[in Japanese]

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[in Japanese]

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In order to investigate the effects of wind on rooting and growth of tobacco in its early stage, potted seedlings of flue-cured tobacco (variety; Coker 319) were grown under the condition of the constant wind (3 m/s). The results were obtained as follows; 1. The soil of the wind plot lost moisture from its surface faster than that of control plot under ventilating air current only, especially near the surface of soil. The.soil temperature became lowered by the wind slightly in daytime, while scarcely in nighttime. 2. The rate of leaf emergence of tobacco was apparently depressed by the wind. Its stem length, leaf area and dry leaf weight were distinctly less than those of control tobacco (grown under ventilating air current only), and dry root weight of the wind-treated tobacco was slightly inferior to that of control tobacco. 3. Because of the poor growth of top caused by the wind, the smaller T/R ratio was resulted in the wind-treated tobacco as compared with that in control tobacco. The roots of the former grew longer and reached deepcr in soil than of the latter. 4. When the influence of soil moisture loss on the growth of tobacco in the wind plot was excluded by adjusting the soil moisture tension of the both plots at the same level ( l2 mmHg at 7-9 cm in depth), the growth of top of tobacco in the wind plot was still kept poor as mentioned above, even though it was only slightly improved by the treatment. It was concluded that the windy weather in Okinawa can possibly be the major cause of the poor rooting and growth of tobacco in its early stage in the field there which had been considered to be a typical tendency of tobacco growing in the district of Okinawa.

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[in Japanese]

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This paper deals with preparations for the preservation of globoids in the seeds as well as with some histochemical and ultrastructural characteristics. In the preliminary examination on the extraction of metachromatic substances from globoids in aleurone grains of plant seeds and of authentic phytin specimens, the substances were extracted within 15 minutes at pH values lower than 4 and higher than 11 and within 12 hours at pH 7 while not extracted in the pH range 8 to 10. Further experiments were performed to determine an available procedure for the retention of globoid. Some aldehydes and osmium tetroxide produced usable images but permanganate did not produce any acceptable image. Cacodylate buffer was preferable to phosphate buffer. In the usual procedures of fixation and dehydration, the overall time within 6 hours was recommended because a prolonged time caused the decrease in size of globoid owing to the extraction of substances from the globoid. The images such as large globoid cavities and absence or very small size of globoids in aleurone grains seem to be an artefact occurred during the preparation of materials. The addition of cations such as magnesium and calcium to the fixatives and the dehydration series was suggested to reduce the loss of materials in the globoids. In the uranyl staining of thin section, the uranyl acetate in a sodium acetate or a veronal acetate buffer at pH 6 was used to prevent the extraction and dispersion of electron dense substances from globoid. As embedding media, glycol methacrylate and Spurr's epoxy resin were the most available for light and electron microscopies, respectively. The nature of globoid as a phytin containing particle was confirmed with histo-chemical and ultrastructural methods. Inclusions in aleurone grains and lipid granules among several seeds were compared. On the base of these results, the terminology of inclusions in aleurone grains of lettuce seed and the localization of phytin in globoid of sorghum seed were discussed.

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To analyze the compensatory growth and yield observed in rice plants adjacent to empty hills and to evaluate the limit of the distance between planted and empty hills allowing safe and effective replanting of young seedlings, field experiments were conducted in Central Japan in 1966. Within a plot, the distance between rows was 33 cm and that between hills was 12 cm. As shown in Fig. 1, four treatments consisting of rows where planting was omitted in 2, 3, 4, 5 consecutive hills were set up (treatments 1, 2, 3 and 4). In treatment 5, 2 sets of 2 consecutive hills without plants were separated by a hill where rice had been plantd. Effect of standard fertilizer application was compared in each treatment with that in which fertilizers were not appplied. Results of the experiment can be summarized as follows : 1. Effect of compensation on number of panicles and on yield were nearly the same with or without the application of fertilizers. 2. The rate of increase of panicle number in rice plants adjacent to hills without plants was higher than that of the weight of a head, as compared with controls in plots with or without the application of fertilizers. However the rate of increase of the weight of a head, as compared with controls was slightly higher in plots where fertilizers had been applied. Accordingly the yield component which showed the most significant compensatory effect was represented by the number of panicles. 3. The compensatory effect and yield in plants adjacent to empty hills was particularly evident in plants located in the same row, as compared with those in adjacent rows. Within the same row, plants adjacent to empty hills showed a significant compensatory effect on yield which increased with the distance separating both groups of hills. 4. Yield compensatory effect represented by panicle weight per hill was calculated jointly in fertilized and non-fertilized plots, as the difference in compensation rate between both groups of plots was not evident. Compensatory rates in yield were 99%, 96%, 93∼92% and 98%, respectively in treatments 1, 2, 3 and 4 and 5. 5. Limits of compensation for yield allowing safe replanting of young seedlings were within a distance ranging between 24 to 36 cm (i.e. in treatments 1 and 2).

