Journal of the Japanese Society for Horticultural Science
Online ISSN : 1880-358X
Print ISSN : 0013-7626
ISSN-L : 0013-7626
Volume 66 , Issue 2
Showing 1-26 articles out of 26 articles from the selected issue
  • Matsuo Itoh, Katsura Manabe
    1997 Volume 66 Issue 2 Pages 221-228
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    The movement and effects of soil-applied herbicide, diuron (Karmex ?? ), in 'Kyoho' grape (Vitis vinifera L. × V. labrusca L.) vineyards and 'Hakuho' peach (Prunus persica Batsch. var. vulgaris Maxim.) orchards were examined. Field experiments were conducted at eight sites differing in soil texture. Mobility of diuron in soils was evaluated by bioassay using soil samples collected from every site. Herbicidal activity of diuron and fruit tree injury were related to its mobility in soils. Diuron lost its activity as it moved down in sandy loam soil.
    Consecutive application of the herbicide at 4.71 kg a. i. /ha severely injured the fruit trees although the compound sequentially applied at the recommended commercial rate of 1.57 kg a. i. /ha, was not injurious to both grape vines and peach trees. Serious damage from the compound occurred in soils where it was distributed extensively and leached gradually. The injury was serious in sandy soils, but it was slight in soils with high organic matter. The exposure duration of roots to diuron in soil also seemed to be another factor causing injury. Serious injury appeared when the herbicide leached from the soil suraface into more than 17 cm over 1 month. Consequently, the phytotoxicity of soil-applied herbicides such as diuron on fruit trees seems to be primarily attributed to the mobility of herbicides in soil, and secondly to the duration of their leachates in contact with the roots.
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  • Tsuneo Ogata, Hiroyuki Fujita, Shuji Shiozaki, Shosaku Horiuchi, Kenji ...
    1997 Volume 66 Issue 2 Pages 229-234
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Inhibition of physiological fruit drop in satsuma mandarin with AVG (2-aminoethoxy vinyl glycine) was evaluated. The rate of ethylene production by the fruit and the levels of ACC, ABA-like and IAA-like substances in the fruit were determined. The relationship between the dynamics of these substances and physiological fruit drop is discussed.
    AVG sprayed at petal fall significantly inhibited fruit drop of 33-year-old satsuma cv. Miyagawa-Wase. There was no difference between the quality of AVG treated and untreated fruit at harvest.
    AVG significantly inhibited the release of ethylene from young fruit for 2 weeks after treatment, and decreased ACC content in fruit for 3 weeks. These inhibitions disappeared by 4 weeks after application.
    The level of ABA-like substance in untreated fruit increased in the early stage of fruit drop, whereas that of treated fruit remained low. The AVG treatment increased the level of IAA-like substance which remained higher than that of the control throughout the experiment.
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  • Junko Watanabe, Robert M Pool, Kazuo N Watanabe
    1997 Volume 66 Issue 2 Pages 235-244
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    The ability of LAI 2000 Plant Canopy Analyzer to estimate the leaf area index (LAI)of grapevines canopies accurately was evaluated. This indirectly estimated LAI ofgrapevine canopies was compared to the directly measured (observed) LAI, using fullydeveloped V. labrusca L. cultivar, 'Concord', canopies in 1993; In 1994, 'Concord' and'Chardonnay' canopies at different growing stages were similarly analyzed.
    Calibration was required to obtain reliable estimates of LAI because the growth habitof grapevines did not satisfy the requirement for random foliage distribution when ap-plying gap fraction analysis. The most improtant consideration was sensor view field, which should be maximized when viewing randomly distributed canopies. Variablestested included reading postition, reading direction, view zenith angle and view openingangle.
    It was easier to apply gap fraction analysis with a vigorous cultivar, 'Concord', be-cause of its large canopy and more random foliage distribution than with 'Chardonnay'.For the latter, a typical V. vinifera grapevine, the view field needed to be narrowed be-cause of its low vigor, pruning and training system, and non-random leaf distribution.Estimating leaf area in the middle or late season was easier than in early season whengaps between rows were large and foliage distribution was highly variable.
