Diversity of angiosperms

We study plant diversity from a comprehensive perspective through fieldwork in Japan and overseas, genetic and chemical analyses in the laboratory, and experiments using the facilities of the Botanical Garden. This is an area of research where students can enjoy the joy of discovering and elucidating the wonders of plants by studying them in their natural environment. In particular, we analyze how the diversity of angiosperm flowers and leaves has been shaped by their adaptive backgrounds, focusing on their relationships with pollinators and herbivores. By viewing flowers and leaves through their relationships with other organisms, we seek to answer why angiosperm flowers and leaves are as diverse as we see them.

In addition, the Koishikawa Botanical Garden is engaged in a conservation and propagation project focusing on endangered plants endemic to the Ogasawara Islands, and we are studying the natural history of endangered plants on the islands in order to establish effective conservation measures.

The Herbarium TI of the University of Tokyo is the largest herbarium in Japan, with a total collection of over 1.9 million specimens, of which about 800,000 specimens of ferns, gymnosperms, and sympetalae are maintained at the Koishikawa Botanical Garden (monocotyledons and apopetalae are maintained at the University Museum), and are used for research activities from all over the world.

Plant adaptations to terrestrial environments

Land plants have adapted to the terrestrial environments and covered the diverse climatic habitats on earth by acquiring various physiological and morphological characteristics. For plants that are sessile and cannot move their tissues quickly, their physiological mechanisms allow to properly response to the fluctuating environments. Their shape, involving the distinct macro-scale morphological traits to nano-scale anatomical traits, is directly related to their function and play a pivotal role in coping with various subjected stresses. Besides, plants can plastically or genetically change their shapes and physiological traits in response to the environment.

We aim to quantify the functions and performances of the plant morphological and physiological traits, and to elucidate the adaption to diverse terrestrial habitats and the evolution of these traits. We are particularly studying plant water use and adaptation to the elevational habitats, using the plants in Nikko Botanical Gardens and naturally occurring in mountains in Nikko and the other area in Japan.