Journal of the Japanese Society for Horticultural Science
Online ISSN : 1880-358X
Print ISSN : 0013-7626
ISSN-L : 0013-7626
Volume 58 , Issue 1
Showing 1-32 articles out of 32 articles from the selected issue
  • Satoru KONDO, Yuji TAKAHASHI
    1989 Volume 58 Issue 1 Pages 1-8
    Published: 1989
    Released: July 05, 2007
    The present report aims to analyze the mechanism of fruit abscission under high night-temperature (HNT) conditions which promote the abscission.
    The relationship between the rate of fruit abscission and ethylene evolution was investigated for the apple cultivars Tsugaru, Starking Delicious (SD) and Fuji. The rate of fruit abscisson of ′SD′ was the highest, followed by that of ′Tsugaru′ and then ′Fuji′. Ethylene evolution from these fruits also showed a similar trend.
    Application of 100ppm ethephon gradually increased the rate of seed abortion and fruit abscission with time after treatment. Aminoethoxy-vinylglycine (AVG) application prevented ethylene evolution and reduced the rate of seed abortion, fruit abscission and cellulase activity in the abscission zone.
    Based on these results, it is concluded that the increase in endogenous ethylene levels of fruit prevented seed development and caused fruit abscission under HNT treatment, and that the most susceptible cultivars were the ones in which ethylene evolution was the highest.
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  • Satoru KONDO, Noboru MIZUNO
    1989 Volume 58 Issue 1 Pages 9-16
    Published: 1989
    Released: July 05, 2007
    The relationship between the early drop of apple fruit, and auxin, gibberellin and cytokinin-like substances in the seeds was investigated from 16 days after full bloom (AFB) by comparing ‘Starking Delicious’ and ‘Fuji’ apple fruits. In addition, the effects of a spray of 2-methyl-4-chlorophenoxy butyric acid ethyl solution (MCPB, 10ppm), a solution containing gibberellin A3 and gibberellin A4 at 50ppm each (GA3+GA4), and a 6-benzylamino purine solution (BA, 100ppm) were investigated under shading treatment which promoted fruit abscission.
    1. In both cultivars, auxin-like activity in the seeds hardly differed from 16 days to 60 days AFB. However, MCPB spray slightly reduced fruit abscission, although most fruits were small since seed abortion had been increased by the shading treatment.
    2. The level of gibberellin-like substances in the seeds of ‘Fuji’ increased on and after 23 days AFB, whereas that of ‘Starking Delicious’ increased on and after 42 days AFB when early fruit drop ceased. Moreover, the GA3+GA4 spray satisfactorily reduced fruit abscission and promoted fruit growth regardless of seed abortion by the shading treatment. Therefore, it is considered that gibberellins in the seeds are closely associated with early fruit drop and fruit growth.
    3. The peak level of cytokinin-like substances of ‘Fuji’ at 25 days AFB was 6 days earlier than that of ‘Starking Delicious’. Hence, BA was sprayed on the 19th day AFB when the level of cytokinin-like substances of ‘Starking Delicious’ was low, although, it increased fruit abscission. This may have been influenced by ethylene evolution from the fruit which increased after the BA spray.
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  • Shoji NORO, Niro KUDO, Takaharu KITSUWA
    1989 Volume 58 Issue 1 Pages 17-24
    Published: 1989
    Released: July 05, 2007
    Many apple growers in Japan use double paper bags for the yellow colored apple cv. Mutsu, to enhance red color formation and to remove ground color.
    To study the cause of the red color formation, young fruits of the yellow colored apple cvs, Mutsu and Golden Delicious, were covered individually with commercial double paper bags for shading from early June to late September, according to the usual way in Aomori Prefecture. The fruits were harvested in middle October, and anthocyanin content was measured for bagged and unbagged fruits. The anthocyanin level was greater in bagged fruits than in unbagged ones in both cultivars.
    Sugars and organic acids in the apple skin of both cultivars obtained from late August to middle October were analyzed by gas chromatography (GC) with a capillary column, after being derivatized with trimethylsilyl agents.
    In both cultivars, the main sugars were glucose, fructose, sorbitol and sucrose, and the main organic acids were malic and quinic acids. Throughout the period tested, the content of fructose was much higher in the bagged fruit than in the unbagged fruit in both cultivars. But no differences were found in the other main components between bagged and unbagged fruits in either cultivar.
    Compositional changes in other minor organic acids were also investigated between bagged and unbagged fruits in both cultivars, using GC and gas chromatography-mass spectrometry; citric acid was identified as a component which had the most quantitative difference. A small amount of citric acid was detected before coloring, and it decreased slightly at the later stages of coloring in the unbagged fruit. However, in the bagged fruit, a large amount of citric acid was detected before the stages of coloring, and it decreased remarkably at the later stages.
    Commercial citric acid (sodium salt) and fructose were applied to disks of unripe skin from bagged and unbagged fruits of both yellow cultivars, and the disks were irradiated with the light of a discharge lamp. When citric acid was applied, the content of anthocyanin increased compared to that of the control only in the skin of the bagged fruit of both cultivars. When fructose was applied, the anthocyanin level in the skin of both cultivars did not increase, regardless of bagging treatment.
    Thus, citric acid appears to be related to the development of anthocyanin only in bagged fruit of the yellow apple cultivars described above.
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  • Takenori ASADA
    1989 Volume 58 Issue 1 Pages 25-29
    Published: 1989
    Released: July 05, 2007
    The relationship between leaf area and branch diameter was examined to establish a method for estimating orchard leaf area. Measurements were obtained from 15-25-year-old “Fuji” apple trees on a domestic clonal rootstock (Malus prunifolia) trained to an open-center or modified center-leader shape in 22 commercial orchards of various soil conditions located in Aomori prefecture.
    The relationship between leaf area (Y) and branch diameter (X) was represented by a single regression equation:
    log Y=-0.710+2.145log X
    The correlation was fairly high (r=0.931), considering that the sample branches were taken under a wide range of orchard conditions. This was considered to be attributable to the facts that samples were selected from branches of at most 5cm in diameter measured at the point just below the lowest leafy branchlets.
