Artificial palm plant indoor].
A tropical plant with ornamental foliage, Trachycarpus fortunei Schltr, was used for the indoor plant research. The research on characteristics of the indoor plant such as growth, morphology, leafing cycle, the lignification of leaf and stem and the use of the indoor plant as a food resource for silkworm pupae were conducted. The plant cultivated in a growth chamber was taller and larger than one cultivated in natural condition. The height and diameter of stem were 100 cm and 30 cm, respectively, in indoor cultivation and 70 cm and 20 cm in natural condition. The accumulation time of leaf, diameter of leaf blade and length of leaf blade were longer in indoor than in natural condition. The lignification of stem was longer in indoor than in natural condition. In the feeding experiment of silkworm pupae, the titer of egg protein in the body was significantly higher than the other protein in the body. The plant cultivated in indoor was shown higher viability than the other cultivated in natural condition. The results suggest that this indoor cultivation method could maintain the quality of the plant and supply the plant continuously in a year round. The study showed the possibility of indoor cultivation of this plant for the plant industry and that would lead to the establishment of a cultivation system for ornamental plants in the future. It is expected that this study would contribute to the development of artificial palms. Artificial palms would be supplied to homes or offices in an economically efficient manner. They could be expected to be widely used in our society, and these artificial palms would contribute to the improvement of living environment. (author)
The endothelial lesions, such as diabetic angiopathy, atherosclerosis and hypertension, cause vascular diseases. Many researchers have tried to clarify the mechanism of endothelial lesion. It is reported that NO, a potent vasodilator, is generated by endothelial cells. A mutation in the eNOS gene results in endothelial dysfunction, and it has been also reported that NO, released from endothelial cells, regulates vascular smooth muscle contraction. On the other hand, O2- and H2O2, which are vasoactive species, are released from endothelial cells. Moreover, other investigators have suggested that endothelial cells regulate smooth muscle cells, while NO, O2- and H2O2 released from endothelial cells regulate smooth muscle contraction. NO, O2- and H2O2 released from endothelial cells, regulate vascular smooth muscle contraction. It has been also reported that the interaction between NO and O2- stimulates the growth of cells in culture, however, its functional significance in vivo is unknown. In this review, the relationship between NO, O2- and H2O2 released from endothelial cells and the regulation of vascular smooth muscle contraction is reviewed. A proposal of the functional roles of NO, O2- and H2O2 released from endothelial cells in vivo, is proposed.
Stages of development of Salix webbiana Karsten (Salicaceae)
The development of Salix webbiana Karsten was studied from its seed to the mature plant. The period of development of Salix webbiana in nature is about 2 years. The period of its growing in Korea, however, is only one year, and the period in nature during winter and spring is about half a year. Salix webbiana is a pioneer in a forest. In the natural environment, Salix webbiana was exposed to temperatures of 15–25°C in the period of seed germination, seedling growth and the growth of adventitious roots. Its survival, maintenance of its characteristics, and the occurrence of new shoot buds are closely associated with the presence of stable summer temperatures above 20°C. The new shoot buds develop, and Salix webbiana regenerates a new shoot within about 20–50 days. During the growth of the shoots, the stolons extend upward to create a rhizome. The new shoot and the rhizome co-operate for vegetative growth. From the time of emergence of the first branches, Salix webbiana leaves emerge gradually with the tip of new shoot bud and become fully expanded. Although its leaves are green and glossy, Salix webbiana produces only one leaf in early winter and grows another leaf after the leaves are fully expanded. Salix webbiana takes advantage of high summer temperatures and has a growth rate of more than 4 cm per day in summer. It produces many branches and a large number of fine shoots (4–5) that grow by apical growth. The diameter of a new shoot is about 30 cm within one year. The most rapid growth is associated with the greatest number of branches. From a leaf bud, four new shoots bud from the shoot. Each new shoot grows by apical growth and produces about 10 leaves within one year. The leaves are produced by an apical meristem, and a new shoot bud develops into a new leaf. The phyllotaxy of Salix webbiana is alternately, and the leaves are positioned upward. The leaf is green, shiny and glossy, and the leaf blade is typically ovate with a slender stalk. The leaf blade is 8–12 cm long and 5–7 cm wide, and its major vein is thick. From a leaf bud, a new shoot bud grows to the fourth to fifth branch of the previous year, and a lateral bud emerges on its major axis. The upper lateral bud will grow by apical growth to become the sixth branch. The lateral buds arising on the axillary bud were observed from the first leaf. They could grow into the first branch.