Japanese Journal of Crop Science
Online ISSN : 1349-0990
Print ISSN : 0011-1848
ISSN-L : 0011-1848
Volume 35, Issue 3-4
Displaying 1-23 of 23 articles from this issue
  • J. P. Patel
    1966 Volume 35 Issue 3-4 Pages 115-119
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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  • Yuko OGURA
    1966 Volume 35 Issue 3-4 Pages 120-125
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    1. The effects of soil moisture on the rate of transpiration from tobacco plant (variety, Bright Yellow) were studied. The plant was maintained in an air conditioned glasshouse in a 1/5, 000 Wagner's pot packed with soil kept at a constant moisture. The moisture levels, 20, 40, 60. and 80 volume %, were designed in all. The rate of transpiration was measurd by means of the weighing method during the whole growth stages. The transpiration per plant and per unit energy of radiation showed a peak in every moisture level before the stage of the maximum leaf area, and this peak appeared higher and earlier under the high moisture level than the others. 2. The rate of transpiration per unit leaf area showed a peak in earlier stage than above mentioned. The difference was clearly seen between different moisture levels, but it became indistinct after the topping. This may be due to that the rate of transpiration per unit area from each leaf has a peak in considerably early stage of its expansion and that the moisture of a leaf is usually increased with that of the soil. 3. "The water requirement" per unit leaf weight was higher with the high moisture levels and the delay of the harvest. The time of harvest especially of the tobacco plant, affected largely on "the water requirement".
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  • Yuko OGURA
    1966 Volume 35 Issue 3-4 Pages 126-130
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    Some experiments were conducted on the method for measuring transpiration by the moisture absorption of granular CaCl2. Following the results of preliminary test, the degree of moisture absorption was limited within ten per cent bf the dry weight or a quarter of maximum absorption to hold the error due to free-pass-moisture less than one per cent. On the comparison of the evaporation from a evaporative pan and the absorption by this method, any significant difference was not found at 95 per cent confidence level, and it was concluded that this method was accurate enough for practical use. As the rate of transpiration varies considerably with air velocity, the velocity at the leaf surface was fixed at a value between 1 to 2 cm per second. The distribution of transpiration by the leaves on various ous positions of the stem was shown. A leaf chamber was devised for measuring the partial transpiration in a leaf. The rate of transpiration from the upper and lower surfaces of a leaf was measured separarely. The difference was also shown on the rate of transpiration from the apical and basal parts of a leaf-blade.
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  • Seiichi AKAMATSU
    1966 Volume 35 Issue 3-4 Pages 131-136
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    Pot tests were attempted at Faculty of Agriculture, Okayama University in 1963 as to the relationship of seeding density to plant growth and rice yield in case where rice seed was sown by broadcasting by hand directly on the submerged paddy field. Size of each pot: 1 meter long, 0.8 meter in width, and 1 meter in depth. Sample rice variety: PI-5. Tests were made by four replications as to the seven plots (from 30-hill plot to 210-hill plot) aligned at random. Fertilizers were applied according to the customary practice. Test results can be summarized as follows : (1) At the earlier plant growth stage, culm height of rice plants in the densely sown plots was higher than that in the sparsely sown ones, but vice versa at the later plant growth stage. (2) At the peak tillering stage, the number of tillers per unit area in the densely sown plots showed an increase over that in the sparsely sown ones, but after that stage, the former showed a marked decrease in the number of tillers. At the harvesting time, the number of panicles in 90-hill plot was greatest, reaching 502 panicles per square meter and that in 30-hill plot was smallest, showing 304 panicles and that in the plot sown more densely showed a decrease to about 405 panicles. (3) Rice yield in 90-hill plot was highest. This is due to the greatest number of panicles therein. (4) Rice yield in the plots sown densely more than 120 hills was lower than that in 90-hill plot. This can be ascribed to the inadequate amount of the customary fertilizer application for the densely sown plots in the later plant growth stage. Consequently, if improved split-application practice be designed, rice yield in the densely sown plots would show more favorable trend than that in other plots.
