The dependence of vegetative propagation on the production of individual plants was examined in Disporum smilacinum A. Gray on the basis of shading experiments and field surveys. This species typically showed four types of reproductive behavior: sterile plants producing one plantlet (no propagation), sterile plants producing more than two plantlets (vegetative propagation), fertile plants producing one plantlet (sexual reproduction) and fertile plants producing more than two plantlets (both sexual reproduction and vegetative propagation).The propagation of D. smilacinum was clearly related to the annual net production of each individual plant. The probability of a mother plant producing more than two vegetative propagules (plantlets) increased with net production of the plant in the current year. The number of propagules per plant and runner length increased with net production.It was possible to explain the types of reproductive behavior of this species on the basis of both the initial plant size before sprouting and its net production during the growing season. There was a critical initial plant size for sexual reproduction and a critical level of production for vegetative propagation.

The effects of light intensity on population growth rates (λ) of diploid and triploid experimental populations of Disporum sessile were examined by growth experiments varying light intensity and by using a projection matrix model. λ of the diploid population was shown to have greater dependence on light intensity. This parameter under good light conditions was higher than that of the triploid population, but less than that under conditions of shade. This was due to the differences in reproductive traits of both populations. Diploids produce many small daughter plantlets and seedlings, and triploids produce a few daughter plantlets. The difference in λ between the two populations should contribute to enlargement of the habitat of D. sessile.

Disporum sessile (Liliaceae), a perennial herb of temperate forests is composed of diploid (2n=16) and triploid (2n=24) populations. The size structure differed remarkably as triploid populations had few small plants and no seedlings. Triploid flowering plants were considerably larger than diploids. Triploids that flowered were 2.5 times larger than diploids that flowered and the size of vegetative ramets produced by triploids was twice as large. In triploids, fruiting rates were quite low only with inviable seeds and vegetative propagule size was greater than that of diploids. As regards growth parameters that help to increase plant size, triploids were superior to diploids. Differences in growth and reproductive parameters between diploids and triploids may contribute to forming different patch sizes.

Self-assembled lipid membranes formed onto gold surfaces by several methods were examined in seeking membranes suitable for detecting membrane active compounds, especially, ion-channel forming peptides. Dielectric spectroscopy was used for monitoring the membrane formation and for characterizing the electrical and structural properties of the membranes. With the membrane of a thiophospholipid/phosphatidyl choline mixture, voltage-dependent conductance changes were found when the membrane was subjected to alamethicin, a channel forming peptide. The conductance changes were characteristic of the alamethicin channel formation, suggesting the feasibility of the membrane for the sensor of membrane active compounds.Keywords: solid supported membrane/bilayer lipid membrane/dielectric spectroscopy/impedance spectroscopy/alamethicin