This paper presents further studies of correlations between the auxin content and the growth and sex expression of the cucumber plant. The results obtained in the previous report indicated that the higher auxin content, restricting the vegetative growth, induced the sex reversion. For the purpose of increasing the auxin content the spray of 10 ppm solution of naphtha leneacetic acid was applied in the following two ways. (1) NAA sprays of 10 ppm were repeated at 2-, 4-, 6-, and 8-day intervals during 40 days in the cold bed. With shortening of the interval of the repe-tition, the male flower formation being retarded, the female flower formation was progressively accelerated. Under the short day condition (8 hours) at 2-and 4-day intervals applications, and under the long day condition (15 hours) at 2-day intervals application, no male flower being formed, the first female flower bloomed as the first flower on the fourth node. (2) NAA sprays of 10 ppm were repeated at 4-day intervals between once and ten times in the cold frame. With thrice applications, the female flower formation was noticeably accelerated. The female flower formation progressed according with the repetition times of spray application. At nine times of repeated applications, without forming any male flower, the first female flower bloomed as the first flower on the fourth node. (3) It may be reasonably concluded that auxin level in the cucumber plant is responsible for the sex expression as the physiological ground. The higher auxin level, restricting male flower forma-tion, favors the female flower formation. It is previously shown by the authors that the cucum-ber flower is hermaphroditic in nature. Sex pattern shown in the cucumber development is of the physiological nature progressing in accordance with the plant growth, thoroughly associated with the auxin content.
Some experiments were carried out in 1949 and 1951 to study the effects of light intensity on the reproduction of the bean, using the dwarf variety “Masterpiece” The results obtained are summarized as follows. (1) The reduction of light intensity lowered the assimilation ability of bean plants. Severe restriction of light (less than 30% of natural light intensity in the field) checked remarkably the plant growth. (2) As the light intensity was reduced, the latent flower buds increased and the number of flowers decreased. Furthermore, the shading brought the increase of flower-dropping and the decrease of pod-setting. (3) Severe restriction of light resulted in the increase of flower bud dropping and the reduction of flower number as well as of pod number by half compared with the control plot. (4) The reduction of light intensity had almost no effects on the functions of pollen, i.e. germination of pollen grains, elongation of pollen-tube, amount of starch, etc.
1. In these experiments two varieties, Tokina-shi and Nerima, were used as materials. Fertility was determined by pollen behavior on stigmas instead of by seed counts. 2. The results of self-and cross pollinations in variety Tokinashi were exceedingly complex. Ten plants examined were divided into eight classes on the basis of cross-relations. All these plants were self-incompatible. In inter-class pollinations there were both cross-compatible and -incompati-ble combinations. Differences in the reciprocal reactions between certain classes were also found (Table 1 and Diagram 1). 3. Self-and cross-pollinations in sister plants obtained by bud-selfing a self-incompatible plant (No. 9 in Diagram 1) were attempted in 1955 as progeny test. These ten plants were divided into three classes (α, β and γ). Classes α and β were cross-compatible in both directions, but all other combinations were fully incompatible (Table 2 and Diagram 2). 4. The results of self-and cross-pollinations in variety Nerima were analogous to those of variety Tokinashi (Table 3 and Diagram 3). 5. These results closely resemble those of variety Shogoin (TATEBE 1944), and may well be explained if the following items are assumed: (a) Both self- and cross-incompatibility are determined by two pairs of incompatible genes (S and I). S is assumed to be epistatic to I, but hypostatic to II (S>I, S<II). (b) The interactions in fertilization. are determined by the sporophytic origin of pollen. A genetic explanation for the results was given in diagrams 4, 5 and 6. This interpretation is analogous to RILEY'S hypothesis on Capsella (1932, 1936).
This study was carried out to ascertain the effects of cold storage of seeds on the flower-bud differentiation and bolting of carrots. The varieties used were Kokubu, Kintoki and Gosun. (1) The influence of vernalization (at 2_??_3°C for 1, 2 and 3 months) on the flower-bud differentiation and bolting of carrots was clear, though the response of each variety to the vernalization was not same. (2) The variety Kintoki was the most sensitive to the vernalization treatments, and the Kokubu was the least. (3) In this experiment two months treatments showed the most effective influence upon the flowering.
