Journal of the Japanese Society for Horticultural Science
Online ISSN : 1880-358X
Print ISSN : 0013-7626
ISSN-L : 0013-7626
Volume 57 , Issue 2
Showing 1-24 articles out of 24 articles from the selected issue
  • Hirotaka TORIKATA, Yoshio KOBAYASHI, Hiromi SUGANUMA
    1988 Volume 57 Issue 2 Pages 145-151
    Published: 1988
    Released: July 05, 2007
    Five cultivars of pecan, ‘Success’, ‘Nelies’, ‘Schley’, ‘Stuart’ and ‘Curtis, ’ were grown at the University Farm of Nagoya University, Togocho, Aichi Prefecture, and the flowering and fruiting of these cultivars were examined.
    1. The male catkins of pecan appear 1 aterally on the one-year-old shoots, and the female inflorescences occurred at the terminals of the shoots produced in the current year. The 5 cultivars flowered from late May to early June and the fruit matured in November. That is, the fruit required 154 to 182 days for maturation, and matured during the frost-free period.
    2. The studies on flowering showed that ‘Success’ flowered early each year with adicogamy or protandry. ‘Nelies’, ‘Schley’, ‘Stuart’, and ‘Curtis’ flowered relatively late with adicogamy or proterogyny.
    The studies on pollination and fruiting showed that ‘Success’, ‘Stuart’ and ‘Nelies’ were self-compatible, but it was questionable whether enough pollination would occur naturally. Since there are no plants of the Carya family in Japan, the importance of growing pollinator trees for shedding of pollen during the recipient stage of female inflorescences is stressed.
    3. The weight of 100 nuts of ‘Nelies’ was the heaviest, being about 600g, followed by ‘Success’, ‘Schley’ and ‘Stuart’ which weighed between 580 and 595g. The weight of 100 nuts of ‘Curtis’ was the lightest, being 290g. The percents of edible parts of the nuts were 55-39% in the five cultivars.
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  • Osamu KISHIMOTO, Fumiko KOTONO, Masashi TERASAWA, Akihiro FUJIKAKE
    1988 Volume 57 Issue 2 Pages 152-158
    Published: 1988
    Released: July 05, 2007
    Recently, the fruits of Japanese pear trees were attacked by some kinds of bird just before ripening. Sometimes a few days of bird injury damaged more than 80% of harvestable fruits in the orchards of Tochigi prefecture. More than 60% of the pear orchards of Tochigi prefecture were covered with Russel nets (9mm mesh) or smaller meshes in order to protect them from hail, pest and bird damages.
    The bird population increased with urbanization of the surrounding areas of pear orchards, because the birds, under consideration mainly gray starling, Sturnus cineraceus, can live together with man just like the Japanese sparrows.
    1. Shade treatments were used with single white cheesecloth (#510) as 30% shade, and double sheets of white and black (#6100) cheesecloths as 70% shade of full sunlight. The use of cheesecloth or Russel net in commercial orchards shaded about 20 to 30% of sunlight.
    2. Solar radiation was recorded in hourly calories per square centimeter using a Neo actinometer (Eiko Seiki Sangyo Co. Ltd). Hourly relative light intensities were calculated for each treatment block which recorded more than 20cal/cm2/hr, because less than 20cal. showed ambiguously for each block with diffused light and others.
    3. All of the trees tested had three primary scaffold branches. Each of them was used for a plot. The shade treatment was carried out from 1978 to 1982 with three trees in each year, but the trees tested were not used continuously for two years.
    4. The results showed that the decreasing rate of solar radiation in fruit bearing zone of a tree was positively correlated with higher shade treatment.
    5. Effects of shading were clearly expressed in harvesting time, sugar contents in fruit juice and specific leaf weight (grams of leaf dry matter per decimeter square). The shade of 70% of full sunlight was statistically significant in these three parameters. Although 30% shade significantly decreased specific leaf weight, it did not clearly affect the above-mentioned components over a five-year period.
    6. Shaded plots did not clearly affect fruit yield, mean fruit weight and mean leaf area.
    7. These results safely suggest that a shade of 30% of full sunlight can be used for netting in order to control bird injury in commercial pear orchards.
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  • Tetsuro SANADA, Teruo NISHIDA, Fukio IKEDA
    1988 Volume 57 Issue 2 Pages 159-166
    Published: 1988
    Released: July 05, 2007
    A resistant mutant of Japanese pear to black spot disease was induced from the susceptible ‘Nijisseiki’ by chronic irradiation in a gamma-field. The symptoms of black spot disease on the mutant observed under field conditions for a period of 5 years after selection were minimal. Characteristics and degree of resistance of this mutant were examined.
