Journal of the Japanese Society for Horticultural Science
Online ISSN : 1880-358X
Print ISSN : 0013-7626
ISSN-L : 0013-7626
Volume 43, Issue 2
Displaying 1-13 of 13 articles from this issue
  • II. Effects of SADH and CCC Applied Directly to Clusters on Berry Set and Shoot Growth in Kyoho and Muscat of Alexandria Grapes
    Ryuji NAITO, Hisafumi UEDA, Takaaki HAYASHI
    1974 Volume 43 Issue 2 Pages 109-114
    Published: 1974
    Released on J-STAGE: July 05, 2007
    JOURNAL FREE ACCESS
    Further studies were conducted in 1971 and 1972 to reaffirm the effects of SADH and CCC on berry set and shoot growth of grapes when applied directly to clusters before anthesis.
    In Kyoho grape, the direct application of SADH to clusters by dipping at 500ppm or by spraying at 2500ppm was as effective as the shoot spraying at 2500ppm for increasing set of seeded berries, but only the latter treatment had the inhibitory effect on shoot elongation during blooming and set stages.
    The same trend was detected in Muscat of Alexandria grape to which CCC was applied at 200ppm by cluster dipping or shoot spraying. These results were completely in agreement with those obtained in our previous investigation. Shoot pinching before anthesis was also applied to the grapes as a comparative treatment, but it did not significantly increase the berry set. The leaf development was depressed only by the shoot spray treatment. Further, in no case the pollen germination was affected.
    The mechanism of promoting set of grapes by the applications of growth retardants was discussed in relation to their effect on shoot growth.
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  • II. Correlation between the Osmotic Values, Soluble Solids and Water Contents and Seasonal Changes in Specific Gravity of Leaf and Stem Tissue Powders
    Hirotaka TORIKATA, Mikihiro HARA, Tetsuji MORI, Masanori OHKAWA
    1974 Volume 43 Issue 2 Pages 115-124
    Published: 1974
    Released on J-STAGE: July 05, 2007
    JOURNAL FREE ACCESS
    Stems and leaves from satsuma mandarin trees bearing different crop loads were sampled during the year and analyzed for osmotic concentration, soluble solids and water content in the expressed sap. Seasonal fluctuation in the specific gravity and concentration of water extract of tissue powder in leaves and stems were also examined. The following results were observed.
    1) With respect to leaves, high positive simple and partial correlations were established between osmotic value and soluble solids content, while conversely, a negative but high simple correlation was found between osmotic value and water content. Hence, it seems that osmotic value of the sap is dominantly affected by the soluble solids content. Higher correlation ship was detected between these variables in alternate bearing trees than in annual bearers.
    2) With stems, positive simple and partial correlations were found between the osmotic concentration and soluble solids content in the expressed sap in the annual bearing trees but not in the biennial bearers. Their values were lower for stems than for leaves from the same trees. No correlation existed between the osmotic value of stem sap and the water content.
    3) Comparison between water and soluble solids contents of leaves revealed a negative simple correlation, whereas in stems, both negative simple and partial correlations existed. Thus, it is concluded that the soluble solids content of the sap in the stem is greatly influenced by the water content.
    4) Evaluation of environmental factors revealed that high negative correlations existed between osmotic value of leaf sap and both dry and wet-bulb temperatures (°C), the latter being higher than the former. This finding indicates that the osmotic value of the leaf is governed in part by the vapor pressure deficit or relative humidity of the atmosphere. Although no such distinct correlation was found in the stem samples, a negative one was recognized between the osmotic value and the amount of precipitation. Hence, it appears that humidity in the soil or atmosphere affects the osmotic values of the sap in the stem.
    5) Comparison of seasonal changes in specific gravity of tissue powder obtained from bearing and non-bearing shoots revealed that no difference existed between leaves from these shoots collected on the same dates, whereas the specific gravity of non-bearing stems was consistently higher than that of bearing ones especially in the summer and fall months.
    6) The seasonal trends in total carbohydrate and nitrogen contents in young satsuma mandarin shoots expressed as percentage dry weight were paralleled to those in specific gravity of the powdered tissue. Hence a high positive correlation was found to exist between these variables.
    7) In the leaves, a low positive simple correlation was found between the specific gravity of tissue powder and the solute ratio, but not in the stems.
    8) Slight differences of the concentrations of water extracts obtained from powdered leaves were observed between non-bearing and bearing shoots. However, the concentrations of stem extracts from non-bearing shoots were noticeably higher than those from bearing ones from summer to winter.
