The activity of fractionated gibberellin (GA)-like substances extracted from the seed, pericarp and calyx tissues of Kaki‘Fuyu’(Japanese persimmon) collected 20 days after full bloom was determined, and the main active component in calyx tissue was characterized by means of selected bioassays and thin-layer chromatography. The highest activity was detected in the acidic ethyl acetate fraction of seed, whereas the lower was found in almost equal amounts in the same fractions of pericarp and calyx. In each fraction, the activity occurred at the Rf zones of GA1 and/or GA3 on paper chromatograms. The purified active component(s) of calyx exhibited biological responses similar to GA1 and/or GA3 in dwarf pea and cucumber assays. However, the component(s) re-purified by a partition column technique corresponded closely in Rf with GA3 rather than GA1 on thin-layer chromatograms. The main active component in calyx therefore seems to be identical with GA3.
1. To observe the effects of spring leaves (spring cycle leaves of the current year) or old leaves on flowering and fruit set, experiments were conducted with secondary scaffold branches of Satsuma mandarin (Citrus unshiu MARC.) trees grown under field conditions. Treatments were as follows; (1) all spring and old leaves were removed from the shoot (no-leaf plot); (2) all old leaves were removed and enlarging spring leaves were retained (new-leaf plot); (3) developing spring leaves were removed and old leaves were retained (old-leaf plot); (4) both spring and old leaves were kept intact (control plot). When the above treatments were applied from early spring to the end of July, old-leaf plot gave the best development of floral organs at full bloom. These development of floral parts was reduced in the following order, no-leaf, control and new-leaf plot. Fruit set and fruit growth for the first month after blooming were also greatest in old-leaf plot. The ranking for these criteria was: control>no-leaf> new-leaf plots. Not only was the development of floral organs in new-leaf plot the poorest among the four plots, most of the fruits abscised in this plot immediately after bloom. In the remaining three treatments marked fruit drop was observed in early July, particularly, in old-leaf plot. This observation suggests that old leaves play an important role for fruit set and growth during the first month after blooming, but that new leaves are required for sustained fruit growth. When treatments were started two weeks after bloom, fruit set was best in control plot followed in order by new-leaf and old-leaf plots; almost all fruits were shed in the no-leaf plot. Fruit growth in control and new-leaf plots was superior than that in old-leaf and no-leaf plots. When treatments were made in August, fruits remaining on the trees in no-leaf and old-leaf plots decreased to 48.9% and 63.6%, respectively, but fruit sets in both new-leaf and control plots remained unchanged (100%). Treatments initiated during September resulted in no fruit abscission in any plots. 2. With 3-year-old Satsuma mandarin trees grown in the pots, the effects of leaf age, temperature and light intensity on the development of floral organs were investigated. Leaf removal was done as described in the above experiments, while the temperature was kept at 23°C and 30°C in the conditioned growth chamber and the light intensity was varied from 10 to 100% of full sunlight. Flowering was accelerated at 30°C, but floral organs developed better at 23°C. At both temperatures, fresh weight of floral organs in the first inflorescence was smallest in new-leaf plot compared to the other treatments. Light intensity was no significant effect on the development of floral organs. At three light intensities, fresh weight of floral organs was smallest in new-leaf plot compared to the other treatments. Tree growth was suppressed proportionately with decreasing light intensity in all treatments. As the light intensities decreased from 100% to 10%, the percentage of old leaves abscised increased; that of the control plot being greater than in the old-leaf plot.
