Yasutaka Miura

Using Lichen Tissue Cultures in Modern Biology

We conducted physiological, pharmacological, and chemical studies using tissue cul- tures derived from natural lichens. Cultured tissues of about 200 lichen species were initiated from vegetative thalli collected in various regions of the world. The cultures grew on both complex and defined media. Growth was significantly affected by temperature, as well as by carbon and nitrogen sources. Some tissue cultures produced secondary substances (i.e., depsidones and usnic acid), but most acetone extracts did not show the same patterns of TLC spots as the corresponding natural thalli. Some lichen tissue cultures produced more usnic acid than natural thalli. Several pharma- cological activities were screened for both tissue cultures and natural lichens.

Direct somatic embryogenesis from protoplasts of Foeniculum vulgare.

Protoplasts prepared from an embryogenic cell suspension culture of fennel gave rise to somatic embryoids directly through unequal cell divisions of enlarged, ellipsoidal cells, when embedded in hormone-free LS agarose medium. On the other hand, protoplasts embedded in LS agarose medium containing 2,4-D and kinetin proliferated through unpolarized cell divisions to form calli, which gave somatic embryoids on the surface upon transfer onto the same medium. In either case, somatic embryoids germinated to develop into normal plantlets when cultured on hormone-free LS agar medium under illumination.