The cytoplasmic proteins from root of six crop plants, which showed various degree of tolerance to highly acidic soil, were divided into Fraction I and Fraction II. The characters of these fractions are summarized as follows: (1) Concerning the electrophoretic patterns of Fr. I, migration distance toward the positive side decreased in the followinc order : rice ≒ buckwheat < maize < sorghum < tobacco < mint. The plants of less lime requirement showed shorter distance with the exception of tobacco. (2) The amount of Ca or Al uptake by one mg. of Fr. I increased in the same order as that of the distance in the pattern obtained with Fr. I of the six crops except tobacco. (3) As the root contained Fr. I much more than Fr. II, Ca or Al uptake by root is considered to be due principally to binding with Fr. I based on the formula, (cation uptake by one mg. Fr. I or II) × (percentage of Fr. I or II in root). (4) The migration distance of Fr. I from plants susceptible to soil acidity such as sorghum and mint decreased with changing pH values from 8.9 to 6.1 and the depression of Ca uptake of the two crops showed the same tendency. (5) No relationship was noticed between the patterns of Fr. II and the lime requiremnt, and also no relationship was seen between the patterns of Fr. II and Al or Ca uptake per one mg. of Fr. II protein. (6) The tolerance of the crop plants to soil acidity seemed primarily due number of negatively charged carboxyl sites and others in Fr. I of the root. In tobacco plants, the experiment suggested that the free site of Fr. I protein readily bound each other as a result of electrostatic reaction. (7) The experiment also showed that slight absorption of phosphate occurred by Fr. I protein and this fact suggests that the phosphate uptake by root is not closely related with Fr.I protein.

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The present study was designed to evaluate the effects of different water temperatures under different air temperatures upon the vegetative growth of rice plant. Pot cultured rice plants were grouped in sixteen plots. Each plot was subjected to different combination of day and night water temperatures for twenty days in four water bathes regulated at 26°C, 30°C, 34°C, and 37°C, respectively. These tests were conducted at nine different periods from April to November. (1) Plant height increased lineary as the air temperature ascended, but those gradients were weaker under the conditions of high water temperature, especially, more than 34°C at night. Optimal water temperature for plant height lowered with increasing air temperature. (2) Favourable effects of daily wide range of water temperature on the number of tillers were clear, especially, at the period with optimal air temperature (ca. 20°C-26°C) for increasing of tillers. (3) High air temperature had effectiveness to weiden the optimal water temperature range in which the number of main stem's leaves increases. (4) Both effects of air and water temperatures on the weights of top and root, showed similar trend of the effect on the plant height. In general, it is assumed that opimal water temperature for rice growth lowered inversly as the air temperature ries.

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A physiological function of culm-node-parts of the culm of rice plant at grain maturing stage was investigated. The term, culm-node-part represents the complex of basements of a leaf-sheath and of an elongated internode, as shown in Fig. 1. This culm-node-part can readily be distinguished in a longitudinal section by staining with ninhydrin, TTC, or iodine. The form of each culm-node-part in a culm varies apparently with the positions of the node. The proportion of internode basement to leaf-sheath basement in an uppermost culm-node-part was 85.0%, while that of the third node from top was 45.5% in dry weight with the variety Manryo (Table 1). In other words, the nearer to the panicle, the greater the proportion of internode basement is. Amylase activity of culm-node-parts was determined as shown in Table 2. The activity in an internode basement was greater at upper node, but that of leaf-sheath basement was conversely decreased at upper node. Such high amylase activity in the uppermost internode basement seems to favor sugar translocation from the culm to the panicle. On other hand, the low activity in the terminal leaf-sheath basement seems to be due to the decreasing leaf area in the upper leaf. Changes in form and amylase activity in culm nodes as described above might have some bearing on the translocation of carbohydrates to the maturing grains. As is generally known, the cutting of leaf-blade at or ten days before heading results in the decreased yield, the removal of flag leaf being most deteriorating. Thus the terminal leaf-blade must have an important function to grains yield. Thereupon, the effect of removing leaf blade on the amylase activity in the culm-node-parts was investigated. The activity was clearly decreased in the culm-node-part with treated leaf as shown in Table 3 and starch content in the internodes just above the culm-node-part with treated leaf was also clearly decreased (Table 4). Hitherto, it has been though that the main reason for the decreased grain yield caused by the leaf-blade cutting is the decrease of leaf area during the maturing stage. However, the results obtained in this experiment suggest that the yield decrease caused by leaf cutting is not only due to the decreased leafarea but to the decrease in translocation of assimilates resulting from the lowering in amylase activity in the culm-node-parts. To prevent a decline of a physiological activity in the culm-node-part will be important for better grains maturing.