    1. The induced mutant obviously differed from ‘Nijisseiki’ in the susceptibility to the disease when spores or the phytotoxin of the pathogen were artificially inoculated on leaves and fruits. Resistance to black spot disease exhibited by this mutant, however, seemed to be rather intermediate when compared to the full resistance exhibited by the resistant ‘Chojuro’.
    2. Degree of resistance to alternaria blotch which is one of the apple diseases, was examined in the induced mutant and ‘Nijisseiki’, since it had been reported that ‘Nijisseiki’ was susceptible to this apple disease, too. Both materials were susceptible to alternaria blotch, but the susceptibility of the mutant was very low. These results suggested that there would be no serious problem of infection by black spot or alternaria blotch disease in practical cultivation of this mutant.
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    1988 Volume 57 Issue 2 Pages 167-172
    Published: 1988
    Released: July 05, 2007
    Changes in ethylene evolution of intact fruits on persimmon trees were measured in order to investigate the relationship between ethylene evolution and physiological fruit drop at the stage of three to four weeks after full bloom.
    1. Ethylene evolution of intact fruits on trees without irrigation (pot culture, cv. Matsumotowase Fuyu) and on shaded trees in the orchard (cv. Hiratanenashi) increased rapidly in a half or one day before fruit abscission. The amount of ethylene evolution was 150-300nl/fruit/0.5h just before abscission.
    2. When fruits on ‘Matsumotowase Fuyu’ tree were treated with ACC, ethylene evolution significantly increased in proportion to the concentration of ACC. Especially, ethylene evolution of fruits treated with 5, 000ppm ACC increased 50-150 times more than in control fruits. But fruit abscission was not observed.
    3. The application of 500ppm AVG to intact fruits on the ‘Hiratanenashi’ tree reduced ethylene evolution. However, the rate of fruit drop was not different from that of the control, indicating that the abscission layer may have developed despite the inhibition of ethylene synthesis.
    4. It was recognized by continuously measuring the fruit diameter, that abscising fruit had stopped growth five or six days before abscission.
    5. These results may indicate that internal ethylene is not associated with physiological drop of fruits at the stage of three to four weeks after full bloom.
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  • Hisashi YAMADA, Kiyoshi HAMAMOTO, Akira SUGIURA, Takashi TOMANA
    1988 Volume 57 Issue 2 Pages 173-177
    Published: 1988
    Released: July 05, 2007
    Using 2 apple cultivars, ‘Golden Delicious’ and ‘Fuji’, each grafted on M7 rootstocks, the effect of controlled ambient temperature around the fruit on maturation of apple fruits was investigated during maturation stage. On-tree fruits were enclosed in acrylic cylinders whose inside temperature was regulated at 14°C, 21°C and 28°C for ‘Golden Delicious’ and at 10°C, 17°C and 24°C for ‘Fuji’.
    1. Fruit weight of ‘Golden Delicious’ was greater at 21°C than at other temperatures, but that of ‘Fuji’ was not affected by fruit temperature.
    2. Shape index of fruit (length/diameter) was highest at highest fruit temperatures in both cultivars.
    3. Total sugar content in the flesh of ‘Golden Delicious’ was generally increased with increasing fruit temperature, while that of ‘Fuji’ was highest at 24°C, followed by 10°C and 17°C in that order.
    4. In both cultivars, the lower the fruit temperature, the more sucrose and the less fructose and glucose accumulated. On the other hand, the level of sorbitol was not affected by fruit temperature.
    5. Malic acid content in the flesh was generally decreased with increasing fruit temperature in both cultivars.
    6. Anthocyanin content in the skin of ‘Fuji’ fruit was highest at 10°C, followed by 17°C. However, anthocyanin accumulation was inhibited at 24°C.
    7. These results suggest that the maturation process of apple fruit on the tree is directly affected by fruit temperature per se late in the season.
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  • Takashi TOMANA, Hisashi YAMADA
    1988 Volume 57 Issue 2 Pages 178-183
    Published: 1988
    Released: July 05, 2007
    Sugar composition of apple fruits during maturation period was compared with fruits of 3 cultivars, ‘Jonathan’, ‘Golden Delicious’ and ‘Fuji’, grown at 4 or 6 different locations. The result was discussed in relation to the thermal conditions of the locations.
    1. With ‘Golden Delicious’ and ‘Fuji’ fruits grown at Takatsuki where sugar determinations were started at immature stage, the ratio of sucrose to total sugar increased rapidly from the end of August or early September while those of glucose and fructose to total sugar decreased. With ‘Jonathan’, however, such changes in sugar metabolism were not clearly observed.