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  • Masao HOSHINO, Shuichi NISHIMURA, Tadakatsu OKUBO
    1966 Volume 35 Issue 3-4 Pages 137-141
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    Whole plants of Ladino clover were exposed in light to 14CO2 for 4 1/2 hours and distribution of 14C in ethanol, acid, alkali-soluble fractions and residue immediately after and 4 days after 14CO2 treatment were investigated. Young leaves assimilate actively and retain considerable parts of their assimilates as a structural component, i.e., alkali-soluble fraction and residue (mainly protein and cellulose). The biosynthesis in these fractons seemes to be progressing rapidly, and even immediately after 14CO2 treatment 14C was widely distributed in the structural fractions of young parts of plant. Older leaves use greater parts of their assimilates by respiration and send them to other parts of plant. therefore 14C activity decreased significantly from immediately after 14CO2 treatment to 4 days after treatment. 14C-assimilates were translocated and accumulated as a structural or reserved fraction, namely, acid and alkali-soluble fractions and residue to young parts of stolon near growing points. 14C-assimilates in older part of stolon immediately after 14CO2 treatment were mainly in ethanol soluble fraction. Four days after treatment 14C activity decreased significantly and 14C was distributed in reserved and structural fractions, but in small amounts. Young parts of petiole, root, lateral buds and growing points of stolon were important sink of assimilates in Ladino clover.
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  • Masaki HORIE, Iwao YAMAMURA, Toshio HOSOYAMA
    1966 Volume 35 Issue 3-4 Pages 142-147
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    In order to find out the complex characteristics composed by six morphological characters in rire varieties this experiment was carried out at Horinouchi Experiment Farm of Niigata Agricultural Experiment Station. Fourty varieties of rice were cultured under standard fertiliziug and normal spacing of plants at Horinouchi Experiment Farm, and the following six characters were employed in order to obtain the complex characteristics number of panicle (x1), culm length (x2), panicle length (x3), panicle weight of the longest stalk (x4), panicle weight per plant (x5) and total weight per plant (x6). The complex characteristics were estimated by the principal component analysis which was one of the multivariate analyses, and then studies on the varietal differences by these complex characteristics were performed. The results were as follows: (1) The complex characteristics of rice varieties in this experiment can be shown by three principal components as indices of complex characteristcs. These three indices of complex characteristics are as follows : X1=0.580x1-0.178x2-0.458x3-0.445x4+0.163x5+0.253x6 X2=0.211x1+0.337x2+0.217x8+0.408x4+0.700x5+0.636x6 X3=0.153x1+0.877x2-0.008x3-0.038x4-0.155x5-0.036x6 (2) The first index of complex characteristics is mainly concerned with whether the variety is a tiller-number type or a panicle-weight type. The second index is mainly concerned with the yield of variety on a plant basis and the third index, with plant height.
