日本作物学会紀事
Online ISSN : 1349-0990
Print ISSN : 0011-1848
ISSN-L : 0011-1848
23 巻, 3 号
選択された号の論文の19件中1~19を表示しています
  • 山田 登, 太田 保夫, 長田 明夫
    1955 年 23 巻 3 号 p. 155-161
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    When rice plants are submerged under water in the case of flooding, the oxygen content in the internal atmosphere of rice plants is remarkably decreased due to the insufficient supply of oxygen to the plants. Under reduced oxygen tension, aerobic respiration is reduced and at the same time anaerobic respiration is promoted, both resulting in the increased consumption of hexoses with decreased evolution of energy. Accordingly the amount of available carbohydrates in the plants is exhausted rapidly and protein is exposed to hydrolysis. Extent of protein hydrolysis depends on the oxygen tension; low oxygen tension inhibits hydrolysis. Bubbling of water with air or exposure of submerged plants to light favour protein hydrolysis. Initial increase of soluble nitrogen fractions such as amino acids and final exhaustion of these fractions indicates the production of soluble nitrogen fractions by protein hydrolysis as the utilization of these fractions as respiration-substrate. Therefore the resistance of rice plants for submersion is determined by the following three factors-(a) amount of available carbohydrates contained in the plants, (b) velocity of subsrrate consumption; rate of respiration, and (c) oxygen tension. The higher oxygen tension results in the less consumption of carbohydrates and longer lasted supply of respiration-substrate by protein hydrolysis.
  • 榎本 中衛, 山田 一郎, 穗積 清之
    1955 年 23 巻 3 号 p. 162
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    The authors examined the growth of pollen tube and its varietal differences of rice plants, using Japanese and foreign varieties. The germination media for pollen were made of 5% potato starch paste containing 15% sucrose. The main results were as follows: 1) In all tests, it was found that 50∼100% of pollen used showed their germination. 2) The germination of pollen grain begun immediately after it had been set on the medium and this initial rapid growth of pollen-tube continued for 10∼20 minutes, after that the growth became very slow and ceased after 20∼30 minutes. And at last the length of pollen tube was measured to be 50∼110μ. 3) Comparing Japanese varieties with foreign ones, though no difference was found in the speed of the initial growth, the cease of pollen-tube elongation was delayed longer by 5∼10 minutes in foreign varieties. 4) The length of pollen-tube of Japanese varieties were observed to be somewhat shoter (50∼80μ) that of foreign ones (70∼110μ), and this difference was proved to be significant, statistically.
  • 渡部 忠世, 北川 幸二, 八木 義和, 榎本 中衛
    1955 年 23 巻 3 号 p. 163-166
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    This report deals with the comparison between the soils of two experimental plots, the ridge culture and level culture (the control) in respect to the contents of two forms of nitrogen (NH3 and NO3) and carbondioxide. At the same time, the growth and yields of rice plants grown there were also tested. The main results were as follows:- i) The decrease of NH3-N contents occured more rapidly in the ridge soils than in the controls for NH3-N was more exhausted in the former soils than in the latter. On the contrary, more NO3-N was found in the ridge soils than the controls. These facts might be due to the persistence of the oxidative layers in ridge soils. ii) More carbondioxide were therefore always found in the ridge soils than in the controls. iii) Plant height, tillers and nitrogen contents in leaf-blades surpassed in the ridge plots than in the controls. Above facts were observed during the vegetative growth period, from planting to the beginning of the differentiation of primordial ear. In the generative stage of the growth, however, this tendency became quite reversed. iv) In regards to the maximum length and dry weights of roots the ridge plots exceeded the controls during the whole course of the growth. But the top-to-root ratio was generally higher in the controls than in the ridges. v) The heading date seemed to be somewhat promoted in the ridge plots than in the controls. vi) Plants of the control plot were superior in grain weights per plant and number of grains per ear to those of the ridge plot. Especially the grain wieghts compared with the weights of culms and leaves were remarkably smaller in the ridge plots. vii) Here it might be said that the plant growth in the ridge plots looked just like that of the so-called Akiochi, which means the poor grain harvest in spite of the preceding vigorous vegetative growth. Consequently, in every year, 11∼23% decrease of yield per unit area appeared in the ridge plots compared with the controls. viii) In short, the vegetative vigor of plants of the ridge plots might be favoured by its better physical soil conditions during the vegetative growth period. But as plants developed into the generative growth, gradually the declination of vegetative growth is shown due to the nutritive deficiency occured in ridge soil. This nutritive deficiency was largely attributed to the striking development of the oxidative state in soils as already reported in the previous paper, and consequently caused the yield decrease.