    2. In most of the locations, the ratio of fructose to total sugar in ‘Jonathan’ and ‘Golden Delicious’ decreased with the advance of fruit maturation while the trend in the ratio in ‘Fuji’ was different dependent on locations. No clear difference was found in the ratio of fructose to total sugar among the different locations in all cultivars.
    3. The ratio of glucose to total sugar was nearly constant or decreased gradually in all cultivars. General tendency was that fruits grown at cooler locations had lower glucose ratios than those at warmer locations during maturation period.
    4. In ‘Jonathan’ and ‘Golden Delicious’, the ratio of sucrose to total sugar increased with the advance of fruit maturation in most of the locations, but in late maturing ‘Fuji’, changing patterns were different among different locations. In all cultivars, fruits grown at cooler locations generally had higher sucrose ratios than those at warmer locations.
    5. The ratio of sorbitol to total sugar was low and no clear difference was found among different locations in all cultivars.
    6. From these results, it is suggested that in general, apple fruits grown at cooler locations have higher sucrose and lower glucose ratios than those at warmer locations throughout the maturation period.
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  • Masashi FUKUMOTO, Koji AOBA, Hiroto YOSHIOKA, Koushirou NAGAI
    1988 Volume 57 Issue 2 Pages 184-190
    Published: 1988
    Released: July 05, 2007
    “Fuji” apple trees on Malus prunifolia rootstock showed a higher incidence of bitter pit (a physiological disorder of apple fruit) when ammonium salt rather than nitrate was supplied in the nutrient solution. The number of spots induced by bitter pit was intimately associated with a decrease in the calcium content of the fruits.
    Proton transport and (K++Mg2+)-ATPase activity were observed in the microsomal fraction of the fruit flesh of apple. Sodium vanadate at 0.1mM decreased (K++Mg2+)-ATPase activity to 8% of the control and inhibited the proton transport. Neither the proton transport nor the (K++Mg2+)-ATPase activity was inhibitedby nitrate at 50mM. On a continuous sucrose density gradient the distribution of the vanadate-sensitive ATPase activity was different from those of NADPH-cytochrome c reductase and cytochrome c oxidase activities. In apples seriously affected with bitter pit, proton transport and the vanadate-sensitive ATPase were reduced respectively to 37% and 55% of the levels in healthy fruit, while fruits slightly affected with bitter pit showed a higher activity of the vanadate-sensitive ATPase and a similar proton transport activity to that in healthy fruit.
    The relationship between bitter pit disorder and the changes in the microsomal proton transport and vanadate-sensitive ATPase activities is discussed.
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  • Yasutaka KUBO, Satoshi TAIRA, Shinji ISHIO, Akira SUGIURA, Takashi TOM ...
    1988 Volume 57 Issue 2 Pages 191-199
    Published: 1988
    Released: July 05, 2007
    Seasonal changes in anthocyanin and total phenol content and PAL activity in the fruit skin, and in ethylene production by whole fruit, were determined with 4 apple cultivars grown in the southwest of Japan; ‘Fuji’, ‘Jonathan’, ‘Starking Delicious’ (SD), and ‘Golden Delicious’ (GD). Also the effect bagging of fruit, a Japanese conventional practice to improve fruit appearance, on these characterisitics was investigated.
    In all cultivars, higher PAL activity in the skin was observed at earlier stages of fruit development, followed by a rapid decline toward the preclimacteric to a considerably lower level. Then it gradually increased again with the onset of coloration and ethylene production. ‘Jonathan’ and ‘SD’ developed more anthocyanin and higher PAL activity than ‘Fuji’.
    In spite of no anthocyanin development, ‘GD’ also showed higher PAL activity. Good color development was observed in red cultivars by fruit bagging, followed by removal of the bag. However, anthocyanin content at harvest was almost same in fruits with or without bagging.
    Shading the fruit by UV cut-off film following removal of paper bags considerably inhibited anthocyanin formation in red cultivars. Bagging did not show any consistent effect on ethylene production.When ‘SD’ fruit was kept bagged with paper bags or shaded by UV cut-off film after removal of paper bags, both anthocyanin accumulation and PAL activity were inhibited or reduced, suggesting their positive relationship in this cultivar. In other cultivars, however, a considerably high level of PAL was found with bagged fruits in spite of coloration.
    In conclusion, a higher level of PAL activity in apple skin during ripening seems to be essential to the development of anthocyanin, but it does not always result in good color development.