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  • Masaki HORIE, Iwao YAMAMURA, Toshio HOSOYAMA
    1966 Volume 35 Issue 3-4 Pages 148-154
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    Studies were performed on the varietal differences of the morphological complex characteristics in rice varieties at different planting spaces. Spacing between plants in the row employed in this experiment was 5 cm and 25 cm, while spacing between rows in both plots was 20 cm. In the previous paper (3), the normal planting space was 15 cm within the row. All the other neccessary materials and methods in the present case were in accordance with the previous experiment (3). The results are as follows : (1) The complex characteristics of rice varieties in the 5 cm-plot can be shown by two principal components as indices of complex characteristics, and on the other hand in the 25 cm-plot it can be shown by three indices as in the case of 15 cm-plot. These indices of complex characteristics are : 5 cm-plot: X1=-0.371x1+0.462x2+0.525x3+0.548x4+0.144x5+0.152x6 X2=0.503x1-0.091x2-0.094x3+0.012x4+0.646x5+0.662x6 25 cm-plot: X1=0.563x1-0.188x2-0.463x3-0.467x4+0.126x5+0.233x6 X2=0.215x1+0.288x2+0.259x3+0.387x4+0.705x5+0.604x6 X3=0.011x1+0.860x2-0.027x3-0.027x4-0.181x5+0.178x6 (2) The meaniag of these indices in the 5 cm-plot is as follows: The first index is mainly concerned with the plant type whether the the variety is a shortculmed, tiller-number type or a long-culmed, panicle weight type, and the second index is mainly concerned with its per plant yield. (3) In the 25 cm-plot, the weaning of each index is the same as in the 15 cm-plot. (4) In any case, it seems that the complex characteristics of rice varieties in each plot under the standard fertilizing conditions can be shown by the three factors : the plant type whether the variety is a tiller-number type or a panicle weight type, the per plant yield, and the plant height.
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  • Masaki HORIE, Iwao YAMAMURA, Toshio HOSOYAMA
    1966 Volume 35 Issue 3-4 Pages 155-160
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    According to the line previously reported (2, 3), studies on the varietal differences of the morphological complex characteristics in rice varieties were performed with the data from three planting spaces being put together. Namely, spacing between plants in the row was 5 cm, 15 cm and 25 cm, while the spacing between rows was 20 cm in the whole plots. All the other neccessary matarials and methods were in accordance with the previous experiments (2, 3). The results were as follows : (1) The complex charcteristics of rice varieties in the whole plots putted together can be shown by two principal components as indices of complex characteristics, the result being the same as in the 5 cm-plot in the previous paper (3). These indices of complex characteristics are : X1=0.457x1+0.123x2+0.293x3+0.368x4+0.499x5+0.490x6 X2=-0.296x1+0.529x2+0.613x3+0.494x4-0.064x5-0.091x6 (2) The meaning of these indices is as follows: The first index is mainly concerned with the per plant yield of the variety. The difference in the first index is attributable to the difference of planting spaces. The second index is mainly concerned with the plant type which were whether it is a long-culmed, heavy panicle-type or a short-culmed, tillering type, the meaning of this index being the same as in the first index in the 5 cm-plot. (3) The plant type shown by the second index of complex characteristics was changed by difference of planting spaces, and there were three types in these changes. One of the reasons of these changes was mentioned.
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  • Jun INOUYE, Yoshiichi OKADA, Tsukuda KATAYAMA
    1966 Volume 35 Issue 3-4 Pages 161-167
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    Recently direct-sowing culture of paddy rice has been put into practice and it has given rise to a problem in seedling-emergence. This experiment was made on the strength of elongation of coleoptile using strain meter. The measurement of the strength was made in darkness at 30°C. In this experiment about 15-30 mm length of coleoptile was used as material. In some cases, strength of elongation of foliage leaves was measured. Results were as follows: 1. Strength of elongation of coleoptile of paddy rice plants decreased with the increase of soil moisture content. The strength of "Ariake" was about 15 g in 15 percent moisture plot, 12 g in 20 percent moisture plot and only 0.6 g in 25 percent moisture plot. The strength was more vigorous in coleoptile of well ripened seed than that of poorly ripened seed. 2. Strength of elongation of coleoptile differed in each type of rice plants, i.e., in 15 percent moisture plot, 15.9 g-11.8 g of paddy rice plants and 11.7 g-10.3 g of upland rice plants in japonica type, and 18.9 g-9.9 g of rice plants in indica type. 3. As regards the coleoptile of paddy rice plants, no positive relationship between the strength of elongation of coleoptile and the height or maturity was observed. 4. Strength of elongation of imperfect leaf was about 22 g and that of the 1st leaf was about 4 g in 15 percent moisture plot.