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Seeds of four forage crop plants were sown on untilled grassland of various pH value with varying lime nitrogen application. (1) The growth of forage crop plants sown on untilled acidic grassland, primarily depends, when the weeds were few, upon the chemical property of the soil which was changed with pH value. In the plots of denser weed population, however, sunlight was insufficient for the growth. In very heavily shaded plots, forage crop could not survive. The growth of forage crop was primarily related to the amount of sunlight at 1 to 2 cm, above the soil surface. (2) Wild grasses having thickly arranged, wide leaves intercepted sunlight more strongly. Among the same species, the taller weed plants intercepted more sunlight. The taller forage crops received less damage than the shorter ones. (3) Growth of both forage crops and wild grasses was smaller on the soil of lower pH value. The experiment plots, highly acidic grassland of organic volcanic ash soil, were deficient in N, P, Ca, and K, and were excessive in Al. When lime nitrogen was applied to such plots, the soil was still deficient in P and K in the upper layer of soil. As the change of pH values of soil, induced by the dispersion of lime nitrogen on soil surface, was seen only within the depth of 0-6 cm, the growth of perennial weed plants with deep rhizomes was largely influenced by the fertility before dispersion. Cogon grass, which was tolerant to soil acidity, grew vigorously when the soil was rich in NO₃-N.

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The study was carried out to make clear the actual state of the productivity of paddy rice in Chugoku district from the standpoints of regional and yearly variations and other trends of yield by analysing the statistical data from 1955 to 1962. The results obtained are summarized as follows: 1. The high productivity regions of paddy rice in Chugoku district cover its littoral zone and Miyoshi basin. Yamaguchi prefecture, while, Tajima, Iwami and Oki regions are the lowest. 2. The yearly fluctuations in the yield of paddy rice in the mountainous zone along the Chugoku mountain range is unstable, but stable in Setouchi littoral zone, Tajima region and Tottori prefecture. 3. The yield of paddy rice in Shimane prefecture and the mountainous zone along the Chugoku mountain range is increasing year by year, but is stagnant in the basin and plateau of the San-yo region. In the Setouchi littoral zone and the Mimasaka region stagnation or rather declivity is shown.

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The regional characteristics were analized from the standpoints of the similarity of yearly fluctuations of yield, the type of grain production and the state of damages of paddy rice in the Chugoku district. Based on the results thus obtained the regional classification of the trend of productivity was given, which may be summarized as follows: 1. The Chugoku district is divided into four regions, the Setouchi region, the mountainous zone, the eastern and western areas of the San-in region, each showing similar variation of yield. 2. The damage percentage in the Chugoku district is only 7-8%. The largest damage is caused by diseases, and the weather damage ranks next. In the San-yo region, the damage by diseases and insects is large. The large weather damage is added to this in Yamaguchi prefecture. The large damage in the eastern area of San-in is due to weather, while in the western area to diseases and insects. 3. Putting all the results together the writers obtain the following regional classification ; the Chugoku district is divided into six regions, that is, the Setouchi littoral zone (high, stable and stagnant yield area), the Suonada littoral zone (low, stable and stagnant Yield area), the Tottori littoral zone (high, stable and stagnant yield area), the Izumo plane zone (high or middle, unstable and increasing yield area), the Iwami littoral zone (middle or low, unstable and increasing yield area), and the Chugoku mountain range zone (middle, unstable and increasing yield area).