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  • Mebelo Mataa, Shigeto Tominaga, Itaru Kozaki
    1997 Volume 66 Issue 2 Pages 245-251
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    This study focused on the effect of exogenous gibberellic acid (GA3), auxin (2, 4-D), and synthetic urea-based cytokinin (CPPU) and their application time on non-structural carbohydrate partitioning in the leaves and the interaction with fruit development in ponkan (Citrus reticulata Blanco cv. Yoshida), a low yielding citrus cultivar. Hormones were applied at: 200 ppm GA3, 10 ppm 2, 4-D, and 20 ppm CPPU, either singly or in combination at anthesis and/or 30 days later. GA3 applied 30 days after anthesis increased the proportion of sucrose to glucose and fructose in the sap and reduced starch content. The increase in sucrose appeared 60 days after anthesis but starch decrease occurred 120 days after anthesis. Double application did not exert any significant effects. 2, 4-D treatments reduced fruit set slighthy, but did not affect sugar accumulation patterns. A single application of CPPU or in combination with other growth regulators at anthesis increased total sugar content, reduced fruit set, caused severe leaf chlorosis, and leaf drop.
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  • Shiping Wang, Goro Okamoto, Ken Hirano
    1997 Volume 66 Issue 2 Pages 253-259
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    The buried and raised soil bed systems which restrict root volume were compared for their effects on root environment, vine growth, and fruit development of 'Hone' grapes. In the buried beds, the soil and roots were enveloped with a polyester sheet that allowed free movement of moisture but which roots did not penetrate. In the raised beds, the root zones were sub-divided into two types: 1) isolated at the ground level with a plastic sheet, and 2) non-isolated.
    The characteristics and / or advantages of the buried bed system over those of the raised bed system are: a) the soil temperature was 0.8 to 1.7 °C higher from April to June; b) soil moisture changed slower so that it required less frequent irrigation; c) new primary and secondary roots were longer and their peroxidase activity was higher; d) leaf nitrogen and chlorophyll contents were higher; e) photosynthetic rate of leaves was faster during anthesis and berry set; f) shoot growth was more vigorous, and g) growth of berries, development of skin coloration, accumulation of total soluble solids content (TSS), and decrease in acid content were hastened.
    The above findings indicate that the buried bed system is suitable for dry regions because it promoted better vine growth and berry quality and required less frequent irrigation compared with the raised bed system.
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  • Goro Okamoto, Yoko Minami, Ken Hirano
    1997 Volume 66 Issue 2 Pages 261-265
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    To identify granules present in abnormally swollen rachises of 'Muscat of Alexandria' grape, six kinds of histochemical tests as well as SEM and TEM observations were made. Most of the granules with the diameter ranging from 1 to 2 μm were supposed to be not starch grains but mainly polyphenol substances, based on the staining reactions with iodine, Sudan black and vanillin. Smaller granules (0.1 to 0.5 μm diameter) were suggested to be vesicles from their irregular size, non-staining reaction to hematoxilin, eosin and Bismark brown, lack of ribosome-like particles, and double membrane structure. They may be not the cause of the abnormal cell division but are produced as a result of unusual cell physiology.
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  • Akira Suzuki, Toru Kikuchi, Koji Aoba
    1997 Volume 66 Issue 2 Pages 267-272
    Published: 1997
    Released: May 15, 2008
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    Flower buds and immature berries in the highbush blueberry 'Jersey' were treated by dipping them in 1-aminocyclopropane-1-carboxylic acid (ACC) or aminooxyacetic acid (AOA) to examine the effects of ethylene on fruit set and maturation. ACC treatment to flower bud 10 days before bloom immediately increased ethylene evolution from flower bud at the stage in which no ethylene evolved in the untreated control bud. The treatment promoted flower and berry abscission indicating that ethylene concentration above the natural level induced flowers and young berries to abscise although ethylene evolution increased 5 days after anthesis. ACC treatment of immature berry also increased ethylene evolution and accelerated maturation. As a result, the harvest was advanced and picking period shortened. AOA treatment as an inhibitor of ethylene evolution did not clearly effect ethylene evolution. Our results indicate that by regulating ethylene evolution, the amount of fruiting and the time of maturation could be controlled.
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  • Hitoshi Ohara, Satoshi Okamoto, Keiko Kishida, Katsuya Ookawa, Hiroyuk ...
    1997 Volume 66 Issue 2 Pages 273-281
    Published: 1997
    Released: May 15, 2008
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    Effects of ethephon application on the fruit ripening of 'Hayward' kiwifruit [Actinidia deliciosa (A. Chev.) C. F. Liang and A. R. Ferguson var. deliciosa] on the vine were investigated.