The experiment was conducted with young trees of Satsuma Orange (Citrus unshiu MARC.) under artificially controlled climates (Phytotron). Though the average day temperature common to all 3 treatments was 18°C, the amplitudes of diurnal fluctuations in temperature were 0°C (daytime 18°C-nighttime 18°C), 10°C (23-13) and 20°C (28-8) respectively (Table 1). 1. The difference of the fruit enlargement between 0°C (18-18) and 10°C (23-13) treatments was not recognized. On the contrary, under 20°C (28-8) the depression in fruit enlargement was found significantly in the former half of Stage 3 of fruit growth, but in the latter half of Stage 3 the fruit continued to grow without color development and developed the greatest fruit diameter at the end of the experiment. Greater amplitudes of diurnal fluctuation in temperature did not accelerate the fruit growth rate at all time of Stage 3 (Fig. 1, Table 2). 2. Color development in the fruit rind was influenced by diurnal fluctuation in temperature. The earliest and brightest color development was observed under 0°C (18-18) and then 10°C (23-13). The palest color was found under 20°C (28-8) Color development in the fruit rind was affected not only by low night temperature, but also by high daytime temperature (Fig. 2, Tables 3, 4). The temperature 18°C at the daytime and at night seemed to be favorable for the decomposition of chlorophylls and production of carotenoids. Greater diurnal fluctuation in temperature was not necessary for the promotion of rind color development. 3. Free acid concentration in the juice was influenced by diurnal fluctuation in temperature. Less diurnal fluctuation tended to produced lower acid fruit. However, acid concentration was influenced strongly by the night temperature rather than by diurnal fluctuation, that is, higher night temperature produced lower acid fruit (Fig. 4). High sugar concentration in the juice resulted from 0°C (18-18) and 10°C (23-13) treatments, but under 20°C (28-8) it was very low. Greater diurnal fluctuation in temperature did not promote the accumulation of sugar in the fruit (Fig. 4). The total soluble solids-acid ratio was the highest under 0°C (18-18). Less diurnal fluctuation in temperature produced earlier and better marketing quality (Fig. 5). Diurnal fluctuation in air temperature was not necessary for the production of better quality fruit of Satsuma orange.
Muskmelon plants were grown in sand culture and fertilized with a complete nutrient solution containing 1, 10, 20 and 30ppm Mn at pH 4.0 or 6.0. Top growth, fruit weight, and soluble solids at 30ppm Mn were inferior to those below 20ppm Mn regardless of pH levels. External appearance of the fruit became poorer as Mn concentrations were raised from 10 to 30ppm. As Mn concentrations were raised from 1 to 30ppm, Mn toxicity symptoms were intensified, and Mn contents in the plant parts increased, while ratios of Fe: Mn in the leaves decreased. Critical Mn in the leaves for appearance of toxicity symptoms was nearly 2000ppm. Mean Mn content in the leaves and stems at pH 4 was higher than those at pH 6, while Mn content in the roots at pH 6 was much higher than those at pH 4.
The purpose of the present study was to know diurnal changes of air temperature favourable for the raising of cucumber seedlings. Activities of assimilation and distribution of photosynthates in plant parts were measured by a G.M. counter using tracer techniques. Seeds of cucumber, variety “Natsu-Sairaku No.3” were sown on Jan. 16, 1971, and transplanted into plastic pots, 12cm in diameter, on Jan. 28 at the stage of cotyledon expansion. Then the pots were placed in the phytotron which day and night temperatures were programmed with consideration of the diurnal change of natural temperature. The day temperature was set from 10:00AM to 2:00PM and the night one from 2:00AM to 6:00AM. The shift between day and night temperatures were made as moderate as possible. This temperature regulating system was called “the gradient temperature control system”. To clarify the effect of day or night temperature, temperatures were maintained at 28°C for the day temperature and 14°C for the night temperature (abbr. 28°-14°), 25°-14°, 20°-14°, 15°-14°, and 25°-18°, 25°-14°, 25°-10° (Fig.1). Seedlings raised under the condition of 25°-14° were taken as control. On Feb. 25, whole plants were exposed to 14CO2 for 60 minutes in the artificial light, 18, 000lux at the plant level, and the distribution of 14C-radioactivities in the plant is determined immediately after 14CO2 feeding (Exp. A) or after being kept for one night at the corresponding night temperature (Exp. B). The experiments of A and B were done separately. When the plants were raised at 14°C for the night temperature, the effect of day temperature on growth was as follows; the growth shown in dry weight at 28°-14° was almost the same as that of control (25°-14°), but at 20°-14° and 15°-14°, those were 80 and 70% of control, respectively (Table 2). Senescence of lower leaves of plants grown at 28°C during the day and 14°C at night was accelerated in comparison with control (Fig. 2). When the plants were raised at 25°C for the day temperature, the effect of night temperature was as follows; at 25°-18°, plants grew heavier and broader in the leaf area (Table 2), and higher (Table 1) than control (25°-14°), and senescence of lower leaves was accelerated (Fig.2). Their photosynthetic activity (14C-radioactivity per dry weight) was lower than control, and dry weight per unit leaf area (cm2) was the lowest (Fig.3). The translocation of photosynthates in the plants grown at 28°-14°, 25°-14°, and 20°-14° was greater than in those grown at 15°-14°. The translocation of photosynthates in the plants grown at 25°-18°, 25°-14° was greater than in those grown at 25°-10°. However, the acceleration of respiration rates in plants grown at 25°-18° resulted in a release of CO2 from 14C-photosynthates outside of the plant. In so far as seedlings were raisen under the gradient temperature control system, the best possible growth of seedlings from the view point of 14CO2-assimilation and translocation of photosynthates was given when they were grown at 20°-28°C for day- and 14°C for night-temperature. Among them, when seedlings raised at 28°C day temperature, the senescence of lower leaves was promoted and at 20°C day temperature, the production of dry matter was lower than at 25°C or 28°C day temperature. Therefore, the alternation of temperature at 25°C for the day temperature and 14°C for the night temperature was most suitable for the healthful growth of seedlings.