  • 馬場 赳
    1955 年 23 巻 3 号 p. 167-168
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    Conspicuous varietal differences were found with the rice plant grown on the soil of the paddy field where H2S is produced as regard to the degree of the root-rot caused by H2S. The varieties having high adaptability to "Akiochi" (fall-down) paddy field showed higher resisting capacity for the root-rot disease as compaired with those having low adaptability. The writer has devised a convenient method to test the varietal resisting capacity for root-rot disease. The method is as follows:- The plant is taken from the paddy field and its root is immersed in a diluted solution of H2S. After several days either the degree of blackening of the root due to FeS or the degree of root-rot is measured. The varieties resistant to root-rot have always lower degree of blackening and root-rot as compaired with non-resistant ones.
  • 嵐 嘉一, 江口 広
    1955 年 23 巻 3 号 p. 169-173
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    With the same object as mentioned in our previous reports on the growing habit of leaf of rice plant, the present investigation was carried out to make clear the growing process of internodes of culm and seasonal changes of starch content in them according to their node order. The results obtained are summarized as follows: I. Growth process of internodes of culm. 1. Elongation process of the internodes of culm according to their order is shown in Fig. 1. 2. As shown in Fig. 2, the weight of total culm or each internode of culm increases gradually with the in development until it shows the 1st maximum weight at about 12 days after heading. Then it decreases gradually, and reaches to the minimum value at about 37 days after heading. From that minimum-weight time it increases slow lyagain till the ripening time. The 1st maximum-weight time shows the beginning of the growth process of grain and the minimum-weight time corresponds nearly to the finishing stage of its growth. II. Changes of the starch conteut in internodes of culm. 1. Seasonal changes of the starch content in each internode of culm of normal rice plant shows the same tendency as in the case of internode weight as shown in Fig. 3. The beginning of the decrease of starch content from the maximum condition is due to its vigorous translocation to panicle and, at the time of minimum starch content, the rice grain grows nearly into full weight and does not need more carholydrate. So, after this period, starch content begins to increase again untill the ripening time-secondary stage increase. One of the main causes that effect the change of weight of internodes is considered to be the change of the starch content in them. 2. Starch content in culm is generally higher in lower internodes and with the ascent of node order it tends to decrease. But, within the 13 th to 15 th internodes its difference is not so large. Only the 16th internode (the uppermost one) has very small content. 3. In "Akiochi" rice plant, the changes of starch content in accordance with its growth are as similar as in normal plant, but there is a same difference as in the absolute amount of starch accumulation from the normal one. 4. As shown in Fig. 4, the starch content in the lower internodes of "Akiochi" plant is much less than that in normal one, but from lower to the higher internodes the difference decreased gradually. In the uppermost internode (in lower part) and in the panicle stalk that finishes its growth at the later stage starch remains much more than in the normal one. Moreover, in the lower internodes of "Akiochi" plant, the secondary increase of starch is much less than in the normal one, starch accumulation not occuring at all especially in the upper internode and the panicle stalk. 5. The fact that the starch content in lower internodes of the "Akiochi" plant is lower than that in normal ones may be due to weaker carbon-assimilation and earlier translocation of carbohydrates from the internode to the panicle. The higher content of starch in the upper internodes and the panicle stalk of the abnormal plant comparred with that of the normal one may be due to the retardation of carbohydrate translocation from these parts to the panicle in later stages. These facts are altogether considered to cause the imperfect development of rice grains in "Akiochi" plants.
