この要旨の出典：
Lux,A., T.Homma, S.Morita, J.Abe and E.Tanimoto 1999. Preliminary
study of tea root anatomy. Root Research 8(4):*.
Tea is an important plant for the production of refreshing drinks. Tea plants (Camellia sinensis) are evergreen and long-living shrubs which are mostly propagated by stem cuttings. Because the knowledge of tea root anatomy is quite limited, we have studied the structure of seminal and adventitious roots grown under different conditions.
Seeds of tea cultivar Yabukita were grown in perlite in greenhouse. Cuttings of the same cultivar were planted in the field, hydroponic-cultured in the greenhouse and grown in the mist chamber. Roots of those materials were fixed by glutaraldehyde - osmium tetroxide for light microscopy. The samples were embedded in Spurr resin and 1 um thick sections were made to stain with tolidine and basic fuchsin. For histochemistry berberine - toluidine blue and fluorol yellow were used to visualize Casparian bands and suberin lamellae, respectively. The sections were observed and pictured by Olympus Vanox-T microscope.
Seminal and adventitious roots of tea plants have distinct anatomy. Seminal roots are thick and they have an extensive parenchymatic pith. Root hairs are present and Casparian bands are developed both in exodermis and endodermis close to the apex. Adventitous roots are thin, with 3-4 poles of xylem and phloem and without pith. No root hairs are formed under any growing conditions. Casparian bands were developed very close to the root apex. Endodermal Casparian bands were formed at 0.1, 0.2, 0.5 cm from the root tip in soil, mist and hydroponic culture respectively. Suberin lamellae formation occurred at 1, 5, and 5 cm, in these conditions respectively. Exdodermal Casparian bands were developed at 0.1 cm in soil, 0.1 cm in mist culture and 0.2 cm in hydroponis culture. Such development of functional exodermis sooner than endodermis in tea roots is quite exceptional. This early development of apoplastic barrier close to the root tip is supposed to play an important role in regulation of radial transport in tea roots.
Acknowledgement: One of the authors (A.L.) ackowledges
hospitality extended by NIVOT during his stay in Kanaya.
講演では、上記のチャの根の内部形態に関する話題のほか、スロバキアにおける環境保全への植物利用のための研究の紹介などもありました。