As an inoculum source the mycelium was isolated from fruiting-body of Tricholorna giganteum which collected in the Ogasawara. The used culture medium was potato-dextrose yeast agar (PDYA) medium containing LVD (prepared from softwood sulphite pulp waste) . The optimum conditions of mycelial growth were initial pH 5.5 and D-mannose as carbon source, and the best promotional concentration of LVD added to medium was 0.8%. In the artificial cultivation the medium containing hardwood sawdust, rice bran and wheat bran (400: 23: 35v/v) and keeping 60-65% moisture was employed. In the bottle culture polypropylene bottle containing the above medium (550g) was used and cultured at 24°C. After 40 days culture, surface of the medium in bottle were covered with rice hulls, sand or farm soil and the bottles were cultured at 26-27°C and 85-90% humidity to form the fruiting-body. In these cultivations, farm soil gave the best formation of fruiting-body. The yeilds of fruiting-body on the floor and shelving in the green house were 670 and 600 g per a bag containing 2.5 kg medium, respectively.

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The rectangular hyperbola, non-rectangular hyperbola, and monomolecular function as empirical models of photosynthetic light-response curve, were applied to data acquired from saplings of two Quercus species growing in the shaded undergrowth of a deciduous secondary-forest. The rectangular hyperbola gave unacceptably high estimates of the initial slope (φ) and the upper asymptotic maximum (P_max) . The monomolecular function gave the best estimates for P_max. However, the non-rectangular hyperbola was considered to be more reliable in estimating values of φ. In the three parameters estimated by the non-rectangular hyperbola, the interspecific difference in P_max was almost negligible. As for θ, a curvature factor (dimensionless), Q. mongolica var. grosseserrata showed higher values although limited to a growth season and statistically nonsignificant. It was the parameter φ that the interspecific difference was significant, where Q. serrata showed higher values. From the estimation that the higher values of parameter φ act more effectively on the leaf carbon gain in heavily shaded forest floors, the saplings of Q. serrata were understood to be more shade-tolerant than Q. mongolica var. grosseserrata.

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The effect of increased amount of CO₂ on the sugar concentration, sucrose synthase (E.C. 2.4.1.13) and sucrose phosphate synthase (E.C. 2.4.1.14) activities in developing tomato (Lycopersicon esculentum Mill. cv. Lady First) fruits was studied. The CO₂-enriched tomatoes had significantly higher fruit weight, higher total and reducing sugars during development compared to the control. The sucrose synthase activity was sig-nificantly higher in enriched fruits up to 50 days after anthesis and after that decreased drastically, while it was decreased gradually in the controls. The decrease in sucrose synthase activity was accompanied by decreasing sucrose concentration. There were no significant differences in sucrose concentration and sucrose phosphate synthase activity between the treatments. The sucrose phosphate synthase activity showed relatively constant throughout the fruit development.

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Roots and leaves of freesia corms in forcing culture must be developed even during low temperature treatment. It is also difficult to plant them since their roots and leaves have already become long after the cold treatment. Therefore, skill in the management is required. This study was carried out to find the effect of spot cooling on the forcing culture by using a spot air-conditioner instead of low temperature treatment of the corms. Corms of freesia ‘Rijnveld's Golden Yellow’ of which the dormancy had been broken by high temperature storage at 30°C and ethylene application were used. They were stored under moist condition at 9°C for 0, 4 or 6 weeks, or at 9°C for 6 weeks and then 15°C for 2 weeks on 11 August. After the temperature treatment they were planted on two soil beds (9.4m×0.7m each) in a green-house. One was a spot cooling bed with the spot air-conditioner and the other was a control bed without air-conditioner. The spot cooling bed was covered with tunnel-shaped sheet 30 cm in height to insulate the bed, and cool air was channeled into the tunnel. The spot cooling continued until 5 October when the mean air temperature in the greenhouse went below 20°C. The air temperature on the spot cooling bed was maintained about 4-7°C lower than that on the control bed. Corms which received spot cooling from 11 August for 8 weeks without 9°C treatment flowered on 13 December and the quality for cut flowers was improved. The use of the spot air-conditioner made it possible to reduce the troublesome work concerned with low temperature treatment and planting as mentioned above. For these reasons, spot cooling was proved to be effective in forcing culture of freesia.

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Features of figure of plant have been expected as useful indices of status of growth. For example, leaf tip angle is known as a significant index of inner water potential status. However, it is very difficult to measure leaf tip angle of all foliages manually. Efficient method of measuring leaf tip angle is necessary. In this paper, a new method of image measurement of leaf tip angle for small foliage or seedling was proposed and its availability was studied. Wedge-shaped feature, which is one of textural features, contains information about tip angle of line in image. Using this characteristic, the method of measuring both average and three dimensional distribution of leaf tip angle was developed. First, fundamental availability of this method was confirmed with simulated images which contain a lot of small three dimensional disks randomly distributed in a cubic area. As a result, wedge-shaped features could indicate average of tip angle properly. Further, an outline of three dimensional distribution of tip angle was reconstructed properly from two dimensional distributions of tip angle derived from images taken from several directions. Second, practical availability of this method was studied with images of real plants (Chinese-cabbage and tomato) . Consequently, this method can detect differences between controlled figures and treated ones properly.

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In vitro propagation of perennial pea (Lathyrus latifolius L.) was achieved by subculturing shoot-section with nodes on Murashige and Skoog (MS) based medium with 0.44 μM N⁶-benzylaminopurine (BA) . A proliferation rate of 2.5 per 18 days was achieved. Shoots elongated from these in vitro-cultured nodes could be rooted on the medium with 0 or 0.49 μM 3-indolebutyric acid (IBA) . Plantlets produced were readily acclimatized on the soil.

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Mass propagation of balloon flower (Platycodon grandiflorum) was achieved by subculturing shoot-sections and separated axillary shoots on MS based medium with cytokinin. A proliferation rate of 3.3 per 15-day culture period was achieved on the medium with 4.4 μM ⁶N-benzyladenine (BA) . The elongated shoots from these in vitro-cultured explants could be rooted on MS based medium with 0.49 μM 3-indolebutyric acid (IBA) . Most of the plants were successfully acclimatized and all of them flowered in a greenhouse.

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In order to investigate the mechanism of rhythmic motions of a root, we attempted to measure biomechanical properties of the root by non-contact via an ultrasonic wave. An experimental system is composed of a newly developed transducer positioner, a CCD camera positioner, a turn table, the pulser/receiver, and so on. In this system, we used the spot focused immersion ultrasonic transducer, and by applying image processing data of a root, it can keep the focal length of the transducer and the ultrasonic beam angle in vertical direction to the surface of a root. In addition, it can measure changes with the lapse of time at any point of a root by the full automation. By using this system, we observed differences of dynamic characteristics of a root in various points in the vertical direction.

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