In the previous reports, it is shown that the pinching of the main stem of the cucumber plant induces the transformation of the primordia of the staminate nodes into the bisexual or the pistillate flower and further into the vine, in case the normal laterals are trimmed off. It is showh also that the application of the synthetic growth substances induces the sex reversion in cucumber and the possible cause of the sex expression may be attributed to the auxin level in the plant. In the present report, the pinched stem tip is treated with the lanolin paste of α-naphthaleneace-tic acid and 2, 3, 5-triiodobenzoic acid for the eva-luation of the auxin action to influence the sex reversion of the primordia of remaining staminate flower nodes. The effect of pinching upon the lateral buds is generally explained to be due to the elimination of the auxin production and trans-location from the apical bud. In case of the plant, treated with α-naphthalene-acetic acid, no sign of the transformation of the staminate nodes is found as in the case of the nonpinched plant in which the apical bud continues to supply auxin to the lateral buds, inhibiting their capacity to develop. In the case of the 2, 3, 5-triiodobenzoic acid treat-ed plant, the transformation of the upper staminate nodes being restricted, the lower staminate nodes show sign of the influence of the pinching effect. It may be explained that the anti-auxin action of 2, 3, 5-triiodobenzoic acid, cancelling the effect of pinching to draw out the capacity of the upper staminate nodes dominating to development, enables the lower nodes to response to the pinching effect. The transformation of the primordia of the sta-minate nodes, as a response to the pinching effect of the main stem, reflect in its turn the auxin relationship occurring in the remaining stem. It may be reasonably concluded that the sex expression of the cucumber plant is possibly attri-butable to auxin relationship of the respective nodes.
This paper deals with the results of studies on the flowering and fruiting in peas. 11 varieties -were used and they were sown twice, i.e., on Nov. 29th. (1952) and March 10th. (1953). (1) Early varieties tend to flower and to finish flowering earlier than late ones. There are varie-tal differences in the number of flowers per plant. Total number of flowers depends upon the tall-ness (pole or dwarf), the number of 2-flowered inflorescences, branching habit and so on. (2) The number of pods per plant varies with varieties. Among the pods, some parthenocarpic ones are found and they generally seem to develop from flowers which open later in the flowering period. (3) In the plot sown on Nov. 29th., flowers set well during the early and middle periods of flowering season, but in the end period set percentage is very low. But in the plot sown on March 10th, there is no such clear tendencies. (4) The order of flowering among the nodes which bear flowers is the same as that of the de-velopment of flower buds. Most pods distribute at the rather lower nodes of main stem and com-paratively vigorous branches. (5) The number of 2-flowered inflorescences per plant is considerably larger in some varieties than in some other varieties. The distal flowers of the most 2-flowered inflorescences open on the next day of the anthesis of the proximal ones. (6) In 2-podded cluster, the proximal pod is longer and contains more seeds than the distal pod. But because there is little difference in the number of ovules per pod between the proximal and distal pod, the fertility of the ovules in the proximal pod is higher than that of the distal one.
The root of the Japanese radish is much lar-ger than that of the radish. Consequently the root development requires a much longer period than that of the radish. The growth period is usually about 100 days in autumn. The present paper deals with the change of root-shape during development. Results obtained permit us to make a following conclusion: In early stage there is practically no difference in root-shape between round- and long-shaped varieties. The root may undergo sudden growth in thickness from 41 to 55 days after sowing, and forms almost proper shape, although its size is yet small. The typical root-shape and size are gradually formed with further development.
The effect of MH on the respiration of onion bulbs and potato tubers was studied at the end of 5months after harvest. The leaves of onion (Yellow Danvers Flat) were sprayed with 0.25% solu-tion of MH 2 weeks before the harvest, and the potato plants (Irish Cobbler) were similary treated with 0. 1, 0.2, 0.3 and 0.5% solution of MH 3weeks before the harvest. The experimental results are summarized as follows. 1. The onion bulbs; (a) The decrease in oxygen uptake in the disk part (bottom part)of the treated bulb was observed in comparision with the control, while the _??_ifference in leaf part (scaly leaf) was not signi-_??_cant in this respect. The same tendency was also _??_bserved in the experiment in vitro. (b) Respiratory quotient (R. Q.) in the disk _??_art of treated onions was less than the control, _??_ut in the leaf part the value was larger than he control. (c) The activity of dehydrogenase and catalase in the onion disk part treated with MH was less than the untreated onion. 2. The potato tubers; (a) The respiration of potato tubers was stimulated at all degrees of the concentration of MH throughout the experiment, especially it was remarkable by the application of 0.5%MH. (b) R. Q. value in the treated tubers was always less than the untreated one as it was found in the disk part of onion. (c) Dehydrogenase and catalase activities increased with treatment, not alike in the case of the onion bulb. 3. It seems appropriate to conclude that the growth inhibition and the physiological disorder of onion bulbs and potato tubers received MH treatment must have been induced by the disturbance of the respiratory mechanism and/or the alteration of metabolic pathway.