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  • Takuma GEMMA
    1966 Volume 35 Issue 3-4 Pages 168-171
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    1) The vascular connection between tops and roots was traced after dyeing and also observed by microscopic photographs. It seems that the inner rings are connected with the older leaves and the outer rings with the younger leaves. Since the arrangement of the vascular bundles is thought to be governed by the phylotaxis (5/13), each leaf corresponds to 5/13=0.385 of each ring, in other words, 13/5=2.6 leaves correspond to one vascular ring. 2) On the basis of the premise as mentioned above, area and life span of each leaf and the volume of corresponding root tissue layor originated from its vascular cambium at harvesting time were measured. Then the correlation coefficient of the followings was calculated: (1) leaf area of 2.6 leaves and each volume of the corresponding root tissue layer originated from its vascular cambium. (2) leaf area of 2.6 leaves × life span of them and volume of corresponding root tissue layer originated from its vascular cambium. The correlation coefficient of (1) was 0.923*** and (2) 0.882***. By these findings, the suppositional structure of sugar beet was ascertained and thikening growth of root was shown to be strongly governed by the area and life span of corresponding leaf, especially by the former.
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  • Teruyoshi NAGAO
    1966 Volume 35 Issue 3-4 Pages 172-176
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    In order to make clear the effect of particle size and moisture content of soil upon the number of vascular bundles in the primary roots of tobacco, the 27∼50 day's seedlings of the variety Bright Yellow which had been grown in the nursery bed, were transplanted to the pots with the soil of various sizes of sand particles and various soil moisture contents ranging from 30 to 100%. Afterwards, the number of vascular bundles in the primary roots developed from the main ones were measured. The result of the experiment revealed that the number of vascular bundles in the primary roots increases with the decreasing size of soil particles and with increasing soil humidity and, furthermore, that the vascular numbers have an intimate correlation with the diameter of the roots. Variability of vascular numbers has a connection with the position of the primary roots on the main ones, namely, the primary roots form higher positions bear more vascular bundles than those from the lower ones. Differential diffusion of air and dissolved oxygen due to different particle sizes and soil humidities will designate the branching at corresponding positions on the main roots and, moreover, the number of vascular bundles in the developing primary roots.
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  • Hiroyoshi CHUJO
    1966 Volume 35 Issue 3-4 Pages 177-186
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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  • Hiroyoshi CHUJO
    1966 Volume 35 Issue 3-4 Pages 187-194
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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  • Yasumasa KATO
    1966 Volume 35 Issue 3-4 Pages 195-204
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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  • Ken-ichi HAYASHI
    1966 Volume 35 Issue 3-4 Pages 205-211
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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  • Shizuo TAKEGAMI
    1966 Volume 35 Issue 3-4 Pages 212-215
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    In this study, an attempt was made to find a more simple method of inoculating scab onto leaf blade, because of the inconvenience and the troublesomeness of the previous method including fixation of vinyl ring containing potato agar medium on the leaf blade to be inoculated. It was found that the use of small pieces of wheat or spinach leaves gave a more satisf factory result than the use of potato agar medium. The procedures used were as follows: 1. Small pieces of each 8 mm in diameter are punched from wheat or spinach leaves and soaked in boiling water for 3 minutes. 2. Three layers of the boiled leaf pieces are placed on the region of leaf blade to be inoculated, and adhered with cellotape followed by wrapping with wrap-film. 3. The treated plants are kept at 20∼25°C. Moreover, the comparison of wheat and spinach leaved indicates that spinach is superior to wheat leaf as the inoculating medium, and results in the more severe and more rapid infection of scab.