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The regional differences of the meteorological and other natural conditions, having influence upon the productivity of paddy rice in the Chugoku district were investigated. The results obtained are summarized as follows: 1. The configuration of the district forms a great slope on either side of the Chugoku mountain range and its rivers are short with small quantity of water. Accordingly, many paddy fields distribute themselves over the inclined planes along the coast, depending the water supply on the irrigation ponds and rainwater. 2. Since the soil of the paddy field in this district can hold little water and fertilizer because of its basic constituent mainly consisting of acid rock, the basis contained in the soil are liable to be quickly melted and washed away. This becomes also the cause of acceleration of superannuation and "Akiochi" (Autumnal low-crop) due to unusual deoxidation under high temperature, as we have often experienced in many paddy fields. 3. The meteorological condition shows little difference among the regions when viewed from the civil day. But when the growth stage of the paddy rices are compared, it is found that the deeper the district is located in the mountains, the lower the temperature at the former half-stage of growth becomes, and the duration of sunshine at a maximum tillering stage becomes the shorter and the more unstable. Therefore, the mountainous regions may be said unfavourable for securing proper number of panicles.

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The studies were undertaken to explore the relation between equilibrium moisture content in kernel and the grain texture in several varieties of rice and some kinds of kernels at high, medium and low relative humidities. 1. The soft varieties those have somewhat soft and coarse portion in their endosperm tissues^<> approach to higher equilibrium moisture contents at high relative humidity, but to lower equilibrium moisture contents at lower relative humidity in comparison with the hard varieties. (Table 2, Fig. 1, Fig. 2). 2. Chalky kernels and other unfully ripened kernels approach to higher equilibrium moisture contents at high relative humidity, and to lower equilibrium moisture contents at low relative humidity in shorter duration than normal kernels, because those Kernels have the soft and coarse portion in the outer tissue of endosperm. (Fhg. 1, Fig. 3). 3. Generaly, at the same relative humidity, equilibrium moisture content is lower at high temperature than at low temperature¹⁾. The soft varieties are more sensitive to these effects of temperatures, therefore, equilibrium moisture contents in them are higher at high relative humidity and low temperature and are lower at low relative humidity and high temperature in a marked degree than those in hard varieties. (Fig. 4, Fig. 5). 4. At the same relative humidity, equilibrium moisture contents is lower in brown rice than in polished rice because the moisture content of bran is lower than polished rice at usual relative humidity (lower than 80%). (Fig. 6).

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1. In 1964 there ocurred a wheat plant sterile phenomenon at high sterile rate of 70% at Narabara area in Nagano prefecture. 2. The frost-damaged wheat plants were, as compared with normal ones, characterized by such outward appearances as shortness in culm-height, withered leaf apex, yellowish spikes, non-flowering, dead ovaries, abnormal pollen, etc. 3. Based upon the fact-finding survey results, it was inferred that such sterile phenomenon was caused by the death of ovaries and abnomal pollen due to the attack by low temperature of -0.5°C in shelter temperarature at the earing stage. 4. The exactness of the above inference was evidenced by tests using a refrigerator, and it was also clarified that the causes for the occurrence of chilling injury and frost injury at the earing stage were just the same in essence, but different merely in the disparity between them in the degrees of temperatures at the earing stage.

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1. Sterility of wheat plants caused by chilling injury could be distinguished more easily and exactly from sterility of any other descriptions, when overall tests are made, 4 to 5 days after flowering, as to such factors as shortness in internodes at spike necks, reopened glumes, abnormality of pollen, in addition to the primary factor, i. e., size and form of ovaries. 2. The sterile injury could be prevented to some extent by means of timely seeding, adop tion of low-temperature resistant varieties, and cultural practice for growing of healthy plants, but it is regarded as the most safe measure among othrs to culture 6-rowed barley in place of wheat crop, because 6-rowed barley is fairly great resistant to the chilling or frost injury.

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Field experiments were conducted to find out the fertilizer response and dependence on fertilizer of rice plants cultivated in different seasons from 1957 to 1960. Three different seasonal rice cultures were tested, namely, the first, early seasonal culture (transplanted in May and harvested in August or September), the second, ordinary seasonal culture (transplanted in June and harvested in October) and the third, late seasonal culture (transplanted in July and harvested in late October). Norin No.17 was applied in the first, Miho-nishiki was applied in the second, Kogane-nishiki was applied in the third and also Norin No. 29 was tested in each seasonal culture. The results obtained are as follows: 1. Early seasonal culture increased in the number of tillers and panicles per unit area as compared with the other two seasonal cultures both in fertilized and non-fertilized plots. However, the superiority of number of tillers and panicles was not remarkable in the non-fertilized plot. This can be attributed to less appearance of soil fertility due to the lower temperature during the tillering stage. 2. The rice yield increased in proportion to the earliness of transplantation, particularly in case of Norin No. 29. The rate of difference in rice yield between fertilized and non-fertilized plots was the highest in early transplanted plot. In case of the late seasonal culture, about 90 % of the yield was produced even in the non-fertilized plot as compared with the fertilized one. On the contrary, in the heavy fertilized plot, the highest yield was produced in the early seasonal culture. The yield in the ordinary culture showed the intermediate tendency. It was then concluded that the fetilizer response of the rice plants was higher in the early seasonal culture and dependence on soil fertility was higher in the late seasonal culture, as compared with the other two cultures, respectively. 3. Positive high correlations were found between the weight of rice straw and its yield and between number of panicles per unit area and yield in all plots. Effectiveness of increased number of panicles on yield was particularly higher in the early seasonal culture and its effectiveness was much strengthened by increased fertilizer. The high productivity of rice would be expected in the early seasonal culture under heavy fertilized plot.