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The influence of variety and crop year on lipid content and fatty acid composition of brown rice was investigated on the 24 lowland non-glutinous varieties cultivated at Hiroshima Agricultural Experiment Station in 1976 and 1977. Lipid content and stearic acid, oleic acid, and linoleic acid contents were significantly affected by variety and crop year and palmitoleic acid and linolenic acid contents were significantly affected by crop year. As to the fatty acid composition in 1976 and both the years (1976+1977), the daily mean temperature during ripening showed significantly positive correlations with palmitoleic acid, stearic acid, oleic acid, and arachidic acid contents and negative correlations with myristic acid, palmitic acid, lino-leic acid, and linolenic acid contents. On the other hand, no significant correlation between daily mean temperature during ripening and fatty acid content was observed in 1977. With respect to the reason, it was presumed that there was no marked difference in the temperature among the varieties in 1977 because of higher temperature from the middle of August to the middle of September as compared with 1976. Oleic acid content showed significantly negative correlations with linoleic acid and linolenic acid contents and linoleic acid content showed significantly positive correlation with linolenic acid content in 1976, 1977, and both the years. The relation between oleic acid content (X%) and linoleic acid content (Y%) was expressed by the following regression equation from the values of both the years. Y=-0.759X+68.21.

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[in Japanese]

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The deep water irrigation is one of the most effective countermeasures against the sterility induced by a cool temperature at the booting stage. For the purpose of estimating the water depth necessary for protecting susceptible spikelets, the vertical distribution of spikeltts at the critical stage was surveyed in the whole panicles of a rice plant in paddy fields, uslng 4 varieties in Hokkaido during the years 1972 to 1975. The following relations were observed as to the height of susceptible spikelets above ground. Variety: Norin 20, Yukara > Eiko, Shiokari, Yunami. Year: 1973 > 1972. Fertilizer level : high > medium > low. Seedling age: 5th≒4th-leaf stage. Tiller: main stem > primary > secondary. The results of the present study showed that the water depth covering about 80% of the cool-susceptible spikelets is l7-20 cm and higher than the conventional 12-15 cm depth recommended by Sakai (1949).

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Changes of pericarp gibberellins in both acidic ethylacetate and n-butanol fractions during development in three varieties of kidney bean, two dwarfs and a tall, were examined. In early stage of pod growth, the gibberellin contents in the pericarps increased in all three varieties. After the full growth in the length of pericarps, gibberellin content decreased rapidly in Masterpiece, a dwarf one, whereas in other two varieties the gibberellin concentrations of full ripened pericarps were slightly lower (Mantle, a dwarf) or almost the same (Kentucky VVonder, a tall) in both fractions as compared with those of the pericarps in earlier developing stages. Those results indicate that the change of gibberellin production along with their pericarp development are greatly dependent on varieties. Addition to this, very high gibberellin content such like as 4.2 μg GA₃ equivalent per 1 g dry weight, for example, is detected in the pericarps of Masterpiece just after the stage for vegetable use. Available informations are indicating that gibberellin activity is generally higher in tall varieties than in dwarf ones, however, the results obtained in this experiment indicate that the pericarps of tall variety Kentucky Wonder showed rather small activity than that of dwarfs suggesting that gibberellin concentration in pericarps are not always parallel to those in seeds.

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The purpose of this study is to make clear the effects of sink on the translocation process of ¹⁴C-photosynthates from the leaves of several leaf plastochron indices (LPI) at different stages of development in Ipomoea grafts. 1. Two combination grafts were obtained by grafting the scion of improved variety (I. batatas POIRET var. Okinawa No. 100) on the stock of the wild type plant (I. trfida (H.B.K.) Don.·T-15) and the stock of Okinawa No. 100. 2. The leaves of LPI 4, 7, l2 and 19 in the respective grafts were exposed to ¹⁴CO₂ gas for 30 minutes. The distinctions of leaves in each LPI were as follows: LPI 4, the leaves reached the beginning stage of rapid leaf expansion; LPI 7, the leaf areas were found about 65% of matured leaves; LPI 12 and 19, the leaves reached in full expansion stage. The plants were harvested in the lapse of 1 hour after the beginning of the exposure to ¹⁴CO₂ gas. 3. In case where the leaves of LPI 4 were exposed to ¹⁴CO₂ gas, ¹⁴C-photosynthates translocated slightly in upward and downward direction. In case of the leaves at LPI 7, downward translocation of ¹⁴C-photosynthates was more predominant in the grafts of Okinawa No. 100 stock than that in the grafts of T-15 stocks. On the other hand, the differences of upward translocation were not recognized between grafts. At LPI 12 leaves, downward translocation increased more than that of LPI 7 in the grafts of T-15 stocks. In case of the leaves at LPI 19, the differences of translocation pattern of ¹⁴C-photosynthates were not found between the grafts, and then the translocation of ¹⁴C-photosynthates was found predominantly in downward direction at both stock grafts. 4. From the above mentioned results, it may be considered that the translocations of ¹⁴C-photosynthatcs from the leaves of LPI 4 are not liable to be affected by the stock types, that those of the leaves at LPI 7 are apt to be affected remarkably in downward translocation by the stock type, and that those of the LPI 19 are not liable to be affected in upward and downward translocation by the stock types.