  • 中川 勝八
    1955 年 23 巻 3 号 p. 174-177
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    Kiel unu probo por montri kaj esplori analize la produktivecon de kulturita kampo la autoro proponas novan metodon, en kiu li uzas la indikajn nombrojn F, E kaj U. F indikas la tutan produktorezultaton, E signifas efikecon por unuo da areo efektive plantata, kaj U montras la proporcionde areo utiligita (plantita) kontrau areo ekzistanta. La rilato inter la trri nombroj estas jene: F=U. E. Kaj oni povas kalkuli ilin per la jenaj formuloj: [numerical formula] En tiuj, [A]: areo de kulturita kampo, Ak: areo plantita de kreskajo k, (Tk): keoficiento koncerne la tempdauron okupita de kreskajo k, Rk=rk/rko, en kiu rk: rikolto por unuo da areo de kreskajo k, kaj rko: norma kvanto por la antaua, kaj (lk): koeficiento koncerne la valoron de rikoltajo el unuo da areo de kreskajo k. La koeficientoj (T) kaj (l) estas provizore deciditaj sur la esploroj faritaj antau jaroj. T estas relativa longeco le tempdauro, de alplantado (semado) gis rikoltado, kaj L estas relativa grandeco de kultura laboro investita por unuo da areo, per kiu la autoro deziras reprezenti la relativan grandecon de tuta kvanto da investo (laboro, sterko ktp.). Per la supre dirita metodo (kiel la normo ro la meznombro tut-landa en la sama jaro estis uzata), la autoro analize pritraktas ladiferencojn inter la diferencojn inter la produkto-rezultatojn de la titolitaj kampoj en ciuj distriktoj de Japanujo en 1926.
  • 中山 治彦, 沢村 浩
    1955 年 23 巻 3 号 p. 178-182
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    1. On the grade of the progress of the thermo-phase and high night-temperature treatment of wheat plants, the following two experiments were carried. Exp. I: The effects of the treatment before and after the initiation of the young panicle was studied using the spring wheat (Saitama-No. 27) and the winter wheat (Akasabi-Shirazu-No. 1). Exp. 2: The effects of the treatment upon the winter wheat (Akasabi-Shirazu-No. 1) which varies in the grade of the vernalization was studied. 2. The materials were treated in two green-houses, the one being heated during night time to raise the night-temperature average about 6°C higher than the other one or control. The plants were adequately managed. 3. The development of the wheat plants were promoted by the high night-temperature treatment, but the grade of the development of the spring wheat was much larger than winter wheat. In case of the winter wheat, the promotive effect was observed when only the plants passed through the thermo-phase, the development of the plants when incompletely vernalizes was delayed. 4. The growth rate of the wheat plant was promoted by the treatment. In case of the spring wheat, the numbers of leaf was increased by the treatment before the initiation of young panicle, the height of plant was increased at the initiation of the young panicle, the tiller increased after the initiation of the young panicle. In case of the winter wheat, The same results were obtainned but not so clear. 5. The numbers of ear, the length of ear and the numbers of grain per ear were decreased by the treament after the initiation in spring wheat. The ear-weight and the grain-numbers per ear were decreased in winter wheat.
  • 川井 一之, 岡田 正行
    1955 年 23 巻 3 号 p. 183-184
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    Spraying treatment of soil surface with Krilium brought a remarkable effect in controlling the erosion during the rainy season of sloped fields of diluvial soils planted with sweet potato and increased the yield of that crop. Krilium treatment promoted remarkably the formation of water stable soil aggregates, especially those larger than 2mm. in diameter, and improved the physical properties of the soil namely, for example, the porociity, the percolation and capillary movement of water the moisture holding capasity, moisture equivalent, the wilting coefficient, etc.
  • 仁木 巖雄
    1955 年 23 巻 3 号 p. 185
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    In the present report, the author classified the forage crops into five phenological types according to the season in whicn they grow most vigorously (Table. 1.) The reason why each of them belongs to a particular phenological type may be that it is characterized by its own seasonality. As each crop requires a particular complex of seasonal environments for growth, it cannot thrive vigorously when the latter is not suitable. And there exists no crop which can adapt to all seasons. Therefore for successful introduction of new crop production into acertain district, it is necessary to know the seasonality of the plant. The vernalization treatment may be one of the methods to change the phenological type of the crop. The four seasons here defined are as follows: summer; - the season with temperatures sustained above 20°C, autumn - from 20°C to 5°C, winter - below 5°C and spring - from 5°C to 20°C. Most parts of Japan have distinctive four seasons respectively. Most grasses of foreign origins and some root forages as the swede, for example, are generally difficult to be raised in most districts of japan, except certain regions of especially high altitudes or high latitudes, where the "summer season" as defined above is nearly absent, there remaining only the three "seasens" to which these crops can adapt.
