Journal of the Japanese Society for Horticultural Science
Online ISSN : 1880-358X
Print ISSN : 0013-7626
ISSN-L : 0013-7626
Volume 43 , Issue 3
Showing 1-14 articles out of 14 articles from the selected issue
  • Akira HINO, Shyoji AMANO, Yasunori SAWAMURA, Senji SASAKI, Tadayuki KU ...
    1974 Volume 43 Issue 3 Pages 209-214
    Published: 1974
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    1. Photosynthetic activity was compared among several kinds of fruit trees and grape vines in relation to the development of leaf tissues. Seasonal change of photosynthetic activity was also examined.
    2. The period from the sprouting to the commencement of apparent photosynthesis was shortest in peach and longest in satsuma mandarin trees. It was closely related to the rate of leaf tissue development. The developing rate of palisade and spongy parenchyma in the leaf tissue was earliest in the former and latest in the latter.
    3. In each deciduous fruit tree and grape vine, the photosythetic activity was markedly increased during the period from the sprouting to the maturing stage of leaves. After a slight decrease in photosynthetic activity occurred in mid summer, an increasing trend was observed subsequently. It continued from late summer to early autumn and then the activity declined abruptly.
    4. The photosynthetic activity of old satsuma leaves increased rapidly with rise in air temperature, and thus it became rather higher than that of spring cycle leaves. In July, however, there appeared a reverse trend of photosynthetic activity between current spring cycle and old leaves. Much the same situation as this continued until autumn.
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  • Ryuji NAITO, Kiyoshi MIURA, Kazuhiro MATSUDA
    1974 Volume 43 Issue 3 Pages 215-223
    Published: 1974
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Benzyladenine (BA) and urea, each alone or both, were applied as additives to the prebloom gibberellic acid (GA3) application to promote the set and growth of GA-induced seedless Delaware grapes.
    The addition of BA increased the set of seedless berries, and as the result increased the weight per cluster at maturity. The addition of urea was not so much effective as that of BA. Trough the addition of both BA and urea was as promotive as that of BA alone for berry set, the former distinctively increased the weight per berry as compared to the latter being almost ineffective. Any of these treatments did not affect seedlessness ratio which was higher than 98% in every experiment conducted in three years, and also did not affect berry qualities such as soluble solids and free acids in juice and skin color.
    Observations around blooming time indicated that these treatments, especially the addition of both BA and urea pronouncedly accelerated the growth of clusters and florets (berries), and that the increased berry growth was highly connected with the stimulated cell expansion of pericarp tissue. Further, from the quantitative changes of chlorophyll and protein-N in florets (berries) or clusters around blooming time, it is assumed that nitrogen metabolism in these tissues is enhanced by these treatments, particularly by the combined addition of the two compounds, and this may more or less relate to the increased set and growth of seedless berries. The possibility that urea may promote the absorption of GA and BA is also discussed.
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  • Yoshitsugu SOBAJIMA, Masashi ISHIDA, Akitsugu INABA, Hisao HORIGUCHI
    1974 Volume 43 Issue 3 Pages 224-228
    Published: 1974
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Cytokinin activity in Japanese persimmon fruits (cvs. Fuyu and Hiratanenashi) was studied with bioassay using tobacco callus (Nicotiana tabacum, cv. Wisconsin No. 38), and relationships between levels of endogenous cytokinins and fruit development were observed.
    Activity in Fuyu and Hiratanenashi persimmon gradually decreased prior to bloom. The activity in pollinated Fuyu fruit increased markedly until 30 days after flowering, whereas the activity in the non-pollinated fruit remained very low during the same period. All the non-pollinated fruit dropped toward the end of June. Actvity in both pollinated and non-pollinated Hiratanenashi fruits continued to decrease after flowering. Sixty days after flowering activity in both cultivars almost completely disappeared.
    Activity in the calyx of both cultivars was much lower than in the fruit and diminished quickly after flowering.