1) The methanol extract of gladioli corms was purified with ethyl acetate and sodium bicarbonate. The final acidic fraction was paper and column chromatographed, then three crude inhibitors were separated. 2) Inhibiting activities of inhibitors I and III were examined by the dripping of the solution on corms and by soaking cormlets in it. The inhibiting activity of inhibitor III was slightly higher than that of inhibitor I. 3) Inhibitor II was identified as abscisic acid based on its UV absorption on the paper chromatogram, the Avena coleoptile assay and its O.R.D, measurements. Abscisic acid inhibited sprouting of the bud in gladiolus cormlets at a dosage of 10-4 M. 4) Purification and identification of inhibitors I and III are being carried out. Synergistic action of inhibitors with abscisic acid is also discussed.
An investigation was made to determine the effects of steam sterilization and pH in soil having a high level of Mn, on the growth and flowering of carnation cvs. ‘Coral’ and ‘Yosooi’. Chemical composition of plant parts and chemical properties of the soil were examined. Treatments were arranged factorially, involving 4 pH levels in the soil (high, medium, low and very low) with sterilized and unsterilized soil. 1. In sterilized soil, the number of cut flowers and top fresh weight of both ‘Coral’ and ‘Yosooi’ were decreased at very low pH. In unsterilized soil, those of ‘Yosooi’ were decreased at low and very low pH, and no flowering plants in ‘Coral’ were obtained at low and very low pH. The time of flowering in ‘Yosooi’ was slightly earlier in sterilized soil than that in unsterilized soil. In ‘Coral’, it was markedly retarded in sterilized soil as soil pH was lowered from medium to very low. 2. Mn in the various parts of flowering and non-flowering plants of ‘Yosooi’ was significantly increased as soil pH was gradually lowered whether the soil was sterilized or not. Mn in ‘Coral’ showed the same tendency as ‘Yosooi’. Mn content in the leaves of flowering plants of ‘Coral’ was much higher than that of ‘Yosooi’ except those with high pH. The content of N and K, and the ratio of Fe: Mn in the leaves of non-flowering plants of both ‘Coral’ and ‘Yosooi’ were decreased as soil pH was lowered regardless of whether or not the soil was sterilized except for the K content at very low pH. The flowering plants of both ‘Coral’ and ‘Yosooi’ showed the same tendency as the non-flowering plants. 3. The intensity of tip burn symptom in the leaves of both ‘Coral’ and ‘Yosooi’ was intensified as soil pH was lowered regardless of whether or not the soil was sterilized. Chlorosis appeared in the young leaves and stems of both ‘Coral’ and ‘Yosooi’ at low and very low pH, and the intensity of chiorosis in ‘Coral’ was much more severe than that in ‘Yosooi’. Mn contents in the leaves and stems of chlorotic plants were much higher than those of normal plants, while N, K, Ca and Fe contents in the leaves of chlorotic plants were much lower than those of normal plants. 4. As soil pH was lowered from high to very low, water soluble Mn, NH4-N and Al contents, and E.C. values were increased at the conclusion of the experiment, while easily reducible Mn was decreased. When the soil was sterilized, exchangeable Mn was slightly high, while NH4-N and E.C. values were slightly low. The results of this study suggest that the growth suppression, tip burn symptom in the leaves, and chlorosis in the young leaves and stems of carnation grown in soil having a high level of Mn are highly associated with the excess Mn absorbed by the plant.