  • 馬場 赳, 稲田 勝美
    1955 年 23 巻 3 号 p. 187-191
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    To make clear the physiological significance of redox-potential of tissue fluid of the rice plant some experiments were conducted. The Eh value of tissue fluid was determined electrically using homogenate of tissue obtained by means of Waring Blendor. 1. According to our previous work the Eh value on a fine day begins to descend with the sunrise, arrives at a minimum value after noon, and rises again thereafter. To explain the cause of this diurnal changes in Eh value some experiments concerning the influence of light intensity and water temperature on the Eh value were carried out (Table l, 2). The usual course of diurnal changes in Eh value of leaf was changed by shading on a fair weather. That is, temporary shading delayed often the time of descent of Eh value during the day, causing in general a slight rise in its daily average value, while cantinued sheding decreased the diurnal range of Eh value, causing a considerable rise in its daily avarage value. Lower water temperature than optimum lowered the Eh value of shoot and root (Table 3). From these facts the diurnal changes seen on fair weather seem to be caused by sunlight, presumably through its inflnence upon the photosynthetic activity of the leaf. 2. Eh value of the leaf was determined at 6 a. m. every 3-7 days throughout the whole growth cycle of three varieties (Fig. 1). Regardless of the variety the Eh value of leaf ascended generally with the progress of growth stages, arriving at a maximum value in late August and early September and descended afterward with the approach of harvesting time. The Eh value showed some fluctuations; descending on a continued fine weather and ascending on a continued bad weather. 3. Varietal differences in the Eh value of leaf were studied using adult plant grown in a paddy field (Table 4). Varieties having a high resistance to "Akiochi", root-rot and Sesame leaf spot showed generally a high Eh value of the leaf as cnmpaired with those having a low resirtance.
  • 松島 省三, 山口 俊二, 岡部 俊
    1955 年 23 巻 3 号 p. 192-197
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    (1) Since the yields of cereal crops can be said to be the products of their Carbon assimilation, it is very important, as fundamental data for increasing or forecasting their yields, to trace up their responses of the rate of assimilation to the various external conditions in different growing stages. Many former photosynthetic experiments were carried out on detached leaves or in-natural conditions, while the authors tried to measure the rate of corbon assimilation, using whole plant, under as nearly natural conditions as possible with the purpose of applying the results to cultural practices and yield-forecasts of crops. (2) Refering to the method of THOMAS and HILL (1937, '50), the authors constructed a apparetus to measure the rate of carbon assimilation. The apparatus consists of 4 sets. 0ne set of them is shown in Fig. 1. A blower (A) pumps out air stream with constant flow into a cooler (B). Being measured by oriffice (C) and manometer (J), the flow of the air can be adjusted by the blower from 30 litres to 150 litres per minute, in proportion to the rate of carbon assimilation, not to reduce the concentration of carbon-dioxide lower than 80 percent of the normal one. The size of plant-chamber is 50cm. square and 50cm. high for seedling plants and 50cm. square and 100cm. high for adult plants. The most part of the air stream going into the plant-chamber is sent out from a out-let (F), but a part of it is sucked out by a pump (M) as an air sample. The sampled air is pumped out again by the pump (M) into a absorber (O) placed in a waterbath (P) of constant temperature (30 ± 0.02°C) at the velocity of about 300 ml./min. The absorbing solution is 0.005 N sodium hydroxide, containing 1 percent butyl alcohol. A sintered glass dish fixed in the bottom of the absorber breaks up the air stream into very fine bubbles, the alcohol causes foaming and thus prolongs the period of contact between the bubbles and the liqued. The progress of the absorption is determined by measuring the electrical conductivity of the solution with impedance bridge (1000 cycle/sec.), as it changes from hydroxide to carbonate. From the calibration curves between electrical conductivity and the solution differing in the ratio of content of sodium hydroxide and sodium carbonate the amount of the absorbed carbon-dioxide can be easily