To clarify phylogenetic relationships among Capsicum annuum, C. chinense and C. frutescens and among accessions within each species, RAPD analysis was carried out for 87 accessions of these species including C. praetermissum as an out group. Thirteen arbitrary primers of 10-mer generated 99 polymorphic bands. A dendrogram was constructed by the NJ method using RAPD data. Three major clusters corresponded to 3 species with the exception of 4 accessions. The cluster of C. frutescens separated into sub-clusters corresponding to collected areas and there were a few genetically different groups in Asia. Species-specific RAPD bands were observed, which facilitated efficient identification of a species. Introgression among three species was assumed because 4 accessions had peculiar morphological characters and species-specific RAPD bands from two different species together.

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Coloring area rates in petals of Eustoma picotee cultivars were measured using an image analyzing system and the stability of the coloring pattern was evaluated by the standard deviation value. The analysis indicated significant differences in the properties of the coloring area and its stability among 16 cultivars. Many cultivars showed an increase in the coloring area rate and a decrease in its stability in petals under 20°C constant condition compared with petals under natural summer temperature condition. The cultivars could be classified to the following three types; stable type, unstable type, and unstable type under a constant temperature of 20°C. Irregular coloring occurred under each condition by cultivars with a standard deviation value is more than 16 except for cv. ‘Hikoboshi’. The picotee stability of each Eustoma cultivar was appropriately appreciable by the standard deviation value of the coloring area rates in petals grown under a constant temperature of 20°C.

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Tomato seedling growth and nutrient concentrations in biodegradable paper pots composed of corn or palm were investigated under different irrigation frequencies before the seedlings were transplanted. In comparison with the seedlings in plastic pots (control), seedlings in biodegradable pots developed shorter shoot and root lengths, fewer leaves, smaller leaf area, and showed a lighter dry weight. The concentrations of nitrogen, phosphate, and potassium in the seedlings in the biodegradable pots were similar to those in the control. The only exception was phosphate in the biodegradable pots made from palm. These findings indicate that differences in plant growth between the control and the biodegradable pots were not caused by differences in nutrient absorption ability. Plant growth in the biodegradable pots made from corn was improved by increasing the irrigation frequency; however, the growth rate was still less than that of the control. This suggests that other factors, in addition to irrigation frequency, are related to the lower growth rate of seedlings in biodegradable pots.

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Growth and nutrient concentrations in tomato seedlings grown in different types of biodegradable pots and plastic pots as control were investigated after transplanting with different amounts of fertilizer. The seedlings in biodegradable pots made with corn or palm were planted with the pots intact, while the plastic pots were removed before the control plants were planted. By 11 days after transplanting, the plants in biodegradable pots had developed shorter shoots and fewer leaves than the control plants. However, in the period subsequent to 11 days after transplanting, the plants in biodegradable pots given heavy applications of fertilizer grew similarly to the controls. At 26 days after transplanting, the concentrations of nitrogen, phosphate, and potassium in plants grown in biodegradable pots receiving the same fertilizer treatment as the control were similar to the control plants, with the exception of phosphate levels in the plants in biodegradable pots made with palm. These nutrient concentrations in plants in biodegradable pots that received heavy fertilizer after transplanting were higher than those in the controls. By 26 days after transplanting, the plants in biodegradable pots had roots extending from the bottom hole and/or biodegraded parts of the pots, and had produced new root systems outside of the pots; however, the pots were not fully degraded in the soil. This suggests that the low growth rate of the plants in biodegradable pots within the initial 11 days after transplanting was caused by the restricted root zone of the plants.

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The effects of various such culture conditions as culture temperature, and concentration of sucrose, gelling reagents and plant growth regulators on the growth and development of embryos excised from immature seeds of Lilium japonicum Thunb. were examined. The embryos as cultured explants were obtained from the capsule in early September. Embryos with 3-5 mm in length were cultured in vitro on Murashige and Skoog medium (pH 5.7) under controlled lighting conditions (45 μmol · m^-2 · s^-1, 16/8 hr: light/dark). The optimal temperature for germination, growth and bulb formation was 20∼25°C. The plantlets were effectively established on MS hormone-free medium containing 3% sucrose and gelled with 0.8% agar or 0.4% gellan gum. Further-more, 1∼10 μM of exogenous Kinetin or BA promoted embryo growth within 30 days of culture. 1∼10 μM of exogenous IAA promoted multiple bulblet formation. The results indicate that our in vitro method for successfully raising plantlets can be efficiently applied to mass seedling propagation of Lilium japonicum Thunb.