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  • Toshishige FUJII, Mikio NAKANO
    1974 Volume 43 Issue 2 Pages 125-131
    Published: 1974
    Released on J-STAGE: July 05, 2007
    JOURNAL FREE ACCESS
    The relationship between rooting and budding of the cuttings of dormant grape vine, cv. ‘Delaware’ was mainly studied from 1969 to 1972. The results were as follows:
    1. Optimum temperature of bottom heat was 21°C or more for rooting of the cuttings in early spring. Further, not only bottom heat but also appropriate warm temperatures to the aerial portion were necessary to get better rooting, because warm air temperatures promoted bud-break of the cuttings.
    2. Growing buds on the cuttings promoted rooting, and if the buds were removed at planting, rooting percentages and the number of roots reduced markedly. Auxin treatment applied to the disbudded cuttings failed to produce as many roots as those of the control, but it increased the root number slightly as compared with the disbudded control. It is presumed that unknown substances promotive for rooting of the cuttings may exist in the growing buds and act on rooting synergistically with auxins.
    3. Defoliating treatment on the dormant cuttings in the fall showed a little promotion on both rooting and budding. The disbudded cuttings at the leaf fall rooted, but the undisbudded ones did not. All the cuttings in the fall, however, did not produce desirable number of roots even if better rooting percentages were obtained.
    4. Among plant growth regulators applied to the cuttings after dormancy, both ABA and NAA appeared to promote rooting but not budding.
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  • III. Manganese Excess in Relation to Soil pH and Light Intensity
    Masao MASUI, Akira ISHIDA
    1974 Volume 43 Issue 2 Pages 132-138
    Published: 1974
    Released on J-STAGE: July 05, 2007
    JOURNAL FREE ACCESS
    Muskmelon plants were planted in soils adjusted at 4 pH levels -7.75(high), 6.16 (medium), 5.06 (low), and 4.68 (very low) and grown under light intensities, 70% of day light, and full day light in the greenhouse. Fruit weight and soluble solids decreased as soil pH was lowered from medium to very low. Top dry weight decreased at the very low pH. Mn increased in the leaves, stems and fruits with decreasing soil pH. Toxicity symptoms in the leaf blades, stems and petioles intensified as soil pH was lowered from medium to very low. The water soluble Mn at the high, medium, low and very low pH were 0, 16, 194 and 325ppm, respectively. The high correlation between the fruit growth and Mn content in the plant, and the excessively high level of Mn found in the plant from the low or very low pH suggest that the influence of soil pH on Mn toxicity was most likely an indirect effect of the treatment. However, Al, Ca, Fe and soluble salts also may have been responsible, in part, for the plant and fruit growth. Plant growth and Mn content in the plant except for the fruit were not influenced by light intensities in the greenhouse in this experiment.
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  • Akira SUGIYAMA, Taikichi TAKANO
    1974 Volume 43 Issue 2 Pages 139-149
    Published: 1974
    Released on J-STAGE: July 05, 2007
    JOURNAL FREE ACCESS
    The aim of this investigation is to examine spectral characteristics of anthocyanin complexes from purple flowers of Cineraria cruenta MASS. in order to help to resolve some of the speculation about flower coloration.
    With consideration for anthocyanins existing in natural state in plant tissues, pigments were extracted with water, precipitated with four times volume of 99% ethyl alcohol, then chromatographed on Sephadex LH-20, using 10% aq. ethyl alcohol as an eluent to separate five anthocyanins. Each fraction was precipitated by the addition of excess ethyl alcohol. Of five anthocyanins separated, the yield of two pigments was high. Pigment from dark red fraction (F3) and from purple fraction (F4) gave a yield of 0.275 gram and 0.35 gram, respectively, per kilogram of fresh materials.
    There were these visible absorption maxima of these two anthocyanin complexes in strictly neutral solution at 585-588, 542-546 and 505-512nm. They were markedly difference from anthocyanin-chloride and “genuine anthocyanins”. Differences on absorption spectra between two anthocyanin complexes were in the position of maximum in the ultraviolet region and also in that of shoulder and minimum existing 420-475nm. From the spectral change obtained by ionic exchange chromatography, alkaline hydrolysis and the use of various kinds of solvents, it was suggested that the acylated and ionic bondings in the structure shift the position of maximum, minimum and shoulder.
    It may be concluded that F4 (purple fraction) is an acylated complex and F3 (dark red fraction) non acylated one of cyanidin type of anthocyanins.