    In 1990, when 200 ppm ethepon (dissolved with 50% ethanol) was applied at approximately 6-, 5-, 4-, 3-, 2- and 1-week prior to commercial harvest, the 4- and 3-week treatments made the fruits edible. Brix, flesh firmness, and titratable acidity of the fruits were about 13%, 0.61.2 kg/cm2 and 1.11.2%, respectively. On the other hand, 50% ethanol application was ineffective on fruit ripening. When ethephon was applied at various concentrations 3 weeks before commercial harvest, the 50 and 100 ppm treatments were ineffective on fruit ripening, whereas the 500 ppm treatment hastened fruit ripening more than the 200 ppm treatment.
    In 1991, when fruits were treated with 200 ppm ethephon, they did not ripen as fast and uniformly as they did in 1990. We attribute the difference to the lower air temperature and shorter duration of sunshine during the 1991 experiments. From the above results, we postulated that the air temperature and duration of solar radiation after ethephon application strongly affect the kiwifruit ripening on the vine.
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  • Naoki Yamauchil, Xiaoming Xia, Fumio Hashinaga
    1997 Volume 66 Issue 2 Pages 283-288
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Effects of flavonoid pigments on chlorophyll (Chl) degradation by Chl degrading peroxidase in the flavedo of Wase satsuma mandarin (Citrus unshiu Marc. var. praecox Tanaka 'Okitsuwase') fruit were studied. Chl was degraded when hydrogen peroxide was added to a reaction mixture containing Chl and a phosphate buffer extract from the flavedo.Chlorophyllide, which was formed by the action of chlorophyllase in the extract, was also degraded while flavonoid content decreased concomitantly. Analyses of the flavonoids with HPLC showed that hesperidin and narirutin were the major flavedo flavonoids; the former decreased significantly, whereas the latter showed almost no change during the Chl degradation reaction. In ethylene-treated fruits, flavedo hesperidin content decreasedwith the degreening during storage, indicating that flavonoid oxidation by Chl degrading peroxidase could be involved in Chl degradation.
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  • Komori Sadao, Soejima Junichi, Tsuchiya Shichiro, Masuda Tetsuo, Bessh ...
    1997 Volume 66 Issue 2 Pages 289-295
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Two types of unfruitfulness were found in our apple breeding programs; one was in the reciprocal cross between 'Kizashi' and 'Golden Delicious' and the other in the crosses of HCR6T132, a strain bred in Purdue university, U. S. A., with pollen of other culti-vars.
    The reciprocal cross between 'Kizashi' and 'Golden Delicious' resulted in very low rates of fruit set. Microscopic examinations revealed that pollen of both cultivars germi-nated normally on the stigma, but their tubes ceased growth in the upper part of the style; a number of pollen tubes formed swollen tips, indicating that the sterility was con-trolled by gametophytic incompatibility mechanisms.
    HCR6T132 yielded a high rate of fruit set when it was used as a pollen parent, where-as it failed as a seed parent. The unfruitfulness of the strain as a seed parent could not be ascribed to the incompatibility, because there was no difference in pollen tube be-havior, compared with the cross compatible combinations.
    It was found that the fruit set was reduced when HCR6T132 flowers were emascu-lated (petals and anthers were removed) just before pollination; the injured flowers evolved much more ethylene than the intact ones. On intact flowers, the strains retains its fruitfulness, as did the treatment with AVG (aminoethoxyvinyl glycine), an ethylene synthesis inhibitor, to the emasculated flowers. These results revealed that the strain is probably very sensitive to ethylene and/or produces much wound ethylene, and that the unfruitfulness is ascribed to ethylene induced by emasculation.
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  • Hideki Tanaka, Yasunori Mizuta, Takao Ichii
    1997 Volume 66 Issue 2 Pages 297-306
    Published: 1997
    Released: May 15, 2008
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    Seasonal changes of lipid compositions in leaves of Natsudaidai 'Kawanonatsudaidai' (Citrus natsudaidai Hayata), a cold-sensitive species, and Yuzu 'Tadanishiki' (Citrus junos sieb. ex Tanaka), a frost-hardy species, were studied.
    Glycolipids were mainly monogalactosyl diglyceride (MGDG) and digalactosyl diglyceride (DGDG), whereas the phospholipids were mainly phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylglycerol (PG). The main fatty acids in both lipids were palmitic acid (16 : 0), stearic acid (18 : 0), oleic acid (18 : 1), linoleic acid (18 : 2), and linolenic acid (18 : 3). PG contained trans-Δ3-hexadecenic acid (16 : 1).