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  • Noboru IKENAGA, Rinitsu MORITA, Takeo SAITO
    1966 Volume 35 Issue 3-4 Pages 216-222
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    This experiment was carried out in order to make clear the relation of the sowing time to the plant growth and rice yields. Sample varieties used for this experiment were extremely early-maturing varieties (Yukara and Sasahonami) and early-maturing varieties (Fujiminori and Koshijiwase). Seeds were sown in varied seeding density ranging over four times from the late May to early July. The authors tested the growth and yields affected by variations in sowing time. 1) Grain yields decreased linearly with the delay in sowing time, showing a decrease of 0.3 to 0.45 kg. per are per day. The decrease in yields from the yields in late May sown was at the rate of 0.5 to 0.9 per cent. This was thought that the reduction in yields was caused by decrease in the dry matter accumulation in panicles and by failure in full-ripeness. 2) The decrease in dry matter accumulation in panicles with the delay in sowing time was due to the reduction in the rate of increase in dry matter production during the ripening periods. The lowering of increasing rate in dry matter during the ripening periods was due to the decrease in the net assimilation rate and leaf dry weight, and affected greatly by the decrease in the net assimilation rate in the case of extremely early-maturing varieties and by the decrease in the leaf dry weight in the case of early-maturing ones. 3) The failure in full-ripeness by the delay in sowing time was due to the lowered ratio of "the quantity of dry matter accumulation in panicles per unit area" to "the number of hulls per unit area". namely, it was due to the rate of decrease in the number of hulls per unit area was less than that of decrease in the quantity of dry matter accumulation in panicles per unit area. 4) During the ripening period, the leaf dry weight in extremely early-maturing varieties were less than in early-maturing varieties, but net assimilation rate in extremely early-maturing ones was higher than in the early-maturing ones. As a result, no significant differeces were found in the rate of increase in dry matter weight between both varieties. Consequently, in the variation of sowing date no significant differences were found in yields between extremely early-maturing varieties and early-maturing ones. 5) Yukara showed higher yield than Sasahonami, and Fujiminori than Koshijiwase. This was ascribed to the fact that Sasahonami was very poor in ripeness (excess of hulls) and the dry matter increasing rate for Fujiminori was high throughout the entire plant growth period. There were generally a few differences in yields according to seeding density.
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  • Noboru IKENAGA, Rinitsu MORITA, Yoichiroo MASUO
    1966 Volume 35 Issue 3-4 Pages 223-227
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    This experiment was carried out in order to find out how to keep from decrease in yields caused by the delay in sowing time. The experiment plots were combined the different times of heading (late July, early and late August and early September) with the amounts of top dressing of nitrogen (0, 0.2, 0.5, 0.8 kg. per are) at heading time. Sample varieties used for this experiment were Yukara (extremely early-maturing variety) and Fujiminori (early-maturing variety). 1) The rate of matter increase in both varieties during the ripening stage showed marked increases with the increase in nitrogen supply at heading time, because a higher rate of dry matter increase during the ripening stage was resulted from the increase in leaf dry weight due to the development of leaves of the lately emerged ears in the upper nodes of plants and keeping from death of leaves. 2) The increase in dry matter production during the ripening stage led to the increase in the accumulation of dry matter in panicles, but the relation between them was not so close. Consequently, it was found that the increase in the quantity of accumulation of dry matter in panicles per unit area were not so large as increase in dry matter production per unit area. These results were thought to be ascribed to the accumulation of greater amounts of dry matter in the base of stems and to the lately emerged eares in upper nodes of plants. 3) According to the increasing rate of dry matter production, higher yields in those plots headed in late July were obtained by increase in the number of panicles per unit area due to the lately emerged ears in upper nodes, and in those plots headed on other dates high yields were obtained by a higher rate of ripening. Viewed generally, it was found that the grain yields tended to increase more with the increased supply of nitrogen. 4) The grain yields in both varieties tended to decrease more with the delay in heading time, but the effect of top dressing of nitrogen on grain yields was greater in the case of later heading time than in the case of earlier heading time. Accordingly, by the top dressing of nitrogen at heading time, grain yields were prevented from being reduced due to the delay in heading time (sowing date). 5) The yields increasing rate in the later heading time was high, as compared with that in the earlier heading time. It was due to the fact that in the case of later heading time the yields showed marked increases in comparison with the increase in dry matter accumulation in the panicles. The cause therefore can be ascribed to the fact that in the case of later heading time partially ripened grains (which occur frequently) can be transformed into fully ripened grains on account of increase in dry matter production in panicles by the effect of the additional application of nitrogen at time of heading.
