探究学習としての維管束の観察

―トルイジンブルー染色を利用した教材開発―

抄録

Under the curriculum of new course of study (2008) the learning on vascular system in junior high school becomes more significant. The students are expected to learn the vascular system through inquiry. For guiding students’ inquiry I investigated the vascular bundle of angiosperm stems using the polychromatic staining method by toluidine blue O and developed some teaching materials and method. The basic investigation on vascular bundle of plants in surroundings showed that the metachromasia of toluidine blue O was observed in the 80 % of 63 angiosperms species. In such species the xylem and the phloem could be differentiated easily by color. The xylem was stained blue or greenish blue while the phloem was stained reddish or bluish purple. Some species such as Lamium amplexicaule, Cyperus cyperoides, Mirabilis jalapa showed the suitable morphological feature of vascular system to study the patterns and diversity of plants. The developed teaching materials and method for inquiry are as follows: (1) Work sheets guiding observation of vascular system stained by toluidine blue O; (2) Photographic plates and information photo cards for comparative observation or the activity of classification of vascular system; (3) Work sheets and photographic plate on vascular system of climbing plants for relating the structure of stem to the adaptation in the environment.