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The carbon dioxide exchanges of the artificial communities of rape planted in pots were measured at both the beginning of flowering and the middle stage of ripening. The photosynthetic system of plant was mainly consisted of leaves at the beginning of flowering, and of pods at the middle stage of ripening. Using the data obtaincd, we compared gross photosynthesis at both stages and examined the relationship between PAI (pod area index) and the balance in matter production of pods at the middle stage of pod development. 1. The initial slope of photosynthesis-light curve of leaves rose with increasing LAI, whereas that of pods remained constant at all PAI's. The saturating light intensity of leaves was constant at all LAI's, whereas that of pods rose with increasing PAI. 2. Net production per day at the middle stage of ripening reached its maximum value at PAI 4, without declining at PAI 6 which is nearly the maximum value attainable in actual cultivation.

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The carbon dioxide exchanges of the detached pod of rapeseed were measured in an assimilation chamber under controlled environments once in 12 days throughout the period of pod development. From the results presented in Figs. 1, 3, 4, 5 and 6, carbon content of the pod and the actual climatic data, the contribution to the total require-ments for the growth of pod was sought as to pod photosynthesis and translocation from other organs. The following results were obtained: 1. Apparent photosynthesis of the pod showed a value near to 10.5 mgCO₂/dm₂ surface area/h during 12-36 days after flowering, and then declined rapidly as the pod matured. The optimum temperature for the apparent photosynthesis of the pod was 20∼25°C during the whole period of pod development. 2. Dark respiration of the pod was high (6.3 mgCO₂/g dry weight/h) at the early stage of pod development, and declined rapidly as the pod matured. Temperature coeffcient, 〓₁₀, for the dark respiration of the pod was 2.2 for 10-30°C. 3. The dry weight of pericarp increased rapidly after flowering, and reached the maximum value at the earlier stage of pod development. On the other hand, the dry weight of seed increased gradually after flowering, and reached the maximum value at the later stage of pod development. Most of the dry matter needed for pod growth was translocated from other organs during the period of pericarp growth, and was provided by pod photosynthesis during seed development. 4. For the whole period of pod development, the contribution of gross photosynthesis by the pod and of translocation from other organs to total requirements were 70% and 30%, respectively. The proportion of respiration by the pod and of pod growth to total requirements were 39% and 61%, respectively.

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[in Japanese]

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[in Japanese]

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The effect of temperature during the ripening period on the seed yield and its quality was investigated using cv. Miyagishirome. The temperature treatments were composed of eight plots: five day/night temperature plots (30°/25°, 30°/20°, 25°/20°, 25°/15° and 17°/12°C, day and night temperatures being constant, respectively), two gradual temperature change plots (the diurnal temperature gradually changes along with sine curves designated as 25°/20°and 17°/12°, the daily mean temperature being almost the same to the respective 25°/20° and 17°/12° plot) and outdoor control (average daily mean temperature was about 21°C). The results obtained are summarized as follows: 1. The dry weight per plant was in the following orders: 25°/20°>30°/25°≥17°/12° in case of 5°C daily range, and 25°/15°>30°/20° in case of 10°C daily range. When the day temperature was the same, the dry weight per plant grown under 10°C lower nights was greater than that under 5°C lower nights. There was little difference in dry matter production between the gradual temperature change plots and the suddenly change plots. The dry weight of the outdoor control was almost the same as that of 25°/20°. 2. Seed yield per plant was greater at 25°/15° and 30°/20° plots, followed by 25°/20°, 25°/20°, 30°/25° and outdoors in that order, and very small both at 17°/12° and 17°/12°. Numbers of pod and seed per plant tended to increase with increase of temperature in case of 5°C daily range, while those of 25°/15° and 30°/20° were almost same. Numbers of pod and seed of 10°C daily range were greater than those of 5°C daily range when the day temperatures were same, and those of the outdoor control were similar to those of 25°/20°. 100-seed weight was very great at 25°/20° and 25°/20°, followed by 25°/15°, 30°/20°, outdoor control, 30°/25° in that order and those of 17°/12°, 17°/12° were extremely small. 3. N, K, TAC (Total Available Carbohydrate) and seed oil accumulation perplant were paralleled with dry matter accumulation in response to temperature. P accumulation tended to increase with increase of temperature. At maturity most of N, P, K and TAC accumulated in seeds, Mg+Ca in pod shells and Fe and Na in roots, respectively. The concentration of Fe and oil in seeds tended to increase and that of carbohydrate to decrease with increase of temperature. Saturated fatty acids in seed oil such as palmitic, stearic and oleic acid with one double bond tended to increase and other unsaturated acids such as linoleic and linolenic to decrease with increase of temperature. 4. The larger seeds ripened outdoors or at 25°/20°, 25°/15° and 30°/20° showed a higher germination percentage. 5. In the regime of this experiment, day temperature of 25° to 30° with 10°C daily range during the ripening period seemed to be optimum for dry matter accumulation, nutrient absorption, seed yield, and seed characters, suggesting that the optimum temperature for ripening is a ittle lower than that for vegetative growth.