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  • Mamoru NAGAI
    1966 Volume 35 Issue 3-4 Pages 228-233
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    The experiment was performed to find some regularity on the changes of day intervals required for the emergence of each consecutive leaves on the stem of rice plants. As experimental materials, some varieties of rice plants were grown in Wagner pots with soil or water media, by direct sowing method. The results obtained are as follows: 1) The day intervals required for each leaf emergence on the main stem differed according to the growth stages of the plants. Namely, the intervals at the early growth stage (earlier than 7 th leaf-age) were short and hardly differed among each leaf, then, became gradually longer as the growth stages advanced. And the intervals became longest at 1 st or 2 nd leaf below the bootleaf, the intervals of which were a little shorter than those of its predecessors. 2) Therefore, the changes of the day intervals through out the growth period might be divided into three periods. These periods could be considered from a different view of the plant growth, that is, the first period meight be corresponded to the most vigorous growth period of tillers, the second period to the one when tillering is unstable or almost none and the third period to the reproductive period of the plants. 3) The day intervals of the tillers were a little shorter than those of the main stem. But, wherever tillering might occur, the changes of day intervals of tillers caught up the very trends of the main stem after the emergence of 1 st or 2 nd leaf. 4) In regard to varietal difference of the intervals, no clear difference was found except for the 1 or 2 leaves below the boot-leaf.
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  • Mamoru NAGAI
    1966 Volume 35 Issue 3-4 Pages 234-238
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    This investigation was carried to observed the growing processes from differentiation to withering of leaves on the main stem at definite positions and was to know the leaf emerging sequence in connection with these observation. The materials were grown in Wagner pot with soil by direct sowing method. The results obtained can be summarized as follows: 1) When a leaf attained its full size, the shoot always had four immature leaves. 2) Both of the elongation period and life duration (the period from its full emergence to the time when the area of its blade had 50 % greened) of lower leaves were shorter than those of upper. In other words, the longer the elongation period required for the leaf, the longer the life duration became. And the leaf emmerged at the early stages of shorter day intervals required shorter life duration, and vice versa. 3) The elongation speed per day of lower leaves was faster than that of upper. 4) The leaf-blade length and the leaf-sheath length became longer from lower to upper one and longest at the 3 rd (blade) or 4 th (sheath) leaf below the boot leaf, and thereafter the leaves emergenced were shorter than those of their predecessors. But, these facts could not be applied to a plant which has only a few number of leaves on the main stem. These observations suggest that the day intervals of leaf emergence have no relation with the length of immediately lower leaf sheath.
