Journal of the Japanese Society for Horticultural Science
Online ISSN : 1880-358X
Print ISSN : 0013-7626
ISSN-L : 0013-7626
Volume 62 , Issue 3
Showing 1-25 articles out of 25 articles from the selected issue
  • Hiroo Koike, Hiromu Makita, Kazuyuki Tsukahara
    1993 Volume 62 Issue 3 Pages 499-504
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Marubakaido (Mains prunifolia Bork, var. ringo Asami) has been used as the main understock with dwarfing interstems, such as M. 9 and M. 26, for apple trees in Japan because it can easily be propagated by hardwood cuttings. The use of M. 9 as an interstem with Marubakaido resulted in severe growth retardation or death of trees because the M. 9 introduced into our area was infected with the apple-chlorotic-leaf-spot virus (ACLSV) to which Marubakaido is highly susceptible. Furthermore, when M. 9 was used as a rootstock, a similar reduction in tree growth occurred.
    ACLSV-free clone, M. 9- (minus), was developed from heat-treated shoot tips of M. 9 rootstock. The influence of this clone as a rootstock for 9 seasons and as an interstem for 4 years on the growth and yield of apple trees was evaluated in comparison with ACLSV-free M. 26 rootstock.
    1. 'Fuji'/M. 9- scion/stock combination was smaller than 'Fuji'/M. 26 after 9 growing seasons. A severe growth reduction observed on 'Fuji'/M. 9 combination in the previous experiment was not observed in this study. Cumulative yield per trunk cross-sectional area was higher in M. 9- than it was in M. 26. It was not clear whether ACLSV or other latent viruses were responsible for the severe growth reducition. We determined that M. 9- is a promising rootstock for controlling the size of apple trees if the trees are planted at distances of 1.5×4 to 2×4.5 m.
    2. When Marubakaido-N1, a weeping subclone selected from Nagano Prefecture, was used as the understock for 'Sekaiichi', 'Tsugaru' and 'Fuji' with M. 26 and M. 9- as the interstems, the 4-year-old trees with M. 26 grew less vigorously and produced smaller fruit than did the same combinations with M. 9- interstem. The incidence of burrknots and trunk flattening was more severe on M. 26 interstems; these 2 conditions may be related to the greater growth retardation on this rootstock. We consider M. 9- to be more promising than M. 26 as an interstem for controlling the size of apple trees.
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  • Akira Kitajima, Yoshitake Ohshita, Mikio Nakano, Masashi Ishida
    1993 Volume 62 Issue 3 Pages 505-512
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Fruit set, growth, and quality of seeded and parthenocarpic fruit of kaki cv. Fuyu were investigated. The objectives were: a) to compare the effect of pollination of flowers, borne on apical (terminal) and two lateral shoots, on non-pollinated (prevented pollination) flowers on adjacent shoots, and b) to determine the feasibility of producing a seedless 'Fuyu' crop under ordinary orchard conditions.
    1. The set of parthenocarpic fruit from a basal (lower) lateral shoot was slightly lower and their size significantly smaller than was that of seeded fruit on adjacent shoots through the fruit growth Stage II.
    2. The parthenocarpic fruit from the apical and two lateral shoots was significantly larger than the seeded fruit on basal lateral shoot which originated from one-yr-old wood on which apical and upper lateral shoot flowers were also pollinated.
    3. These results suggest that a competition exists for assimilates between seeded and parthenocarpic fruit on different shoots arising from the same one-yr-old wood. The intensity of this competition among the fruit probably begins at the latter half of the fruit growth Stage I.
    4. The set and weight of parthenocarpic fruit on a main branch were excellent at harvest and equivalent to the seeded fruit on the same tree.
    5. Under ordinary orchard conditions, if all flowers on a tree were prevented from pollinating, fruit set was better and their weight and soluble solids contents were as good as those of seeded fruit derived from flowers on a separate hand-pollinated tree. The parthe nocarpic fruit was slightly flatter than the seeded ones.
    We concluded that it might be possible to produce seedless 'Fuyu' fruit of excellent quality under ordinary orchard conditions, if all flowers of a tree were prevented from pollinating.