    PG was less unsaturated phospholipid than were PC and PE, whereas MGDG was more unsaturated than was DGDG.
    Phospholipid levels (PC and PE) were high during winter in Natsudaidai and Yuzu. The 18 : 3 and 18 : 2 compositions in glycolipid (MGDG) increased and the double bond index (D. B. I.) attained a high level in winter. The 18 : 2 and 18 : 3 compositions in phospholipid (PC) increased and D. B. I. approached maximum during winter. Phospholipid contents and 18 : 3 compositions in glycolipid (MGDG) and phospholipid (PC) were higher in Yuzu than they were in Natsudaidai.
    Sterol contents increased during winter concomitantly with phospholipid and β-sitosterol; the sterols were higher in Yuzu than in Natsudaidai.
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  • Hong-gi Jang, Nukaya Akira
    1997 Volume 66 Issue 2 Pages 307-312
    Published: 1997
    Released: May 15, 2008
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    The relationship between nutrient concentration and uptake of nutrients by muskmelon (Cucumis melo L. cv. Earl's Favourite) grown in rockwool was studied to determine mineral absorption characteristics. Muskmelons were supplied one-third, two-thirds, and full strength Enshi solution. Leaf and stem fresh weights were markedly reduced when the plants were grown in one-third strength. Fresh weight and soluble solids content of fruits were highest in plants grown in full strength, followed by two-thirds, and one-third strength, respectively, but there were no distinct differences in their external appearance. During the early growth stages, the uptake rate of mineral elements (me/plant day) and the uptake concentration (uptake ratio of mineral elements to nutrient solution, me/liter) were highest in plants grown in full strength, followed by two-thirds, and one-third strength, respectively, but the uptake rate and concentration did not differ among treat- ments during growth after pollination. These results suggest that in rockwool culture of muskmelon, maintaining a higher nutrient concentration until pollination or pinching re-sults in higher yield and quality of fruit. Furthermore, these findings also suggest that mineral concentration in the root environment is not as critical to nutrient uptake and fruit production at later stages.
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  • Xiu Feng Wang, Tadashi Ito
    1997 Volume 66 Issue 2 Pages 313-319
    Published: 1997
    Released: May 15, 2008
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    The effect of NO3-N in the additional nutrient solution 6 to 18 days before harvest on the growth, yield, and NO3 content in spinach (Spinacia oleracea L. cv. 'Sunlight') plants was studied.
    There was no significant difference in top fresh weight and yield between the plants exposed to 6 and 8 me•liter-1 NO3-N for 14 days before iarvest. The NO3 content in plants grown in 6 me•liter-1 NO3-N solution in this period decreased to the critical amount of European standard of 3000ppm NO3 in the autumn crop, whereas residual concentration of NO3-N in the nutrient solution decreased to 24.8ppm and 33.4ppm at 6 and 8 me•liter-1, respectively.
    Economically satisfactory growth and yield were obtained in the plants grown with 3/4 strength of Enshi-shoho nutrient solution until the appropriate plant size was attained and then they were transferred to a NO3-N-free solution 6 days prior to harvest- ing. The NO3 content in those plants decreased to 700ppm in FW basis, whereas re- sidual concentration of NO3-N in the solution decreased significantly by lengthening the NO3-N starvation period.
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  • Yasutaka Kano, Mamoru Yamabe, Kenji Ishimoto
    1997 Volume 66 Issue 2 Pages 321-329
    Published: 1997
    Released: May 15, 2008
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    Cucumber plant, 'Kagafuto' kyuri is mainly cultivated in the Utsugi district of Kanaza- wa City, Ishikawa Prefecture of Japan. The cucumbers are harvested when they weigh about 800 g and cooked in salads or dishes with a liquid starch dressing. The frequently bitter and unmarketable fruit harvested from April to May prompted this study.
    1. In the semi-forcing culture practiced in Ishikawa Pefecture, more fruits harvested on April 22 were bitter, especially those borne on the first lateral shoot than were those on the secondary lateral. The cucumbers on the first lateral shoot were harvested 19 days earlier than were those on the secondary lateral.
    2. High occurrence of bitter fruit was observed on the first lateral shoot whether the main shoot was kept as the leader or pruned back to the first lateral shoot. Whether the leader was headed or not, harvesting of the first lateral shoot began 17 days earlier than were those on the secondary.
    3. Regardless of the own-rooted plant and the grafted plant, the bitterness in the leaf intensified according to the leaf height on the plant, with the highest leaves being the most bitter.