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  • Kazuo NAGATO, Morie EBATA, Yoichi KISHI
    1966 Volume 35 Issue 3-4 Pages 239-244
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    Though varietal differences exist in the extent of effects, generally speaking, high tempeatures during ripening period accelerate the respiratiion of rice plant and hasten the maturation of kernel, consequently, the development of kernel and accumulation of starch into kernel are accelerated in the early period of maturation, yet they are depressed in the late period. Thus, high temperatures have various influences upon the grain development and the grain qualities. In this experiment, 8 varieties of Indica and one variety of Japonica were subjected to the temperatures of 23° and 30°C during ripening, and the following fesults were obtained: 1) Effects on the dimensions of kernel: The high temperatures lessened the length and breadth of kernel and the 100-grain weight in almost all varieties. The ventral radius was lengthened because of the acceleration of development in early period and the dorsal radius was shortened on accounts of the depression of development in the late period, so that the dorsoventral ratio was lessened at high temperature. Such varieties as Fujisaka-5, Prelude and Magnolia which showed remarkable decrease in dorsoventral ratio were assumed to be less adaptable to high temperature. (table 1, 2) 2) Effect on the thickness of bran: Number of layers of aleurone cells, thickness of aleurone layer and thickness of pericarp and testa were measured on the dorsal ridge and flank region as representatives of bran layer of kernel. In general, number of layers of aleurone cells and thickness of aleurone layer on the dorsal ridge and thickness of aleurone layer on the flank region increased on account of the acceleration of development in early period, and thickness of pericarp and testa on the flank region was thickened according as the depression of starch accumulation in the late period. High temperature had no marked effect on the thickness of pericarp and testa on the dorsal ridge and number of layers of aleurone cells on the flank region. (table 3) 3) Effect on the occurrence of the white-ridge kernel: Occurrence of the white-ridge kernel is due to the acceleration of developmemt in the early period and the depression of starch accumulation in the late period, accordingly, occurrence of them is closely connected with decrease of dordo-ventral ratio as reported previously5). This relation was recognized in this experiment and the white-ridge kernels occurred numerously in such varieties as Fujisaka-5, Prelude and Magnolia of which dorso-ventral ratios markedly decreased at high temperature. (table 4, 2) 4) Effect on the occurrence of the milky-white kernel: The milky-white kernels (chalky rice) caused by high temperature occurred on account of deficient accumulation of starch in the early period of maturation, because of the competition for absorption of nutrients as a result of rapid maturation. Therefore, they had linear or spindle-shaped opaque part on the middle of cross section. As shown in table 4, the milky-white kernels occurred numerously at high temperature in all varieties, especialy in Tadukan, Tepa-I and Ubaisen, and these vaeieties are thought to be undesirable in the tropics. 5) Effect on the occurrence of the basal-white kernel: Basal wuite kernels are produced by the depression of starch accmulation in the last period of maturation, therefore, the occurrence of them has a connection with the increase of thickness of pericarp and testa on the flank regin of kernel. In this study, basal-white kernels noticeably increased at high temperature in all varieties, especially in Prelude, Tadukan, Tepa-I, Ubaisen and Fujisaka-5 assumed to be less adaptable to high temperature. (Table 3, 4) 6) Effect on the cooking qualities: Water-uptake ratio and total solids content were examined at cooking temperatures ranging from 65° to 75°C, because these characteristics of different kind of rice were mast distiguishable in this range of temperatures. [the rest omitted]
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  • Kazuo NAGATO, Yoichi KISHI
    1966 Volume 35 Issue 3-4 Pages 245-256
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
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    To examine the varietal difference of swelling behaviour and total solids content in residual cooking liquid, milled white rice sampled of 58 varieties were treated with excess water fqr 30 minutes at temperatures ranging from 60° to 96°C. Swelling behaviour was experssed as the water-uptake ratio (weight of cooked rice)/(weight of raw rice), because the water-uptake ratio was colosely related to the swelling in the volume as shown in fig. 1. The total solid content was experssed as percent of raw rice, (dry weight of total solids) × 100/(dry weight of raw rice). The results are summarized. as follows: 1) In general, Japonica varieties began to swell at the lower temperatures than did Indica varieties, and among Indicas many of the semi-hard varieties (medium-grain), swelled at the lower temperatures than did the hard varieties (long-grain). Therefore, at the lower temperatures than 75°C, Japonicas and many of semi-hard varieties had higher water-uptake ratios than had Indicas and the hard varieties respectively, wereas at the temperature of 96°C, the hard varieties had the higher water-uptake ratios than any of the other varieties tested. (fig. 2) The varietal differences of water-uptake ratio were most distinct in the range from 65° to 75°C. 2) Among Japonicas, the varieties matured under lower temperatures began to swell at the lower cooking temperature than did those matured under higher temperatures. This relation was observed among the different samples of the same varieties matured under different temperatures.