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    1988 Volume 57 Issue 2 Pages 200-205
    Published: 1988
    Released: July 05, 2007
    Mesophyll protoplasts were isolated from the plantlets of Chinese cabbage, c. v. ‘Nozaki No. 2’, cultured aseptically. Suitable media for protoplast culture, callus proliferation and shoot regeneration from calluses, especially the concentrations of growth regulators, were investigated.
    1. Protoplasts were cultured in the liquid media of 1/2 MS salts containing various concentrations of auxins and cytokinins. For initial cell divisions, the most suitable combination of growth regulators was 5mg/l NAA and 0.5-1mg/l kinetin or 2.5-5mg/l 2, 4-D and 0.5-1mg/l kinetin. The 2, 4-D was more effective than NAA, while the lower level of 2, 4-D (0.5mg/l) showed the best effect on cell colony formation.
    2. Cell colonies developed in liquid media were transferred to the 1/2 or 1/1 MS agar medium with various concentrations of 2, 4-D and kinetin. For callus proliferation, the combination of 1 or 2mg/l 2, 4-D and 0.5 or 1mg/l kinetin was the most suitable. When the growth regulator concentration was constant, 1/1 MS medium was more effective than 1/2 MS.
    3. On the MS agar medium with 1mg/l zeatin, 29% and 57% of calluses differentiated shoots and roots, respectively. These shoots rooted on MS agar me dium.
    From these results, it is suggested that an efficient system for plant regeneration from Chinese cabbage mesophyll protoplasts can be established by combining the suitable culture media for cell-division, colony formation, callus proliferation and shoot regeneration.
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    1988 Volume 57 Issue 2 Pages 206-214
    Published: 1988
    Released: July 05, 2007
    The high incidence of sesame-like black spots in the midrib and vein regions of Chinese cabbage leaves has been recognized in Toyama and other prefectures. The symptom of this physiological disorder is so-called Goma-sho. In severe cases, the market price of the Chinese cabbage is reduced markedly.
    Data concerning the causes of Goma-sho and its prevention, however, are lacking. The purpose of this study was to investigate the physiological mechanism of Goma-sho. In the present study, the characteristics of this physiological disorder during the growing period of Chinese cabbage under a field condition were surveyed and then the incident regions in midrib and vein tissues were observed by using histological and histochemical methods.
    1. Symptoms of Goma-sho in cv. Hibari and Taibyo 60 nichi could be divided into two types. Type 1 occurred in midrib of immature leaves and was closely related to excessive growth of leaf tissue during the early period of growth. Type 2 was found in mature leaves and was connected with a decrease in the ratios of outer to inner leaves.
    2. By the histological test, before the appearance of black spots, swelling of granules occurred in disordered epidermal cells, followed by the cell wall becoming brownish. The browning part of the cell wall elongated with the swelling granules and nuclei, and plasmolyzed cells occurred around the browning cells.
    3. By the histochemical test, chlorogenic acid and polyphenol oxidase were found in the browning cells, and polyphenol and peroxidase were distributed in the disordered tissue.
    4. In the disordered cells, nitrite accumulated around the granules. The granules were also expanded.
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  • Koki KANAHAMA, Takashi SAITO
    1988 Volume 57 Issue 2 Pages 215-221
    Published: 1988
    Released: July 05, 2007
    Pathways of 14C-photosythates from the 7th leaf on the 7th node of the main stem to the internodes above and below the 7th leaf, and to the fruit on the 7th node were investigated with radiocarbon.
    The internodes were sampled 20 and 90min, and 20h after the beginning of 14CO2 feeding, for 10 and 60min, respectively. Twenty min after the beginning of 14CO2 feeding, 14C-activity was detected only in the 6th internode just below the 7th leaf, and, moreover, only in the vascular bundle connected directly to the 7th leaf. After 90min and 20h, however, 14C-activity was detected in all of the internodes observed, but was still highest in the 6th internode. In all internodes, 14C-activity as % of that in the 6th internode increased with time after 14CO2 feeding, although the increase was somewhat delayed in the intermodes above the 7th leaf.
    The fruit were harvested 2, 4 and 20h after the beginning of 14CO2 feedingto the 7th leaf. After 2h, 14C-activity was found high only in the vascular bundle(s) situated on the 7th leaf side in the receptacle, septum, fruit axis and placenta. Moreover, 2h after 14CO2 feeding, 14C-activity in the vascular bundle with the highest value in each fruit part was highest in the receptacle, followed by the septum and fruit axis, and lowest in the placenta. At a later time after 14CO2 feeding, however, they showed gradually higher values which became comparable to that of the receptacle.