    4. The bitterness was strong in young fruit, but it decreased with age and size.
    5. Shoots in which stems were longer and leaves were heavier (bitter line) bore bitter fruits at higher frequencies than did short shoots with smaller leaves (non-bitter line).
    6. The total leaf nitrogen content of the bitter line was equal to that of the non-bitter line but the leaf nitrate ion content of the former was less than half of the latter.
    From these results, I postulate that in young, vigorous plants, a large amount of cucur- bitacin C, the bitter constituent, is synthesized, compared with older, less vigorous plants.
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  • Guo Shi Rong, Shoji Tachibana
    1997 Volume 66 Issue 2 Pages 331-337
    Published: 1997
    Released: May 15, 2008
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    The root systems of tomato (Lycopersicon esculentum Mill., cv. Hausu-Momotaro) and cucumber (Cucumis sativus L., cv. Sharp I) seedlings were subjected to four different dissolved O2 (DO) levels in nutrient solution for 8 days under artificial light conditions. The DO levels were kept constant at 1, 2, 4 and 8 ppm, and the solution temperature was controlled at 22 and 30°C for tomato and at 25 and 33°C for cucumber.
    1. Growth of tomato plants at 1 and 2 ppm DO was inferior to that at higher DO levels, irrespective of solution temperatures.
    2. Growth of cucumber plants was slightly retarded even at 1 ppm when the solution was held at 25°C. At 33°C, the growth was significantly inhibited at 1 and 2 ppm DO levels, similar to tomato.
    These results suggest that to control the vegetative growth of young plants in DFT by means of the DO level, lowering the DO level to about 2 ppm is appropriate for tomato. For cucumber, however, it seems necessary to lower the DO level well below 1 ppm to control effectively its vegetative growth. Possible causes of the difference in the tolerance to low DO levels between tomato and cucumber are discussed as to the morphological changes and iron-induced oxygen radical formation in the roots.
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  • Yutaka Sato, Makoto Nagai
    1997 Volume 66 Issue 2 Pages 339-345
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Bulbs of spring-sown onion cultivars are generally very firm and pungent. In this study, we attempted to improve bulb qualities, such as pungency, bulb firmness, and scale thickness without decreasing storability.
    1. On the basis of sensory tests, pungency was found to be highly correlated with the amount of enzymatically formed pyruvic acid (EFPA) so that EFPA can be used as a reli- able index of pungency. The EFPA is higher and the bulb firmer in spring-sown varieties than are those of autumn-sown ones; the scale thickness in the spring-sown varieties is thinner than that in the autumn-sown varieties. The percentage of healthy bulbs after four months of storage in spring-sown varieties was much higher than that in autumn- sown varieties. A significant correlation exists between pungency, bulb firmness, scale thickness, and long storage life. These correlations make it difficult to produce new F1 varieties having both good bulb qualities and long storability.
    2. To improve the bulb qualities in spring-sown onion, pollen parent genotypes were selected from the autumn-sown variety 'Chyosei'. Pedigree line 'CS-3' developed from 'Chyosei', inbred for two generations, was promising as a pollen parent. 'CS-3' was then crossed with the cytoplasmic male sterile (CMS) line '2935A'. The resulting F1 plants have improved bulb qualities and long storability.
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  • Han Zhang, Fumio Hashinaga
    1997 Volume 66 Issue 2 Pages 347-352
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Seeds of 'Sunny' lettuce, Chinese cabbage, 'Tsumamina', Japanese radish, 'Tokinashi' and 'Kaiware' were exposed to positive- and negative-DC and AC fields with a frequency of 60 Hz. Six intensities of electrical fields, ranging from 18 to 105 kV•m-1, were ap-plied to seeds held in the dark at 25°C and a relative humidity of 60%. The effect of the treatments on the percentage germination and the mean days to complete germination was recorded.
    1. The AC electrical field in an experimental range from 18 to 105 kV•m-1 hastened germination rate and shortened the mean days of germination for 'Tsumamina', 'Toki-nashi' and 'Kaiware' seeds. The seeds 'Kaiware' daikon were most responsive.
    2. The germination rate of 'Sunny' lettuce seeds was stimulated by DC from 65 to 105 kV•m-1 and all AC electrical fields, but their mean days to complete seed germination was unaffected.
    3. Under AC electrical fields of more than 50 kV•m-1, early growth of the seedlings, especially those 'Tokinashi' and 'Kaiware' daikon, was significantly promoted compared with that of the control. On the other hand, DC positive and negative fields had promo-tive and inhibitory effects depending on the field strengths.