    The following method was proposed for estimating the total leaf area of an apple tree. The leaf area on all individual branches of less than 5cm in diameter is estimated from their diameter, using the regression equation presented above. The values of the leaf area of individual branches are then summed up for the whole tree.
    The leaf area of scaffold branches which was estimated using this method gave a close approximation to the actual leaf area (r=0.920).
    It is concluded that the above estimation method provides a rapid and reasonably accurate measurement of the total orchard leaf area and can be used for a satisfactorily wide range of orchards.
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  • Hiroto YOSHIOKA, Kouji AOBA, Masashi FUKUMOTO
    1989 Volume 58 Issue 1 Pages 31-36
    Published: 1989
    Released: July 05, 2007
    Apple fruits of ‘Starking Delicious’, ‘Jonagold’, ‘Golden Delicious’, ‘Fuji’, and ‘Rails Janet’ were harvested at maturity and stored at 20°C for studies of the relationships between time of maturity and storability of fruits.
    1. No relationship was found between time of maturity and the firmness of the fruits at maturity, although the fruit softened more rapidly in early season cultivars than in late season ones during storage at 20°C.
    2. Except for cultivar ‘Fuji’, the late season cultivars contained higher acid content at maturity but decreased more sharply during storage than early season cultivars. NADP-malic enzyme activity in fruits showed higher activity in late season cultivars than early season ones.
    3. The late season cultivars ‘Fuji’ and ‘Rails Janet’, showed very low ethylene evolution rate and ethylene concentration in the central core during storage, compared to the others. The ratio of ethylene evolution rate to ethylene concentration in the central cores in ‘Fuji’ and ‘Ralls Janet’ was low cempared to the other cultivars. However, except for these two, the late season cultivars showed higher ethylene evolution rates and ethylene concentrations in central cores than the early season ones, and there was no relationship between fruit storability and the ratio of ethylene evolution rate to ethylene concentration.
    4. 1-Aminocyclopropane-1-carbonic acid (ACC) content in the fruit tended to increase, accompanying the increase of ethylene evolution, during storage in all cultivars. In ‘Fuji’ and ‘Rails Janet’, the fruit contained appreciable amounts of ACC just after harvest when ethylene evolution was not detected.
    These results suggest that the regulation of fruit softening and NADP-malic enzyme activity during apple fruit ripening is related to time of maturity of the fruit.
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  • Kiyoshi BANNO, Kaname YOSHIDA, Shinji HAYASHI, Kenji TANABE
    1989 Volume 58 Issue 1 Pages 37-42
    Published: 1989
    Released: July 05, 2007
    In vitro propagation of Japanese pear (Pyrus serotina Rehd.) cvs. ‘Nijisseiki’, ‘Shinsui’, ‘Kosui’, ‘Hosui’ and ‘Yagumo’ was investigated.
    1. Shoot tips (<0.5mm) of each cultivar were cultured in half-strength Murashige and Skoog medium (1/2MS) containing 1mg/l BA and 0.1mg/l IBA. Shoot growth and proliferation of ‘Shinsui’ and ‘Nijisseiki’ were less than with other cultivars at the culture establishment stage, but gradually became better after 4 subcultures.
    2. The best agar for shoot growth and proliferation was powder agar. The best basal medium was woody plant medium (WPM) for ‘Nijisseiki’, and ‘Osa-nijisseiki’, and 1/2MS for the other cultivars.
    3. Rooting from shoots occurred after the 7th subculture and the percentage of rooting gradually increased by repeated subcultures. The best rooting was obtained when shoots were pretreated on modified Linsmaier ahd Skoog medium (1/2 Macro-LS) supplemented with 162mg/l phloroglucinol (PG) and 2mg/l IBA and kept in the dark for 5 days, then transplanted to hormone-free 1/2 Macro-LS supplemented with 162mg/l PG.
    4. Rooted plantlets were transferred to peatmoss in containers and were gradually acclimatized in a growth chamber under 24h photoperiod for 2 weeks. After being transplanted to soil, plantlets of each cultivar began to grow well.
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  • Hirokazu FUKUI, Mineo SUGIYAMA, Mitsuo NAKAMURA
    1989 Volume 58 Issue 1 Pages 43-47
    Published: 1989
    Released: July 05, 2007
    Aseptic shoot cultures were initiated from shoot tips (1mm) of Diospyros kaki Thunb. cv. ‘Nishimurawase’. Shoot tips were excised from dormant axillary buds and cultured in vitro. The best shoot growth was obtained on MS medium containing half strength nitrogen supplemented with 6-(4-Hydroxy-3-methyl-trans-2-butenylamino) purine (zeatin) at 10-5M; 6-benzylaminopurine (BAP) and 6-(γ, γ-dimethylallylamino) purine (2iP) was ineffective. A five-fold proliferation rate was obtained by single node cutting of elongated shoot.
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  • Masashi ISHIDA, Hideshi MATSUYAMA, Akira KITAJIMA, Yoshitsugu SOBAJIMA
    1989 Volume 58 Issue 1 Pages 49-54
    Published: 1989
    Released: July 05, 2007
    Medium composition for successful shoot tip culture to multiply the suckers induced from a promising dwarfing rootstock (Prunus japonica THUNB.) on which certain peach cultivars had been grafted, was investigated with respect to cytokinin and auxin levels under continuous light at 25°C.
    Shoot tip cultures of P. japonica were established to proliferate shoots on 1/2 or 1/3 strength modified Murashige and Skoog (MS) medium. Sub-cultures treated with BA 0.5mg/l produced elongated shoots suitable for rooting.
    Sorbitol was effective as a carbon source for shoot multiplication during culture.
    Elongated shoots were incubated on media with and without auxin for 30 days. Rooting was better when shoots dipped in IBA solution (50ppm) were then incubated on a medium without hormones. NO3/NH4 mole ratio based on total N in the MS medium was studied.
    The best combination for shoot growth was 1/3 strength MS when both forms were present in the same ratio.