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The availability of charcoal as vegetable growing media was discussed from the perspective of recycling agricultural wastes. The charcoal was made from pruned shoot of Japanese pear (Pyrus pyrifolia var. culta Rehd.) which is the most abundant agricultural waste product from orchards at the Center for Environment, Health and Field Sciences, Chiba University.
Charcoal mixed with commercial growing media, though the charcoal particle size and mixing proportion varied, hardly affected the growth of Brassica campestris var. peruviridis cv. Gokurakuten. Fine charcoal (0.1 to 1.0cm) mixed at a volume of 20% decreased the amount of NO₃-N in discharged water, especially during the early part of cultivation. At the end of cultivation, the cation exchange capacity (CEC) of the media tended to be increased by raising plant, not by mixing the charcoal. When charcoal was mixed with clay soil without fertilizer, coarse charcoal (0.5 to 2.0 cm) improved the soil CEC, and fine charcoal (0.1 to 0.5 cm) increased the soil potassium concentration.
In conclusion, charcoal made from pruned shoots of Japanese pear can be used as vegetable growing media and will improve soil properties, while possibly decreasing NO₃-N discharge.

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We developed a transpiration measurement system for satsuma mandarin trees to analyze water movement under a mulching sheet cultivation system in summer, and showed that the daily average water loss from a tree ranged from 22-25 liters in September. These data indicated that most of the water absorbed from roots evaporated from leaves and the amount of water stored in fruit was slight. The transpiration rate changed depending on the weather conditions, showing the highest correlation to the solar radiation among air temperature, humidity and solar radiation. As the soil water concentration was decreased by mulching cultivation using porous sheets, the transpiration rate from tree leaves was decreased 0 to 40% from that of trees under the non-mulching cultivation, with a 15% decrease on average. The amount of water evaporation from soil surface covered with porous mulching sheets was ca 30% of that from bare soil.

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Reducing agents, such as sodium thiosulfate, sodium sulfite, sodium hydrosulfite and ascorbic acid, were added at the concentration of 0.01 mM to nutrient solution containing 0.5 mg Cl · liter^-1 of hypochlorous acid and 0.67 me · liter^-1 of ammonium in order to remove hypochlorous acid and chloramine from the nutrient solution. Thereafter, lettuce (Lactuca sativa L.) was cultured with the nutrient solution. By the addition of any reducing agents to the nutrient solution, occurrence of root injury and growth inhibition were avoided. When reducing agents, such as sodium thiosulfate and ascorbic acid, were added up to a concentration of 0.1 mM, occurrence of root injury and growth inhibition were also avoided.

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‘Mizunasu’ eggplants were grown in heated plastic houses kept at the minimum air temperature of 14°C, 16°C and 18°C. At 14°C, low temperature injuries were observed and marketable yield was remarkably lower than that at 16°C or 18°C. The yield and fruit color at 16°C were similar to those at 18°C. The fruit shape at 16°C was slightly more slender than that at 18°C. At 16°C, the mesocarp of the fruit was firm and the NaCl permeability into the fruit was decreased compared to that at 18°C. However, the ‘Mizunasu’ eggplant fruit is valued mainly by the appearance (fruit color and shape) in the present markets, so the market value of fruit cultivated at 16°C was similar to that at 18°C. On estimation by yield, the appearance of fruits and the heating cost, the minimum air temperature of 16°C was suitable for ‘Mizunasu’ eggplant production in heated plastic houses.

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The differences between male and female plants in the growth, development and quality of Japanese butterbur hybrids were investigated. Regarding total spike yield, male plants were superior to female plants from ‘Mizubuki’ (Gunma) × ‘Yatsugashira’ and ‘Mizubuki’ (Gunma) × ‘Line 4’. However, bracts of male plants began to open earlier than those of female plants, and the marketable yield of male plants remarkably fell due to the openning bracts in February when spikes of Japanese butterbur were in demand. However, since bracts of female plants began to open later than those of male plants, marketable yield from female plants was higher in February. Female plants showed superior in the cold hardiness of spikes compared to that shown by male plants. Furthermore, spikes of female plants were tighter than those of male plants. These results suggested that female plants were more desirable than male plants for selecting a new cultivar for harvesting spikes from hybrid plants of ‘Mizubuki’ (Gunma) × ‘Yatsugashira’ and ‘Mizubuki’ (Gunma) × ‘Line 4’ in February. Although differences were seen in length and diameter of a petiole, there were no differences in the number of petioles, yield and quality of petioles between male and female plants from ‘Mizubuki’ (Gunma) × ‘Yatsugashira’. It suggested that gender was not much related in selecting a new cultivar for harvesting petioles from hybrid plants of ‘Mizubuki’ (Gunma) × ‘Yatsugashira’.