read at the accuracy of 0.01 mg. Basing upon the difference of the amount of absorbed carbon-dioxide between blanck set and assimilation set, the rate of photosynthesis (apparent assimilation) can be easily calculated. (I....Solarimeter, H.....Thermocup, G.....Small cooler, Q.....Platinum electrode, U.....Gas-meter) Using the present apparatas, the authors made some experiments with rice plants. Results obtained are summarized as follows. (3) Relation between the rate of carbon assimilation and light intensity. From the results of measurements, using 3 varieties and controlling the sunlight with white clothes and natural clouds, in their various growing stages from seedling stage until ripening, it was made clear that the rate of carbon assimilation increases with light intensity up to about 0.5 cal./cm2.min., but it does not almost increase in greater intensities than 0.6 cal./cm2.min. throughout their growing periods, except the later period than about 17 days after heading. In other words, so-called "light curve" of rice plant resembles closely with Blackman's curve, and its light saturation point seems to be about 0.6 cal./cm2.min., except in late stage. In later stages than 17 days after heading both the rate of photosynthesis and the light intensity of saturation seemed to begin to fall off day by day. (Fig. 2 and 3) (4) Diurnal changes of the rate of carbon assimilation. For the experiments in cloudless days, using Norin-No. 25 and No. [the rest omitted]
  • 中山 治彦, 清沢 茂久
    1955 年 23 巻 3 号 p. 198-199
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    1. To study the effects of high night temperature upon the growth and heading of rice plants the following experiment was done, in which the early var., Riku-u-132, and the late var., Norin-18, were used. On May 15 they were sown in nursery bed, and on May 23 transplanted to the Wagner's pot. The plants were adequately managed. The materials were treated in two greenhouses, the one being heated during night time to raise the temperature of average 7°C higher than the other, or the control. The treatments were made at the young seedling stage, elongating stage, tillering stage, and booting stage. At each stage they were carried into the warm-night greenhouse during 30 days. The other treatment was all through the whole life. 2. By the treatment at the youg seedling stage and elongating stage, the rate of appearance of new leaf was increased but the plant height was decreased. By the treatment at the tillering stage the number of tiller was decreased. They were shown in the both varieties. Generally the number of ear decreased when treated, and earlier the treatment cleare was that phenomenon. The time of heading did not differ between the whole life treatments and the control, but with regards to the treatments at various stages, the heading delayed. The dry weight of harvested plants decreased by the warm-night treatment and this was particularly clear in the variety Ri-ku-u-132. 3. From these results, it is recognized that high night temperature treatment has an inhibitory effects upon the rice plants at the seedling and the tillering stage. The authors suppose that the effects may be related to the consumption of nutrients in the plant and that the optimum night temperatures for the growth may differ bettween the late and early varieties.
  • 守屋 直助, 池田 十五, 星野 正生
    1955 年 23 巻 3 号 p. 200-201
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    The present paper reports on the effect of tripping on seed production in alfalfa whose seed production is generally difficult in this country. It is considered from the data obtained that the flowering behavior which has the most important role in the fertilization throughout the whole period of tiowering is the colliding of stigma with standard petal soon after tripping rather than at time of the tripping, because the colliding seems to scatter the pollen grains caught by tripping as a mass on the stigmatic membrane which presumably furnishes the most suitable bed for their germination, to bury them in it, and to expose the conductive tissue in the style by transformation of the stigmatic tissue. It is a problem yet to be solved that whether this transformation of stigmatic tissue results in effective penetration of pollen tube into style or not. (Received April. 4, 1954)
  • 花田 毅一
    1955 年 23 巻 3 号 p. 202-204