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The physical property, chemical composition, and suitability for food processing of soybean seeds were investigated on the seeds by dry treatment after harvest, i.e. natural drying and air drying by non-heated and heated at 20°C, 30°C, and 40°C. The seeds stored at 15°C with R.H. 65% and 75%, at 30°C with R.H. 65% and 75%, and room storage with paper bag for 30, 60, 120, 130, 270, and 360 days, respectively, were further investigated on suitability for food processing. The moisture contents of seeds under the storage were as follows: R.H. 65%: 10.7% to 11.4% at 15°C and 9.6% to 10.5% at 30°C, R.H. 75%: 14.5% to 14.9% at 15°C and 13.8% to 15.1% at 30°C, and room storage: 8.3% to 12.7%, respectively. On the changes of suitability for food proccssing by storage, absorbability of water in seeds, germinability, extractability of protein by hot water from soaked seeds, pH of soybean milk, and increasing weight ratio of steamed seeds to raw seeds were decreased, while soluble matter and protein in soaked water, and moisture content, hardness and coloration of steamed seeds were increased. Among the stored conditions, the seeds at 15°C with R.H. 65%, 75%, and room storage well retained the suitability for food processing, whereas remarkable deteriorations were observed at 30°C with R.H. 75%. Among the heated-air drying seeds, the influence of storage for food processing was significantly observed in the seeds dried at 40°C. From the results, the undesirable influence of storage was observed on Miso, Natto, or cooked beans making as compared with Tofu making.

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The detachment of root caps was examined microscopically, using rice crown roots grown by "leaf-cutting" method. An agar-immersion process was newly introduced to secure tissues from sloughing off during microtome-sectioning procedures. Root caps of just-emerging crown roots are designated here as "primary root caps". Their structures are characterized by predominantly stratified cell layers, arranging parallely to the tip surfaces. Contrastively, the structures differ from those of the later appearing, ordinary root caps with well defined cell files, i.e. columella. Within several days after their emergence, the "primary root caps" tended to dissociate and detach from root tips. The ways of their detachment were classified into the following three types; (1) the "cylindrically-detaching" type, (2) the "penetratedly-detaching" type, and (3) the "falling-off" type, respectively. In the former two types, detached cell layers remaining on the basal parts suppressed the outgrowth of root hairs and lateral roots. Following the detachment of the "primary root caps", in the "denuded" ordinary root caps, the falling at the tips of single cells or small cell groups seemed to be prevalent. The mechanism of the detachment of the "primary root caps" may be attributed to the mutual dissociation of their cell layers due to their different growth rates, and also to the collapse of their cell layers at the tips due to the development of columella.

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In the previous article, two substances named inhibitors A and B were isolated from the seed coats of Bupleurum falcatum seeds. In present experiments, these inhibitors were developed on thin-layer chromatograms and chemical and physiological properties of inhibitors were observed. The results obtained are as follows: 1. On the thin-layer chromatograms using the solvent of n-butyl alcohol saturated with ammonia, eight spots were found from inhibitor A, while nine spots were found from inhibitor B. These results were the almost same with those of separation by paper chromatography. The separating power of thinlayer chromatography, however, were better than that of paper chromatography. The inhibition of germination in lettuce seeds was observed with only one spot of inhibitor B, which showed the typical color reaction with the phenol reagents. 2. Under the UV light of spectrophotometer, both inhibitors A and B showed the maximum absorption at 280 nm, though different absorption spectra were observed between inhibitor A and B. 3. When inhibitor B, which showed remarkable physiological activities, was applied to non-dormant Bupleurum falcatum seeds with soaking in water solution at various concentration, it was observed that RNA content in seeds was not affected but amylase activity was lowered at the concentration of more than 50 ppm.

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