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  • Hiroyuki Fukuda, Fumitaka Takishita
    1993 Volume 62 Issue 3 Pages 513-517
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Growth characteristics and dry matter production in 'Jonagold' apple trees on M. 26 dwarfing rootstock were compared with those on Maruba-Kaido (Motifs prunifolia Borkh. var. ringo Asami), an invigorating rootstock during 1991. Fresh weights of scion and root- stock of trees on Maruba-Kaido were 14.2 and 12.6 times heavier, respectively, than those on M. 26. Top (scion) /rootstock fresh weight ratio (T/R), however, did not differ significantly between these trees on different rootstocks, indicating that the scion and rootstock sections of the trees grew proportionately.
    The ratio of tree weights (T + R) to leaf weights (B) of the trees on Maruba-kaido was 1.5 times greater than that of the trees on M. 26. This indicates that leaves on trees on Maruba-Kaido contributed to the production of more woody tissue than did those on trees on M. 26. However, we found that the fruit/leaf dry weight ratio (F/L) of 'Jonagold'/M. 26 was about twice that of 'Jonagold'/Maruba-Kaido. In spite of a relatively heavier fruit load the average weight per fruit and the annual incremental change in wood volume did not differ significantly between these trees on different rootstocks.
    Our findings on the relationship between (T+R) /B and F/L elucidate how invigorating and dwarfing apple rootstocks can affect assimilate partitioning.
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  • Naosuke Nii
    1993 Volume 62 Issue 3 Pages 519-526
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Effects of fruiting on leaf characteristics, photosynthesis, and root growth were assessed on small peach trees (Prunus persica (L.) Batsch. cv. Hakuto) after adjusting the number of fruits per tree.
    1. Compared to leaves on non-bearing trees, those on fruiting trees were thinner, less wide, and darker green. The more intense green pigmentation indicates that the chlorophyll was more concentrated in leaves of bearing than in those from non-bearing trees. During the fruit maturation stage, former accumulated more starch in the chloroplasts than leaves of the latter as determined by the I-KI staining method, transmission electron microscopy, and starch analysis. The photosynthetic rate per unit leaf area (Pn) was faster in leaves of fruiting limbs during the fruit maturation stage; no significant difference in Pn between leaves of fruiting and defruited branches was detected during Stage II of fruit development.
    2. The elongation of new roots in fruiting trees was reduced proportionately to increasing fruit number during the fruit growth period, whereas the new roots on non-bearing trees continued to elongate throughout the vegetative period. At fruit harvest, the total root volume of non-bearing trees was larger and the starch content per root dry weight was higher. On fruiting trees, renewed root growth was observed several days after harvest while the starch in the roots continued to accumulate until the leaves senesced.
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  • Noboru Suzuki, Xinyan Wang, Hiroshi Inoue
    1993 Volume 62 Issue 3 Pages 527-531
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Three experiments on the effects of temperature on the development of winter buds of Japanese apricots (Prunus mume Sieb. et Zucc.) and subsequent shoot growth were conducted in growth chambers and under field conditions.
    1. From mid-October to mid-February, one-year-old potted seedlings and excised shoots were transferred monthly from field to the growth chamber kept at 15 °C or 25 °C to determine the end of bud dormancy. Bud dormancy of seedlings and that of excised shoots were broken by mid-December.
    2. The development of leaf and flower buds of 'Nanko' cuttings were compared in growth chambers kept at 0°, 5°, 10°, 15°, 20°, and 25 °C from early January to anthesis. Flowering occurred earlier than did sprouting of leaf buds in cuttings kept at 15 °C or above. No difference was observed between dates of anthesis and sprouting of leaf buds of shoots kept at 10 °C or 5 °C. At 0 °C, flower buds did not develop fully; leaf buds sprouted but the leaves did not expand.
    3. One-year-old 'Nanko' trees grafted on seedling mume rootstocks were moved on 1 March to growth chambers kept at 10°-15°, 15°, 20°, and 25 °C and held until the end of shoot growth. After sprouting of leaf buds, trees were thinned to 10 shoots per tree. The most vigorous shoot growth was observed in the 10° - 15 °C treatment, in which trees were kept at 10 °C for two months and then transferred to 15 °C. At 20° and 25 °C, shoots ceased their growth earlier than did those in lower temperature regimens.