    Zeatin and other unknown substances were supposed to be responsible for the activity in the crude extract of Fuyu fruit.
    Levels of cytokinin compounds in persimmon fruits seem to be closely related to the growth at early stages, especially in pollinated Fuyu, but probably have no influence 60 days after flowering in both cultivars.
    The differences in cytokinin activity between Fuyu and Hiratanenashi at early stages of fruit development would be of interest for further study.
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  • Masao TOYAMA
    1974 Volume 43 Issue 3 Pages 229-236
    Published: 1974
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    To study the relationship between the growth of cucumber seedlings and the fraction systems of sand, the present experiments have been performed in a phytotron growth-room and in a plastic house from July through August in 1969. Results obtained in both phytotron and house were compared with each other.
    1. In the comparison between very coarse sand (2-1mm) and fine sand (0.2- 0.02mm) media, under the four different kinds of day-lengths, i. e., 8, 12, 16 and 24 hours, the largest difference in the fresh and dry weights of the tops and of the roots of cucumbers was found under the 16-hour day condition. The difference in the growth between the two different culture media became significant on the 8th day of experiment.
    2. Several growth characters, such as stem length, leaf area, top and root weights, were compared among the three different media, very coarse, coarse (1.0-0.5 mm) and medium (0.5-0.2mm), revealing that there prevails a similar tendency with each respective medium. Each growth character was compared by its growth index which was expressed as a percentage of the standard value realizing in fine medium. Thus the growth indices for medium became to range between 80-90%, for coarse 40-50%, and for very coarse 35-40%, as against 100% for fine medium.
    3. When very coarse sand medium was mixed with medium or with fine sands, being increased in quantity by weight ratio with an interval of 20%, the dry top weight of seedling showed a steady increase until the mixed proportion attained 40 % in the case of medium, and to 20% in the case of fine. Quite similar results were obtained in both in the phytotron growth-room and in the plastic house
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  • Bunjiro TAKAHASHI, Tuneo EGUCHI, Kazuo YONEDA
    1974 Volume 43 Issue 3 Pages 237-246
    Published: 1974
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Tomatoes
    1) Tomatoes, cv.‘Shin-Hogyoku No. 2’were grown under constant temperature regimes of 17, 15 and 13°C and at two levels of N, P and K in 1964 to study the interaction of those factors on the differentiation and subsequent development of flower buds.
    2) The plant growth both in bed soil at 2(NPK) (high level of fertilizer) and in volcanic loam at NPK (low level of fertilizer) was promoted at 17°C and restricted in the lower temperature ranges of 15 to 13°C. The seedlings in the 2(NPK) plot grown under the same temperature were larger than those in the NPK plot. The growth was found to be most remarkable at 17°C in the high level of fertilizer as in the previous report (7).
    3) The differentiation and its subsequent development of flower buds both in bed soil at 2(NPK) and in NPK plots were accelerated at 17°C and retarded in the lower temperature ranges of 15 to 13°C.
    4) The differentiation and its subsequent development of flower buds in bed soil at 2 (NPK) plot were earlier than those at NPK plot. The most favorable conditions for them were combination of temperature range of 17°C and high level fertilizer (bed soil at 2(NPK)).
    5) The number of flower buds per plant was increased at 17°C in high level of fertilizer (the bed soil at 2(NPK)) plot, and decreased at the lower temperature of 15 to 13°C. At the lower level of fertilizer (NPK) plot, it was fewer and there was no difference among the temperature ranges of 17, 15 and 13°C.
    6) From the results in 1963 and 1964 of tomatoes, it was found that effect of high level of fertilizer on the growth, the differentiation and development of flower buds were most marked at 17°C in the temperature ranges from 30 to 13°C (30, 24, 17, 15 and 13°C).
    Eggplants
    1) Eggplants, cv.‘Kisshin No. 2’were grown under constant temperature regimes of 30, 24, and 17°C and two levels of N, P and K in 1965 to study the interaction of those factors on flower bud differentiation and their subsequent development.