To compare the effects of CO2 concentrations at two humidity levels (98-100% RH, and 85-95% RH), fruits were stored in the air mixed with 0, 5, 10 and 20% CO2 at 4°C for 50 days. At the higher CO2 levels, button browning was equally retarded at both humidity levels, and development of granulation and decrease of acidity were retarded markedly at low humidity. Acidity decreased considerably at 20% CO2. Under high humidity conditions, water content in the peel and ethanol content in the juice increased, and abnormal flavor developed at the higher CO2 levels. At 10% and 20% CO2, internal O2 levels decreased extremely in fruits with watery breakdown. At low humidity, no injuries were found, and the optimum CO2 level in CA storage seemed to be higher and more storage merits of CO2 were obtained than at high humidity. To compare the effects of low O2 levels with and without 5% CO2, fruits were stored in the mixed gases (0% CO2+5% O2, 5% CO2+7% O2). Without CO2, no distinct effects of low O2 were found in button browning and acidity. Granulation was retarded, and abnormal flavor and ethanol accumulation were found at low O2 levels. Combined with 5% CO2, low O2 levels retarded decrease of acidity markedly, and accelerated development of abnormal flavor at high humidity. At 5% CO2+7% O2 under low humidity conditions, no abnormal flavor developed and acidity did notdecrease, and the best storage quality was obtained. In citrus CA storage, there seemed to be three peculiarities (1, susceptibility to low O2 storage, 2. gas diffusion resistance of the peel, as important factor for storage, 3. unfavorable under high humidity conditions). Disccusions were made about the abnormal flavor in relation to high water content in the peel, high gas diffusion resistance of the peel, low internal O2 level, anaerobic respiration and ethanol accumulation in the juice.
To clarify the effects of CO2 levels during storage and residual effects of CO2 during ripening after removal from storage, fruits were stored at 4°C and 20°C in the air mixed with 0, 2, 5, 10, 20 and 50% CO2, for 15 and 9 days, respectively. To compare the effects of 3% O2 with and without 5% CO2, and to study the effects of delayed storage under CA conditions, some of the fruits were stored immediately at 1°C for 20 days, and another were ripened for 3 days in air at 20°C before storage. After removal from storage, fruits were ripened in air at 20°C and the residual effects of mixed gases were examined. 1. At 20°C, ripening was retarded by CO2 treatments, but mealiness, abnormal flavor, flesh browning and peel browning developed at the higher CO2 levels. At 4°C, only the yellowing of the ground color was retarded at the levels above 5% CO2, and abnormal flavor developed at 20 and 50% CO2. 2. The longer fruits were stored, the faster fruits ripened after storage. At the higher CO2 levels, however, the more suppressive effects on ripening were found, and peeling injury was reduced, on the other hand, flesh browning developed. 3. In delayed storage, mealiness and peeling injury were reduced, but fruits ripened quickly and the residual effects of CO2 was unclear. More abnormal flavor and flesh browning by CO2 were found than in the immediate storage. 4. Without CO2, no marked differences were found between fruits in air and in 3% O2. Combined with 5% CO2, 3% O2 markedly retarded the ripening after 20 days at 1°C, and reduced peeling iniury, but promoted the incidence of abnormal flavor and flesh browning. 5. Disccusions were made about relations among storage temperatures, fruit maturities and gas conditions in CA storage of white peaches.
1. The chlorophyll in the rind was unaffected during the treatment of sealing with ethylene for 15 hrs. However, after exposing the fruit to air the chlorophyll content decreased rapidly for 3-4 days. 2. The greener the fruit treated with ethylene the greater the decrease in chlorophyll. This phenomenon was observed in comparing immature fruits with mature fruits and greener parts with less greener parts on the rind of the same fruit. 3. The ethylene treatment did not effect the carotenoid content of the rind. 4. The ethylene treatment affected equally the degreening of the fruit of early maturing and late maturing cultivars. However, coloring was more marked in late maturing cultivars due to the presence of a greater amount of carotenoids in the rind. 5. It is not necessary to treat the fruit with ethylene when harvested. There was no difference in coloring whether treated at harvest or 5 days after harvest. 6. When the chlorophyll did not disappear completely after treating with ethylene, retreating with ethylene was effective.