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  • Takuya Tetsumura, Ryutaro Tao, Hisajiro Yukinaga
    1993 Volume 62 Issue 3 Pages 533-538
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    We studied the factors influencing the acclimatization of Japanese persimmon (Diospyros kaki Thunb. cv. Nishimurawase) micropropagules derived from shoot tips and evaluated their field performance. During acclimatization, optimum plantlet survival was at 28 °C, but most died at 22° or 34 °C. Plantlets grew better under continuous lighting than under a 16 hr photoperiod. Enhanced PPF stimulated growth of the micropropagules and raised their survival rate. When shoots were transplanted into pots, immediately after the root-ing treatment, none survived. On the other hand, when transplanted after root induction on the rooting medium, almost all of them survived. The highest plant growth rate was obtained with those plantlets cultured for 20 days on the rooting medium. Although plant-lets grew vigorously when transferred outside, they grew better when transplanted in the field than in partly glazed pots. Rejuvenation did not occur in the shoot tip culture of Japanese persimmon, because some of the plantlets planted in the pots bore both male and female flowers four months after being transferred outside.
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  • Noboru Suzuki, Xinyan Wang, Ikuo Kataoka, Hiroshi Inoue
    1993 Volume 62 Issue 3 Pages 539-542
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    The effects of temperature on flowering and pollen germination in Japanese apricot (Prunus mume Sieb. et Zucc.) cv. Nanko were investigated in a growth chamber where day and night temperatures were kept constant at 5°, 10°, 15° and 20 °C and under field conditions from mid-January to mid-April.
    1. At higher temperatures, anthesis was earlier and flowering period was shorter than they were at lower temperatures. Trees kept at 5 °C required more days to flower than did those in the field. All floral organs, including the ovary, were bigger at full bloom at lower than at higher temperatures.
    2. Pollen, collected from trees in all temperature treatments, germinated and grew within 4 hours at temperatures ranging from 0° to 30 °C when cultured on 1% ager and 20% sucrose. The germination rates at higher temperatures were more rapid than they were at 10 °C and below. Although some pollen germinated at 0 °C, the optimum range was between 20° to 25 °C in all treatments. Pollen tubes grew longer under higher germination temperatures up to 25 °C. Flowers kept at 15 °C had the longest tubes; those kept at 5 °C had the shortest.
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  • Osamu Arakawa
    1993 Volume 62 Issue 3 Pages 543-546
    Published: 1993
    Released: May 15, 2008
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    Ultraviolet (UV) radiation, provided by a fluorescent lamp with 1.3 W • m-2 and emission peak at 312 nm (UV312), was much more effective on anthocyanin synthesis in light-colored sweet cherry, cv. Sato Nishiki, than was white fluorescent lamp with 4.0 W • m-2. Anthocyanin accumulation was linearly correlated to the duration of irradiation with UV312 light and the storage in the dark after irradiation. The use of cut-off filters revealed that the most effective wavelength of UV312 was in the region of UV-B (UV from 280 to 320 nm). The effect of UV-B on anthocyanin production in 'Sato Nishiki' seemed to have an important role in the development of the desirable red skin color under field light conditions.
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  • Naosuke Nii, Maki Kato, Yuki Hirano, Tooru Funaguma
    1993 Volume 62 Issue 3 Pages 547-554
    Published: 1993
    Released: May 15, 2008
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    The effects of the different levels of nitrogen application on leaf characteristics including starch accumulation and photosynthesis were determined in two-year-old peach trees (Prunus persica (L.) Batsch. cv. Ohkubo). The nitrogen content on dry weight basis in the leaves was the lowest in the zero-nitrogen plot (N-0) : 2.5%, and increased with increasing the nitrogen application; 1.5 g plot (N-1.5), 2.9%; 3.0 g plot (N-3.0), 3.4%; and 6.0 g plot (N-6.0), 3.8%. Compared with those in higher nitrogen plots, the leaves on N-0 plot were thinner, smaller, and yellowish: chlorophyll content per unit leaf area was lower at decreasing levels of nitrogen application. The starch content in the chloroplasts of the leaves from the N-0 plot was higher than those from plots in which nitrogen was added. Amylase activity, which was the lowest in the leaves of N-0 plot, was in inverse proportion to the starch accumulation; amylase activity in leaves from the N-3.0 and N-6.0 plots, which contained less starch content, was higher. In the chloroplasts of the leaves from the N-0 plot, chloroplast nucleoids were localized at the periphery of the plastids, whereas they were evenly distributed in chloroplasts of leaves with higher nitrogen contents. The photosynthetic rate per unit leaf area was the lowest in N-0 plot, and increased with nitrogen application: the difference, however, between nitrogen plots was not significant.