    2) The plant growth both in bed soil at 2(NPK) and in volcanic loam at NPK was promoted most remarkably at 30°C and restricted in the temperature ranges of 24 to 17°C. The seedlings in the 2(NPK) plot were larger than those in the NPK plot.
    3) The differentiation and its subsequent development of flower buds both in bed soil at 2(NPK) and NPK plot were promoted at 30°C and retarded in the temperature ranges of 24 to 17°C.
    4) The differentiation and its subsequent development of flower buds in the 2(N PK) plot were earlier than those in the NPK plot. The morphological differentiation of flower buds was not found at the temperature of 17°C in low level of fertilizer (NPK) in this experiment.
    5) The number of flower buds both in bed soil at 2(NPK) and in NPK was greatest at 30°C and fewer at 24 and 17°C. The 2(NPK) plot had much more flower buds than the NPK plot.
    6) In case of eggplants, the effect of high level of fertilizer on growth and the differentiation, development and number of flower buds was small under the low temperature of 17°C, but it was very great under the high temperature of 30°C.
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  • Ryozo SAKIYAMA, Glnzo ITO, Kinzo KAWATEI
    1974 Volume 43 Issue 3 Pages 247-254
    Published: 1974
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    In Japan transplanting machines are seldom used commercially yet, but have been tested on their usefulness for several crops at several experiment stations. In considering the transplanting work, however, attention has never been paid so much to the labor requirement of removing plants from the seedbed by hand as to the efficiency of the transplanting machine itself.
    This investigation was made to find some efficient operations for saving time in removing cabbage plants from the seedbed.
    Labor required for removing plants from the seedbed was nearly comparable to that for transplanting which was carried out with a one-row hand-fed machine operated by a gang of three. This indicates that time-saving operations are needed for removing plants as well as for transplanting in order to increase output of workers.
    Time study on removing plants from the seedbed showed that large saving of time was possible if plants could be lifted up without sorting out inadequate ones, which was indispensable for drilled plants. Pulling plants by holding the stem was also an efficient way compared with lifting out them by grasping the underground part. By the former way, however, the plants lost nearly all fine roots, so that it was feared that their survival rate might be low after setting out. To loose the soil between rows made the lifting operation somewhat easier.
    An operation of separating entangled plants as occurred on drilled plants, which had been hitherto considered unavoidable, was found omissible in view of maintaining the accuracy of planting at the standard speed of the transplanting machine. The elimination of this operation may contribute to some extent to overall saving of time.
    The drilled seedlings, transplanted into rectangular arrangement in the seedbed, grew into more uniform plants and could be lifted up from the seedbed with less time required, as compared with those being left untransplanted. This reduction of time was resulted from the easier operation to sort out unsuitable plants, as each plant grew uniformly and with reasonable spacing.
    Precision planting of seeds produced more uniform plants than the rectangular transplanting of drilled seedlings did, so it was also expected to reduce time for lifting up the plants and was regarded as being worthy of consideration.
    On planting seed precisely in the seedbed, density and distance of seeds were investigated in relation to the growth and uniformity of plants, with the distance between rows being fixed at 10cm in view of practical standpoint. To plant seeds at 40cm2 per seed was better than at 20 or 30cm2 per seed, and one or two seeds per hill better than three seeds per hill, in that plants grew more uniformly and a higher rate of suitable plants was obtained for mechanical transplanting.
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  • Tamio TATEBE
    1974 Volume 43 Issue 3 Pages 255-259
    Published: 1974
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    It was found that in Japanese radish some of compatible pollen grains on the stigma begin to germinate in 40 minutes after cross-pollination while many of them germinate in 50 to 60 minutes (at the temperature of 22°C, Table 1).
    The behavior of pollen germination and tube growth of Japanese radish is similar to that of Brassica (KROH, 1964) (Fig. 1-11).