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  • Hideki MURAYAMA, Ryutaro TAO, Tatsumi TANAKA, Akira SUGIURA
    1989 Volume 58 Issue 1 Pages 55-61
    Published: 1989
    Released: July 05, 2007
    Using 7 Japanese persimmon cultivars (‘Hiratanenashi’, ‘Jiro’, ‘Hana-gosho’, ‘Aizumishirazu’, ‘E-gosho’, ‘Kurogaki’ and 2 strains, normal and dwarf, of ‘Nishimura-wase’), optimal micropropagational conditions for culture establishment, shoot proliferation and rooting were investigated.
    1. For culture establishment, both the types (N6-Benzyladenine: BA or N6-Isopentenyladenine: 2iP) and concentrations (1_??_20mg•l-1) of cytokinin were tested with dormant bud explants of ‘Jiro’ and ‘Kurogaki’ on modified MS medium with nitrates reduced to half strength (MS(1/2 NO3)). Optimum concentrations of BA and 2iP for ‘Jiro’ were 5mg•l-1 and 5_??_20mg•l-1, respectively, and those for ‘Kurogaki’, 2_??_5mg•l-1 and 5-20mg•l-1. Explants of ‘Jiro’ produced more shoots than those of ‘Kurogaki’ during this stage and were established more easily. Other cultivars except ‘Hana-gosho’ could be established readily on the MS (1/2 NO3)medium supplemented with 5mg•l-1 BA.
    2. For shoot proliferation and elongation also, both the types (BA or 2iP) and concentrations (1_??_20mg•l-1) of cytokinin were tested with ‘Jiro’, ‘Aizumishirazu’, ‘E-gosho’, ‘Kurogaki’ and 2 strains of ‘Nishimura-wase’ explants which had been established and subcultured on MS (1/2 NO3) medium supplemented with 5mg•l-1 BA. BA was more effective for shoot proliferation, while 2iP was better for shoot elongation. In most cases, optimum concentration of each cytokinin was 5mg•l-1. The dwarf strain of ‘Nishimura-wase’ was more responsive to either cytokinin than the normal strain.
    3. For rooting, periods of dark treatment (0_??_15 days) and 3-indolebutyric acid (IBA) concentrations (0_??_1000mg•l-1)for acute exposure were tested with ‘Hiratanenashi’ shoots which had been elongated at 5mg•l-1 2iP in the MS (1/2 NO3) medium. More than 6 days of darkness enhanced rooting, with the highest rooting percent being 9 days of treatment. Optimum IBA concentration for rooting was 250mg•l-1. Shoot cuttings of 5 cvs, ‘Hiratanenashi’, ‘Jiro’, ‘Aizumishirazu’, ‘E-gosho’ and ‘Kurogaki’ rooted with final rootings of 96%, 80%, 74%, 44% and 8%, respectively, by this best combination of darkness and IBA treatment.
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    1989 Volume 58 Issue 1 Pages 63-67
    Published: 1989
    Released: July 05, 2007
    The effect of N form on the development of chlorosis was examined on rabbiteye blueberry plants grown at pHs regulated with little variation. One-year-old rooted cuttings were grown in flowing solution culture. Treatments were composed of combinations of 3 forms of N (NH4, NH4NO3 and NO3) and 2 levels of pH (4 and 6). Each treatment was applied to 5 plants in separate 3.5l root compartments in a 75l reservoir. The pH of the solution in the reservoir was adjusted to the initial value once a day.
    At pH 6, chlorosis developed on NH4- or NH4NO3- fed plants 2 to 3 weeks after initiation of the treatment, but not on NO3- fed ones. The growth of shoots and roots was poorer at pH 6 than at pH 4 with all forms of N. Dry weight of young leaves and stems was not different among N forms at pH 6 but at pH 4 it was greater for NH4- fed plants than for NO3-fed ones.
    No significant difference was found in Fe concentration of young leaves between chlorotic and healthy plants, although chlorophyll content was closely related to Fe concentration. P concentration and P/Fe ratio of young leaves were higher for chlorotic plants than for healthy ones.
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  • Yasuhiro MURAI, Eiji YUDA, Hiroyuki MATSUI, Shoichi NAKAGAWA
    1989 Volume 58 Issue 1 Pages 69-73
    Published: 1989
    Released: July 05, 2007
    Soluble protein and amino acid contents in leaf and bark tissues of ‘Kawano natsudaidai’ were investigated in relation to flower bud formation. Physiological flower bud formation of ‘Kawano natsudaidai’ was initiated early in November and ended early February. Protein content in leaf and bark tissues of non-bearing shoots was always higher than in both tissues of bearing shoots. Particularly, protein content in non-bearing shoots increased markedly at early stage of flower bud formation. But there were no significant differences in amino acid content in leaf and bark tissues of bearing and non-bearing shoots. When solutions of GA3 (250ppm) and BA (300ppm) were separately sprayed on non-bearing shoots, protein content in leaf and bark tissues, and also amino acid content in bark sharply decreased with the GA3 application. However, they were not affected by the BA application. Both GA3 and BA solutions were sprayed on nonbearing shoots, and percentages of flower set in the following season were investigated. Only the GA3 application drastically inhibited the percentages of flower set, when compared to the control, BA application had little effect on the percentage of flower set.
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  • Hiroshi INOUE
    1989 Volume 58 Issue 1 Pages 75-82
    Published: 1989
    Released: July 05, 2007
    One-year to three-year-old satsuma trees (cv. Okitsu Wase or Miyagawa Wase) on trifoliate orange rootstocks grown at 15, 20, 25 and 30°C in a growth chamber were observed for flower bud differentiation and development.
    1. One-year-old trees were grown in a growth chamber from March 1 or April 1. On trees grown at 15°C, flowers but no leaves were produce instead of summer flushes. On trees grown at 20°C, a smaller number of leafless flowers and some leafy ones were produced. On trees grown at 25 and 30°C, summer shoots grew vigorously and flower buds did not differentiate.
    2. In mid-June, when spring shoots ceased their growth and their stems became mature, one-year-old trees were transferred into 20 and 15°C growth chambers. They were kept there for several months, and then transferred to 25°C rooms. On the trees grown at 15°C for 2 months or more and at 20t for 2.5 months or more, flower buds were produced. More flower buds developed on the trees grown at lower temperatures for longer periods. Flowers of trees grown at 15°C or 20°C until flowering had large and flat ovaries. Flowers of trees that were transferred to the 25°C room before flowering had small and long ovaries.