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  • Shuji Furusawa, Masaharu Masuda, Kuniyoshi Konishi
    1993 Volume 62 Issue 3 Pages 555-560
    Published: 1993
    Released: May 15, 2008
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    The effect of polyethylene glycol (PEG) on adventitious bud formation on excised hypocotyl segments of tomato seedling cv. KNVF-R, an interspecific hybrid rootstock between Lycopersicon esculentum x L. hirsutum, was investigated.
    1. Segments excised from hypocotyls shorter than 8 cm, and incubated under light intensity exceeding 3 klx formed buds; the optimum segment length was 4 mm. About 95% of the segments formed adventitious buds in 1/2 strength Murashige-Skoog basal medium supplemented with 50 g•liter-1 PEG-6000 and 30 g•liter-1 sucrose. However, when the number of segments per flask (containing 40 ml of medium) exceeded 50, the percentage of segments which initiated buds decreased.
    2. Mannitol and PEG-1500 were not effective at all. Abscisic acid (ABA) at 10 mg• liter-1 stimulated bud formation.
    3. Segments with buds of 2 mm length rooted within 2 weeks on a basal medium (1/2 MS supplemented with 30 g•liter-1 sucrose and 8 g•liter-1 agar)
    All regenerated plants were established by transplanting to a vermiculite potting mixture.
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  • Kai Lin Hu, Sachiko Matsubara, Kenji Murakami
    1993 Volume 62 Issue 3 Pages 561-565
    Published: 1993
    Released: May 15, 2008
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    Immature anthers of carrot (Daucus carota L.) were cultured on the Murashige and Skoog solid medium containing various combinations of phytohormones. Calli were obtained on the medium containing 0.011 mg•liter -1 2, 4-D and 01 mg•liter-1 kinetin. The highest rate of callus formation (12%) was obtained on the medium containing 1 mg•liter-1 of both 2, 4-D and kinetin. Embryoids were obtained on the medium containing 1 mg•liter-1 2, 4-D and 00.1 mg•liter-1 kinetin. The highest rate of embryoid formation (15%) was obtained on the medium containing 1 mg•liter-1 2, 4-D without kinetin. Embryoids transferred to solid MS medium grew plantlets. Plants were planted to pots after acclimatization and chromosome number in root tips were observed. Among 18 plants obtained from the embryoids and calli, 16 plants were haploid (2n=9), and the other two plants were aneuploids (2n=10 and 11).
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  • Tomio Johjima
    1993 Volume 62 Issue 3 Pages 567-574
    Published: 1993
    Released: May 15, 2008
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    In the present study, cis and trans carotenes of recessive homozygote tt tomato lines were qualitatively and quantitatively analyzed by micro-thin-layer chromatography (m-TLC).
    1. Four cultivars and 4 lines were used: 3 tangerine tomatoes (RRtt), 'Jubilee', MM-Rt and RC-Rt; 2 yellowish tangerine tomatoes (rrtt), GJ-rt and MM-rt; 2 red tomatoes (RRTT), 'Moneymaker' and 'Red Cherry', and one yellow tomato (rrTT), 'Golden Queen'.
    2. The carotenes of RRtt and rrtt lines were separated into 11 spots (J1J10 and J5-2) by m-TLC on MgO: alumina: cellurose: CaSO4 (10 : 6 : 2 : 2, w/w/w/w), using the tech- nique of stepwise development of solvent mixtures, n-hexane: isopropanol: MeOH, from 100 : 2 : 0.2 (v/v/v) to 100 : 0 : 0 (v/v/v) (hexane alone).
    These 11 carotenes were identified to be the mixture phytoene and phytofluene (not separated), β-carotene, ζ-carotene, proneurosporene, pro-lycopene, pro-γ-carotene, trans- neurosporene, and four distinct lycopene compounds, poly-cis -lycopene (b), poly-cis - lycopene (a), neolycopene and trans -lycopene.
    3. When these carotenes were isomerized by iodine catalysis, the 11 spots were shifted to 6 spots. The chemical behavior of these isomerized carotenes was almost identical to that of the carotenes isolated from red tomatoes; namely, a mixture of phytoene and phy- tofluene and the trans forms of β-, ζ-and γ-carotene, neurosporene and lycopene.