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    According to Dr. YAMASAKI the resistance of germinating seeds of wheat varieties to the toxic action of KClO3 shows a close relation with their physiological characters, i. e., cold resistance and spring versus winter type. The present study was made to determine the best stages of germination for testing the toxic resistance of varieties concerned. Seeds of winter wheat (Nishimura) were rendered to germinate at 20°C every 6 hours for 60 hours with a view to obtaining germinated seeds of various growth stages. Those germinated seeds and dormant seeds were treated at the same time with 0.6 % KClO3 solution at 20°C for 20 hours, and then, after being washed with water, were grown with water in the laboratory. The resistance to KClO3 toxicity was tested by comparing the coleoptyle length after treatment with that treated with pure water (control). It wasfound as the result that the further the germination had proceeded, the lower became the resisting capacity to the toxicity. (cf. fig. 1) On the other hand, the contents of reducing sugar and reduced ascorbic acid which are considered, as had been reported by Dr. YAMASAKI, to reduce KClO3 to make KClO (severe poison to plants), in the germinated seeds of various growth stages were determined. The results showed that they increased rapidly up to about 4 days after seeding, and then tended to decrease slowly (cf. table 2). Here, it is interesting to note that the decrease of the resistance to the toxicant of germinated seeds along their growth stage meets well with the increase of the abovementioned substances. Accordingly, attention must be paid in testing of resistance to KClO3 toxicity, to employ germinated seeds with coleoptyles about 5 to 10 mm in length, in order to obtain clearer results. (Received April. 4, 1954)
  • 大熊 規矩男, 須山 勇
    1955 年 23 巻 3 号 p. 204
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    1. Cultivated tobacco plants in field were topped, and water solution of Maleic Hydrazide was applied to the plants. Difference between the standard plots and MH applied plots, in the fresh leaf weight did not proved itself. The drying percentage the yield quantity and the quality of harvested leaves, and the total price of them per unit area, however, showed remarkable increase, especialy in plots, sprayed with 0.5 % solution of MH-30, each 20cc on every tobacco plant. 2. In regards to the effect of sucker prevention, the results of tests with various MH supplied from 4 companies each in two concentrations, namely 0.2 and 0.4 %, indicated that MH-30 was always superiors to MH-40. (Received April. 4, 1954)
  • 茶村 修吾
    1955 年 23 巻 3 号 p. 205
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    Mint plants may practially be propagated by means of stem cuttage. Sufficient amounts of cuttings to plant an area ca 8 times large of that of mother plant field, can be obtained, and, the rhizome growth is found more abundant by this mathod than by usual raising. (Received April. 4, 1954)
  • 宮崎 幸男, 高城 正勝
    1955 年 23 巻 3 号 p. 206
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    Experimental plots were divided into five classes soil moistures of which were kept at 100 %, 80 %, 60 %, 40 %, and 25 %, respectively of the water capacity, and the effects of the soil moisture upon the growth and the oil content of lemon-grass were investigated in 1952. 1. At 80 %, the growth of the plant was best, and at 60 %, it was somewhat inferior. But at 100 % and 40 %, the remarkable obstruction of the growth due to excess or deficiency of soil moisture was recognized. And at 25 %, the effects of drought were found serious recognized. 2. The water content of the fresh leaves was highest at 80 % soil moisture, and the effect was more conspicuous in leaf-sheaths than in leaf-blades. 3. The oil content of the fresh leaves was highest at 100 % moistened soil, slightly decreasing with the soil moisture. At 25 %, the decrease of the oil content by the drought was remarkable. 4. Among three plots of 100 %, 80 %, and 60 %, the specific gravity of the oil was highest at 100 %, the excess of the soil moisture being found to make it higher. 5. The reflactive index of the oil was lowest at 60 %, and both the excess and the deficiency of the soil moisture made it higher. 6. The citlal content of the oil was highest at 80 % and both the excess and the deficiency of the soil moisture made it lower. (Received April. 4, 1954)
  • 戸苅 義次, 武田 友四郎, 丸田 宏
    1955 年 23 巻 3 号 p. 207-213