    3. Three-year-old trees were put in 15, 20 and 25t rooms at the time of morphological flower bud differentiation (March 20) and one month before and after. Flower bud development was observed in February, whereas microscopic evidence of differentiation was not evident. Flowering periods on trees grown at higher temperature were shorter.
    4. Two-or 3-year-old trees were put in 20 and 25°C rooms at half-month intervals from late September to next March. Flower buds were produced on the trees put at 25°C in late October and later. On the trees put at 20°C in early November and before, few flower buds were produced and they dropped before flowering.
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  • Sunao TACHIBANA, Shigeo NAKAI
    1989 Volume 58 Issue 1 Pages 83-89
    Published: 1989
    Released: July 05, 2007
    Two-year-old trees of ‘Miyagawa Wase’, an early maturing variety of satsuma mandarin, were planted in 1967 at various planting densities, and grown under different cultural treatments until they were 21 years old.
    Planting densities were 1, 250, 2, 500, 5, 000, and 10, 000 trees/ha. Cultural treatments were shallow plowing (0.3m in depth)+less fertilization (half of standard fertilization) and deep plowing (0.6m in depth)+standard fertilization (N, P2O5, K2O: 270, 240, 220 kg/ha) with no pruning+no fruit thinning or pruning (light, open-center training)+fruit thinning (number of leaves per fruit: 35).
    Effects of planting density and cultural treatments on the crown density (percentage of land covered by canopy) were examined during the period from 1969 to 1986 (tree age from 4 to 21 years). At the level of maximum yield, crown density was also examined at each planting density.
    The results were as follows:
    1. Crown density rapidly increased toward 100% with increasing planting density.
    2. At planting densities of 1, 250 and 2, 500 trees/ha, crown densities increased more rapidly under deep plowing+standard fertilization than under shallow plowing+less fertilization, and with no pruning+no fruit thinning than with pruning+fruit thinning. At densities of 5, 000 and 10, 000 trees/ha, there were no distinct differences in the crown densities among different cultural treatments.
    3. When crown density reached approximately 1000, maximum yield was obtained in each planting density. The average maximum yield was 66 t/ha.
    4. From the above results, it is expected that when the crown density is maintained at 80% level by suitable tree thinning, the trees will produce fruit at approximately 60t/ha with high quality.
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  • Sunao TACHIBANA, Shigeo NAKAI
    1989 Volume 58 Issue 1 Pages 91-96
    Published: 1989
    Released: July 05, 2007
    Two-year-old trees of ‘Miyagawa Wase’, an early-maturing cultivar of satsuma mandarin, were planted in 1967 under four different planting densities: 1, 250, 2, 500, 5, 000 and 10, 000 trees/ha. The relationships between crown density and yield, and between crown density and leaf area index (LAI) were investigated from data obtained from 1969 to 1986 (tree age 4 to 21 years). The contribution of several factors such as crown density, LAI and planting density affecting yield was also determined.
    1. The relationships between crown density and yield, and between crown density and LAI showed a close fitness to the quadratic curve proofs. Quadratic regression coefficients became smaller as planting density increased. Yield per unit leaf area decreased with increasing planting densities.
    2. The crown density which gave the highest yield (64t/ha) was estimated to be 99%, as the quadratic curve showed. At this time LAI was estimated to be 6.8. LAI then increased toward the highest value (8.2) during six years after the orchard was almost covered by foliage.
    3. In analyzing variation of yield, LAI made the greatest contribution. The contribution of crown density and planting density to yield was so small that effects of these factors were expected to be largely due to their influence on LAI.
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  • Setsuo MORIOKA, Shigeki YAHATA
    1989 Volume 58 Issue 1 Pages 97-103
    Published: 1989
    Released: July 05, 2007
    The influence of fruit load index (FLI) (fruit number per 10, 000 leaves) just before fruit thinning on the average fruit weight and fruit yield in that year, and on flower bud formation in the following year were investigated in three cultivars of satsuma mandarin. Fruit thinning methods to improve the uniformity of fruit harvested from each tree group including trees of various FLI just before fruit thinning were discussed.
    1. When fruit were thinned to the same FLI, the FLI just before fruit thinning scarcely influenced average fruit weight of the trees of ‘Hayashi Unshu’, (a late ripening cultivar). However, there was a significant negative correlation between those two parameters, resulting the differences of 20 to 30g in average fruit weight between trees of 300 and 1, 100 FLI just before fruit thinning, in ‘Okitsu Wase’ and ‘Miyagawa Wase’ (both early ripening cultivars).
    2. Fruit yield per 10, 000 leaves increased greatly with increasing FLI in the nonthinned tree group, while yield in the trees of higher FLI just before fruit thinning was slightly lower in each tree group thinned to the same FLI.
    3. If trees have excessive flowers or have a high FLI just before fruit thinning in a certain year, this is likely to decrease average fruit weight and fruit yield in that year at any FLI after fruit thinning.
    4. The trees with fruits thinned to lower FLI flowered in the following year more than non-thinned trees of a similar FLI just before fruit thinning. Within each tree group thinned to the same FLI, the amount of flowers decreased with increasing FLI just before fruit thinning.
    5. Tees with more than 700-800 FLI just before fruit thinning seldom flowered well enough to gain sufficient yield in following year, even if they were thinned severely.
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  • Hiroaki INOUE, Bunjiro TAKAHASHI
    1989 Volume 58 Issue 1 Pages 105-111
    Published: 1989
    Released: July 05, 2007
    1. In order to clarify the time of flower bud differentiation and subsequent development in avocado trees (Persea americana Mill.) in Japan, flower buds of the cultivars, ‘Zutano’ (6 to 7-year-old), ‘Jalna’ (5-year-old) and ‘Fuerte’ (20 to 28-year-old) were studied morphologically using a stereoscope and a scanning electron microscope (SEM) during 1979-81.