    4. The amounts of carotenes developed on m-TLC were directly measured by chromato- scanner, using standard linear regression. Tangerine tomatoes (RRtt) contained 130 142 μg total carotene•g-1 fruit fresh weight which was about twice that of red toma- toes (RRTT, 7175 μg•g-1) and 5 to 10 times that of rrtt lines (1526μg•g-1). Yellow tomato (rrTT) contained about 4μg•g-1 total carotene.
    5. Recessive homozygote tt lines were characterized by a large number of cis form carotenes and a high concentration of cis and trans forms of ζ-carotenes (1944%), neurosporenes (1822%) and lycopenes (2048%). In addition, pro-γ-carotene was con- tained in a quantity similar to that of β-carotene, which suggests the presence of a new pathway leading to the formation of pro-γ-carotene in the biosynthesis of β-carotene.
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  • Kenji Yamane, Satoko Abiru, Nobuaki Fujishige, Ryozo Sakiyama, Ryosuke ...
    1993 Volume 62 Issue 3 Pages 575-580
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Export of soluble sugar, changes in all membrane permeability, and production rate of ethylene in the perianths of the lower florets on the gladiolus spikes were determined as related to physiological events affecting the wilting of perianths after they were fully unfolded.
    1. Perianths appeared to be wilting between 2 and 3 days after unfolding fully (DAU). Concurrent with the onset of wilting, perianths rapidly decreased in fresh and dry weights.
    2. Between 1 and 2 DAU, one day before perianths started to wilt, total soluble sugar contents began to decrease. Between 2 and 3 DAU, the largest loss of total soluble sugars occurred, most of which was possibly due to export from perianths to other parts.
    Concurrent with the export of sugars, an increase in leakage of ions from perianth tissues was observed.
    3. Rates in ethylene production of perianths did not show a significant change in relation to the time of wilting.
    Depletion of sugars was discussed as related to the disintegration of membranes, which could cause perianths to wilt.
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  • Tokiko Nagashima
    1993 Volume 62 Issue 3 Pages 581-594
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    The ability of seeds of 47 orchid species, collected at differnt stages of embryo development, to germinate was studied.
    1. Most immature seeds collected when the embryos were pretetrad through the intermediary stages germinated poorly and grew slowly. They had a tendency to require longer developmental periods before they germinated.
    2. The highest % germination (rate) was attained when embryos were between the octant stage and completion of embryogenesis. Most orchid species attained maximum germination rates after completion of embryogenesis except in Cypripedium japonicum and Cephalanthera falcata. The maximum % germination (rate) ranged between 0.8%100 %; seeds of all species developed well after germination except those of Cypripedium japonicum.
    3. No close relationship was recognized among embryos collected at the earlist developmental, intermediate and mature stages versus the developmental stage of the ovary at anthesis.
    4. Orchids were grouped into 4 types with respect to their % germination (rate) after attaining maximum.
    Type a : The highest germination rate was observed at final stage just before yellowing and dehiscence of ovary.
    Type b : The highest germination rate was attained at final stage and the germination rate has possibility to change according to the progress of developmental stage.
    Type c : Germination rate decreased as embryogenesis progressed.
    Type d : The germination rate continued at maximum until the embryo matured.
    The largest number of species was categorized as Type c.
    5. The days between sowing and germination ranged from 3 to 305 depending on the stage of embryogenesis and species. Based on the relationship between the days from sowing date to germination and developmental stages of the harvested embryos, the species were grouped into two types : a, the interval before germination was shortened with increasing embryo age or b, the period became prolonged with embryo age.
    Much more species were classified as Type a than Type b.
    6. Among the media tested, Hyponex medium was suitable for embryo culture, but the Murashige and Skoog medium resulted in better % germination (rate) and seedling growth for Gastrodia elata and Cymbidium hosai.
    7. No common characteristics of subfamily were recognized among the 47 species with respect to embryogenesis and seed germination.
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  • Satoshi Kubota, Kazuo Yoneda
    1993 Volume 62 Issue 3 Pages 595-600
    Published: 1993
    Released: May 15, 2008
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    The effects of high, moderate, and low light intensities on floral induction and nitrogen nutrition in Phalaenopsis grown at 23°/18°C, 28°/23°C, and 33°/28 °C (day/night) were ascertained.