1. In this study, the authors observed the phy-siological changes in onion bulbs when stored under different gaseous conditions and different humidities for 4 months after the sprouting period. The experiments were carried on from 1952 to 19 54 at room temperature in the laboratory of the University of Osaka Pref. 2. The storage conditions were as follows; (a) Onion bulbs were enclosed simply in desiccators: In this case, both percentage of CO2 and humidity in the vessel were rapidly increased, a rapid decrease of O2 concentration also being found at the same time. (b) Enclosed with CaCl2 in desiccators: CO2 accumulation in the vessel was somewhat less than (a) and the relative humidity was measured as low as 40_??_50%. (c) Enclosed with soda-lime in desiccators: CO2 given off by respiration was completely absorbed in soda-lime, the relative humidity being as low as (b) and O2 concentration finally decreased to 0.9% after the storage for 4 months. 3. It was found that onions stored under the, condition (a) brought about the functional disorder, a half of samples showing internal break down at 50 days after they were enclosed, and all bulbs disintegrated after 4 months. Under the condition (b), the percentage of disintegrated bulb was less than (a). It seems that the dry condition caused the inhibition of metabolic activities of onion bulbs to some extent. 4. Under the condition (c), a few onions sprout-ed at early period, but most onions were kept in good condition for 4 months storage period (Oct._??_Feb.). There was a very little decrease of total sugar and ascorbic acid content in bulbs during the storage, showing that the metabolism of onion bulbs was extremly suppressed under such environment. When onions were removed from the condition (c) to normal air at early period, sprouting com-menced in a short time, but the sprouting ability was not kept after the storage for 4 months. After the storage period exceeded 4 months, it was also found that even under the condition (c), the functional disorder like (a) and (b) occurred. Further, all onions which kept at 20°C throughout the storage period showed the functional disorder at 4 months after they were enclosed, notwith-standing O2 concentration remaining 3.7_??_4.2%. 5. Judging from the result given above, it seems that such environmental condition as 40_??_50% relative humidity and about 1% O2 concentration result in prolonging the storage period of onion as long as 4 months over ordinary storage period, at natural temperature condition prevailing in temperate zone.
1. The author presumed the temperature for flower bud formation, comparing the leaf-stage for bolting of the onions sown in autumn, with the temperature of spring. 2. The onions which reached to the leaf-stage for bulb-division, were able to form flower buds only with low temperatur: that is below 5°C on the mean temperature, below 10°C on the max-imum, and below 0°C on the minimum. 3. The onions which reached to the leaf-stage for bulb-division, were retarded growth and ob-structed bulb-division for a time by replanting. In this case, the flower bud formation occurred at 10°C on the mean temperature, 13°C on the maximum and 2_??_3°C on the minimum. 4. It seemed that the period of low temperature which the onions needed for flower bud formation was about 4_??_5 days.
The effect of foliar sprays of vitamin B1 on the photosynthesis of the following four kinds of hor-ticultural plants, namely, sweet potatoes (var. Norin No. 1), kidney beans (var. Masterpiece), potatoes (var. Danshaku) and cabbages (var. Nagaokakohai), have been studied by the method determining the rate of absorption of carbon dioxide by leaves under natural conditions, or of the conventional WARBURG manometry. The conclusion obtained was as follows. The thiamine solution of moderate concentration sprayed on leaves, promoted their photosynthesis.