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  • Hui-min Xuel, Hajime Araki, Toshinari Kanazawa, Takashi Harada, Toshir ...
    1997 Volume 66 Issue 2 Pages 353-358
    Published: 1997
    Released: May 15, 2008
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    This study was carried out to establish an efficient method for propagating Chinese chive (Allium tuberosum Rottler) through callus culture. Compact and white callus was in-duced from seedlings on AZ medium supplemented with 10 μM 2, 4-dichlorophenoxyace- tic acid (2, 4-D), 1 to 10 μM 2, 4-D and 0.01 to 0.1μM 6-benzyladenine (BA), and from 3-4 mm immature embryos cultures on 1 to 10 μM 2, 4-D and 0 to 10μM BA. Seedling-derived callus proliferated when subcultured on Murashige and Skoog (MS) medium containing 1, μM 2, 4-D. Higher rates of the multiple shoot formation were obtained from these proliferated calli on MS medium supplemented with 25, uM BA with or without a-naphthaleneacetic acid (NAA). Multiple shoot growth and plant regeneration rate were accelerated when shoots were transferred to a medium without plant growth regulators. Regenerated plantlets developed vigorously after being successfully accli-mated in soil.
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  • Hui-lian Xu, Laurent Gauthier, Pierre-Andre Dube, Andre Gosselin
    1997 Volume 66 Issue 2 Pages 359-370
    Published: 1997
    Released: May 15, 2008
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    Greenhouse tomato plants (Lycopersicon esculentum Mill. cv. Capello) were grown in peat bags and rockwool slabs to examine the effects of varying the electrical conductivity (EC) of the nutrient solution and substrate matric water potential (Ψsub) on plant water rela- tions. EC of the nutrient solution delivered to peat bags varied between 1 to 4 dS•m-1 with Ψsub of either-5 kPa or-9 kPa as the setpoint for starting the irrigation. The EC variations were adjusted automatically by a computer system according to potential eva- potranspiration (PET), which was calculated from radiation and vapor pressure deficit. Plants in rockwool slabs were treated with three EC levels, 2.5, 4.0 and 5.5 dS•m-1. Plants in both peat bags and rockwool slabs were overwatered once a week to leach accumulated salts out of the substrates. Before plants were overwatered, leaf water potential (ΨL) was lower in the plants treated with high EC and low Ψsub, but turgor potential (P) was maintained close to the control value. This was attributed to the osmo- tic adjustment caused mainly by the active solute accumulation. After plants under high EC or low Ψsub were overwatered, ΨL recovered to the control level, and P became high- er because of the lower osmotic potential (π) than in the control plants. At a given ΨL, the plants under variable EC, high EC, and low Ψsub maintained higher leaf relative wa- ter content (ζ). These leaves had high turgid water content, high symplasmic (osmotically active) water content, low apoplasmic (osmotically inactive) watger content and low ζ at the point of zero turgor (incipient plasmolysis). EC variations in peat bags according to PET caused osmotic adjustment and turgor regulation although the extent was small. Maintenance of P after overwatering was directly proportional to stomatal conductance and photsynthetic rate. Our results suggested that tomato plants adjusted their internal water status and compartment of tissue water in symplasmic and apoplasmic fractions in response to high EC and low Ψsub and that varying EC together with overwatering plants once a week not only reduced salinity stress but also favored turgor maintenance.
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  • Yukihiro Ikeda
    1997 Volume 66 Issue 2 Pages 371-377
    Published: 1997
    Released: May 15, 2008
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    This study was carried out to establish a year-round production system of Lilium rubellum by retarding or accelerating the flowering process. the system involved alternating temperatures during a long or short cold storage of bulbs.
    1. Flowering was successfully retarded from mid-July to late December by storing bulbs at 0 °C from late December of the previous year, and planting them in a glasshouse from 22 June to 22 November. Planting the chilled bulbs during the summer reduced the flowering percentage and the number of days from planting to flowering. It also stunted plant growth and yielded poor quality flowers. However, such adoverse effects were partly prevented and flower quality improved by planting the bulbs in a glasshouse maintained at 25/15 °C (day/night).
