To detect any factors occurring in the early development of the cucumber flower that might contribute to our knowledge of sex determination, it seemed desirable to follow the growth of the flower bud from differentiation, with special reference to the stamen and pistil formation. Figs. 1 and 2 show the staminate flower buds, growing successively. Fig. 3 shows the pistillate flower buds, the growth of the second flower bud being far restricted. The modes of the growth succession of the flower buds as above related show the first sign of the nodal sex expression. Fig. 4 shows the prominent growth of the stamens, indicating the staminate flower formation. Fig. 5 shows the maximal growth of the pistil of the staminate flower. Fig. 6 shows the first sign of the pistillate flower, the pistil is progressively growing and the growth of the stamen is inhibited. Fig. 7 shows the maximal growth of the stamen in the pistllate flower. It will thus be observed that all cucumer flowers in the primordial stages bear both sets of sex organs, and hence are apparently potentially herma-phroditic. Fig. 8 shows the staminate flower buds and the primordia of the lateral branch. Fig. 9 shows the pistillate flower buds and the primordia of the lateral branch. The stem is pinched for the purpose of inducing the sex reversion of the staminate flower buds. The staminate flower buds are transformed into the bisexual flower and the pistillate flower and also into the lateral branch somewhat malformed at the basal portion. Fig. 10 shows the bisexual flower and the fruiting of the pistillate flower which is developed through the sex reversion of the staminate flower buds, induced by the pinching of the stem. Fig. 11 shows the induced pistil development in the staminate flower bud. Fig. 12 shows the stamens filled with the pollens and the developing pistil in the bisexual flower bud induced by the stem pinching. Fig. 13 shows the development of the pistil in the staminate flower buds as induced by the stem pinching. Fig. 14 shows the normal lateral branch (left) and the induced lateral branch (rlgbt) transformed from the staminate flower primordia, showing the malformed leaves and the short internodes. Fig. 15 shows the transforming flower primordia to develop to form the induced lateral branch. It may be concluded that the sex determination of the flower buds was induced before the morpho-logical expression became appreciable with respect to the stamen and pistil development. Application of the growth substance and the stem pinching bring about the sex reversion and even the transformation of the staminate flower buds to the lateral branch.
This paper deals with the germination tests of pollen in common beans, using chiefly a tall variety Kentucky Wonder and in part a dwarf variety Masterpiece. (1) The artificial medium containing 1% agar and 30% sucrose is most suitable for the pollen germination and the optimum hydrogen ion concentration is 5.4_??_6.0. (2) The germinability of pollen is already recognized at the afternoon before the flowering. The percentage of germination increases, towards the time of anther-dehiscence and then decreases rapidly and the pollen grains almost lose their vitality 5_??_6 hours after the anthesis. (3) The pollen of common bean is the starchypollen. (4) The number of pollen grains per anther is very small, but it seems to be more thean that of peanut. (5) The optimum temperature for the pollen-germination is 20_??_25°C and the temperature above 35°C is very injurious to the pollen-germination. (6) The most favorable humidity for the pollen-germination is 80%. The resistance of the pollen to water is very weak. (7) When common bean plants are treated by high temperature (25_??_30°C), the germinability of their pollen grains is injured seriously.
The crossing technique of common beans was studied, using a dwarf variety Masterpiee. (1) When a flower is castrated on the day before flowering, there is a danger of breaking anthers during the operation and following self fertilization and moreover it becomes difficult to work because the pistil grows to curve spirally. (2) On the contrary, if the castration is done at the four or five days before flowering, it is difficult to operate because of the very small size of bud and there is a danger of injuring the pistil. (3) The most favourable time of castration, therfore, seems to be about 3 days before flowering. (4) It appears to be preferable to pollinate within 24 hours after the castration, in the morning if possible.
1. Experiment was made in order to know the effects of soil conditioner upon the physical properties of soil in relation to the growth of peach seedlings. 2. The total shoot growth of peach seedlings under broadcast treatment (Aerotil) without deep tillage was superior to the other treatments at the early stage, but the seedlings on the deep tillaged plots applying manure made the most growth at the later season. With respect to the total shoot length at the end of the growth, seedlings on the deep tillaged soil mixed with soil conditioner made far more growth than the control treated with neither cultivation nor soil conditioner application. It is doubtful whether these results are due to the effect of soil conditioner or of deep tillage itself. As for the difference between concentrations of A-22, seedlings applied with the concentration of 0.1% showed more growth than that of 0.01%. 3. After the leaf fall, fresh weights of top and root were measured. Seedlings on the deep tillaged plots applying manure made the best growth and the broadcast treatment without deep tillage was the next. On the other band, seedlings in the control plots made markedly less growth than the other treatments and the difference of trunk cir-cumference was highly significant. Root penetration could not be observed under the soil depth of forty centimeters in the control plots and broadcast plots. Therefore, broadcast treatment without deep tillage is expected to be effective, especially in the case of making seedling stock during only one year, but it is doubtful if this effect continues thereafter. 4. The soil class of the experimental field is loam and the total pore space and air capacity of the subsoil layer was about 50% and 3% respectively. Deep extension of the root was almost impossible under these conditions, therefore the later effect of deep tillage will be considerably great. Total pore space of the plots treated with 0.1% A-22 are appeared to be slightly more than the others, but the differences between the various treatments deeply tillaged is insignificant. There was no definite difference between different treat-ments about the soil moisture and soil aggregation. For the practical use, considering both price and effect, it will be concluded that the soil conditioner application is not a very profitable method for orchard soil improvement. However, as mentioned above, the soil conditioners will be effective and profitable when they are applied on the soil surface of nursery field to prevent the crust formation on the surface soil.