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    The apparatus deviced by us, gives a nearly instantaneous measuring of the CO2-exchange for a whole plant under natural conditions, and the measurement can be carried for a long time. This apparatus is divided into 4 main parts: (1) The main stream system consisting of plant chamber, gas-meter and exhauster. The chamber is set upon a Wagner's pot in which the plant is cultured, the air is supplied to the chamber by driving the exhauster, and its volume indicated by gas-meter. (2) Air-sampling-cylinder. A pair of air-sampling-cylinders driving at the intervals of 5 min. alternatively, Samples 350 cc. of air per min. from main stream and delivers it to the absorber. (3) Absorber, which holds 50cc. of CO2-absorbing solution (1/(50) NaOH+1% Butyl-Alcohol), catches CO2 completely from the air sample. (4) An electrode, which is inserted in absorber, measuring the changes of electro-conductivity caused by CO2 absorption with the help of Kohlraushe's Bridge. In 1953, CO2 exchange in rice plant cultured in a pot was investigated by applying the apparatus mentioned above, and data obtained are as follows: (1) Diurnal changes of apparent photosynthesis and respiration were investigated at various growing stages. The total daily CO2 assimilation level increases gradually in proportion to the growth, and reaches the maximum amount at the end of the vegetative stage or the beginning of the reproductive stage, then decreases gradually and keeps nearly the same level from booting to heading, and then decreases rapidly during the ripening stage. Otherwise total night respiration level increases gradually accompanying with the growth, and the maximum level appears in the stage from booting to heading, and then decreases gradually. (2) The balance between growth (dry-matter productivity) and carbon dioxide exchange. Fig. 14 shows the total daily apparent assimilation and respiration at each of the main stages of growth. The theoretical curve of increase in dry matter and the actual one are also shown here, the former is calculted from net assimilation value, assumed on the basis of chemical analysis that the dry plant material centains 44 % of carbon, and the latter is derived from the actual growth curve (fig. 15). There is approximate concordance between the experimental curve and the theoretical one in the early stages of growth, however, the former is considerably lower than the latter in later growing stages. This is due to unfavourable climate in the later stage of growth, and also due to the fact thet the estimation is made theoretically for sunny days only. (3) The relation of photosynthesis to light intensity (Lux) is illustrated in fig. 16. There seems to be different demands for light for their maximum photosynthesis according to the vegetative or reproductive stage. It will be found there is no appreciable increase in the rate of assimilation over 60∼70 K. Lux at booting stage and 50∼60 K. Lux at vegetative stage. And in both cases, when the light intensity drops under 20 K. Lux, sudden reduction takes place in the rate of assimilation. (4) During the daytime, in which vigorous CO2 assimilation continues, CO2 concentration in field keeps the valu of about 55 mg per 100 liters of air, in late afternoon this gradually increases and a sudden increase in CO2 concentration takes place after sun set, and then increases gradually during the nighttime, and finally reaches the maximum value of about 70 mg per 100 liters of air berore sun rise. The concentration level decreases abruptly after the sun rise, and returns to the low daytime level of 55 mg until 10 a.m. (Received April. 4, 1954)
  • 山田 登, 村田 吉男, 長田 明夫, 猪山 純一郎
    1955 年 23 巻 3 号 p. 214-222
    発行日: 1955/04/01
    公開日: 2008/02/14
    ジャーナル フリー
    1. 圃場に栽培した水稲農林 36 号及び陸羽 132 号を用い, その光合成作用に及ぼす光及び温度の影響, 並びに光合成能力の日変化について研究した. 2. 測定装置には, 温度, 光及び通気量を自由に且つ独立に変えて, 同時に12点の測定を行い得るような通気式の装置を新たに組立てて用いた. 測定材料としては, 完全に展開した最上位の1, 2番目の葉を用い, その約10枚を切り取つて同化室に入れ, 60l/hr/100cm2 葉面積の割合で外気を通じ, 1000 w の電球によつて最大 10 万ルクスの照明を与えて, 30分間に吸収同化された CO2 量を滴定法によつて定量した. 3. 25℃ 及び 15℃ の測定では, 水稲の葉の光合成作用は 4~5 万ルクスに於て光飽和に達するが, 35℃ ではこれよりかなり低い処で最高値を示し, それより強い光の下では反つて抑制される. 4. 5 万ルクスの光の下で温度の影響を見ると, 広い範囲 (18.5°~33.5℃)にわたつて, 光合成は殆んど一定の値を示すが, 弱光の下では著しく温度に支配され, 温度と共に上昇する. 5. このように水稲の葉の光合成は温度及び光の両者の組合せによつてその受ける影響が異り, 低温弱光の下で著しく低下するだけでなく, 高温強光の下でもかなりの抑制作用を受ける. 6 水稲の葉の内在的光合成能力はその日の晴曇によつて異つた日変化を示す. 即ち晴天の日には朝夕高く日中やや低下するが, 曇天の日には朝最も高く午後に至るほど低下する. この現象には前歴としての光の強さが関係することが明かにされた. また盛夏の自然温度, 自然照度の下に光合成の日変化を測定すると, いわゆる日中低下現象が見られた. 7. 15°~40℃ の間に於ける水稲の葉の呼吸作用の温度係数 (Q10) は時期によつて 1.66~2.06 の変動を示し, 平均 1.87 であつた. また同一の温度で測定すれば, 光合成の強さはほぼ呼吸作用に比例した時期的変化を示す.
feedback
Top