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  • Koichi YASUI, Keiichi MIYATA, Junko KUNISADA, Kuniyoshi KONISHI
    1974 Volume 43 Issue 2 Pages 150-160
    Published: 1974
    Released on J-STAGE: July 05, 2007
    JOURNAL FREE ACCESS
    The processes of formation and maturation of freesia corms were studied by histological and histochemical procedures.
    The experiments consisted of two parts. In the first experiment, cormlets of cv. ‘Rynveld′s Golden Yellow’, after forced to sprout, were planted in the greenhouse on September 18, and were harvested at intervals of one or two weeks until May 21 of the following year. At each sampling date, new corms were fixed and examined microscopically.
    In the other experiment, the corms grown in the greenhouse were harvested at about monthly intervals from March to June. The quantitative changes of RNA contents in the cells of the apical meristem of new corm, which were involved in maturation, were investigated histochemically. For the corms harvested in June, the effect of warm storage on the RNA contents was also examined by the same procedures.
    The results obtained were summerized as follows:
    1. The mother cormlet, average weight of which was about 1.0g, had five alternately arranged primordia of leaves in its main bud. The outer four of these five primordia developed to sheath leaves, and the innermost one developed into the first foliage leaf.
    2. After growth for eight to nine weeks, remarkable swelling of internodes between the second and the fourth foliage leaf was observed. The swelling of internodes resulted from the rapid cell division in the parenchyma of cortex. This was the start of the formation of new corm. At the same time, the differentiation of inflorescence was observed on the shoot apex.
    3. The development in diameter of new corm mostly depended on thickening growth of the cortex. The thickening growth of the cortex might be divided into three stages.
    At the initial stage, 12 weeks from forcing to sprout, the thickening growth of the cortex depended on cell multiplication. At the second stage, the succeeding five weeks of growth, cell division and cell enlargement were observed simultaneously. At the third stage of the last 20 weeks of growth, cell division had nearly ceased and the thickening growth of the cortex was caused by cell enlargement.
    4. In ten weeks after planting, growth of the daughter plant had been released from dependence upon the reserved substances of mother cormlet. At the same time, storage starch grains appeared in the parenchyma cells of new corm.
    5. At the early stage of growth, thickening was exclusively caused by increase in the number of cells due to the apical meristem activity of new corm. In the successive thickening growth of new corm, however, the actively dividing cells which diffused in the parenchyma of cortex played an important role. Therefore, it may be concluded that the pattern of the thickening growth of freesia corm is “diffuse thickening growth”, which is one of the pattern of thickening growth observed in stems of monocotyledons.
    6. A large amount of RNA was observed in the apical meristem of new corm harvested in March, demonstrated by the azure B method. The measurement by microspectrophotometry, however, showed that the RNA contents of cell in the apical meristem decreased progressively thereafter. Almost all the RNA in the meristem disappeared when new corms were placed in warm storage.
    When the new corms were moved to optimum conditions for sprouting, the RNA content in the meristem increased rapidly. In this case, within a certain range, the longer the period of warm storage, the more rapid the increase of RNA content was.
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  • VII. Flowering season in some new mutabilis Hybrids and newly Introduced Chinese species
    Yoshishige TACHIBANA
    1974 Volume 43 Issue 2 Pages 161-164
    Published: 1974
    Released on J-STAGE: July 05, 2007
    JOURNAL FREE ACCESS
    1. Six hybrid strains with different flower colors were obtained by the cross pollination, Hibiscus mutabilis (cotton rose) × H. meehanii (a hybrid of North American herbaceous species) (Table 1-3). The flowering habits of hybrid plants (offsprings, all of which were woody plants) were compared with the parents and another mutabilis hybrid, H. mutabilis rubra. The flowering of mutabilis begins in September and ends in October., while that of meehanii starts in July and closes almost completely before the end of September. The flowering season of the new hybrids was longer than the combined flowering season of the parents. One of the hybrid strains flowered even more abundantly than either of the parents (Table 4-5 ; Fig. 1, 2).
    2. Two newly introduced Chinese arboreal species, paramutabilis and sinosyriacus, both started flowering in June and displayed the most abundant flowers in early July. However their flowering declined suddenly in late July and they flowered only sporadically thereafter (or and did not greatly increase thereafter). This seasonal trend of flowering is more closely related to that of syriacus than to that of mutabilis (Table 6, Fig. 3).