    In 8 hours after cross-pollination a number of pollen tubes penetrate the style and the longest tubes reach the ovary.
    The embryosac of Japanese radish is of Polygonum-type, and antipodal cells degenerate within 8 hours after pollination (Fig. 12).
    It seems that fertilization is accomplished within 24 hours after cross-pollination (Fig. 13-17).
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  • Takaya OSAWA, Hideo IKEDA
    1974 Volume 43 Issue 3 Pages 260-266
    Published: 1974
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Fourteen species of vegetable crops were grown in solution culture in order to evaluate the relative tolerance of the vegetable crops to manganese. Hoagland′s No. 1 solution was used as the basic nutrient solution. Iron, in the form of Fe-EDTA, was supplied at the rate of 3ppm. Manganese was added at levels of 0.5 (control), 3, 10, 30, and 100ppm. The pH of the solution was adjusted to 6.0. The plants were grown under differential treatment for four weeks.
    1. The relative tolerance of the vegetable crops to manganese was evaluated in terms of the concentration of manganese in the nutrient solution which corresponded to a 50 per cent reduction in top dry weight. This point was not reached even at the highest manganese level, 100ppm, in radish, Welsh onion, pepper, and Japanese honewort (Cryptotaenia japonica HASSK.); it was reached between 30 and 100ppm in lettuce, spinach, carrot, eggplant, and cabbage, between 10 and 30ppm in celery and tomato, and between 3 and 10ppm in turnip, kidney bean, and cucumber.
    2. Symptoms of manganese toxicity in various species showed considerable variety. Brown necrotic spots and chlorosis were observed in many species; in general both of these symptoms were developed at lower manganese levels in less tolerant species than in more tolerant species. Brown necrotic spots occurred in the marginal area of older leaves or along the lower portion of stems. At least part of the chlorosis resembled iron deficiency symptom, but most chlorosis occurred as marginal chlorosis which was not identical with iron deficiency. Excess of manganese induced no serious abnormality in roots except a brownish discoloration in some species.
    3. In most crops the concentration of manganese in leaves was less than 200ppm on a dry weight basis in the control and markedly increased with the increase of manganese in the nutrient solution. The more the species was tolerant to manganese, the more the accumulation of the element in leaves corresponding to the 50 per cent yield reduction increased. The threshold value of manganese concentration in leaves associated with the occurrence of brown necrotic spots was generally lower in less tolerant species than in more tolerant species.
    4. The effect of excessive manganese on the iron concentration in leaves varied with the species. No clear relationship was found between the occurrence of chlorosis and the iron concentration in leaves.
    5. The concentration of copper, zinc, nitrogen, phosphorus, and potassium in leaves had no relationship to the manganese toxicity, while the concentration of calcium and magnesium in leaves in some species was considerably decreased by the excess of manganese.
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  • Takaya OSAWA, Hideo IKEDA
    1974 Volume 43 Issue 3 Pages 267-272
    Published: 1974
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Fourteen species of vegetable crops were grown in solution culture in order to evaluate the relative tolerance of the vegetable crops to copper. Hoagland's No. 1 solution was used as the basic nutrient solution. Iron, in the form of Fe-EDTA, was supplied at the rate of 3ppm. Copper was added at levels of 0.02 (control), 0.3, 1, 3, and 10ppm. The pH of the solution was adjusted to 6.0. The plants were grown under differential treatment for four weeks.
    1. The relative tolerance of the vegetable crops to copper was evaluated in terms of the concentration of copper in the nutrient solution which corresponded to a 50 per cent reduction in top dry weight. This point was reached between 3 and 10 ppm in Welsh onion, radish, pepper, eggplant, cucumber, tomato, carrot, kidney bean, and celery, and between 1 and 3ppm in spinach, lettuce, cabbage, turnip, and Japanese honewort (Cryptotaenia japonica HASSK.).
