Professor Seisuke Kimura and Rumi Amano (3rd year doctoral student) of Kyoto Sangyo University have proposed a new experiment in junior high school science using the cruciferous plant Rorippa aquatica (R. aquatica).
Of the reproductions of organisms learned in junior high school science, the reproduction of new individuals from roots and leaves is called vegetative reproduction.Until now, strawberries and potatoes have been used as teaching materials for vegetative reproduction, but these vegetative reproductions are those in which new individuals are formed from pre-prepared meristems.On the other hand, R. aquatica, which was taken up this time, is a type that forms new meristems in organs whose roles are completely determined, such as leaves and roots, and has vegetative reproduction properties that could not be learned by conventional teaching materials. There is.
R. aquatica is an amphibious plant that grows on the shores of lakes in North America and is sold as aquatic plants under the name "Water Nasturtium" in Japan.When a leaf is torn by a stream of water, a meristem is formed on the cross section of the leaf to regenerate a new individual. The fact that the reproduction is completed in a relatively short period of about two weeks is also a suitable point as a teaching material for school education.
It is also essential to be able to observe the process of vegetative reproduction with a simple task.The research group simply laid a paper towel soaked in tap water on a plastic bat, lined up the cut R. aquatica leaves, and covered them with plastic wrap to prevent them from drying out. It was shown that it can be observed.
In order to verify its effectiveness as a teaching material, we also practiced classes for third-year students of Koganei Junior High School attached to Tokyo Gakugei University (as of September 3).All students observed the regeneration of new individuals from the cross section of the leaves within 2017 weeks, and in the post-class questionnaire, 9% of the students answered that they were "interested in the reproduction of organisms through the class".It can be said that this proved that it is a teaching material that can not only understand the reproduction of living things but also draw interest.
The results of this research were published in "Biological Education" (published in August 2019) published by The Society of Biological Sciences of Japan, and are said to have been selected as the cover of the issue.