    2. Flowering was adovanced to early February by harvesting bulbs in mid-September, precooling them at 13 °C for 2 weeks and then at 0 °C for 12 weeks, and then planting the bulbs in a glasshouse kept at 10-23 °C. Precooling bulbs at 13 °C for 2 weeks hastened development of flower buds as compared to those kept in pots and lifted 2 weeks later. Flowers of good quality were obtained when bulbs were subjected to chilling at 0 °C when the inner perianth was differentiating.
    3. Flowers of good quality were obtained from early April onwards by exposing plants to naturally low temperatures until late February and then transferring them to a glasshouse kept between 10 and 23 °C.
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  • Mikihiko Terada, Yoshihiro Kageyama, Kuniyoshi Konishi
    1997 Volume 66 Issue 2 Pages 379-383
    Published: 1997
    Released: May 15, 2008
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    Rooted cuttings of rose cv. 'Sonia' were grown in culture solution at various concentrations of nitrogen (N) for about a half year, and the optimal range of N concentration for normal growth, and the relationship between growth and N uptake were investigated. The N concentrations in culture solution were adjusted weekly a 50, 100 or 200 ppm. Plant growth (FW) was determined by weighing weekly the cut flowers, the shoots removed by pruning and defoliated leaves (excised parts), and the other parts, i. e. roots, trunks and old leaves (remaining parts), separately.
    The plant FW increased with decreasing N concentration in the culture solution. The yield (number and weight) and quality of cut flowers were higher in the solution at low rather than high N concentration. The N uptake per 100 g growth in FW decreased with decreasing the N concentration; plants in 50 ppm N absorbed about 0.7 g N per 100 g growth in FW. Thus, we conclude that for normal growth of rose plants, the N concentration in the nutrient solution should be maintained relatively low.
    The weight ratio of cut flowers to whole plant in solution at 50 ppm N, where the plant growth and cut flower yield were highest, was 47%. Therefore, to yield 1 kg cut flowers, the plant must increase 2.1 kg in FW and absorb 15 g N.
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  • Ikuo Miyajima, Shunpei Uemoto, Yusuke Sakata, Ken-ichi Arisumi
    1997 Volume 66 Issue 2 Pages 385-391
    Published: 1997
    Released: May 15, 2008
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    The origin of flower color variation in Rhododendron sataense Nakai, one of the most colorful wild azaleas in southern Kyusyu, was investigated.
    The range of flower color variations and two other morphological characteristics, flower size and petal blotch, of R. sataense were almost the same as those of R. obtusum Planch. The latter whose natural habitat is in the Kirishima Mountains, and is thought to be an interspecific hybrid between R. kiusianum Makino and R. kaempferi Planch. Constitutions of flavonols in the petals, however, were quite different between the two species; R. sataense does not contain methylated flavonols, whereas the R. obtusum in a high percentage of the population.
    We conclude, therefore, that the origin of flower color variations in R. sataense on Takakuma Mountains is not the result of the natural hybridization between R. kiusianum and R. kaempferi, although natural hybrids have been found on the Kirishima Mountains.
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  • Takashi Hosoki, Daisuke Kimura, Ryuichi Hasegawa, Tomomi Nagasako, Kao ...
    1997 Volume 66 Issue 2 Pages 393-400
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Random amplified polymorphic DNA (RAPD) assay was performed to categorize or discriminate 14 tree peony (Paeonia suffruticosa) cultivars, a yellow tree peony (P. lutea), a Chinese peony (P. lactiflora) cultivar, and five interspecific cultivars. Forty decamer primers were screened; 11 of these primers produced 108 reproducible amplified DNA bands useful as polymorphic markers. Twenty one genotypes were discriminated with these markers. The similarity values among the genotypes were also calculated with these markers. The results showed that P. suffruticosa cultivars are clearly distinct species from P. lactiflora and P. lutea. Similarity values of yellow flowering hybrid cultivars, 'Kinkaku', 'Kinshi', 'Kinkoh', 'High Noon', and 'Oriental Gold' were between those of P. suffruticosa cultivars and P. lutea. Among P. suffruticosa cultivars, 'Shishigashira', which was introduced to Shimane Pref. from Shizuoka Pref. in the Edo-period, had lower similarity values with cultivars which originated from the Osaka Pref. during the Meiji era. P. suffruticosa cultivars with closely related parentage showed high similarity values (SVs) with both or either parent (s). Cultivar relationships based on SVs established by RAPD markers agreed partly with those based on morphological data, but not on the basis of petal anthocyanidins.