    2. In 1979-80, flower bud differentiation was observed on November 11 in ‘Zutano’ and ‘Fuerte’, and on November 25 in ‘Jalna’. In 1980-81, the differentiation was observed on November 9 in ‘Fuerte’, and on November 23 in ‘Zutano’ and ‘Jalna’. As the results of this two-time examination, it was shown that time of flower bud differentiation in the south-western warm area of Japan was in November in the three cultivars.
    3. The stages and times of flower bud development were as follows:
    1) No differentiation (flatness of growing point) ... late in October
    2) Differentiation of flower bud (protuberance of growing point) ... November
    3) Perianth formation, pistil and stamen primordia formation ... early in December
    4) Anther dehiscence valve and staminodium formation ... middle in January
    5) Pollen grain and ovule formation ... early in February
    6) Carpel suture and floral formation ... middle in March
    4. In the south-western warm area of Japan, time of flower bud differentiation in avocado trees was later than in deciduous fruit trees, and earlier than in evergreen fruit trees (except loquat).
    5. In 1980-81, flower bud development was inhibited for a short period by the low temperatures of winter, which were lower in the avocado orchard than in 1979-80.
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  • Koichi KATO
    1989 Volume 58 Issue 1 Pages 113-121
    Published: 1989
    Released: July 05, 2007
    If the small fruit varieties (SFV) of green pepper are cultivated in the greenhouse at night temperature 18°C, which is the optimum night temperature for the large fruit variety (LFV) at forced cultivation through winter, the SFV tend to bear unmarketable seedless and dwarf fruits. The SFV are cultivated at night temperature 23°C in commercial production.
    One of the differences in flowering behavior between the SFV and the LFV at night temperature 18°C was related to the delay in anther dehiscence of the SFV on the day of flowering. If cultivated at 18°C, the LFV started to dehisce in the morning corresponding to the flowering. However, the SFV delayed dehiscence up until late in the afternoon and many flowers did not complete dehiscence by 4 p.m.. Furthermore, pollen shedding of the SFV was less in amount as compared to the LFV. Accordingly, the aging of pollen and pistils was considered as a possible cause of a low degree of fertilization.
    According to the experiment conducted in a winter season on the aging of pollen and pistils, interference in fertilization for the above reason was denied, because pistils and pollen maintained their viability for two days and three days after flowering. However, the germination rate of pollen for 24 hours, on nutrient medium placed in the greenhouse, was low at average 11.8% on the day of flowering and the sterile rate of pollen reached 50% at 0 p.m. on the day of flowering. Thus in case of natural pollination, not only the smaller amount of pollen delivered to the stigma but also the poorer viability of pollen seemed to cause the higher rate of unsuccessful fertilization.
    For commercial cultivation of the SFV peppers at lower temperature, it is necessary to increase the amount of pollen used on the flowering day, in order to improve fertility of the SFV. Since fertility of the SFV was improved by artificial pollination from the pollen of the SFV or LFV, the entomophilous method such as pollination by honey bees might be applied in a greenhouse, and interplanting of the LFV might further improve productivity of the SFV.
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  • Hiroyuki MIURA, Mitsuo SHIMIZU, Akio TAZUKE, Masatoshi IWATA
    1989 Volume 58 Issue 1 Pages 123-129
    Published: 1989
    Released: July 05, 2007
    Seedlings of benitade, Polygonum hydropiper L., were irradiated with eight kinds of monochromatic light in the range of 400-730nm for different periods of 1 hour, 9 hours, 3 days and 5 days, at the intensity of about 9Jm-2s-1.
    The anthocyanin content per plant was higher at 665-700nm (red region) on 1 hour irradiation, and at 400-460nm (violet-blue region) and 700-715nm (far red region) on 9 hours irradiation, respectively. Although anthocyanin synthesis was most promoted both at 400-460nm and 665-700nm on 3 days irradiation, two peaks were evident at 460 and 665nm, the latter being 30% higher than the former, on 5 days irradiation. Except on 1 hour irradiation, the anthocyanin content was the least at 560nm (green region).
    The seedlings were irradiated for 30 or 60min alternately with red and far red light with relatively broad wavelength at the intensity of about 6 and 4Jm-2s-1, respectively. In addition, alternate irradiations with red and far red light for 5min each, per hour, was intermittently repeated 7 times. The stimulating effect of red light on anthocyanin synthesis was lost on subsequent irradiation of far red light, however, it was recovered again with re-irradiation of red light. From these results, it seemed that one of the photoreceptors for anthocyanin synthesis in Polygonum would be a phytochrome.
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  • Haruo SUZUKI, Seiichi OBAYASHI, Huiming LUO
    1989 Volume 58 Issue 1 Pages 131-138
    Published: 1989
    Released: July 05, 2007
    For priming of carrot seeds, KNO3, K3PO4, MgCl2•6H2O, NaCl and NaNO3 were similarly effective at -10 bars. No germination during priming treatment was found with K3PO4. The effect of K3PO4 for priming did not decrease very much as the duration of treatment was prolonged. Its effect was considered to be attributable to tertiary phosphate ions, because a similar result was obtained for Na3PO4•12H2O. Osmotic potentials of K3PO4 solutions which showed higher effects on priming were constantly -7.5 bars, while those of NaCl changed from -7.5 to -12.5 bars depending on treatment temperature and duration.
    Germination during priming treatment for eggplants, mitsubas (Cryptotaenia japonica Hassk.), Welsh onions, spinaches and edible burdocks was suppressed clearly more with K3PO4 than with NaCl. For eggplants and edible burdocks, osmotic potentials of K3PO4 solution which showed higher effects on priming were stable even if priming duration was varied. It was noted for mitsubas, Welsh onions and edible burdocks that the priming duration required for higher effects of K3PO4 solution showed a comparatively wide range.
    The effect of tertiary phosphates shown in our experiments may be due to high pHs of their solutions. Tertiary phosphates may be potentially useful and convenient osmotica for priming of seeds of many species.
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  • Hideaki TAKAGI
    1989 Volume 58 Issue 1 Pages 139-147
    Published: 1989
    Released: July 05, 2007
    The growth and development of several garlic cultivars planted in autumn and spring were compared in a cold district, and principles of spring-planting culture were studied.