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  • Shuichiro MATSUI, Mitsuo NAKAMURA
    1988 Volume 57 Issue 2 Pages 222-232
    Published: 1988
    Released: July 05, 2007
    Distribution patterns of flower pigments and the shape of epidermal cells in perianth tissues in 11 genera of Laeliinae orchids were investigated in relation to flower colors.
    1. The 68 species examined were classified into nine groups on the basis of differences in distribution patterns of the carotenoids and anthocyanins contained in epidermal and/or parenchymatous cells in petal tissues. Yellow and orange flowers in such species as Laelia harpophylla and L. cinnabarina contained carotenoids in both epidermal and parenchymatous cells but those of Cattleya dowiana and L. flava contained them only in parenchymatous cells. Red flowers were ascribed to the coexistence of carotenoids and anthocyanins. In Sophronitis coccinea and L. milleri carotenoids were contained in both the epidermal and parenchymatous cells but anthocyanins only in the epidermis, while L. tenebrosa contained anthocyanins only in the parenchymatous cells.
    Purple flowers were classified into three groups according to the presence or absence of anthocyanins in the epidermal and parenchymatous cells. The purplish red flowers of most Cattleya species contained anthocyanins in the parenchymatous cells. Some exceptional Cattleyas, C. intermedia var. aquinii and C. leopoldii, contained anthocyanins in the epidermis of splashed or spotted petals. Laelia species blooming in deep purple flowers contained anthocyanins in the epidermis but those of pale flowers did not.
    2. A Hunter′s diagram of the color chromaticity of petals was divided into three sections according to hue: in the first, the b/a value of yellow to orange petals was more than. 47, due to carotenoid pigmentation only; in the second, the value lay between. 47 and -.13 and the flowers were red due to both carotonoid and anthocyanin pigments with one exception (S. coccinea var. rosea); in the third, with values between -.13 and -1.0, purplish-red, so-called ‘orchid tone’, prevailed.
    In petals containing carotenoids, increased chromas corresponded to greater brightness, but increased chromas caused by intensive anthocyanin coloration in petals and lips corresponded to less brightness, as exemplified in the velvety texture of the lips in Cattleyas.
    3. The size and shape of the upper epidermal cells in petals and lips varied by species, but within the same genus the variations were serial; small cells were square and appeared in glossy flowers, while large ones were triangular and caused the velvety appearance. The augmented size and the change from square to triangular shape might manifest the direction of evolution. Plants with large showy flowers in such species as C. labiata, L. purpurata and Brassavola digbyana had the largest and longest epidermal cells in each genus.
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  • Naotoshi HAKODA, Tomoya AKIHAMA
    1988 Volume 57 Issue 2 Pages 233-242
    Published: 1988
    Released: July 05, 2007
    Principal component analysis and cluster analysis were performed using 44 morphological characters to classify cultivars of Camellia sasanqua THUNB.
    1. The first principal component(Z1) from principal component analysis indicated a high correlation with the factors which seemed to be characterizing the species of C. sasanqua or C. japonica. The second principal component(Z2) was considered to indicate a total character representing horticulturally important factors such as flower size or number of petals.
    These results showed that the classification of cultivars was possible by both approaches, one being the relationship with species and another, the horticultural variation by artificial selection.
    2. Cultivars were divided into 6 groups which had usually been used for the classification on the Z1-Z2 plane using the score of each cultivar. Cultivars of “Vernalis group” were observed at the positions between wild C. sasanqua and C. japonica on the Z1-Z2 plane. Cultivars of “Sasanqua group”, “Hiemalis group”, “Obscura group”, and C. oleifera could be relatively close to wild C. sasanqua.
    3. Cultivars of C. sasanqua were classified into 5 groups by cluster analysis. These results agreed well with the groups which had been widely accepted. However, cultivars of “Sasanqua group” and “Hiemalis group” were divided by horticultural variations such as size or numbers of flower organs, and there was no difference related to the characters of species. It was indicated that “Tagoto-no-tsuki”, a cultivar of “Obscura group”, can be very close to C. oleifera, and it was possible to distinguish them easily from cultivars of other groups.
    4. The results suggest that multivariate analysis is a promising technique to classify cultivars of C. sasanqua which have wide variations because of inter- or intra-specific crossing and artificial selection.