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  • Mikio Aoyama, Hiroshi Ikeda, Astushi Suzuki, Akemi Shimizu
    1997 Volume 66 Issue 2 Pages 401-407
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Chromosome numbers were counted in three individuals of Dendranthema shiwogiku, 16 cultivars of spray type chrysanthemum (D. x grandiflorum), 40 F1 hybrids between D. shiwogiku and a spray type cultivar, and 68 backcross (BC1) hybrids between F1 hybrid and spray type cultivar.
    Aneuploids were observed in D. shiwogiku and spray type cultivars. The chromosome numbers of F1 hybrids varied from 2n=60+B to 68; the average was 2n= 63.9 which is close to the heptaploid chromosome number of 63. Chromosome numbers of BC1 hybrids varied widely from 2n =53 to 65; the average number was 2n =59.0 whose ploidy was considered as the intermediate between hexa- and heptaploidy.
    Aneuploids were also observed in offsprings of each cross, and their average chromosome number was the same as the mean chromosome number of the parents. It seems that the aneuploids in spray type cultivars and heptaploid F1 hybrids are not sterile, and that their chromosomes are divided to two equal parts.
    Small B chromosomes, lacking the constriction, were observed in two individuals of D. shiwogiku (frequency; 67%), one spray type cultivar (6%), 13 F1 hybrids (33%), and 12 BC1 hybrids (18%). The B chromosomes were equally divided as well as the autosomes.
    No correlation exists between chromosome number and diameter of the upper flower head in the spray type cultivars, F1 hybrids, and BC1 hybrids, whereas a significant negative correlation between ploidy level and diameter flower head exists.
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  • Takatoshi Koyakumaru
    1997 Volume 66 Issue 2 Pages 409-418
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Mature-green mume (Japanese apricot, Prunus mume Sieb. et Zucc.) fruit from four culti- vars (Gojiro, Nankou, Hakuoukoume, Shirakaga) was held under air and 3 5% O2 • 9 10% CO2 gas stream with or without ethylene removing agents (ERA) for 7 days at 25°C to investigate the effect of ERA on respiration. 'Hakuoukoume' fruit was also held under various controlled atmospheres (CA) for 10 days at 10°C and 8 days at 25°C to investigate the influence of storage temperature.
    1. Mume fruit exhibited the climacteric respiratory pattern under of air and CA at 25°C, irrespective of ERA. The onset, however, or duration of the climacteric rise was delayed or prolonged with ERA. ERA was more effective under CA than under air. The delay of onset or retardation on duration of the rise with ERA was inversely proportion al to the logarithmical values of the maximum concentrations of residual ethylene.
    2. The respiration rate of mume fruit approaching climacteric peak was reduced with CA, but unaffected with ERA.
    3. The O2 uptake rate of 'Hakuoukoume' under air at 10°C, was reduced to 1/5 of that at 25°C. The rate was further reduced under various CA, especially under high CO2 con- centration at 10°C.
    4. CA of 3 5% O2 • 9 10% CO2 combined with ERA was effective in keeping quality of mume fruit at 25°C. The O2 consumption during the first 3 days of storage under this condition was reduced to 60 90% of that under CA without ERA, and to 20 to 40% of that under air without ERA.
    5. To market ERA-treated mume fruit with good quality stored at ambient temperature, the storage period should be limited to within 4 days; and the ERA should be applied at the preclimacteric stage. To store fruit for a longer period, recommend that they be kept under 4 5% O2 and 8 9% CO2 and 10°C.
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  • Toshiki Asao, Noriyuki Ohtani, Keita Endo, Katsumi Ohta, Takashi Hosok ...
    1997 Volume 66 Issue 2 Pages 419-421
    Published: 1997
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    A method of inducing in vitro flowering and fruiting of strawberry plants obtained by shoot apex culture was investigated. When strawberry plants were cultured in the flask (300 ml), the crown did not enlarge over 3 mm diameter, whereas when cultured in a culture-bottle (100mm × 110mm × 100mm), the crown enlarged to 5 mm diameter.
    A June-bearing type strawberry, 'Toyonoka', and an ever-bearing type, 'Summerberry' with 3 mm crown diameters did not differentiate flower buds, whereas those with 5 mm crown diameters were induced to flowere.
    The percentages of flower buds differentiated by 'Toyonoka' and 'Summerberry' crowns were 22.2 % and 84.2 %, respectively, whereas only 11.1 % and 36.8 %, respectively, flowered.
    Thus, culture-bottle system enabled in vitro flowering of strawberry. Using this system, fruits were obtained by artificial pollination.
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