    1. High light intensity substantially increased total dry matter, sugar content, and nitrogen absorbed. The differential in C assimilation and N uptake resulted in larger plants having lower N content under high light intensity.
    2. The number of expanded leaves, the growth of roots, and the amount of dry matter produced per plant increased under proportionately higher light intensities.
    3. High light intensity preceding 23°/18°C treatment increased the number of in- florescence, but the 28°/23°C treatment advanced their time of emergence to plant exposed to lower light intensities. The temperature sensitivity for floral induction increased in those plants which produced relatively more dry matter per unit N absorbed (larger C/N balance).
    To increase the sensitivity of Phalaenopsis plants to floral induction, they should be grown under high light intensity; because these conditions lead to high sugar content, which in turn, seemingly expedite rapid metabolism of nitrogen.
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  • Satoshi Kubota, Tetsuo Kato, Kazuo Yoneda
    1993 Volume 62 Issue 3 Pages 601-609
    Published: 1993
    Released: May 15, 2008
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    The physico-chemical properties of sphagnum moss, the concentration of fertilizer applications, and the absorption of applied nitrate and calcium ions in clay and plastic pots on the growth of Phalaenopsis plants were examined.
    1. The amount of water held by sphagnum moss compacted from pF 1.8 to 3.0 increased with the density of the moss. The cation exchange capacity (CEC) of the moss, ranging in pH 3.0 to 4.0, was 26 me/100 g but increased to 100120 me/100 g when the pH was adjusted to 7.0. The physico-chemical properties of the moss produced in Japan was slightly different from that produced in New Zealand.
    2. About 50% of the nitrate applied to the potting medium in clay pots was leached by a single watering. When the liquid fertilizer was applied frequently, nitrate content in the medium did not exceed that which remained after a single application because 80% of the nitrate applied was absorbed by the clay pots as a consequence of moisture evaporation from the porous wall. Calcium applied was adsorbed by the medium so that the amount retained gradually exceeded the amount of nitrate.
    3. As a considerable portion of nutrient is absorbed by clay pots, the amount of fertilizer available for the growth of Phalaenopsis plants in clay pots was significantly less than that available in non-porous plastic pots.
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  • Waichiro Kawarabayashi
    1993 Volume 62 Issue 3 Pages 611-618
    Published: 1993
    Released: May 15, 2008
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    Effects of culture conditions on the differentiation and growth of bulblets from bulblet scales of Lilium japonicum in aerated liquid culture were investigated. Based on the results, a practical in vitro mass-production of the bulblets was designed using a simplified culture box.
    1. The agar culture period of scales to obtain a maximum number of bulblets in the following aerated liquid culture appeared to be about 3 months. When the culture period extended beyond 3 months, the number of bulblets tended to decrease. Basal segments of scales produced more bulblets and at a faster rate than did apical segments.
    2. Dissecting the in vitro bulbs into small segments increased the total number and hastened the propagation rate of bulblets, compared to scale segments cut from comparable sized in vitro bulbs.
    3. Using a polypropylene container as a culture box, segments obtained from 90100 in vitro bulbs (total fresh weight, 12.8 g) were cultured in an aerated liquid medium of 1.5 liters. About 2, 000 bulblets, with an average diam. of 4.9 mm, were produced in 16 weeks.
    4. To simplify the propagation process, 300 in vitro bulbs (total fresh weight, 60 g) were cut with several razor blades spaced 2 mm apart. A 10-liter container with 5 liters of liquid medium was used. In this simplified in vitro system, about 4, 500 bulblets, with an average diam. of 5.9 mm, were mass-produced in 24 weeks.
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  • Yu Zhu, Tetsuyuki Takemoto, Susumu Yazawa
    1993 Volume 62 Issue 3 Pages 619-624
    Published: 1993
    Released: May 15, 2008
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    Plantlets were regenerated from three variegated cultivars of caladium (Caladium × hortulanum Birdsey) by in vitro propagation of leaf segments. Leaf segments of 'Freida Hemple' were taken from green and red areas of the leaf blades; those of 'C. R. 5' were obtained from green, white, and red areas; whereas those of 'Pink Cloud' were taken from green, white, and pink areas. The segments were then cultured on modified MS medium supplemented with 1.0 mg • liter-1 BA and 1.0 mg • liter-1 NAA.