    The shoot growth of autumn-planted garlics during the autumn was generally small. Local cultivars in cold districts (=north cultivars) made less growth during the autumn than warm-district cultivars (=south cultivars), and the north late-maturing cultivars made the least growth. The shoot sizes and bulb yields of the north late-maturing cultivars planted in spring were not much less than those of the autumn-planted ones. However, the sizes and yields of the spring-planted south cultivars were much less than those of the autumn-planted ones.
    The maturity dates of autumn- and spring-planted garlics of each cultivar were almost the same. However, in the north cultivars, spring-planted garlics continued vigorous bulb growth until later than autumn-planted ones.
    In spring-planting culture, most cultivars formed intermediate and/or single-cloved bulbs. The rates of such abnormal bulbs of the north cultivars were lower than those of the south ones, and those of the north late-maturing cultivars were much lower.
    Maximum bulb yield of spring-planted garlics was produced when cloves were first stored at outdoor temperatures and then at -2°C from early winter to the planting date.
    Spring-planting culture of garlic in cold districts was a promising cropping procedure when the north late-maturing cultivars were used.
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  • Hisami SASAKI
    1989 Volume 58 Issue 1 Pages 149-153
    Published: 1989
    Released: July 05, 2007
    When hypocotyl segments of the spinach plant were cultured on medium containing IAA (15mg/l) in the presence of GA, those cultivars in which the callus growth was profuse in terms of the concentrations of GA (10-7-10-4M), e.g. ‘HOYO’, ‘TOKAI’ and ‘WAKAKUSA’, showed generally low bud-forming activity. Furthermore, in the cultivars which had relatively high bud-forming capacity on the medium containing IAA plus GA, e.g. ‘NIPPON’ and ‘TOKO’, callus proliferation of their hypocotyl tissue segments were low overall. Root formation derived from hypocotyl segments of ‘TOKO’ and ‘NIPPON’ were markedly enhanced by the simultaneous application of GA to the medium with IAA. While the effective concentrations of GA on bud formation of spinach hypocotyl segments were different among these cultivars, the bud formation was enhanced by the addition of GA at the concentrations ranging from 10-7 to 10-4M, except in the case of ‘TOKAI’. Optimal concentrations of GA on the bud formation of ‘NIPPON’, ‘TOKO’ and ‘HOMO’ were 10-5, 10-6 and 10-4M, respectively. The induction of bud formation of hypocotyl segments in the spinach plant may take place during a relatively early stage of the incubation.
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  • Young Shik KIM, Ryozo SAKIYAMA, Akio TAZUKE
    1989 Volume 58 Issue 1 Pages 155-160
    Published: 1989
    Released: July 05, 2007
    1. The effect of temperature on the elongation rate of spears from 1-year-old asparagus was studied under dark conditions.
    Crowns were dug from the field and planted in pots, which were placed in temperature-controlled chambers. Sprouting of spears was influenced by temperature. It took 11-13 days at 10 and 15°C, and about 4 days at 20 to 40°C from the start of treatments, for sprouting to occur.
    Elongation rates of spears increased with increasing temperatures between 10 and 30°C, and then decreased at 35°C. Spears sprouted but stopped growing very soon at 40°C. The relative growth rate (RGR) of spears decreased curvilinearly with time. The logarithm of RGR decreased linearly with time. This result shows that spears grow doubly exponentially and that growth can be fitted by Gompertz equation (Length=A• exp(-B•exp(-Ct)), t=time).
    The values of the parameters A and B increased linearly with temperature between 10 and 20°C. but not changed between 20 and 30°C. The value of parameter C was increased linearly with temperature between 10 and 30°C. In an Arrhenius plot of parameter C, a linear relation was found between 10 and 30°C, with a discontinuity between 30 and 35°C.
    2. Fresh and dry weight of spears were estimated non-destructively by use of circumference at the base (C) and height (L) for white spears from 1-year-old crowns and green spears from 9-year-old ones.
    Fresh weight correlated very well with C2L for spears. The correlation coefficient was 0.975 for white spears and 0.983 for green spears. Dry weight also correlated very well with C2L but the correlation coefficients were lower than for fresh weight; they were 0.945 for white spears and 0.968 for green spears.
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  • Young Shik KIM, Ryozo SAKIYAMA
    1989 Volume 58 Issue 1 Pages 161-166
    Published: 1989
    Released: July 05, 2007
    The effects of fertilizer and light on the elongation of spears from 1-year-old asparagus and the non-destructive estimation of their fresh and dry weight were studied.
    Crowns were dug from the field and planted in pots, which were placed in temperature-controlled chambers or rooms.
    1. The elongation of spears was not influenced by application of nutrient solution at 20°C, but slightly increased at 30°C, regardless of light treatment.
    2. The elongation of spears was not influenced by light.
    3. The Gompertzequation(Length=A•exp(-B•exp(-C•t)), t=time) was successfully applied to the elongation data. The estimated valus of the parameter C at 30°C were higher than at 20°C. They were not influenced by the treatments of light or nutrient solution.
    4. The fresh and dry weight of spears were plotted against (circumference at the base)2×length for white and green spears. The slope of the linear equation for fresh or dry weight was not affected by nutrient solution or temperature. Light conditions did not influence the slope of the equation for dry weight but did so remarkably for fresh weight, so that the slope was steeper in white spears than in green ones.
    5. It was shown that the rate of dry weight increase of spears was not influenced by light conditions, but the rate of fresh weight increase of white spears was 1.37 times that of green ones. It was also shown that the rate of fresh or dry weight increase was mainly affected by temperature, as, in the case of the elongation rate.
    6. Compared with green spears, white spears had a higher content of water expressed on a dry weight basis, and showed a less gradual decrease in circumference of the stem from base toward tip.
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  • Koki KANAHAMA, Takashi SAITO
    1989 Volume 58 Issue 1 Pages 167-171
    Published: 1989
    Released: July 05, 2007
    In cucumber plants with only one female flower retained between the 6th and 10th nodes from the base, removing all leaves except one between 2 nodes above and 2 nodes below the fruit increased the occurrence and degree of fruit curvature. The concave side of the crooked fruit, however, always faced toward the tendril on the same node with the fruit regardless of the position on the stem of the retained leaf.