The writer made the experiment on the effect of some gelling substances on jelly making by using a balance type of strength tester of his own design. (1) Addition of a small amount of powdered pectin is the most effecctive on fruit jelly formation, and its optimum amount lies between 0.2-0.5% of the products. (2) Agar-agar is effective on jelly formation, but while boiling with acid the jelly loses its jellying power very quickly. (3) Other substances as gelatin, starch, carboxy-methyle-cellulose, Na-alginate, CaCl2, CaSO4, etc. are also some effects, but they need such large amount to be developed unagreeable taste.
1. Some studies on the frost resistance of buds and twigs of apple trees were carried out. 2. One year-twigs of two varieties, Jonathan and Rails Janet, from 30-year old trees were used as material. 3. In cortical cells, the highest value of critical concentration of plasmolysis, 2.4_??_2.5M (glucose), was attained in December. This continued till the end of February and gradually decreased after the beginning of March. 4. The buds on twigs cut in January and February were not killed by exposure to temperature -20°_??_-25°C for a week. 5. It was found in buds on twigs cut in February that the longer the time of freezing, the lower the percentage of germination. Only 20% of total number of treated buds could be germinated after an exposure at -25°C for a week. 6. On the twigs in which cortical cells survived after a freezing, not all the buds always germinated. 7. In cortical cells of winter twigs, the longer the time taken for dehardening, the lower the cell permeability to water. The deplasmolysis time of cells dehardened for six days was five times that of hardy cells. 8. In the process of the freezing of living. cells, intra-cellular freezing as well as extra-cellular freezing was observed. In the latter case, none of the cells were usually killed by freezing. Intra-cellular freezing was, however, fatal without exception. 9. The mechanism of “splitting injury” of trunk by frost was briefly discussed.
Regarding the storage rot of Unshu oranges, the writers made an investigation on sugar consumption in Unshu orange juice in which the three fungi; Aspergillus niger, Rhizopus nigricans, and Cephalothecium roseum were cultured respectively. From the result of paper-chromatographic analy-sis the writers found sucrose, glucose, fructose, and xylose in the juice of Unshu oranges. Aspergillus developed well in juice utilizing at first sucrose and xylose. Rhizopus, however, seemed to utilize fructose at first, and then xylose. Sucrose was not consumed completely during the 20 days cultivation. Cephalothecium used at first sucrose. Uronic acid, perhaps galacturoncic acid as a decomposition product of pectin, was found in juice after 3 or 10 days cultivation of the three fungi. This substance, however, could not be detected 20 days after the cultivation.
In the present paper the writers dealt with the results of experiments on the inflpence of summer orange oil to the development of the fungi which cause soft rot of oranges during the storege. Four fungi, Aspergillus niger, Rhizopus nigricans, Cephalothecium roseum, and Cochliobolus miyabeanus, the causal fungus of Helminthosporium leaf spot of rice. A volatile toxic substance which causes the inhibition of the spore, germination and of the mycelial growth of these fungi was found in summer orange oil. It may presumably be n-decylaldehyde which is found in the fraction distilled under 15mmHg at 108°_??_110°C.