    2. Copper toxicity symptoms occurred much more seriously in roots than in tops. In the 3 and/or 10ppm treatments roots of most species showed brownish discoloration and inhibited growth. Serious root injury resulted in wilting of tops, dying off of older leaves, and subsequent death of plants in susceptible species. Excess of copper induced chlorosis resembled iron deficiency in the majority of species.
    3. In most crops the concentration of copper in leaves was less than 20ppm on a dry weight basis in the control and gradually increased with the increase of copper in the nutrient solution. There was no evident relationship between the copper accumulation in leaves corresponding to the 50 per cent yield reduction and the relative tolerance of vegetable species to copper. Copper accumulated at the higher rate in roots than in leaves with the increase of copper in the nutrient solution.
    4. The effect of excessive copper on the iron concentration in leaves varied with the species. No clear relationship was found between the occurrence of chlorosis and the total iron concentration in leaves.
    5. The concentration of manganese and zinc in leaves had no relationship to the copper toxicity. The concentration of nitrogen, phosphorus, potassium, calcium, and magnesium in leaves in many crops considerably decreased in the 10ppm treatment, where the roots were seriously injured.
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  • Takashi AOBA
    1974 Volume 43 Issue 3 Pages 273-280
    Published: 1974
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    A great number of informations on the periodicity of flowering in plants have been obtained in this half century. While few works have been done on the periodicity of bulb formation. In the previous paper, it was reported that there were two thermo-reactive processes-induction of physiological states for corm formation and development of corms as the thickening growth of stems-for corm formation of reesia.
    It has been known for bulbous iris that when store at 8° to 13°C of low temperature soon after digging, those do not sprout but consume their own food materials to form daughter bulbs within the mother bulbs. Hence the present study was designed to clarify the effect of temperature on both induction and process of bulb formation in bulbous iris, in using the bulbs of“Dominator”and“Wedgwood”iris.
    The results obtained were summarized as follows:
    1.When iris bulbs were stored under various constant temperatures, new daughter bulbs were formed by 5°, 10° and 15°C storages, respectively but were not formed under 0° and 20°C storage.
    2. After treated with various low temperature (0°, 5°, 10° and 15°C) for various days, the bulbs were stored under 17°C in the thermostat. The bulbs exposed to 5° and 10°C for 30 days formed a central bulb within the mother bulb and did not sprout, even if planted on November 6 in a wet sand bed. Bulb formation was delayed by 0° and 15°C of chilling and in this case, the longer the duration of chilling, the more bulb formation was accelerated.
    3. After the bulbs were exposed to 5° and 10°C of chillings for 45 and 60 days they were stored under 5° to 25°C. When the bulbs were stored at 15° to 20°C, bulb formation was accelerated and large bulbs were produced. Whereas, when the bulbs were stored under less than 10°C and more than 25°C, the bulb formation was delayed and a new bulb was scarcely formed in 5°C storage until December 16.
    4. When the bulbs were exposed to 30° to 35°C for 10 to 30 days after the chilling treatment, the development of new daughter bulbs suppressed as the duration of high temperature lengthened.
    5. When the bulbs of various sizes were stored at 17°C after the chilling treatment, the daughter bulb was formed within the mother bulb even in 2.5g of small bulbs, regardless of bulb size.
    6. From the results obtained in this experiment, it seems that in order to form new bulb, bulbous iris must pass through the same two thermo-reactive processes as freesia does. It is evident that such a low temperature storage as 5° to 10°C is apparently effective for the induction of physiological states for bulb formation and somewhat high temperature, 15° to 20°C promoted the development of a new bulb. Further, the chilling effect on induction of bulb formation increased with lengthening of chilling duration up to a certain limit. Exposure to high temperature, 30° to 35°C followed chilling destroyed the physiological states for bulb formation.
    7. Based on the previous results on garlic, freesia and oxalis and on the results mentioned above on bulbous iris, it seems that the acquisition or acceleration of the bulb-and tuber-formation ability by a low temperature treatment is the general characteristic in the bulbous and tuberous crops which produce the bulbs or tubers in early summer, and this phenomenon resembles to vernalization for flower formation.