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  • Lee-Jiuan TAY, Kiyotoshi TAKENO, Yutaka HORI
    1988 Volume 57 Issue 2 Pages 243-249
    Published: 1988
    Released: July 05, 2007
    Suitable culture medium and light condition for each step of in vitro seed germination, growth of protocorms and subsequent development of seedlings were determined in Paphiopedilum spp. The best seed germination and best growth of protocorms were obtained on Norstog medium in darkness. However, no differentiation of leaf nor root occurred in protocorms cultured on Norstog medium regardless of light condition. Although cultures on Burgeff EG-1 medium resulted in poor seed germination, germlings developed readily into seedlings with leaves and roots if cultured in light. Duration of the dark culture on Norstog medium to yield the maximal percentage of seed germination was found six weeks and longer. Healthier protocorms were produced in the culture with longer dark period. Protocorms grown to various developmental stages on Norstog medium in darkness were transplanted onto different media in different light conditions. The best development to seedlings was obtained from the protocorms with diameter 0.5 to 1.0mm transplanted onto Burgeff EG-1 medium and cultured in light.
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  • Yoshiji NIIMI, Yukio ENDO, Eiichi ARISAKA
    1988 Volume 57 Issue 2 Pages 250-257
    Published: 1988
    Released: July 05, 2007
    The transplanting to soil of Lilium rubellum Baker bulblets cultured in a Murashige and Skoog′s medium (see table 1) was investigated.
    Leaf emergence from in vitro cultured bulblets was inhibited after the transplanting into soil without any previous treatment. Temperature treatment (8°C or less) prior to transplanting had the effect of stimulating leaf emergence from the bulblets. Bulblets, chilled at 4°C for 12 weeks, accomplished their leaf emergence 20 days after transplanting, but leaf emergence from bulblets chilled for 10 weeks or less depended on the growth temperatures after transplanting, suggesting that chilling at 4°C for 12 weeks was required to completely break the bulblet dormancy.
    GA3 was applied to non-chilled, partly chilled and fully chilled bulblets by immersing and shaking them in distilled water containing GA3 at a concentration of more than 250mg/l. This treatment stimulated leaf emergence even in non-chilled bulblets after transplanting, but it was less effective for breaking dormancy when compared with the chilling treatment (4°C for 12 weeks). In partly and fully chilled GA3-treated bulblets, the GA3 treatment appeared to have the effect of reducing and substituting for the chilling period in respect to rate and percentage of leaf emergence and in development of bulblets after transplanting.
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    1988 Volume 57 Issue 2 Pages 258-268
    Published: 1988
    Released: July 05, 2007
    To establish a mass production system of virus-free lily bulbs, the effects of different media and cultural conditions on plantlet regeneration from shoot tips were investigated mainly with Lilium lorngiflorum ‘Georgia’.
    1. Murashige and Skoog′s macro elements which contain high nutrient concentrations, especially N and K, promoted plantlet regeneration, the growth of roots and shoots, and the formation of scaly leaf.
    2. An agar concentration of 8g/l and pH of 5.7 in the medium were suitable for development of plantlets.
    3. Shoot elongation and bulblet development were enhanced by the addition of 0.1mg/l NAA to the basal medium. A supplement of 0.1-1.0mg/l BA or 1.0mg/l kinetin induced formation of multiple buds from the shoot tips. When multiple buds were cut into several pieces and cultured on the medium supplemented with 0.1-1.0mg/l BA and 0.1mg/l NAA, new multiple buds or bulblets regenerated from the pieces.
    4. The optimum temperature for shoot development was between 23 and 28°C. Leaf elongation was promoted by the lower temperatures of 23_??_24°C, but was inhibited by the higher temperature of 27_??_28°C. The high temperature, however, promoted enlargement of scaly leaves.
    5. Illumination with white fluorescent lamps promoted leaf elongation in the shoots. Light intensity of 1, 500 to 4, 000lux was optimum for shoot and bulblet development, although scaly leaves developed even under the dark condition.
    6. The inverted placement of shoot tips on the medium induced only callus formation.
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  • Wakanori AMAKI, Yukio YAMAMOTO
    1988 Volume 57 Issue 2 Pages 269-272
    Published: 1988
    Released: July 05, 2007
    The self-incompatibility in Lilium longiflorum was investigated using the differently grafted pistils. Pistils of Lilium longiflorum cv. Georgia and Hinomoto were cut transversely into two parts at 15 or 25mm from stigma tips. They were then grafted in different combinations with silicone rubber tube (2.5mm in inner diameter). Pollen tube growth in the grafted pistils was somewhat reduced as compared with that in the intact style, but the incompatibility responses of the pollen tubes could be studied in the grafted styles.
    In the pistils grafted with different cultivar, the appearance of self-incompatible responses was observed on the style from the same cultivar. The ovary end portion of the grafted styles seemed to be more influential.
