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Volume 46 (1977)
- Issue 4 Pages 461-
- Issue 3 Pages 335-
- Issue 2 Pages 147-
- Issue 1 Pages 1-
Volume 46, Issue 3
Displaying 1-11 of 11 articles from this issue
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Koichi TAJIMA, Norihiro SHIMIZU1977 Volume 46 Issue 3 Pages 335-342
Published: September 30, 1977
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESS -
Choji KAWASHIMA, Bun-en ITOH1977 Volume 46 Issue 3 Pages 343-351
Published: September 30, 1977
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn relation to the number of leaves on a main stem or on a tiller of rice plant, the top shoot units with crown roots in a stem, in other words, the number of shoot units with crown roots from the bottom in it, were observed. The number of leaves ranging from 10 to 21 on a main stem and that from 4 to 10 on a tiller were obtained according to difference of varieties and/or growth conditions. The number of shoot units with crown roots in the main stem was in proportion as the number of leaves on it increased, with increase of the former of 0.68 in lower roots and 0.67 in upper roots for the increase in 1 of the leaves (Figs. 1 and 2). In more detail, however, the number of shoot units with crown roots increased stepwise with increase in the number of leaves (Figs. 1, 2 and Table 2). The number of shoot units without crown roots in the main stem was also proportional to the increase in the number of leaves on it, and increase per leaf was 0.32 in lower roots and 0.33 in upper roots (Figs. 3 and 4). As to the tiller, the number of shoot units with crown roots increased by about one with the increase in one leaf on it (Figs. 5 and 6), and the number of shoot units without crown roots coincided with that of the main stem in the same plant (Figs. 7 and 8). From these results, it is considered that a rice plant with a larger number of leaves on its main stem has older roots in its ripening stage, though it has more numerous shoot units with crown roots. For, it takes more time from the appearance of the crown roots in the top shoot unit to the fully ripened stage in such a plant, because of its plenty of shoot units without crown roots, which develop after all the shoot units with crown roots have appeared.View full abstractDownload PDF (876K) -
Norio Hosoi1977 Volume 46 Issue 3 Pages 352-360
Published: September 30, 1977
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDifference of the thermo-response of heading date, number of main culm leaves and leaf emergence intervals between the culture using mature seedling (5th leaf stage) and the culture using young seedling (2nd leaf stage) have been investigated with 36 paddy rice cultivers of various maturities under five different levels of temperature in semi-open air controlling cabinets. Air temperature in the rice community in the cabinets were kept at 3°C, 1.5°C and 0°C warmer, and 1.5°C and 3°C cooler than that of the open air as an average during rice cultivated period in Morioka (Iwate) in 1974 (Fig. 5). The heading response in varieties to the temperature in culture using mature seedling and that using young seedling were explained in terms of number of main culm leaves and leaf emergence intervals in the following way. 1. The difference of leaf age in varieties among each thermo-condition was larger in culture using young seedling than in culture using mature seedling (Fig. 4), and the response of total leaf number on main culm of varieties to temperatures was a little higher in culture using young seedling than in culture using mature seedling (Table 3). In consequence, the fluctuation in heading of varieties by temperature was larger in culture using young seedling than in culture using mature seedling (Fig. 1). 2. The difference of total leaf number between two cultural methods was larger in late varieties than in early varieties, and was larger under high temperature than low temperature (Table 3). The difference of leaf age of varieties between two culture methods was a little larger under low temperature than under high temperature (Fig. 4). From these results, the difference of heading date between two culture methods was larger in early varieties than in late varieties, and was larger low temperature than under high temperature (Table 1, Fig. 5). From these facts, it can be said that the risk of cool weather damage increase futher in rice culture using young seedling.View full abstractDownload PDF (931K) -
Hirokadzu TAIRA, Harue TAIRA, Kazuhiko YAMAZAKI1977 Volume 46 Issue 3 Pages 361-370
Published: September 30, 1977
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn the previous paper, it was found that the peat soil of normal manuring, as compared with the strong gley soil of normal manuring, gave significantly high protein and ash content of lowland brown rice of 13 Hokkaido varieties and was also found that the early varieties, as compared with the late varieties, had a tendency of higher protein and ash content of the rice. Therefore, investigations have been further carried out to determine the influence of soil types, i.e. the strong gley soil (normal manuring and heavy manuring) and the peat soil (normal manuring), and the above-mentioned varieties on the phosphorus, potassium, magnesium, manganese, and iron content of brown rice. The peat soil of normal manuring gave significantly high phosphorus and magnesium content and low iron content on dry basis and high magnesium content and low iron content in ash by comparison with the strong gley soil of normal manuring or heavy manuring, or both. On the other hand, the early varieties, as compared with the late varieties, had a tendency of higher phosphorus, potassium, and magnesium content on dry basis and lower manganese content in ash. The phosphorus and magnesium content on dry basis showed significantly negative correlations with heading date and date of maturity and positive correlations with ripening mean temperature, and the manganese content in ash showed significantly positive correlations with heading date, date of maturity, and ripening period and negative correlation with ripening mean temperature.View full abstractDownload PDF (990K) -