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Effects of arm- and trunk-girdling on berry quality traits throughout ripening stage of ‘Pione’ grapevines exhibiting more vigorous growth were determined. Arm-girdled vine: the differences in berry weight between the girdled and control were not significant; coloring, anthocyanin content, and °Brix were significantly increased by girdling; there were no significant differences in the decrease in free acidity and the increase in β ratio (ratio of tartaric acid to malic acid) between the girdled and control vines. Trunk girdled vines: coloring of the girdled vines was superior to that of the control; per cent of well-colored grapes (a value above 7 on the color chart) among the total production on August 11 was much high on girdled vines and ranged from 55 to 86%, whereas that on control vines was low at 7%; coloring, anthocyanin content and °Brix were significantly increased by girdling; there were no significant differences in cluster weight, berry weight, free acidity, and β ratio between the girdled and control vines. Results demonstrated that the coloring and °Brix of ‘Pione’ grapevine could be increased by girdling, thereby enabling grape growers to improve the fruit quality produced in the southwest part of Japan which usually has warm-night temperatures in summer.

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The effects of ventilation methods on the growth, fruit quality and yield of watermelon in non-perforated low tunnels were examined. The non-perforated low tunnels are usually ventilated by raising and lowering the edges of the plastic cover. In order to save the daily labor needed to ventilate the tunnels, we tested a treatment method that does not require ventilation for approximately 6 weeks after planting until the fruit set stage. During the initial 4 weeks of this period, the edges of the tunnel were buried with soil (buried) and kept closed. During the latter 2 weeks of this period we left one tunnel slightly open. The control was ventilated as usual. The maximal temperature inside the buried tunnel increased to approximately 50°C, but there was no significant difference in the degree of leaf burn. The growth of watermelon plants in the buried-open tunnel excelled slightly, with heavier fruit weight, higher soluble solid content and yield. The bigger difference in day and night temperature of the buried-open tunnel seemed to be one of the factors contributing to this result. This study demonstrated that it is possible to save most of the labor spent ventilating non-perforated low tunnels for watermelon, and 10% of all the working hours can be reduced. Furthermore, it is expected that growth and productivity will improve when the plants are exposed to high temperatures through the use of this method.

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The effects of light intensity and altered red (R)/far-red (FR) photon flux ratio on nitrate concentration and nitrate reductase (NR) activity in komatsuna (Brassica campestris L. cv. ‘Harumi komatsuna’ and ‘Rakuten’) were investigated. Komatsuna was hydroponically grown in full or half strength nutrient solution under different light intensities (PPFD of 165, 290, 350 and 510 μmol · m^-2 · s^-1) and different R/FR ratios (1.01: control, 0.66: R-intercepted and 1.50: FR-intercepted) conditions. When komatsuna was grown under different light intensities, the nitrate concentration in ‘Harumi komatsuna’ was decreased with increases in light intensity, and the actual NR activity was increased with increase in light intensity. In ‘Rakuten’, the nitrate concentration was decreased and the actual NR activity was increased by increased light intensity at half strength nutrient solution. At full strength nutrient solution, the nitrate concentration was hardly decreased and the actual NR activity did not change with increase in light intensity. When komatsuna was grown under different R/FR ratio conditions, reduction of nitrate concentration was observed only in R-interceptive-treated komatsuna grown with half strength nutrient solution.

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We analyzed the relationships between the yearly variation in the developmental phase and fruit quality of the Japanese pear ‘Kosui’ (Pyrus pyrifolia Nakai) and climatic factors in Mie Prefecture between 1987 and 2004. The annual mean air temperature tended to rise at an annual rate of 0.07°C. This uptrend in the mean temperatures was especially remarkable from September to February. Along with the rise of temperature, the estimated date of breaking of bud endodormancy in ‘Kosui’ pear tended to be delayed at a rate of 0.49 day per year, possibly due to the rising temperatures during late autumn and winter. The dates of full bloom were negatively correlated with mean air temperatures at 10-day intervals from early February to mid-April and some of these mean air temperatures increased with advancing years. As a result, the dates of full bloom became earlier each year at a rate of 0.37 day per year. The date of peak harvest was positively correlated with the annual and became earlier each year at a rate of 0.32 day per year. The number of days from full bloom to peak harvest was not correlated with the annual. These results suggest that the developmental phase of ‘Kosui’ pear in Mie Prefecture is being influenced by global warming. However, the sugar concentration in the fruit was influenced by mean air temperature and mean solar radiation from middle July to middle August and mean precipitation from late July to early August, although, the yearly variations in sugar concentration in the fruit did not parallel the variations in annual mean air temperature.