    14CO2 was administered to a single leaf between the 5th and 9th nodes of plants with one fruit on the 7th node. After 2 hours, the distribution pattern of 14C activity among 10 vascular bundles in the receptacle of the fruit varied with the position of the treated leaf, whereas the direction of fruit curvature was invariable and was not influenced by the position of the treated leaf.
    These results appeared to show that the direction of curvature of cucumber fruit was not determined directly by the inclination in the pathway of photosynthates into the fruit.
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  • Satoshi AOKI, Masayuki ODA, Kazuo HOSINO
    1989 Volume 58 Issue 1 Pages 173-179
    Published: 1989
    Released: July 05, 2007
    To estimate the varietal differences in chilling tolerance of cucumber (Cucumis sativus L.), young seedlings belonging to 20 varieties and grown at 25°C, were chilled at 4°C or 7°C for 2 days and changes in the photosynthetic rate and increase of leaf area were investigated.
    The photosynthetic rate decreased more rapidly in the seedlings exposed to 4°C than in those exposed to 7°C, and the decline became more severe as the duration of chilling increased. The chilling-induced depression of photosynthesis was less pronounced in the spring varieties (except ‘Sagamihanjiro’, ‘Hokkyoku-2’ and ‘Ougonmegami-2’) than in the summer varieties.
    The increase in the apparent leaf area (length×width of leaf) ceased during the chilling treatment, and the normal rate was not restored even after the temperature rose to 20°C. The increase in the apparent leaf area after chilling was more depressed in seedlings exposed to 4°C than in those exposed to 7°C, and was more suppressed in younger seedlings or true leaves. The chilling-induced depression of the increase in the apparent leaf area was less pronounced in the spring varieties than in the summer varieties.
    There was a positive correlation (r=0.864, significant at 5% level) between the chilling-induced depression of photosynthesis and of the increase in the apparent leaf area. Both parameters were also positively correlated (r=0.763, significant at 1% level) among various varieties.
    These results indicate that the chilling tolerance of cucumber can be estimated by analyzing the variations of photosynthesis and the apparent leaf area of cucumber plants exposed to low temperatures.
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  • Yasumasa MIURA, Taka MURAKAMI, Hironobu KOBAYASHI
    1989 Volume 58 Issue 1 Pages 181-186
    Published: 1989
    Released: July 05, 2007
    By 14CO2 fixation in the dark, the translocation of 14C-assimilates in Cattleya plants (Laeliocattleya Culminant ‘La Tuilerie’) was investigated during alternating periods of 11h-light and 13h-dark. Three samples of the 6-year-old plants having 7 to 9 serial shoots, grown in a greenhouse, were pretreated for two weeks in a growth chamber controlled at 25°C during the 11h-light period and at 20°C during 13h-dark period. These plants were then placed in a dark assimilation chamber, and three hours later were fed with 500μCi 14CO2 for an hour. The plants were individually taken out from the chamber, immediately after the absorption of free 14CO2 with 1N KOH and NaOH (A), subsequently at the end of the first light period; 21 hours post 14CO2-feeding (B), and at the end of the second light period; 45 hours post 14CO2-feeding (C). The organs of each shoot, including leaves and pseudobulbs, were dried at 90°C and their radioactivities were measured.
    In plant A the 14CO2 fixation rate was highest in the leaves of middle-aged three shoots, relatively high in those of young three shoots, and significantly low in the old leaves. In plant C it was increasingly higher in the young three leaves compared with those of A and B, but there was no significant difference in the activity among pseudobulbs.
    These results suggest that the assimilates are translocated from middle-aged leaves into younger ones. In addition, comparing the relative specific activity between A and B, it can be surmised that the young leaves have much higher sink capacity.
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  • Tokiko NAGASHIMA
    1989 Volume 58 Issue 1 Pages 187-194
    Published: 1989
    Released: July 05, 2007
    The embryogenic process of Ponerorchis graminofolia Reichb. f., a terrestrial orchid native in japan, was observed and the germination ability of its immature seeds in vitro was also studied.
    1. Ovaries started elongation soon after pollination and reached full size two weeks later.
    2. Ovules started to differentiated after pollination and formed a complate embryo sac with 8 nuclei on the 8th to 9th day. Double fertilization was observed in the ovules 12 to 13 days after pollination, and the fertilized polar nuclei divided into three to five endosperm nuclei.
    3. The seeds increased in size rapidly, reaching a maximum days after pollination. After that time the seed coats began to shrink, then shrinkage stopped and the seeds attained final size 40 days after pollination. Embryo developed continuously during the 40 days.
    4. The embryonic type at the tetrad stage was recognized as C2 type according to Veyret′s classification, belonged to the modified F type (Coerogyne parishii type) after the tetrad stage. The main spherical part of the matured embryo was derived from the apical “ca” cells of proembryos, and the suspensor was derived from the basal “cb” cells.
    5. Mature seeds of this species belong to those socalled hard to germinate. Immature seeds which developed at least beyond the octant stage began to have germination ability, and the highest germination rate (40%) was obtained about 35 to 40 days after pollination, when cultured on a Hyponex medium under light conditions.
    6. A strong correlation was observed between the periods from pollination to fertilization and to embryogenesis completion, and also between the periods from pollination to fertilization and to the stages of immature seed showing the best germination rate, when examined on 47 orchid species and hycrids.
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    1989 Volume 58 Issue 1 Pages 195-209
    Published: 1989
    Released: July 05, 2007
    In vitro cultural conditions were investigated for promoting differentiation and growth of bulblets from segments of various parts of plantlets regenerated through shoot-tip culture of lilies (Lilium spp.). The growth and flowering of the in vitro propagated bulblets were observed in soil culture, and diagnosis of virus was also performed under electron microscope and by sap inoculation to L. formosanum seedlings.
    1. Bulblet differentiation from various tissue segments and the growth of bulblets were enhanced with addition of auxin, especially 0.1mg/l NAA, to the medium. Addition of cytokinin to the medium multiplied the differentiation of bulblet primordia (adventitious buds) remarkably, but retarded their development to bulblets.