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  • Hiroshi UEDA, Hirotaka TORIKATA
    1974 Volume 43 Issue 3 Pages 281-285
    Published: 1974
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    1. In order to obtain a further evidence for decomposition of protein and RNA of mycorrhizal fungi in the course of digestion, a paperchromatographic study was carried out with the extracts of symbiotic (wild) and asymbiotic (aseptic) rhizomes by Cymbydium goeringii REICHB. f. (C. virescsns LINDL.). The results suggest that the symbiotic rhizomes contain many kinds of free amino acids and purine-pyrimidine compounds which appear to be supplied by digestion of fungal matter.
    2. The extracts of asymbiotic/symbiotic rhizomes and of isolated mycorrhizal fungi were bioassayed for cytokinin activity by tobacco callus method. The extract of symbiotic rhizomes exhibited a considerable activity whereas that of asymbiotic rhizomes did little activity. As for mycorrhizal fungi, neither the extract of fungi nor that of the culture medium in which the fungi were cultured showed activity.
    3. The results of the present and previous experiments in this investigation series (3, 4, 5, 6, 7, 8, 9) suggest a possible mechanism of organ differentiation of the wild development of terrestrial cymbidiums such as Cymbidium goeringii. In these species, the stage becoming autotrophic is later than in epiphytic or semiepiphytic cymbidiums. Mycotrophy appears to play a essential role in the shoot and root formation. Shoot formation would be induced by cytokinins supplied from the mycorrhizome. Starch grains derived from mycorrhizal fungi are utilized as the main energy source. Amino acids and RNA-decomposites, supplied through digestion of fungal matter, are transported to the apical region of the rhizome and promote shoot and root formation.
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  • Akira SUGIYAMA, Taikichi TAKANO
    1974 Volume 43 Issue 3 Pages 286-294
    Published: 1974
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    The result of present investigation is in accordance with earlier studies which showed that corollas of chrysanthemum contain cyanidin 3-glucoside as the main anthocyanin. In addition to this pigment, a few anthocyanins have been isolated from many cultivars by the authors.
    To characterize these unknown anthocyanins, an attempt has been made in which the properties of partial hydrolysate and of oxidation products of each anthocyanin in dark red corollas of Chrysanthemum morifolium RAMAT., cultivar“Aka-chu-san” were examined.
    Four anthocyanins (A1, A2, A3, and A4) were chromatographically separated and isolated from the pigment solution of chrysanthemum corollas.
    Only cyanidin was found as the aglycone of their anthocyanins. Two kinds of cyanidin glycosides were obtained by deacylation of four anthocyanins in an alkaline solution. One was cyanidin 3-glucoside (chrysanthemin) from A1 and A2 and the other cyanidin 3-diglucoside from A3 and A4. Their sugars liberated from deacylated anthocyanins were also examined by a method of oxidation with hydrogen peroxide, showing glucose and diglucose respectively.
    The sugars in the glucoside form were found in 3-position of cyanidinskelton by the behavior of partial hydrolysates on chromatogram and by the ratio of E440/Emax of anthocyanin solution using spectrophotometer.
    After alkaline hydrolysis, caffeic acid having the absorption maximum (λ=337nm), was identified in the hydrolysate of A2, A3 and A4.
    This may be the new finding on chrysanthemum anthocyanins.
    In conclusion, A1 is cyanidin 3-glucoside (chrysanthemin), A2 cyanidin 3-caffeoylglucoside, A4 cyanidin 3-caffeoyldiglucoside and A3 cyanidin 3-diglucoside having probably two molecules of caffeic acid. Of these, chrysanthemum and cyanidin 3-caffeoyl glucoside are the main anthocyanins in corollas of chrysanthemum.