    In the pistils grafted with cross-pre-pollinated pistil segment, the incompatible pollen tube growth was faster than in the pistils grafted with non- or self-pre-pollinated pistil segments. The necessary condition for the rapid growth of pollen tube was generated in the styles after cross-pollination, with a qrobable velocity of 0.5cm/h from the stigma to the ovary.
    In self-pre-pollinated pistils, the necessary condition for the rapid growth of pollen tube seemed not to be generated in the style and further any inhibitor for the pollen tube growth was not produced.
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  • Akira ISHIDA, Akira NUKAYA, Hiroo SHIGEOKA
    1988 Volume 57 Issue 2 Pages 273-278
    Published: 1988
    Released: July 05, 2007
    An experiment was conducted to determine the effect of concentrations of boron (B) and calcium(Ca) in nutrient solution on growth, vase life of cut flowers and leaf marginal burn in chrysanthemums (C. morifolium Ramat. cv. Seikonohana) grown in sand or soil. Vase life of cut flowers decreased with increasing B concentrations in the treatment solution. Decrease in the vase life by B treatment was suppressed at high Ca concentrations in the solution. With increasing B concentrations, marginal burn in leaves appeared earliar and the degree became severe. With increasing Ca concentrations, appearance of the burn slightly delayed. Boron in leaves increased with increasing B concentrations. However, it decreased as Ca concentrations increased. Boron in marginal areas of leaves having marginal necrosis was 1, 150 to 1, 725ppm, which was significantly higher than that in the healthy leaf areas
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  • Toyoki KOZAI, Yoshie IWANAMI
    1988 Volume 57 Issue 2 Pages 279-288
    Published: 1988
    Released: July 05, 2007
    Explants of tissue-cultured carnation (Dianthus caryophyllus L.) plantlets were cultured in preparation for growth during the acclimatization stage. Plantlets werecultured in glass test tubes with plastic formed caps in a room with CO2 concentration of 1000-1500vpm and a photosynthetic photon flux of 150μmol m-2s-1 (400-700nm). The effects of the sucrose concentration in the medium on the plantlet growth were also examined under the above mentioned culture conditions.
    The plantlet growth was promoted, to a large extent, by CO2 enrichment under high photon flux. The order of largest to smallest of fresh and dry weight increases of the plantlets during the culture was CO2 enriched treatment with 1% sucrose, CO2 enriched treatment with 0% sucrose, CO2 enriched treatment with 2% sucrose, CO2 nonenriched treatments with 2% sucrose, 1% sucrose, and 0% sucrose. Plantlets grew autotrophically by CO2 enrichment with high photon flux.
    The net photosynthetic and dark respiration rates of the plantlets and the dry weight decreases in total sugar and nutrient salts in the medium were estimated to explain the differences in the dry weight increase of the plantlets in the various treatments. The implications of the results for developing a new mass propagation system of tissue-cultured plantlets are discussed.
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    1988 Volume 57 Issue 2 Pages 289-294
    Published: 1988
    Released: July 05, 2007
    Bulbs exposed to ethylene during storage showed a high flowering percentage and earlier flowering irrespective of their sizes. Non-treated bulbs with even 9cm size showed low flowering percentage. Ethylene exposure at 10μl/l for 3 hours was sufficient to induce high flowering percentage in 8cm sized bulbs, whereas longer exposure than 12 hours was necessary in 7cm sized bulbs. Repeated ethylene treatment for 23 hours daily up to 9 times showed the same effect as a single application and was not detrimental to flowering. Ethylene did not show any effect on flowering at 0.1μl/l. Higher concentration than 0.5μl/l promoted flowering. Shorter duration of ethylene exposure was required with increasing concentration of ethylene. At 10μl/l, the duration of ethylene exposure required to induce high flowering percentage differed with the storage period of bulbs at room temperature, i.e., the longer the storage period, the shorter the duration required.
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  • Masafumi MANAGO
    1988 Volume 57 Issue 2 Pages 295-303
    Published: 1988
    Released: July 05, 2007
    Experiments were carried out over a five year period to clarify the conditions Causing ‘Kohansho’ on Hassaku (Citrus hassaku Hort. ex Tanaka) fruit.
    Kohansho seldom developed under storage conditions of 7 to 8°C, 90+5%RH, but appeared 2 or 3 days after removal from storage. The severest symptoms after storage were found on fruits harvested in late December.
    Kohansho was suppressed by waxing or dipping the fruits in water at 50°C for 5min, but became more pronounced when the fruits were dipped in a 2% solution of CaCO3. The symptoms became more severe at temperatures of 15-20°C and less severe at 7-8°C after removal from storage.