    1. All green and red leaf segments of 'Freida Hemple' formed multiple shoot primordia. In 'C. R. 5' and 'Pink Cloud', the green segments formed the highest number of multiple shoot primordia, whereas the red and pink leaf segments yielded the lowest percentage of primordia.
    2. The variegation pattern of leaf blades in 'Freida 'Hemple' and 'C. R. 5' were stable, whereas in 'Pink Cloud' the patterns were unstable and variants were observed. In 'Pink Cloud' the percentage of variants in which the original white color of the leaf vein changed to green was high in the pink leaf segments but low in the green leaf segments.
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  • Masamichi Yano, Yoshinori Hasegawa
    1993 Volume 62 Issue 3 Pages 625-632
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    The mechanism of autocatalytic ethylene production was studied in relation to kiwifruit ripening.
    1. Ethylene production by kiwifruit was induced by 18- and 24-hr ethylene treatments at 20 °C. On the other hand, the other physiological changes associated with ripening were accelerated even by 15-hr or less.
    2. The physiological changes such as flesh softening, decrease in acid content and increase in respiration rate were appreciably accelerated by 0.1 to 10 ppm of ethylene at 5 °C, while ethylene production, ACC (1-aminocyclopropane-l-carboxylic acid) accumulation and EFE (ethylene forming enzyme) activity were not stimulated by those conditions.
    Hence, it is concluded that autocatalytic ethylene production in kiwifruit is less inducible with ethylene treatment than most physiological changes relating ripening.
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  • Hong Deng, Yoshinori Ueda
    1993 Volume 62 Issue 3 Pages 633-639
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Berries of three strawberry cultivars, Hoko-wase, Toyonaka, and Nyoho, were quick-frozen and stored at -20 °, -40 0, and -80 °C, for 6 months. Strawberries were also frozen slowly or dipped into a sugar solution before freezing and stored at -20 °C.
    1. Berries kept at -40° and -80 °C for 6 months retained their flavor comparable to fresh raw berries. The flavor of strawberries stored at -20 °C deteriorated quickly. The deterioration at -20 °C was slightly retarded by quick-freezing or coating the berries with sugar prior to freezing.
    2. The sugar (Brix), acid and vitamin C content of strawberries did not change much during storage, whereas the anthocyanin content was reduced to less than half after 6 months at each storage temperature.
    3. The total ester content of the strawberries stored at -40 ° and -80 °C remained unchanged, whereas that in berries stored at -20 °C disappeared quickly. The disappearance is attributed to the rapid decomposition and diffusion of esters which led to lower sensory scores. Quick-freezing and dipping in a sugar solution followed by storage at -20 °C were effective in retaining the ester content only for a short period.
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  • Yoshihiro Shiraki, Shigenori Maezawa, Koichi Akimoto
    1993 Volume 62 Issue 3 Pages 641-645
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    The temperatures of shii-take (Lentinus edodes Sing.), a kind of mushroom, harvested at various times of the day and their postharvest respiration rates were measured. The relationship between the two factors are discussed with respect to maintaining their quality and freshness.
    1. Temperatures of shii-take at harvest fluctuated with the ambient air temperature, the former always being lower than the latter. The differences between the two tempera. ture were not constant; the differences in the morning being larger than those measured in the afternoon or evening.
    2. Temperature of shii-take initially increased after being transferred into a constant-temperature incubator but then decreased and gradually reached an equilibrium with the ambient temperature.
    3. The initial respiration rates of shii-take harvested at various times of the day were not constant; the respiration rates decreased during the experiment.
    4. The postharvest respiration rate of shii-take tended to be faster when harvest temperature was high.
    These results show that it is advisable to harvest shii-take when the temperature is low and the respiration rate slow to extend their quality and shelf-life.
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  • Shigenori Maezawa, Hatsuo Yamada, Koichi Akimoto
    1993 Volume 62 Issue 3 Pages 647-653
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Undesirable changes in color from green to yellow (abnormal coloring) on part of the surface of tomato 'Momotaro' are often observed after harvest. In this study, the effects of harvest maturity of the fruits and postharvest ripening temperature on their abnormal yellowing were investigated. Tomatoes 'Momotaro' of five kinds of maturities (indices are as follows : 5= mature green, 4=pinkish-white, 3=pink, 2=red, 1=fully ripe) were incubated at various temperature in the range of 10 °35 °C.