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  • II. Absorption Spectra of Intact Flowers
    Koshiro KAWASE, Yotaro TSUKAMOTO
    1974 Volume 43 Issue 2 Pages 165-173
    Published: 1974
    Released on J-STAGE: July 05, 2007
    JOURNAL FREE ACCESS
    1. Absorption curves of fresh, intact petals of Chrysanthemum morifolium (68 cultivars) were measured with a multipurpose recording spectrophotometer (Model: MPS-50L, Shimadzu) using the opal glass transmission method, for distinction and classification of a wide variety of flower colors.
    The in vivo maxima of anthocyanin absorption were in the range of 530-560nm, carotenoids 420-490nm, and flavonols 350-370nm.
    2. Four patterns of absorption spectra in the visible range were observed. Group (1): Only one absorption maximum due to flavonols is observed in the range of ca. 350-370nm. The flower color of this pattern is white, and only 8 out of 68 cultivars were of this type. Group (2): Two maxima were observed, that is, one in the range of ca. 350-370nm as in group (1) and the other in the range of ca. 540-560nm which is the maximum of anthocyanin pigments. Twenty-six cultivars belonged to this group and their colors were pink or red-purple. Group (3): Absorption curves of this pattern showed the three characteristic peaks of carotenoid pigments in the range of 420-490nm. Fourteen yellow cultivars were found to belong to this group. Group (4): This pattern show the combined absorption of flavonols as in group (1), anthocyanins as in group (2), and carotenoids as in group (3). Twenty cultivars belonged to this group and their colors varied from orange to red.
    3. The flower color was deeper yellow or deeper pink (red-purple), as the optical density at the λmax of carotenoids or anthocyanins was high. In the group (4), flower color varied from orange to red depending on the relative ratio of the optical density of carotenoids and anthocyanins.
    4. In the absorption spectra of all flowers containing carotenoides, these pigments showed λmax almost at the same wave-length, but anthocyanins had different λmax depending on flower color. The λmax due to anthocyanins of red flowers were detected at shorter wave-lengths, while that of orange and pink flowers at longer wave-lengths, and that of red-purple flowers in the region between them.
    The λmax of anthocyanins, in general, shifted to longer wave-lengths with the decrease of their optical density. This may suggest the participation of co-pigmentation by flavonols in the flower color variation.
    Consequently, by measuring the absorption spectra of intact petals, the main pigments related to flower color can be identified both qualitatively and quantitatively.
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  • I. Some Physical Properties of Clay Pots
    Hiroshi TANAKA, Takahiro OKAMOTO
    1974 Volume 43 Issue 2 Pages 174-180
    Published: 1974
    Released on J-STAGE: July 05, 2007
    JOURNAL FREE ACCESS
    Clay pots have been most widely used as plant containers for ornamental plants, but few reports on the physical and chemical properties of clay pots are found. This study was intended to know some physical properties of clay pots-“Suyaki-Bachi”.
    Seven types of 13.5cm size pots were collected from several pot makers at clay pot producing centers such as Tokyo, Ibaraki and Aichi prefecture. Then each test piece was cut out from a pot wall and was used either for the determinations of the permeability to air and water, the apparent porosity, the water absorption, the apparent specific gravity, and the bulk specific gravity or for the microscopic observations of pot walls.
    1. Values of the permeability to air varied from the maximum, 4.70×10-4 of the products of Makabe district, Ibaraki pref. (C), to the minimum, 2.53×10-5ml•cm/ cm•cm2•sec. of those of Edogawa-ku, Tokyo (B), and the values of the products of Hekinan, Aichi pref. (E), Isohara, Ibaraki pref. (D), and the rest were intermediate.
    2. Values of the permeability to water ranged from 4.70×10-6 of the products of Makabe (C) to 3.95×10-8ml•cm/cm•cm2•sec of those of Edogawa-ku (B), and the order of these values was about the same as that of the permeability to air. However, their values were between 1/100 and 1/650 of the permeability to air.
    3. The order of the water absorption of the samples was almost the same as that of the apparent porosity. Samples of Isohara (D) had the lowest value, and those of Tokyo (A and B) the highest. No relation was observed between the permeability to air and water and the apparent porosity.
    4. The value of the apparent specific porosity of pots of C was the highest, while there was no significant difference among the other samples. On the other hand, the values of the bulk specific gravity of the samples of C and D were higher, but those of A and B were lower than the others.