The effects of vitamin B1 sprays on the water absorption, transpiration and osmotic pressure of sweet potato plants, have been studied by the conventional methods which used potatometer and balance, and by the cryoscopic method. The results obtained here as follows: 1. The vitamin B1 solution of moderate concen-tration sprayed on sweet potato plants, promotes their water absorption and transpiration. 2. The foliar sprays of vitamin B1 on sweet potato plants have no significant effects on the osmotic pressure of their roots.
1) On the way of breeding new ornamental types in Hibiscus, intra- and interspecific crosses were made with 8 different species in 1952_??_1954 at the Botanical Garden of Osaka City University, Kisaichi near Osaka City, Japan. 2) Intraspecific cross. i) H. syriacus showed remarkable self-sterility or self-incompatibility. Namely, very few capsules without seeds were got by self-pollination, but the crosses betweeen different races produced capsules at high rates containing numerous fertile seeds. ii) In H. coccineus, about 50% of self-and inter-racial pollination yielded capsules with fertile seeds. The inability of pollen seems to be respon-sible for this low fertility. iii) Self-incompatibility. was not found in H. mutabilis, H. Hamabo, H. Moscheutos, H. Trionum and H. cannabinus. Self-pollination in these species always resulted in high fertility. 3) Interspecific cross. i) About 30 different combinations between 8 species were tested, but most of them yielded no, seeds as shown in Table 9. ii) In all the combinations, having H. Haatabo as mother plant, capsules were produced but con-tained no seeds. iii) Only three combinations, H. mutabilis×H. Moscheutos, H. coccineus×H. Moscheutos, and H. Moscheutos×H. coccineus, produeed fertile: seeds. On the F1 and F2 plants, anotherr report-isnow in preparation.
Since 1954 several original autotetraploid plants of deep-red Calabrian Soapwort, golden yellow Common California Poppy, slightly-double flowering late Cosmos and Rose Campion were produced by treating with the colchicine solution to the germinating seeds or the growing points of seedlings. The tetraploid progenies (2n=56) of Calabrian Soapwort grow more vigorously with distinctly enlarged flowerlets, thickened leaves and dickered stems, but somewhat later flowering and producing a quantity of larger seeds than the original diploids in the greenhouse. So it is expected they will surely become a new decorative strain in future. Although the tetraploids (2n=24) of Common California Poppy reveal a peculiar attractive form of enlarged flowers with wider petals as well as the description of Dalbro (1950), they hardly produce any seeds in the present growing place. Such an occurrence seems to be a typical example of showing characteristics of the general induced autotetraploids which are very unstable for the genetical constitutions and are easily affected by the environmental conditions for growing and seed production. The tetraploid Cosmos plants (2n=48), however, have almost the same sized flowers as those of diploids, even if their stems are so stiffer and leaves are longer and thickened enough. And the main characters of the tetraploid Rose Campion (n=48) are not yet unknown but for the distinctly thickened leaves, owing to unbolting in summer of 1956 caused by their slowly growing perennial habit.
The experiments were carried out to clarify the causes of un-uniformity of time of bud-opening, decrease of number of buds opened, and of decre-ase of shoot-growth in some deciduous fruit trees after warm winter in Kochi prefecture. Young trees of Japanese persimmon (var. Hiratanenashi grafted on Diospyros Lotus seedling), peach (var. Okayamawase on Prunus persica seedling) and of Japanese pear (var. Yakumo on Pyrus serotina seedling) were brought into thermo-static dark rooms, in which the air temperature was maintained at -1_??_0°C, 8_??_11°C and 18_??_23°C, respectively, and they were kept there for 888 hours, 1368 hours or 1992 hours since December 2, 1954 successively, and thereafter they were transfered to warm room (18_??_23°C). When the minimum temperature in the open air became more than 15°C, they were carried out to the open air. At any condition, such as cold (-1_??_0°C), mild (8_??_11°C), or warm (18_??