(1) In the present paper, effects of the following treatments on the reproductive development of “King of Denmark”, a variety of spinach, were studied. (a) Vernalization with 1±1°C. (b) Combination of vernalization and long-day treatment (17 hrs.) supplemented with artificial illumination. (2) Vernalization (for 10, 20, 30 and 40 days) was promotive for the seedstalk elongation of spinach in its earlier stage of growth in proportion to the duration of the treatment. (3) In the growing period in a green house from November to next June in Kyoto, with the coming of long-days of spring, the plants grown from non-vernalized seeds were accelerated to elongate their seedstalks, nullifying their handicap by the lack of vernalization. Of the time of flowering and fruiting, it was hard to find any significant differences between plants vernalized and non-vernalized. (4) Under natural short-day condition (October_??_December), plants vernalized for 0, 15 and 30 days, after they expanded the 3rd. leaf, were exposed to artificial long-day (17 hrs.) for 0, 5, 10 and 20 days. Of these, the only plot which flowered by the end of December was the combination of 30-day vernalization and 20-day long-day (V-30, LD-20). In the other plots, the elongation of seedstalk was remarkable in proportion to the duration of long-day treatment and/or vernalization. (5) With the seedstalk elongation in spinach, it is presumed that at least to a certain degree, a reciprocal quantitative compensation exists between the effects of long-day and vernalization,
1. In order to obtain the basic data for promotion of flowering in slow bolting spinach, the effect of chemical vernalization (auxin and low temperature treatment) and low temperature treatments of seeds to floral initiation were examined with the King of Denmark and other three varieties. Dry seeds were treated with auxin (1 p. p. m. naphthaleneacetic acid) for 24 hours. The temperature treatment was continued for 2 weekes in 3±1°C. Those seeds were sown in spring (March 5), summer (June 15) and fall (Oct. 5). 2. The time of initiation of floral primordia of the four varieties were markedly accelerated by a combination treatment of auxin followed by a low temperature and single treatment of low temperature, as compared with non-treatment controls under the three respective season. 3. The promotion of earliness concerning the bolting and flowering was also markedly shown in plants which received treatments, mentioned above, but showed the differences on the development of flower-stalks with four varieties under the short-day conditions in fall or winter. 4. In the first experiments (sown in March 5), the plants of the King of Denmark variety which received vernalization tretment passed over normally the course of bolting, flowering and fruiting, and obtained seeds amounting to 19.8cc. in average, per plants under the greenhouse conditions, and germination of seed showed the higher percentage. While, the controls not in treatment formed very little flower stalks. From these facts, it will be clear that the acceleration of floral initiation of spinch is induced by immediate effect of vernalization, and that the after-effect of this treatment for seeds may alter the photoperiodic responces of this crops.
(1) The study was carried out to confirm the effect of malefic hydrazide on the inhibition of sprouting of the potato during the storage and also to investigate the physiological changes following the treatment. The spraying of 0. 1, 0. 2, 0.3 and 0.5 per cent solutions of MH was conducted on May 31 (3 weeks prior to the harvest) to the leaves of “Irish Cobbler” potatoes. (2) In potatoes, under normal cultivation, it was found that a gradual decrease of reducing sugar content and a gradual increase of starch were observed at the last stage of tuber development. This tendency was found more conspicuous in the potatoes when they were treated with MH. (3) It was also found that the ascorbic acid content in untreated leaves was rather rapidiy decreasing in aproaching to the harvest, but in the treated plot it was considerably higher during a certain period, then decreased more rapidly to reach to an extent of untreated leaves at the harvest time. The tubers from MH treated plot contained a little higher amount of the ascorbic acid than tubers of untreated plot. (4) In the tubers of untreated plot, the reducing sugar was observed to decrease after the tubers commenced sprouting, but, on the contrary, it was remarkably accumulated in the treated potatoes. The decrease of the starch and total carbohydrate contents in the tubers were lower in the treated potatoes throughout the storage period. (5) Although MH treatment destroys the apical dominance and inhibits the elongation of sprout, the period of dormancy was not prolonged in our experiment. Masses of stolon-like proliferations of buds were formed in such tubers, not producing normal sprouts.
1. The experiment was carried out on the bolting in relation to leaf-stage and nutritional conditions of the onions sown in autumn. The results were as follows. Under same nutritional conditions, the more advanced the leaf-stage, the more boltings occured; but under poor nutritional conditions there were more boltings on the lower leafstage as compared with under adequate nutritional conditions. 2. The onion not bolted, produced bulb-division .after growing to the certain stage, while the onion bolted produced bulb-division with flower bud formation. In any case, there were considerable variations in the leaf-stage to produce bulb-division, but lowest leaf-stage for division seemed to be the ecological characteristic in each variety. Yama-guchi-kodaka divided at 12th. leaf-stage, and Awaji-chu-kodaka, 13 th. leaf-stage. 3. But it was found that bulb-division was -obstructed by the poor nutritional conditions and low temperature. In such conditions, therefore, the variation curve of the leaf-stage for bulb-division tended to move to higher leaf-stages. 4. The leaf-stage for bolting was one-leaf lower than leaf-stage for bulb-division. In the bolting bulb, the division bud was formed with the flower stalk and in the divided bulb, the division bud was formed within the leaf-sheath which corresponded to the flower stalk. So, there was oneleaf difference between both stage from the ana-tomical point of view. 5. For bolting, it seemed necessary that the onion plant, on the leaf-stage for bulb-divison, formed flower bud under lower temperature condition. Further, besides low temperature, such conditions, were necessary, as poor nutrition, extreme lower temperature which tended to obstruct bulb-division. And it was found that onion bulbdivided without flower bud formation under good nutritional condition and temperature in which buld-division was possible.