The present investigation has been carried out to clarify the relationship between the NADP (Nicotinamide Adenine Dinucleotide phosphate) level or the concentration of high energy phosphates and the ripening of tomato fruits. 1) When tomato fruits ripened under usual conditions (without being packaged air-tightly), the NADP level of fruits rose with the lapse of time, reached the highest on the stage of ripeness score 3, and thereafter began to lower. This tendency is similar to that of climacteric rise of respiration of fruits. 2) When the respiration and maturation of fruits were controlled by being packaged with a polyethylene bag, the NADP level was kept nearly constant or rather slightly lowered during the after-ripening. 3) As the results of separative determination of each part of fruits, the NADP level in the jellied pip was found to be higher than that in the flesh part. From the above fact it was deduced that the jellied pip has the more active metabolic rate in which NADP or NADPH are concerned than the flesh part dose, and the metabolic activity of the jellied pip has rather a great influence on the after-ripening of tomato fruits. 4) The sum of high energy phosphates increased with the ripening of fruits, reached the maximum, and thereafter decreased. The period when the maximum was reached was later than that of climacteric rise of respiration. The content of ADP in the jellied pip increased with the after-ripening of fruits after harvest. This result obtained concerning ADP seems to support the proposal in which mechanism of climacteric rise of respiration of tomato fruits was explained based on the change of the content of ADP. 5) On the other hand, when fruits were packaged with a polyethylene bag, not only total amount of high energy phosphates but also concentration of ADP was controlled and kept lower than those of non-packaged fruits. Previous paper reported that restrained color development in packaged fruits would be caused by the impediment in condensation of IPP after phosphatization of MVA. This deduction has been supported by the present results obtained from the determination of concentration of ATP and ADP in both packaged and non-packaged fruits.
While ethylene effect on fruit ripening has received much attention, the mechanism of the effect is not yet clear. As a research of the series of the study concerning the mechanism of ethylene effect, this paper reports the problem of ethylene movement in a banana fruit which was treated at a part of the fruit. The concentration of ethylene applied was 80-100ppm throughout the experiment. When mature-green bananas were treated partly at the central part of peel surface with ethylene, the ripening of the fruit began from the treated part and developed gradually toward untreated part, showing the degreening of peel color and the increase of sugar content in pulp. Mature-green bananas treated at the apical side of fruits evolved a considerable amount of ethylene from the untreated stem side within 3 hours after initiation of ethylene application. Then, carbon dioxide evolution from the parts of both sides began increase between 8-14 hours after treatment. Thus, it seems that the movement of ethylene gas or of its effect in a fruit is considerably rapid. When banana fruits were girdled at the center of fruits and treated with ethylene at one side, ethylene evolution from the untreated other side was markedly less than that of ungirdled fruits, indicating that peel would play an important role in movement of ethylene gas or of its effect in fruit. Treatment on whole fruits with ethylene for 24 hours stimulated fruit _??_ipening obviously, but the treatment for 2 and 6 hours did not show any effect.
In this experiment three factors were regarded concerning the storage stability of freeze-dried carrots, diapose of blanching, addition of L-Ascorbic acid and treated in different temperature. At first the action of blanching shown decreasing 6% of Lycopene during 10 days storage. By the addition of L-Ascorbic acid, the antioxidation power succeeded up to 100 days but after 150-300 days storage restraining power could not continued and some blowning color appeared. If L-Ascorbic acid were added, some anti-oxidation effects could be seen for 30-60 days but not after these days. Moreover increasing moisture contents would be greatly accelerated these reaction. On the other hand, 5% of L-Ascorbic acid were added after blanching it was effected very favourably. Lycopene content decreased only 15-16% during 300 days storage even any discoloration appeared. This condition may be maintained by addition of more higher amount of L-Ascorbic acid. By decreases of lycopene content down to 45-50% some discoloration and special unagreeable odor would be detected.