    2. Cutting bulb scales into segments increased total number of regenerated bulblets per scale.
    3. High sucrose concentration of the medium (60-120g/l) and high incubation temperature (27-28°C) inhibited leaf elongation from bulblets and promoted enlargement of the base of scaly leaves.
    4. Although both leaf and stem-node segments regenerated bulblets, bulb scales were most suitable material for in vitro propagation of lilies because of their high regeneration rate of bulblets and simplicity of their culture process.
    5. In L. longiflorum, in vitro propagated bulblets flowered without cold treatment within one year after transplanting to soil, and bulbs with marketable size for cut-flower production were harvested in the first cultivation in soil. On the other hand, cold treatment to the bulblets of L. speciosum accelerated bolting in soil culture and reduced days to flowering. In the case of L.×formolongo and L. concolor, bulblets propagated by in vitro culture could flower earlier than by conventional cultivation methods in field conditions. Lilies like these two species are considered to be promising materials for practical production of bulblets through in vitro culture.
    6. Diagnosis of virus in bulblets derived from shoot-tip culture of L. longiflorum indicated that these bulblets were freed from virus.
    These results suggested that a large number of virus-free lily bulbs can be propagated in a short time by subculturing bulb scales of in vitro bulblets derived from shoot-tip culture, and that the cultivation time necessary to flowering-bulb production can be reduced remarkably by use of those bulbs.
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  • Yoshihiro UEDA, Hiroaki TOMITA
    1989 Volume 58 Issue 1 Pages 211-220
    Published: 1989
    Released: July 05, 2007
    Pollen grain morphology of 125 taxa of roses was examined by using scanning electron microscope (SEM) and by subsequent principal component analysis, in order to clarify the phylogenetic relationships. Nine categories of pollen-surface type were confirmed by scrutinizing ridge and perforation features on pollen exine. Species belonging to a botanical section or cultivars belonging to a horticultural cultivar group showed specific pollen exine patterns, and it was suggested that the specific pollen exine pattern transmits well from wild species to cultivars during several generations.
    A principal component analysis using six quantitative traits of pollen grains well separated the groups of roses. The wild species with high ploidy levels and the many cultivars belonging to the Hybrid Tea and Floribunda groups were distinguishable from the wild species of low ploidy level and from the other cultivar groups by the score of the first principal component. The species of the section Pimpinellifoliae and their related cultivars were characterized by the score of the second principal component, and the species of the section Indicae and their related cultivars by the score of the third principal component.
    Thus, the features of the perforations and ridges of the pollen exine seem to be good tools to distinguish each botanical section or horticultural cultivar group in roses.
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  • Motoaki DOI, Yasuaki TAKEDA, Tadashi ASAHIRA
    1989 Volume 58 Issue 1 Pages 221-226
    Published: 1989
    Released: July 05, 2007
    Application of 300ppm BA (6-benzylaminopurine) promoted flower initiation and advanced blooming by about half a month in a heated plastic house under long-day conditions in BF-04, BF-08 and BF-13 vegetative lines of Gypsophila paniculata L. ‘Bristol Fairy’, but not in BF-20 line. BA treatment also promoted flowering in BF-08 and BF-13 lines even when grown in an unheated plastic house under nutural daylength. BA treatment seemed to substitute for chilling for the induction of flowering, and consequently plants treated with BA overcame unfavorable growing conditions.
    On the other hand, GA3 (gibberellic acid) did not promote flower initiation in any lines grown in an unheated plastic house under natural daylength.
    Thus, cut flower production of gypsophila from autumn to winter is possible even in an unheated plastic house under natural daylength by the selection of vegetative lines with low chilling requirement such as BF-08 or BF-13, and the application of BA.
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    1989 Volume 58 Issue 1 Pages 227-229
    Published: 1989
    Released: July 05, 2007
    Limonoids in seeds of Sudachi (Citrus sudachi Hort. ex Shirai) were analyzed by high pressure liquid chromatography with a U. V. spectrophotometer. Sudachi seeds contained all of the major limonoids commonly found in other citrus. Limonin was predominant (2.53mg per gram of fresh weight, 50.3% of the total limonoids), followed by ichangensin, deacetylnomilin, nomilin, ichangin and obacunone. The seeds also contained common acidic limonoids such as nomilinic acid, deacetylnomilinic acid and isolimonic acid.
    The presence of ichangensin supports the previous suggestion that Sudachi is related to Yuzu (Citrus junos Sieb. ex Tanaka) and Ichang Chie (Citrus ichangensis Swingle). Ichangensin in Sudachi is most likely inherited from Ichang Chie which has been shown to possess this compound as the predominant limonoid.
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  • Nobuyuki KOZUKUE, Susumu MIZUNO
    1989 Volume 58 Issue 1 Pages 231-235
    Published: 1989
    Released: July 05, 2007
    The concentrations of potato (Solanum tuberosum L. ) glycoalkaloids (PGA) (i. e., α-chaconine and α-solanine) in four different parts of a sprouted ‘MayQueen’ potato tuber were determine by high-performance liquid chromatography (HPLC). The observation of sprouting condition and the changes of both PGA contents of tubers of both ‘Danshaku’ and ‘MayQueen’ during storage at 1°C, 8°C and 20°Cwere also investigated.
    1. On determining PGA content in four different parts of a sprouted potato tuber, it was found that the PGA concentration was highest in the sprout shoot and in the cortex tissues of the peripheral zone of the shoot. In the pith, however, a small amount of α-chaconine and only a trace amount of α-solanine were detected.
    2. The sprouting conditions of two cultivars stored at 1°C, 8°C and 20°C were observed during storage. It was found that two cultivars stored at 20°C sprouted about 7-15mm in length after 20 days of storage, whereas in 1°C-stored potatoes sprouting was not observed until 120 days of storage.
    3. The PGA content of ‘Danshaku’ was found to be lower than that of ‘MayQueen’ and the PGA contents of two cultivars increased with the development of sprout during storage. On the other hand, even in tubers stored under cold temperature, PGA was gradually accumulated in the cortex tissue, while in the pith PGA was not detected.
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