    5. The microscopic observations of pore distribution in pot walls revealed that the finer pores were more abundant than coarser ones throughout all test pieces. It was suggested that pots of good permeability such as C and E had either coarser pores and some cracks or low percentage of finer pores; on the contrary, pots of poor permeability, produced at Tokyo (A and B) or Tokoname (G), had either less pores and low percentage of coarser pores or a large number of finer pores. Pots of Isohara (D), having rather better permeability, seemed to be poor in the number of pores.
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  • X. Effects of Gas Conditions and Harvest Dates on Jonathan Apples in CA Storage
    Ichiro KAJIURA
    1974 Volume 43 Issue 2 Pages 181-188
    Published: 1974
    Released on J-STAGE: July 05, 2007
    JOURNAL FREE ACCESS
    To clarify the effects of CO2 levels (0, 3, 5, 10%) combined with low (3%) and high (19-21%) O2 levels in CA storage, and to compare the flesh brownings in the fruits stored at different stages of maturity, Jonathan apples were picked on both Sep. 30 (152 days after full-bloom) and Oct. 9 (161 days), 1972, and were stored at 4°C for two months.
    The higher the CO2 levels combined with high O2 level, the more slowly the ground color yellowed and the flesh softened. After one month, more acidity was found at 5% CO2 than at 0 and 10% CO2.
    At 3% O2 without CO2, yellowing of the ground color, softening of the flesh and decrease of the acidity were retarded in comparison with that in air.
    At 3% O2, the suppressive effect by CO2 was unclear on the yellowing, but was more marked on the softening. When combined with 5% CO2, the acidity decreased as in air, but with 3% CO2, the highest level of acidity and the best quality were obtained among the treatments.
    More flesh brownings were found in atmospheres with higher CO2 and low O2 level, and in more-matured fruits. In the matured fruits, many of the brownings were found near some vascular bundles, and in some cases, cavities developed in the browned tissues.
    The optimum CO2 level for CA storage seemed to be lower at the low O2 level than at the high O2 level. At 4°C, the optimum gas condition for CA storage of Jonathan seemed to be (CO2 3%+O2 3%). For CA storage, it seemed important to pick the fruits earlier than those for cold storage. Discussions were made about the optimum harvest date in relation to flesh brownings.
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  • I. Seasonal Fluctuations in the Distribution and Concentration of Ascorbic Acid within Pulp and Peel Tissues during Growth of Satsuma Mandarin Fruit
    Toshiharu KUROSAKI, Itsue K. KAWAKAMI
    1974 Volume 43 Issue 2 Pages 189-193
    Published: 1974
    Released on J-STAGE: July 05, 2007
    JOURNAL FREE ACCESS
    Biochemical and histochemical studies were made on satsuma mandarin fruit from blossoming period to harvest time when the fruit becomes edible. Microscopic examinations were conducted on satsuma mandarin fruit to determine the changes in distribution and amount of ascorbic acid in the tissue from blossoming period to maturity.
    (1) Microscopic observation revealed that during the early period of fruit growth there was very little L-ascorbic acid and what could be found was mostly dehydro-ascorbic acid.
    (2) During the growth period of the fruit the outer cells of the fruit peel, especially the cells around the oil vesicles, the cells of the juice sac, and the cells around the vascular bundles showing the existence of L-ascorbic acid. Ascorbic acid in the cells around the oil vesicles and the juice-sac cells showed a tendency to increase with fruit growth. There was an especially remarkable increase of L-ascorbic acid in the cells around the oil vesicles.
    (3) When the fruit was small with very little pulp in the juice-sac, the specific gravity was high, but it became lower with growth of the fruit.
    (4) In the peel of the fruit in an early stage of growth, the ascorbic acid was mostly dehydro-ascorbic acid. As the fruit got ripened, L-ascorbic acid increased, and dehydro-ascorbic acid tended to decrease.
    Contrary to such a ratio of dehydro-ascorbic acid to L-ascorbic acid in the peel, a high percentage of L-ascorbic acid was contained in the pulp at an early period of fruit growth.
    L-ascorbic of the pulp, which was high in concentration at an early period of fruit growth, decreased with progress of fruit growth until September, but after early part of October it showed a remarkable increase and reached to a maximum at the harvest time during November and December.
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  • Kazuo CHACHIN, Yasuo TATSUMI, Kuniyasu OGATA
    1974 Volume 43 Issue 2 Pages 194-198
    Published: 1974
    Released on J-STAGE: July 05, 2007
    JOURNAL FREE ACCESS
    A study was carried out to determine the effect of gamma radiation on the nucleic acid content on buds of potato tubers and the incorporation of 32P into nucleic acid fractions and to observe the morphological changes in buds of irradiated potato tubers.