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In most crown roots of rice plants, usually, the number of secondary lateral roots (per cm of the crown roots) gradually increases from the base towards the tips, comes up to the maximum, and then decreases with decreasing of the diameter of the crown roots. Many other types of branching, are found, i. e., (1) thin crown roots possess abundant secondary lateral roots especially at the apical part. These roots initiate from the upper units of stem and concentrate near the soil surface⁴⁾ ; (2) some crown roots are conspicuously thick in diameter at the base, though branching features are the same as the ordinary ones mentioned above; (3) roots possess numerous secondary lateral roots in their basal parts. These roots appear just after transplanting in a paddy field ; (4) a group of aberrant roots, which is characterized by short shape, covered with few lateral roots (Fig. 3. 6-9); (5) roots often showing a shape similar to "lion-tail", covered very densely with many thick secondary lateral roots⁶⁾ (Fig. 3. 12-14); (6) occasionally, faciated secondary lateral roots are found at the base of the crown roots (Fig. 3. 15-19). These roots possess many thick secondary lateral roots and weak ones which can not emerge outside the epidermis of the crown roots; and (7) another type of roots seemed to have grown in upland field, is found (Fig. 3. 20-21).

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(1) Field tests were made as to the regeneration of Ladino clover after cutting in the warm areas. From the viewpoint of dry matter productive function of Ladino clover grown in plant community, two plots were set up: moderate fertilizerplot (0 kg Urea per are and 3.3 kg KCl per are) and heavy fertilizer plot (1.1 kg Urea per are and 8.2 kg KCl per are). Clover cutting was repeated at intervals of time when the plants reached 30 cm in height. Thus the effects of clover cutting seasons on the Ladino clover regeneration were tested. (2) Ladino clover regeneration was affected greatly by each cutting season (June, August and October), but in every cutting season the plant growth tended to be stopped or slowed down about 20 days after cutting. The dry matter production showed an acclerating increase in June, but showed a marked decrease in and after August, and with the lapse of days after cutting, the dry matter production increasing rate tended to be slowed down or stopped. (3) As to the effects of the fertilizer application amount, the trend was observed that the Ladino clover regeneration in the heavy fertilizer plot was more vigorous in October (when the plant growth was retarded) and it showed increases in the dry matter production in heavy fertilizer plot over that in moderate fertilizer plot in every cutting season, particularly less in the slowdown of Ladino clover regenerating action in heavy fertilizer plot than that in moderate fertilizer plot even in August (high temperature summer month). (4) As high as 1.0 % significant negative correlation was found between net assimilative rate and leaf are a index in each cutting season. The regression coefficients were greater in order of October, August and June. The population's growth rate formed an optimum curve indicating the rise in the rate with the increase in leaf area index and then the fall to some extent, but the maximum values were greater in order of June, August and October. The regression coefficient was smallest in June and largest in October. In the case of heavy fertilizer plot, the peak was reached somewhat later, indicating that the range to approximate the optimum conditions was wider in the case of heavy fertilizer plot than in the case of moderate fertilizer plot. (5) Highly significant negative correlations were found between (a) the relative light intensity on the soil surface of 5cm thick where Ladino clover grown in plant community and (b) the leaf area index. With the increase in leaf area index, relative light intensity showed a decrease functionally. The decreasing rate was higher in order of October, August and June. And it showed a trend that the decreasing rate for moderate fertilizer plot was higher than that for heavy fertilizer plot. Thus it was inferred that the construction of the plant community varied with clover cutting seasons and the fertilizer application amount. (6) Carbohydrate content in Ladino clover runners was greatest in October. It showed a decrease in carbohydrate-content according to the season in which plant growth was forced. Viewed from the effects of fertilizer application amount, the accumulated amount of carbohydrate was larger in heavy fertilizer plot than that in moderate fertilizer plot, because though it showed a marked decrease in carbohydrate-content immediately after clover cutting, it was regained with rapidity.

