并了解真菌科学家常用的科学调查方法。*学习目标和目的本活动的目的是通过比较有菌根真菌或没有菌根真菌生长的植物和其他土壤生物，向学生介绍真菌与根的共生关系。菌根真菌是某些真菌和大多数植物的根之间的联系。这个练习为学生提供了使用科学方法的经验，跨越了需要定期监测的几个课时，并利用了学生在观察植物随时间发展时形成的令人兴奋的视觉联系。主题、活动和评估遵循BSCS开发的5E学习周期模型的参与、探索、解释、阐述和评估阶段（Bybee et al., 2006）。菌根共生的研究符合当前的生命科学标准，课堂实验促进了探究性科学学习的一般标准。除了生命科学内容外，菌根的研究还提供了通过在生命科学背景下应用基础数学来整合生物和数学问题解决能力的机会，磨练科学调查技能，并培养传达科学概念的沟通技巧。这个活动包括到当地的一个公园实地考察，收集自然土壤，然后是一个实验，然后是一个延长的观察期。每个学生或小组应播种和监测两种植物，一种是活土，一种是死土。整个班级收集的累积数据可用于确定植物在接种包括菌根状真菌在内的土壤生物时是否生长不同。…
[ILLUSTRATION OMITTED] Every day humans interact with fungi and their products in foods, medicines, and the environment. Yeasts are used to make bread and beer. Life saving antibiotics like penicillin and cephalosporins are fungal products, as are the enzymes added to detergents to boost their cleaning power. Fungi can cause problems when molds and mildews grow, in our buildings, foods, or cultivated plants. Athlete's toot fungi cause discomfort, while Valley Fever fungus (Coccidioides immitis) and histoplasmosis (Histoplasmosa capsulatum) can cause life-threatening diseases. Despite their many roles in our daily lives, fungi often seem obscure and mysterious and are largely unknown and ignored by the American public. Biology curricula cover fungi in units on bacteria, protists, and primitive plants, but fungi are more closely related to animals than to bacteria or plants (Wainwright et al., 1993). Like animals, fungi are heterotrophs and cannot create their own food; but, like plants, fungi have cell walls, and are for the most part immobile. Most species of fungi have a filamentous body with indeterminate growth: individual fungi can grow indefinitely until they are enormous and ancient. Students are surprised to learn that the largest and oldest organisms on Earth are fungi, not whales and trees (Smith et al., 1992). Fungi are extremely diverse but much of this biodiversity has yet to be described, as only 5% of an estimated 1.5 million fungal species have names (Hawksworth, 2001). Teachers can help make the fungal kingdom less mysterious and obscure by conducting classroom activities involving fungi. We encourage teachers to read Flannery (2004) and visit some excellent Web sites (Table 1) to gain more background about fungi. Here we describe a series of field and laboratory activities to help teachers introduce students to the symbiotic fungi that are ubiquitous in most roots and soil. The primary objectives of these activities are as follows: 1. Gain an appreciation for the influence of invisible soil organisms on plant growth. 2. Learn about symbioses and their range of outcomes in nature. 3. Conduct an experiment, collect data over several weeks, analyze data, and learn about a method of scientific inquiry that fungal scientists commonly use. * Learning Goals & Objectives The purpose of this activity is to introduce students to fungus-root symbioses by comparing plants that are grown with or without mycorrhizal fungi and other soil inhabitants. Mycorrhizal fungi are associations between certain fungi and the roots of most plants. This exercise provides students with experience using the scientific method, spans several class periods requiring periodic monitoring, and takes advantage of the exciting visual connection that students make when watching plants develop over time. The topic, activities, and evaluation follow the stages of Engagement, Exploration, Explanation, Elaboration, and Evaluation of the 5E Learning Cycle Model developed by the BSCS (Bybee et al., 2006). The study of mycorrhizal symbioses fits well within current life science standards, and the classroom experiment promotes the general standards of inquiry-based science learning. Apart from the life science content, the study of mycorrhizae provides opportunities to integrate biological and mathematical problem-solving skills by applying basic mathematics within life science contexts, hone skills in scientific investigations, and develop communication skills to convey scientific concepts. This activity involves a field trip to a local park to collect natural soil, and an experiment followed by an extended observation period. Each student or group should sow and monitor two plants, one with living soil and one with dead soil. The cumulative data collected by the entire class can be used to determine whether or not plants grow differently when inoculated with soil organisms including mycorrhiral fungi. …