_23°C) winter condition, the root-growth of Japanese persimmon occurred after their buds opened and their shoots developed, as in the natural condition of Japan. Their bud-opening time was December 28 in the warm condition, February 16 in the mild, March 15 in the cold, and February 28 in the natural condition. Japanese persimmon had rather longer growth period and grew better owing to the higher winter temperature. The growth cycle of peach and Japanese pear were varied owing to the winter temperature. In the natural condition, buds of peach and Japanese pear opened on the begining of March, after their root-growth on the end of February. In the cold condition, their root-growth were retarded, namely, whereas their buds opened on the begining of March their roots began to elongate on the begining or the middle of March. In the mild condition, their bud-opening and root-growth in spring were retarded, i.e., bigan on the middle of March, and their growth were poor. On the other hand, only one or two buds opended on the end of December in warm condition, and their shoot-development were. retarded, but their root-growth occurred on the be-gining or the middle of January. So, when the air temperature was not cold for some period at least in winter, the bud-opening of peach and Japanese pear were retarded and their growth were poor. When the temperature has been maintained at -1_??_0°C for 888_??_1992 hours since December 2 successively, the number of opened buds increased. This phenomenon was conspicuous on peach and Japanese pear. And many buds of peach and Japanese pear opened uniformly in short time showing the apical dominance, but the bud-opening of Japanese persimmon was retarded under the above condition. And only small number of buds of peach and Japan-ese pear opened slowly showing not the apical dominance, when they were kept at 8_??_11°C, but the bud-opening of Japanese persimmon was hurried up showing the apical dominance under the same condition. When the temperature was 18_??_23°C during the whole winter, only one or two buds opened at the tip of shoot in peach and Japanese pear. The dormancy of peach and Japanese pear were completed owing to the low temperature(-1_??_0°C) for 888 hours since December 2 successively, but the dormancy of Japanese persimmon was complete even after encountered with such mild temperature as 8_??_11°C for the same period. Total hours of duration of temperature below zero in southern district of Kochi prefecture were 154 hours in winter from 1953 to 1954, 210 hours in winter from 1954 to 1955. It is said that 1000 to 1200 hours of duration of the temperature below 7.2°C is necessary for breaking dormancy of peach, and 1400_??_1800 hours on Japanese pear. In the southern district of Kochi, total hours of duration of the temperature below 7°C were 817 and 1002 hours in the winter 1953_??_1954, 1954_??_1955, respectively
In 1953 the authors reported the phase of flesh cell-division and cell-enlargement of the “Nijisseiki” pear. In this report we added the experiments observed on the “Yakumo” pear (early variety) and the “Okusankichi” pear (late variety) and the comparative examination with the“Nijisseiki” pear. In the case of “Yakumo” a flesh cell division took place for 25_??_30 days after florescence, i.e., until the middle of May. At that time a fruit was 16_??_18mm in diameter. The “Yakumo” showed the same tendency as the “Nijisseiki”. In the “Okusankichi” a cell division took place for about 45 days after florescence, i, e., until the beginning of June. A fruit was 28_??_30mm in diameter. In comparison with the “Yakumo” and the “Nijisseiki”, the duration of a flesh cell division of the “Okusankichi” was longer. Further, a cell of the “Okusankichi” was big at the closing period of a cell division and a flesh cell was also big at the harvesting season. As to the same variety a big fruit had more numerous and bigger cell than a little one. In the “Okusankichi” the fleshiness of a fruit near the harvesting season was observed to be influenced by the increase of a cell space as well as the growth of a cell. From the result of this examination, the authors thought that the conditions which effect the determination of cell number, must reasonably be treated.
The authors made a histological observation, using the “Nijisseiki” pear, that a quantity of stored nourishment in a tree bore upon flesh cell-division, i.e., the number of cells. With a view to regulate stored nourishment, the defoliation periods were divided into the following: (1) Sept. 15, (2) Sept. 30, (3) Oct. 15, (4) Oct. 30, (5) the continual plucking period from the flowering-time to the beginning of June, and (6) the standard. The comparison of stored nourishment was made by a iodine reaction. The summary of the effects were as follows. 1. The ceasing period of flesh cell division was rather determined by the number of days after a flowering-time (25_??_30 days after full bloom) than by size of fruits. The size of flesh cell at this stage was 40_??_50μ. 2. The fruits on a tree which had less stored nourishment by a plucking last autumn became small by a small number of cells. 3. Concerning the fruits on a tree which lea-ves were plucked in spring, they were small for thesake of the bpoord growth of each cell rather than the small number of cells. 4. Therefore it came to the conclusion that the number of cells was chiefly controlled by the nourishment in a tree during the period from last autumn to the middle of May, and that the size of each cell was chiefly controlled by the nourish-ment in a tree during the period from May to the harvesting time.