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  • Yoshishige TACHIBANA
    1974 Volume 43 Issue 3 Pages 295-307
    Published: 1974
    Released: July 05, 2007
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    1. F1 seeds and plants were obtained by interspecific crosses between three East-Asian species of Hibiscus, paramutabilis×syriacus, syriacus×paramutabilis and syriacus×sinosyriacus.
    2. Different strains of syriacus resulted in different vigor of the F1 plants in all of the three crosses. Only one out of the six strains used for cross pollination produced healthy hybrid plants which successfully reached maturity (Table 1).
    3. The color, form, size and number of flowers varied considerably even among the hybrid plants originating from the same combination of parents. Some of the hybrids seemed promising for ornamental purpose in that they had larger size and number of flowers than their parents (Table 2, Fig. I).
    4. The seasonal trends of flowering in F1 plants, of which mother plants were syriacus, showed a pattern more or less similar to that of syriacus or intermediate between those of the parents, while the hybrids originating from paramutabilis mothers produced the largest number of flower in August, when the parent species produced the least number (Fig. 2).
    5. The hybrid trees were largely similar to syriacus in their habit. The total number of flowers produced in a season tended to be greater in trees with bigger crown, but was little influenced by the number of current-year branches (Fig. 3).
    6. Hybrid plants were generally intermediate between the parents with respect to such morphological characters as the shape and size of leaf, flower stalk, peduncle and bractlet, the density of hairs on hairs on leaf surface, etc., though there were some exceptions (Table 3 and 5, Fig. 4 and 5).
    7. As compared with that of parents, the pollen of the hybrids was somewhat smaller in mean grain size, greater in size variation and lower in fertility (Table 6, Fig. 6).
    8. The meiosis was fairly normal in pollen mother cells of the three parent species, each having 40 bivalent chromosomes. In F1 cells, the sinapsis and tetrad-formation were also normal without any multipolarity and other serious abnormalities, though a few delayed univalents appeared in some cells (Fig. 7).
    9. Back-crosses with the parents were proved to be fertile. Viable F2 seeds were also obtained by reciprocal crosses between the F1 hybrids (Table 7, 8).
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  • Hirofumi TERAI, Hiroto YOSHIOKA, Kuniyasu OGATA
    1974 Volume 43 Issue 3 Pages 308-313
    Published: 1974
    Released: July 05, 2007
    JOURNALS FREE ACCESS
    Respiration response of peels and pulps of banana fruits to ethylene was investigated.
    Effect of cutting of peels and pulps on respiration was observed with three sizes of slices (4×4cm, 2×2cm, 1×1cm). Green banana peel sections of all sizes showed an initial burst of respiration immediately after cutting and minimized within 8 hours. But pulp sections did not show such burst of respiration after cutting. Both peel and pulp sections exhibited broad peak of respiration 13 and 20 hours after cutting. Respiration rates of smaller size sections were higher than those of larger size sections.
    Peel and pulp sections were treated with 0.1, 1, 10, 100, and 1000ppm of ethylene. Low concentration of ethylene (0.1ppm) hardly stimulated respiration and 1ppm of the gas stimulated it. Saturated concentration of ethylene for stimulative effect of respiration was more than 10ppm on both sections of banana fruits.
    Peels and pulps were treated with 100ppm of ethylene for different periods. When ethylene was applied, respiration of the peels was stimulated, and it was decreased rapidly when ethylene was removed. Respiration of pulps was decreased after treatment for 6 hours, but it increased constantly after treatment for more than 12 hours.
    Changes of respiration rate of peel and pulp sections at each stage of ripening of banana fruits stimulated previously with 100ppm of ethylene were observed. Pulps showed a climacteric pattern of respiration and produced ethylene as a ripening hormone. On the other hand, peels did not show climacteric rise and ethylene production of peels was not observed except senescent stage.
    Respiratory quotient was measured during ripening. Little or no change of RQ occurred in peels and its value remained approximately 1, but RQ of pulps increased 0.7 to 1.5 gradually as ripening progressed.
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