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In the leaves of wheat plant, most of the mesophyll cells which are called the arm-palisade cells have several lateral protuberances developed at right angles to the leaf surface. In this experiment, the mesophyll structure of the wheat leaves, grown under the shades of natural daylight, were observed and following results are obtained. 1) In the leaf blades developing in the shade, the number of protuberances in a cell decrease and the cells having no protuberance increase at the base of the leaf blades inserted at lower levels of the shoot. Diameter of protuberance is larger and its length is shorter in the shade. 2) As far as the cells having the same number of protuberances are concerned, the cells in the shade are longer in length and shorter in width than those in natural daylight. 3) The ratio of the cell surface to the cell volume (S/V) and the number of cells per unit leaf area are decreased in the shade. Therefore, the total cell surface per unit leaf area is smaller in the shade than that in natural daylight. 4) At the base of the leaf blade, the above-mentioned structural changes of the mesophyll are more remarkable than those of the other portions. Accordingly, it may be concluded that the leaves developing in the shade are more resembled to the lower leaves having a structure of shade leaves.

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The process of regeneration was observed histologically, after the tip of seedling root, 2--3cm long, of Zea Mays had been decapitated or incided longitudinally. 1. Decapitation case --- The observation of the root tip which had been decapitated in the plane at different distances from the growing point, revealed that the tissue between the growing point and the part 400μ deep toward the base from the point regenerates a normal root apex (table 1). It was then confirmed that the decapitation brings about a callus formation and the pattern of the root apex is regenerated immediatly and centripetally (fig. 3). After the completion of a root apex, the new root tip starts elongating. 2. Incision case--With a single or a cross incision of a root apex, two or four normal roots were regenerated (fig. 1). The histological observation on incisions at different depths from the growing point, revealed that the callus formation is limmited within the wounded zone 400μ away from the growing point (table 2). The callus fomation in this case spreads basipetally from the growing point, and even late metaxylar vessels produce their derivatives. The position of a new growing point can be recognized at the very early stage of regeneration (fig. 4, 5), but the stele in the basal portion begins to be reconstructed befote the recompletion of the root apex (compare fig. 6A with fig. 4B). The observation on the transections indicated that the kind of the tissue, into which the derivatives of late metaxylar vessels mature, depends upon the position of derivatives in the horizontal plane (fig. 6). All the late metaxylar vessels differentiated soon after the apical meristem has been regenerated, are always connected with some of the old vessel elements (fig. 7). It may thus be concluded that not only basipetal but also acropetal as well as horizontal functions among cells or tissues shoud be recognized in the part of the root tip 400μ deep from the growing point toward the base, and these three functions work together to maintain the normal organization and differentiation. Fig. 1. Normal four roots regenerated after a longitudinal cross inclsion of the root apex. 7 days after the operation. - Fig. 2. External view of root tips 2 days after the incision. Incising depths from the growing point are, from the right, 50-100μ, 100-150μ, 200-250μ, 300-400μ, 400-500μ, and 600-700μ, - Fig. 3. Longitudinal sections of root tips decapitated at the plane 100-150μ away from the growing point. LX, late metaxylar vessel ; DG, dermatogen; CG, calyptrogen. A: 1 day after the operation, callus parenchymatous cells being derived all over the wounded plane. B: 2 days after the operation. C: 4 days after the operation, the pattern of root apex having been almost reformed. ×80. - Fig. 4. Longitudinal sections of the halves of root tips incised longitudinally. The wounded plane is in the right part of each photograph. A : 7 hours, B : 1 day, C : 2 days after the operation. GP, growing point. Note that wound callus formation spreads basipetally from the old growing point and the position of a new growing point has already become recognizable 1 day after the operation. Fig. 5. Transections of a root tip 1 day after incision. A : 200-250μ, B: 150-200μ, C : 100μ, each away from the growing point at the time when the root tip was operated. D: left, 90μ away from the growing point, and right, close to the growing point. Cell division can be recognized more frequently in the apical part than in the basal, and all the late metaxylar vessels have produced their derivatives. ×140. - Fig. 6. Transections of the root tips at the portion of 100-150μ away from the growing point at the time when the root tips were incised. The wounded, plane is in the lower part of each photograph. A: 2 days, B: 4 days, C: 7 days after the operation. EN, endodermis; PX, protoxylar vessel. [the rest omitted]