It was reported already by the author that the germination of edible burdock seeds is promoted by light. The effect of the wave length of radiation on their germination is studied in this report. At first, these seeds were, germinated in Petri-dish under natural room-light, fluorescent light and electric light. Secondly, they were germinated under colored paper. Colored paper was sticked, keeping the color side down, to the cover glass of Petri-dish in which the germination was made. Thirdly, the colored glass filters furnished by the Mazuda Institute were used. Spectral transmission curves of these filters are given in fig. 1 and 2. These filters of 5cm square, individually or com-binedly, fixed to the lids of dark boxes. Petri-dishes were put in these boxes. The Petri-dishes with colored paper or the dark boxes with fliters were put under fluorescent or electric light. The ger-mination of edible burdock seeds was attained perfectly under natural room-light or fluorescent light, but was often inhibited considerably under electric light. This fact is probably due to the inhibitive action of ultra-red rays which are conta-ined much more in the electric light. Inside the Petri-dish covered with colored paper, the germi-nation was inhibited extremely under green or blue paper, and promoted under red or yellow paper. This inhibitive action of green or blue paper seems to be mainly due to the ultra-red rays reflected by the above colored paper, and partially due to the green or blue rays reflected also by them. In the case of the germination under glass-filters, it was promoted under V-R; V-O, V-Y, V-A which transmit wave length of 550_??_700 mμ under fluore-scent light, inhibited to some degree under V-G 1, V-132, V-V 2 which transmit 400_??_500 mμ and inhibited extremely under (V-V1×V-R) or (V-C1×V-R) which transmits 700mμ or above under electric light and 700_??_760mμ under fluorescent light. Under filter IR-D 1 which transmits the ultrared rays 800mμ or above, the germination rate becomes somewhat higher again. Under short ultrared rays, the very small degree of dormancy is detect. ed, that is, seeds that germinate perfectly in the dark often show some depression of germination rate under these rays. Above results agree well with those of FLINT, MEISCHKE or TOOLE et al. According to the author's other studies, about the same results were obtained in the germination of Mitsuba (Cryptotaenia japonica) and ramie seeds which were favored by light, and in the germination of vegetable seeds of Cucurbitaceae and Solanaceae, and Amaranthus seeds which 'were favored by dark. Putting together reports of MEISCHKE, FLINT, etc. and mine; it is very ineteresting that the germination of light-affected seeds all show about the same reaction to the wave-length of radiation whether they are lightfavored (edible burdock, lettuce, etc.) or darkfavored (Amaranthus, egg-plant, etc.), whether their light-reaction is made mainly in the seed coat (edible burdock, Amaranthus retroflexus, etc.) or in the embryos (Cucurbitaceous vegetables, eggplant, etc.), and whether their light-reaction diminishes with age of seed (dormant) (edible burdock, lettuce, etc.) or not (non-dormant) (Cucurbitaceous vegetables, egg-plant, etc.).
1. The germination charctores of 29 kinds of herbaceous flower seeds were studied during the period of 1 to 5 months after harvests. According to their degree of dormancy, they were classified to the following three categories. a) kinds which have no dormancy: Aster, Dianthus, Gaillardia, Gypsophila, Stock. b) kinds which exhibit weak dormancy: Balsam, Calliopsis, Cosmos Orange Flare, Godetia, Helichrysum, Kochia, Pyrethrum, Sweet Willium, Vinca. e) kinds which exhibit somewhat stronger dormancy: Amaranthus, Celosia, Cleome, Coleus, Cosmos late-flowered, Digitalis, Euphorbia, Pansy, Petunia, Phlox, Portulaca, Salvia, Snap-dragon, Torenia, Viola. 2. As the seeds awaked from the dormancy in dry storage conditions, both the germination percentage and germination speed became greater graduatedly. In general, freshly harvested seeds had a narrow requirement of temperature for their germination, but they were found to be able to germinate over a wide range of temperature with their aging. 3. The effective treatments for breaking the dormancy were alternative temperature (20°C, 16 hrs. and 30°C, 8 hrs.), prechilling, 0.2% potassium nitrate, 0.2% thiourea, light and their combination. The degree of their effectiveness varied with kinds and their seed age. 4. Among the treatments used, 0.2%, potassium nitrate was most effective for the most kinds of herbaceous flower seeds; 0.2% thiourea produced abnormal seedlings in many cases, and depressed the germination rate in some. 5. Light promoted the germination of Coleus, Digitalis, Helichrysum and Petunia seeds during their dormancy, while light depressed the germination rate of Amaranthus seeds. The degree of light sensitivity decreased graduatedly during their dry storage period in above both cases. 6. In general, treatments for breaking the dormancy were necessary only in the case of germination test and unnecessary in the seeding. However, Portulaca and Cleome remained dormant until the next seeding season.
1. The flower buds in Daphne odora appear in the terminal buds on current shoots, and the time of flower bud differentiation in Tokyo was at the beginning of July in 1950. 2. In Osmanthus aurantiacus, the flower bud formation occurrs in the lateral buds on curre shoot, and the time of flower bud differentiate, in Kagawaprefecture was at the beginning August in 1953.
This experiment was carried out in order to clarify the effects of high temperature treatments (30°C., 35°C., and 40°C.) on flower forcing of the tulip bulbs for export. The bulbs were treated without ventilation in 1951, and under ventilation in 1952. High tempera-ture treatment under ventilation was more favor-able and promoted flower bud differentiation a few days than the treatment without ventilation. The higher the temperature of the treatment, the more the flowering time promoted; but higher temperature increased the blind. For “Feu Bril-liant”, as 40°C. treatment caused higher percent-age of blind, 35°C. seemed to be suitable. For “William Pitt”, the more drastic treatments (40°C. -one day, or 35°C.-one day-40°C.-one day) were best. The bulbs treated by these methods bloom-ed about ten days earlier than the untreated ones. In the bulbs recieved the high temperature treatments under ventilation, the time of flower bud differentiation was delayed for five days, but the flowering time was distinctly promoted. It is considered form these results that the tulip bulbs treated with high temperature had passed through the rest period more quickly and became percep-tive of the effects of the following cool tempera-ture. As the bulbs treated with high temperature produced weeker flowers, stems and leaves, the bulbs which will be treated for flower forcing with high temperature should be the ones of ex-cellent quality.