    1. Abnormal coloring occurred when fruits with maturity index greater than 3 were ripened at the temperatures above 25 °C and below 15 °C.
    2. Flesh firmness and total soluble solids contents (TSS) of ripe fruit were not influenced by, the stage of maturity at harvest or the ripening temperature.
    3. There were no significant changes in sugar contents of tomato harvested at any maturity index, whereas the citric acid content tended to show a decrease; malic acid content remained nearly constant.
    Our limited data indicate that the 'Momotaro' tomato under our current distribution systems should be harvested at a maturity index of 3 (pink stage) and kept at 20 °C to ripen normally.
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  • Yuko Takeda, Koh-Ichi Yoza, Yoichi Nogata, Hideaki Ohta
    1993 Volume 62 Issue 3 Pages 655-660
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    Levels of polyamines (agmatine, putrescine, and spermidine) in young developing seedlings of kaiware-daikon (Raphanus sativus L.) and the effects of polyamine biosynthesis inhibitors, namely difluoromethylarginine (DFMA) and difluoromethylornithine (DFMO) were investigated.
    1. During seed-germination, a sharp rise and decline of agmatine and putrescine while an increase of spermidine were observed.
    2. Agmatine, putrescine, and spermidine contents in the seedlings and cotyledons gradually decreased throughout the growth period after germination.
    3. The putrescine level in the seedlings treated by DFMA as a specific inhibitor of argininedecarboxylase was reduced to 27% of the control. In contrast, DFMO as a specific inhibitor of ornithinedecarboxylase did not affect the putrescine level in the seedlings.
    These results suggest that the putrescine is mainly synthesized from arginine via agmatine in the seedlings.
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  • Francis M Mathooko, Tetsuo Sotokawa, Yasutaka Kubo, Akitsugu Inaba, Re ...
    1993 Volume 62 Issue 3 Pages 661-667
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    At 20°C, freshness retention of figs (Ficus carica L. cv. Masui Dauphine) by CO2-enriched atmosphere treatment or modified atmosphere packaging were studied in an attempt to reduce deterioration during transportation. CO2-enriched atmosphere treatment inhibited ethylene production, delayed the incidence of mold growth and promoted ethanol production. Majority of the figs exposed to 60% or 80% CO2 for 2 days were still marketable 1 day after transfer to air at 20°C.
    Based on mold growth, figs stored in air and in unperforated polyethylene bags deteriorated slightly faster than those stored in perforated bags. A gas mixture of 80% CO2 +20% O2 or 100% CO2 introduced into the polyethylene bags before sealing were more effective in the control of mold growth compared to air or 100% N2 and equally effective in reducing ethylene accumulation as 100% N2. The results suggest that postharvest deterioration of figs can be reduced by either CO2-enriched atmosphere treatment or through modified atmosphere packaging.
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  • Nobuyuki Kozukue, Hironobu Tsuchida, Susumu Mizuno
    1993 Volume 62 Issue 3 Pages 669-673
    Published: 1993
    Released: May 15, 2008
    JOURNALS FREE ACCESS
    We investigated the changes in chlorophyll (Chl) and potato glycoalkaloid (PGA) contents in the cortex of 'May Queen' potato tubers formed by the duration and intensities of different white fluorescent lights and photoperiods. The fluorescent light intensities and storage temperature on potato tubers in several markets were also examined.
    1. Both Chl and PGA contents in the cortex formed under white fluorescent light increased up to 12, 500 lx, but their contents decreased slightly at 15, 400 lx. The light intensity which induced a maximum production of the two compounds ranged from 8, 000 to 12, 500 lx.
    2. Chlorophyll synthesis in tubers was observed after a daily irradiation (3, 000 3, 900 lx) of 3-hr for 7 days at 15 °C, whereas an increase in PGA content was detectable even after a 30-min irradiation.
    3. The light intensities and storage temperatures on potato tubers displayed in several markets in Himeji city ranged from 2, 200 to 8, 000 Ix and 9 ° to 15 °C, respectively. Therefore, we recommend that potato displays in markets should be shielded from light and kept at 10 °C or below.
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