The present paper reports the effects of foliage thiamine sprays on the chemical composition and the taste of three kinds of garden crops, namely Norin-No.I of sweet potatoes, Danshaku of potatoes, and Masterpiece of Kidney beans. The results obtained were as follows: 1. Foliage thiamine sprays at the most effective concentration improved the flavor of tubers, more-over and they increased, though slightly, the total suger and starch contents of the tubers and bean grains of treated plants as compared with those of the control. 2. The treatment somewhat increased the car-bohydrate content and raised the C/N ratio of stems, leaves, and roots of the plants. In my opinion, these results will serve to explain the fact that the treatment has influence on promoting the root development, the tuber forma-tion and flower bud differentiation, and on short-ening the growing period as well. 3. The treatment increased, though slightly, thiamine contents of tubers and bean grains of the plants. In this case, the form of the increased thiamine was mainly of the free form.
The effect of application of some synthetic soil conditioners, such as A-22, Aerotil (both HPAN) and Krilium-6 (VAMA), on the physical proper-ties of potted soils was studied. Each conditioner was applied at the rate of 0.06 per cent by wei-ght to soil. The soil used was Anzyo clay loam, containing 3.5 per cent humus, 37.5 per cent clay, 13.6 per cent silt, 20.0 per cent fine sand, 26.9 per cent coarse sand, and 56.4 per cent ini-tial soil aggregates. To the contrast, six plots, i.e. untreated, rotted organic matter added, compost, river-sand added, moss mulched and straw mulched, were also used. Each soil was potted, and then weathered at the open field. When the soil dried, the same volume of water was given to each pot. The physical properties of each soil were determined first at the beginning of the experiment (three days after the treatment) and then three or four months after. Appilication of these soil conditioners, without exception, remarkably improved soil structure and especially increased the percentage of watersta-ble aggregates larger than 0.5mm. They also in-creased the aeration porosity, infiltration and percolation rates, but reduced the rate of evaporation from the soil surface. Moreover, the compactibili-ty of the soils and the formation of surface crust in the potted soils were prevented by the treat-ment with the soil conditioners. These physical conditions in the treated soils were satisfactory for pot-soil as well as those of compost-soil. Consequently, it is conceivable that application of the synthetic soil-conditioning polyelectrolytes to the pot-soil or to the bed-soil in greenhouse are very effective. It was found, however, that the effectiveness of the application of the chemicals only to soil surface was not persisted through long period, because of the aggregate destruction by the beating action of rain-drops. The field water capacity, the moisture equivalent and the avail-able water capacity in the soil were unchanged or slightly decreased by the treatmeht. But, the application of the soil conditioners' may indirectly increase the available water in soil by aiding the infiltration but preventing the evaporation.
This study was designed to obtain the nutritional requirement of Amaryllis (Hypeastrum hybridum) as an aid of bulb cultivation. The bulblets of nearly same size propagated by the artificial method in the previous winter were arranged. And three of them were planted per one pot on March 14, each treatment including twelve replicate bulblets. The different fertilizers were applied on the basis of triangular coordinates, with levels of 75, 150, 225 and 300 ppm of nitrogen, phosphorus, and potassium. (The rates are indicated in Table I.) Ammonium nitrate to supply nitrogen, calcium super phosphate to supply phosphate, and potassium sulfate to supply potassium were dissolved in water and applied at weekly interval from May 12 to Nov. 15. The number of leaves, and divided bulblets; the length of leaves; the diameter of bulb; and the weights of total plant, leaf, bulb, and root were measured, and the contents of nutritional ele-ments of each organ were analyzed after fertilizer treatment. The total nitrogen was determined by the Gunning method, total phosphorus by the photoelectric colorimeter, and total potassium by the flame photometer. The analysis of variance for the measurements shows significant differences among the treat-ments. The results of this study are summarized as follows: (1) The good fertilizer rates for Amaryllis growth were 4-4-4 and 3-2-4 plots. (2) Potassium was not effective for the top weight, but effective for the division of bulblet. (3) The plants with high nitrogen level and high potassium level absorbed more nitrogen and potassium than those with low nitrogen level and low potassium levels. However, such fact was not shown in phosphorus. (4) High potassium levels were not conducive to good plant growth unless the nitrogen level was also high.