    Very few symptoms were observed in fruits from Hassaku trees grown in a plastic greenhouse, and the respiration and ethylene evolution rate of these fruits also showed little change after being transferred from storage.
    Dipping fruit in wax or hot water increased the level of CO2 and decreased the level of O2 within the fruits. Occurrence of Kohansho is discussed in relation to these gas conditions within the fruit, and to respiration and ethylene evolution of the fruit.
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  • Hidemi IZUMI, Takuji ITO, Yasuji YOSHIDA
    1988 Volume 57 Issue 2 Pages 304-311
    Published: 1988
    Released: July 05, 2007
    Sugar and ascorbic acid (AsA) contents were determined in flavedo of fruits at growing stages, sampled from both the sunlit exterior area and the shaded dark interior area of the canopy, in a common and an early cultivar of satsuma (Citrus unshiu Marc. cvs. ‘Hayashi’ and ‘Miyagawa’) and in Hassaku (Citrus hassaku Hort. ex Tanaka), in order to clarify the effect of light intensity on sugar and AsA content.
    1. The fruits from the exterior canopy were superior in diameter and weight to those from the interior canopy in each cultivar of satsumas and in Hassaku.
    2. The sunlit exterior fruits were higher in carotenoid content in the flavedo than the shaded interior fruits in every stage, in both satsumas and Hassaku.
    3. AsA content in the flavedo tended to increase with fruit growth in both satsumas and in Hassaku. At the later stages of fruit growth, however, this tendency became less or disappeared. High content of AsA in the flavedo was observed in the fruits from sunlit exterior canopy as compared with those from shaded interior canopy, in every growing stage in each cultivar. As the fruits grew, the difference in AsA content between the fruits from the two areas increased further in ‘Hayashi’, a common satsuma cultivar.
    4. The predominant sugars in the flavedo were fructose, glucose and sucrose in both satsumas and Hassaku. Content of the sugars tended to increase with fruitgrowth. In the later stages of fruit growth, increase of sucrose was less and sometimes the content did not reach the limiting level, showing a similar trend to that of AsA. The sunlit exterior fruits were higher in content of sugars in the flavedo during the growing period than were the shaded interior fruits in all the cultivars.
    5. In ‘Hayashi’, sugar and AsA contents in the flavedo and juice were determined after treatments of girdling, defoliation and application of growth regulators on the fruit surface. Significant positive correlations were found between sucrose and AsA content in the flavedo (+0.82) and in the juice (+0.95).
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  • Shuji FUJITA, Tetsuzo TONO
    1988 Volume 57 Issue 2 Pages 312-318
    Published: 1988
    Released: July 05, 2007
    Rind-oil spot of Hassaku (Citrus hassaku Hort. ex Tanaka) fruits occurred in high percentages when the fruits were stored at 20°C for 10 or 30 days (experimental storage) after removal from cold-storage room (5°C). Changes in ascorbic acid (AsA) and chlorogenic acid (Chl) content of the peel (flavedo and albedo) were determined during the experimental storage.
    AsA content of flavedo was higher than that of albedo and markedly decreased during storage. Rind-oil spot was observed only when AsA content of the flavedo was less than 200mg per 100g fresh weight. A weak AsA oxidase activity was detected in the flavedo and the activity changed slightly during storage. Chl was locally present in the flavedo and increased a little during storage. Polyphenol oxidase activity was very weak in the peel of the fruit.
    AsA and Chl content of the healthy section of flavedo was higher than in the injured section due to rind-oil spot. Brix, acidity and AsA content of the fruit juice varied slightly during storage.
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  • Katsu ISHII, Fujio SHINBORI
    1988 Volume 57 Issue 2 Pages 319-323
    Published: 1988
    Released: July 05, 2007
    The respiration rate (CO2 evolution) and changes in contents of some chemical components and appearance qualities of turnips after harvest were studied in association with precooling.
    1. The respiration rate was roughly doubled for every 10°C rise in temperature. The fewer the days after harvest, the higher the respiration rate was.
    2. The contents of ascorbic acid, chlorophyll, β-cartene and total sugars in the outer leaves were much lower than in the inner leaves even immediately after harvest, and they decreased very rapidly at high temperatures. Thus, the contents in the outermost leaf reached a very low value at high temperatures in only a few days.
    3. Deterioration of the crop appearance such as yellowing and rotting generally began at outer leaves. This fact suggests that it is closely related to the rapid decrease in the contents of those chemical components.
    4. From these results, it appears that trimming outer leaves as much as possible and precooling immediately after harvest are effective in preventing deterioration of the crop appearance.
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