    The dead cells were observed in buds of potato tubers irradiated with above 20 Krad, but in the buds of the 10 Krad-tubers they were a little and some giant cells were observed. The contents of sRNA and rRNA in bud disk (bud including cortex tissue) of unirradiated tuber increased from dormant period to breaking period, but they did not increase in bud disk of the tubers irradiated with the doses of 5 and 10 Krad during this physiological turning period of metabolism.
    The incorporation rates of 32P into sRNA and DNA in bud disk of irradiated tubers were accerelated to some extent at the 5th day after irradiation (dormant period of unirradiated tubers) compared with those in unirradiated ones. It was noted that the incorporation rates of 32P into sRNA and mRNA in the 10 Krad-bud disk decreased between breaking and sprouting period, but not into rRNA and DNA, while the incorporation rates into sRNA, rRNA, DNA and mRNA in bud disk of unirradiated tubers tended to increase respectively. From these results the mechanism of sprout-inhibition of potato tubers by gamma radiation was discussed in a point of nucleic acid metabolism.
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  • IV. On the Respiratory Regulation Associated with Glu-OAA-transamination in Tomato Mitochondria during the Development of the Climacteric
    Hiroyuki YAMANAKA, Kazuo CHACHIN, Kuniyasu OGATA, Shozo KOBAYASHI
    1974 Volume 43 Issue 2 Pages 199-206
    Published: 1974
    Released on J-STAGE: July 05, 2007
    JOURNAL FREE ACCESS
    In this study, the respiratory regulation in tomato mitochondria was investigated in relation to some systems for the removal of Oxaloacetate (OAA).
    Mitochondria were extracted from outer locular wall tissue of tomato fruit. The wall tissues were grated gently in an isolation medium with a stainless-steel grater, and then mitochondria suspension were prepared according to a method of KU et al. The oxidative activity in the isolated mitochondria was measured polarographically using oxygen electrode (Yanagimoto-PO 100). Respiratory control ratios (state 3/ state 4) during the oxidation of malate and succinate in mitochondria were 2.5 to 3.0. The oxidative activity of mitochondria with succinate as substrate was high at mature green stage and decreased during ripening. On the other hand, O2-uptake of whole fruit was low at mature green stage and increased from mature green to breaker and then showed a peak at breaker or light pink. From this, it is supposed that the activity of mitochondria in whole fruit may be suppressed by some inhibitory mechanisms at mature green stage. The inhibition of succinate and malate oxidation by the addition of OAA was observed in mitochondria isolated from tomato fruit. The OAA content in tomato fruit was high at mature green stage and decreased during ripening of fruits. It seems that the oxidative activity of mitochondria in intact fruit may be controlled by the level of OAA.
    Glutamate-OAA transaminase (GOT) activity and the influence of thiamine pyrophosphate (TPP) on the oxidation of malate in mitochondria and citrate synthase activity were determined as the factors for the removal of OAA.
    OAA inhibition of succinate and malate oxidation in mitochondria isolated from tomatoes was relieved by the addition of glutamic acid throughout ripening period, and in this reaction aspartic acid was produced. It is assumed that a transamination reaction between glutamate and OAA gave rise to aspartate and α-ketoglutarate and removed the inhibitory effect of OAA. There would be a action of GOT in tomato mitochondria. TPP is an absolute requirement for the oxidative decarboxylation of pyruvate to acetyl-CoA. The addition of TPP to mitochondria in the presence of pyruvate resulted in a considerable acceleration of the rate of oxidation of malate. This result suggests that TPP may be the limiting factor for the oxidation of both malate and pyruvate. It was found that the effect of TPP in the presence of pyruvate on the oxidation of malate in tomato mitochondria was high at mature green stage and decreased during ripening. Citrate synthase was high at mature green stage and gradually decreased during ripening.
    It is possible to conclude from the results above that the low O2-uptake of tomato fruits at mature green stage may be due to OAA inhibition of mitochondria oxidation, and that the activity of GOT, the effect of TPP in the presence of pyruvate and citrate synthase serving to accelerate the removal of OAA would result in the decrease of OAA level in the whole fruits and the increase of O2-uptake of the whole fruits at the stage of mature green to breaker. The increased glutamate content in tomatoes during ripening may also play a role in the removal of OAA through GOT.
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