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Vatious morphogenic abnormalities as shown in figures were observed in the rice spikelets which were grown under low temperature-day temperature 14-18°C and night temperature 14°C. Morphogenic abnormalities found in the spikelets may be summarized as followings: 1) changes of organs in number, especially increment in number, 2) remarkable phenomena of fusion of inter and/or intra organs of lodicules, stamens and ovaries, 3) appearance of organs of intermediate and bisexual structures, 4) changes in sex expression, promoting femaleness and depressing maleness, 5) continuance of vegetative growth in the spikelets with no formation of sexual organ, incepting only glume and branch primordia, 6) exposure of extraordinarily developed ovule or integument from ovary through the style canal, 7) frequent occurence of abnormally swelled tissue or organ, and 8) appearance of multi-floret spikelets, etc. From the results above mentioned it is considered that the morphogenic regulation in the meristematic tissue of spikelet primordia may become unstable and the disturbance of organ development tends to be occured, by the low temperature treatment. Some discussions were tried on the relationship between the appearance of morphogenic abnormalities due to a low temperature treatment and the level of some growth substances, auxins and gibberellin, in spikelet primordium, based upon the writers' experimental results previously reported.

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1) This study was carried out to make clear the distribution of morphological abnor- mal spikelts induced by gibberellin. 2) It was indicated that the number of spikelets was increased remarkably with the treatment as previously reported and the increase was more conspicuous in upper primary branches than in lower ones. 3) Main morphological abnormalities, such as inception of additional glumes, chandes of stamens and pistils in number were found more frequently in the upper portion of the primary branches. 4) Judging from the above results, it is considered the morphogenic effects of gibberellin on panicle development are more remarkable in the upper or distal portion of panicles or primary branches. This tendency also supported by the writers' studies on the effects of gibberellin on the vascular development in panicles. 5) On the other hand, so called "white hulls" were found frequently in the basal portion of lower primary branches. So, it is concluded that the initiation of "white hulls" should be brought about by a quite different pathway from that of the morphogenic abnormalities. 6) The difference in frequency of the abnormality in glume, stamen and pistil was indicated and discussed from the stand-point of the ontogenic changes in form and related morphogenic substances in the meristematic tissue of spikelet primordium.

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1. This study was carried out to make clear the effects of gibberellin upon the development of vascular bundles in rice panicles. 2. Gibberellin was applied to a variety of paddy rice "Sachikaze", at the concentration of 100 ppm mixed in nutrient solution, at the stage of panicle primordium differentiation. 3. It was cleared that the number of large vascular bundles in rachis and that of small ones in rachis and primary branches had been increased with the gibberellin treatment, though there had been no change in secondary branches and peduncles. 4. The increase of large and small vascular bundles in rachis was accompanied by the increase of primary branches, and the increase of small vascular bundles in primary branches was considered to be followed by that of secondary branches and peduncles. 5. The number of cells composing vascular bundle had been increased in both large and small vascular bundles at every portion with the treatment, and this tendency had been conspicuous acropetally to the distal region of primary branch. 6. Regarding to the number of cells in each element of vascular bundles, except parenchyma cells, the number of cells in every element, especially those of fibre and xylem vessels, had been increased by gibberellin. Sclerenchymatous cells could be foums remarkably not only in vascular bundle but also in the bundle sheath and the neighbourings. This tendency also had been conspicuous acropetally to the distal region of primary branch. 7. Based on the results previously obtained by the writers in which both the increase of spikelets in number and the occurrence of morphogenic abnormalities in spikelet were frequently found at the distal regions of panicle and primary branches, and on the results above mentioned, it was considered that the morphogenic effects of gibberellin on the panicle development should become conspicuous acropetally from base to tip in rice panicle.

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