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To investigate the relationship between sugar concentration, gibberellin levels and flower bud formation of terminal buds of bourse shoots in two apple (Malus domestica Borkh.) cultivars ‘Fuji’ and ‘Megumi’, different bearing levels, seeded and seedless treatments were performed. The flowering rate of terminal buds of bourse shoots bearing seeded fruits was lower than those of non-bearing and seedless fruit trees. In the fresh weight of terminal buds of bourse shoots, all treatments were the same in the beginning of June, and weights of buds from seedless trees were heavier than those of seeded fruit trees in the beginning of July. Assimilate of photosynthate produced by bourse leaves distributed to the terminal buds was affected by fruits rather than seeds, and it decreased as the dry weight of fruits per bourse increased. However, sugar concentrations of terminal buds of bourse shoots in the beginning of June also decreased as they bore more fruits. Decreased sugars of terminal buds were sorbitol and glucose, whereas sucrose was invariable. GA level of non-bearing and one type of seedless fruit tree were lower than three or one seeded fruit per bourse in the beginning of June, and it increased with the presence of seeds rather than with the presence of bearing fruit.

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Effects of Uniconazole-P and Paclobutrazol foliar application on the growth and flowering of Duranta repens L. ‘Takaraduka’ were investigated. Uniconazorle-P was more effective than Paclobutrazol for inhibition of stalk elongation. Uniconazole-P at 12.5 mg · liter^-1 was suitable for cultures in 9 to 12 cm pots. As for Paclobutrazol, an effect was hardly seen at even 300 mg · liter^-1. To increase the number of flower-bearing branches, the timing of Uniconazole-P application was also examined. The most effective treatment was duplicated application 10-14 days after pinching and repeated 2 weeks after the first application. Uniconazole-P decreased the node number necessary for flower bud differentiation of ‘Takaraduka’ to 4-5.

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‘Aki Queen’ is a bright-red grape cultivar, but often bears an undesirable deep berry-colored grape. To improve the productivity of clusters with the desired color, the effects of crop load on coloration were investigated in ‘Aki Queen’ grape. Berry numbers per a leaf were adjusted to 0.14, 0.52, 1.53 and 2.47 by pinching and berry thinning at 32 days after anthesis, and girdling treatement was conducted at the base of the shoot. In plants with 0.14 and 0.52 fractions, total anthocyanin concentrations in the skin of the berry increased over 50 × 10^-6 g · cm^-2 and deep colored berries appeared frequently 76 days after anthesis. The 1.53 fraction, however, bore proper bright red berries with an anthocyanin concentration of about 25 × 10^-6 g · cm^-2 96 days after anthesis. The 2.47 fraction showed slight anthocyanin concentration, resulting in poor coloration. However, we could not find a clear relationship between anthocyanin composition and deep coloration. These data suggest that controling the crop load could adjust ‘Aki Queen’ berry to the proper coloration through regulation of anthocyanin concentration.

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The seasonal variations of L-ascorbic acid and nitrate concentration in spinach purchased at a market in Ayabe city, Kyoto pref. were investigated. Spinach samples were purchased from the market 2-3 times per month between June 2003 and May 2004, and the L-ascorbic acid and nitrate concentrations were measured using an RQ flex system. The L-ascorbic acid concentration was relatively low in summer (Jul.-Aug.), and relatively high from winter to early spring (Jan.-Mar.). A clear increase in the L-ascorbic acid concentration was observed from winter to early spring, due to an increase in L-ascorbic acid concentration in the upper half (blade side) of the edible part. The nitrate concentration was relatively high in summer (Jul.-Sep.), and relatively low from winter to early spring (Jan.-Mar.). A clear increase in the nitrate concentration was observed in summer, which was due to an increase in the nitrate concentration in the lower half (petiole side) of the edible part. There was a correlation between the external factors (leaf color and other aspects) and the two internal factors (L-ascorbic acid and nitrate concentrations). However, this correlation was insufficient to assume the two internal factors based on external factors.

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Carrots stored under snowy ground from 98/12/7 to 99/4/12 were dug up and sampled each month. Volatile compounds of carrots were isolated and identified by gas chromatography and gas chromatography/mass spectrometry. One hundred to 124 compounds were found in each sample. Among a total of 45 compounds identified, 26 were identified for the first time in carrots. Concerning the amount of volatiles in carrots in the period between 98/12-99/3, there was almost no change. In comparison to these findings, in April of 1999, the total of volatile compounds had increased about 2.7 times. The main volatile compounds of carrots were β-caryophyllene, caryophyllene oxide, borneol, bornyl acetate and trans-α-bisabolene. Among these, the amount of β-caryophyllene showed an increase of 12.8 times in April compared to that in December. Further, in April this compound accounted for 32.3% of the total of volatile compounds. Similar to β-caryophyllene, trans-α-bisabolene, α-humulene, β-bisabolene all contributed to the increase in volatile components. Moreover, as for volatile compounds that increased sharply in April, cis or trans-γ-bisabolene were found. This compound accounted for 28.4% of all volatile components in April. Conversely, volatile compounds that decreased were caryophyllene oxide, borneol, bornyl acetate, α-humulene oxide, p-methylacetophenone and 6-methyl-(E, E)-3, 5-heptadien-2-one.

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