(table 1. fig. 3) Therefore, a highly significant negative correlation existed between the water-uptake ratios at cooking temperatures from 65° to 75°C and the mean temperatures during ripening.(r-0.956 at 70°C) 3) Microscopic observations of cooked rice revealed that swelling of rice grains was closely connected with swelling of starch granules and disruption of cells. In Towada and Fujisaka-5, swelling of starch granules and disruption of cells were observed on the outer layers of rice cooked at 70°C and on the fairly inner layers of rice cooked at 80°C. On the other hand, in Blue-bonnet, these changes were not observed when cooked at 70°C, but existed at 80°C. (photo. 1, 2). 4) The swelling of rice grain at the low cooking temperatures (60-75°C) will be attributed to the low geratinization temperature of starch and the fragility of cell membrane, and the swelling at the high temperatures (85-96°C) may be affected by the structure of starch and density of starch in endosperm (hardness distribution in endosperm18)). The rice which has high water-uptake ratio at low cooking temperature is considered to have a tendency to be cooked more easily and to become tender boiled rice. 5) Figure 4 shows that the maxima of total solids contents were at 65°C in glutinous varieties, 70°C or 75°C in Japonicas and 90° or 96°C in Indicas. Then the total solids contents at temperatures from 65° to 75°C were markedly higher in Japonicas than in Indicas and among Indicas some of the semi-hard varieties had fairly high total solids contents. (table 1) 6) Among Japonicas, highly significant negative correlation existed between total solids contents at cooking temperature from 65° to 75°C and mean temperature during ripening (r-0.789 at 65°C). This correlation was not recognized among Indicas in fig. 5 and 6, but according to the previous report19), when ripening temperatures were artificially coctrolled to 23° and 30°C, the rice matured at 23°C had higher total solids contents than had those matured at 30°C in all Indicas examined. Accordingly, swelling behaviour and amounts of total solids in residual liquids depend to a great extent on varieties and to some extent on climatic conditions. [the rest omitted]
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  • Masaharu SHIMIZU, Katsuji KUNO
    1966 Volume 35 Issue 3-4 Pages 257-263
    Published: December 25, 1966
    Released on J-STAGE: February 14, 2008
    JOURNAL FREE ACCESS
    The effects of IAA (3-indoleacetic acid), TIBA (2, 3, 5-triiodobenzoic acid) and x-ray irradiation on the appearance of abnormal spikelets, especially regarding the changes in sex expression, were investigated with a special variety of paddy rice "Akaho". "Akaho" is known to have very unstable characters in regard to the morphogenic regulation of spikelet genetically and to express various abnormalities of spikelet even under usual cultivating conditions. Since this experiment was carried out in phytotron at 25-30°C, in the winter of 1965-1966, the short-day condition promoted female and depressed male sex expression remarkably as seen in other short-day or day-neutral plants grown under the short day condition. With external application of IAA, the femaleness was promoted further and the maleness was suppressed, decreasing the number of stamens and increasing the organs of intermediate structure that were partially transformed stamens to pistil and the pistils of multi-ovary. On the contrary, the application of TIBA and x-ray irradiation showed clear cut inhibitory effects on the shifting tendency of the control plants toward femaleness, increasing stamens and decreasing the pistils of multi-ovary in number, particularly in the plots of x-ray treatment. In these plots, the morphological abnormalities in glumes and the development of additional glumes became to appear more frequently than in the control, on the other hand. From the results above mentioned, it is clarified that an elevation of auxin level promotes the female and depresses the male sex expression in rice plants. Based upon the results obtained in this study and the writers' other obsevations regarding to the effects of gibberellin on the spikelet morphogenesis, it is considered that the endogenous level of gibberellin-like substances may be high at the early stage of spikelet development and afterwards that of auxin-like substances may become dominant absolutely or relatively, in the regions of organogenesis, and the unbalance of these substances in spikelt development seems to induce various kinds of abnormalities in the spikelet morphogenesis.
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