Hiroshi SUGE, Dulce Maria FLORES GALLARDO1977 Volume 46 Issue 3 Pages 371-378
Published: September 30, 1977
Released on J-STAGE: February 14, 2008
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Nobuo CHONAN, Harunosuke KAWAHARA, Toshiaki MATSUDA1977 Volume 46 Issue 3 Pages 379-386
Published: September 30, 1977
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe flag leaves were sampled from rice plants of the paddy field at intervals of 10 days after the full expansion, and ultrastructure of the chloroplasts was observed by electron microscope. When the leaves had just fully expanded, the large starch grains accumulated in the chloroplasts, but afterwards the starch grains gradually decreased and after 30 days they almost disappeared (Figs. 1, 5, 6 and 7). The number of thylakoids per granum continued to increase for 10 days after leaf expansion (Fig. 3). The separation of thylakoid membranes, which is the first sign of destruction, was observed in some chloroplasts at 20 days after leaf expansion (Fig. 6). The size of chloroplasts and the number of grana continued to increase for 30 days after leaf expansion (Figs. 1 and 2), but they were followed by the breakdown of inner membrane system and by the decrease in amount of stroma (Figs. 7 and 8). As the inner membranes breakdown, the leaf colour changed to yellow-green and the plastoglobuli increased in size and number (Fig. 4). At the ripening stage of rice plants, ultrastructure was compared among chloroplasts in the upper five leaves (Table 1). Structural differences were not so marked among chloroplasts in the upper three leaves. However, the chloroplasts in the fourth leaf counted downwards from the flag leaf, showed a disappearance of the starch grains, a decrease in number of the grana, and a spectacular accumulation of the plastoglobuli. In the yellow area of the fifth leaf, the chloroplasts shrank because of the disappearance of grana and stroma (Fig. 9), and finally the chloroplasts envelope disappeared (Fig. 10). The similar pattern of destruction as mentioned above was observed in the chloroplasts from seedling leaves, but the destruction was more rapid than those at the ripening stage.View full abstractDownload PDF (1585K) -
Nobuo CHONAN, Harunosuke KAWAHARA, Toshiaki MATSUDA1977 Volume 46 Issue 3 Pages 387-392
Published: September 30, 1977
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSRice plants were grown in 1/5000 are Wagner pots with different levels of nitrogen basal dressing (non-application, 0.6 g nitrogen per pot, 3.0 g nitrogen per pot), and changes in chloroplasts ultrastructure were observed immediately after the leaves had fully expanded (Table 1, Figs. 1-3). The size of chloroplasts and the number of grana increased by nitrogen application, but the effect was not so marked when the amount of applied nitrogen was increased from 0.6 g to 3.0 g. The starch grains in the chloroplasts were markedly reduced by application of 3.0 g nitrogen. Effect of nitrogen top-dressing was observed on ultrastructure of the chloroplasts in fully expanded leaves of nitrogen-deficient plants (Table 1). In the chloroplasts of nitrogen-deficient plants, the separation of thylakoid membranes, which is the first sign of senescence, was observed at 11 days after leaf expansion (Fig. 4). However, by nitrogen top-dressing the senescence was depressed and the formations of grana and stroma were accerelated (Fig. 5). The size of chloroplasts also increased by nitrogen top-dressing (Table 2), therefore the chloroplasts increased the surface area which contact with inner surface of the cell wall. In the leaves top-dressed by nitrogen, the starch grains were disappeared, but the amount of plastoglobuli was not reduced.View full abstractDownload PDF (1452K) -
Shin-ichiro KAWATA, Kiyoshi NISHIMAKI, Koou YAMAZAKI1977 Volume 46 Issue 3 Pages 393-402
Published: September 30, 1977
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo clarify the geotropic behavior of crown roots of rice plants, the apical structures of various crown roots were examined in relation to their position on culms or to their stages of elongation. The diameters of actively growing root apices were always larger in the lower roots than in the upper ones of the same "shoot unit", reaching the largest near the IXth "shoot unit". Among the actively growing roots, the thicker ones always possessed the following histological characteristics as compared to the thinner ones, irrespective of the difference in their position of culm or on each "shoot unit" : (1) Cortical cell layers are more numerous. (2) Stele diameters are larger. (3) The cells, manifesting meristematic appearance, are more numerous either in stele or in cortical and dermal tissues. (4) Root caps are larger both in diameter and in length, having well developed columella. (5) Cells in columella containing starch grains are more numerous. In the roots of the later elongation stage, the cells of root caps were depleted completely of starch grains. The so-called "lion's-tail-like" roots or "stunted" roots had root caps degraded to various degrees, tending to complete absence. On the basis of these findings, the crown root apices of rice plants were found to have structural constructions closely related to their tip dimensions. Some possible implications of these apical structures of crown roots to their geotropic behaviors were discussed.View full abstractDownload PDF (1249K) -
Shin-ichiro KAWATA, Shigeo MATSUI1977 Volume 46 Issue 3 Pages 403-413
Published: September 30, 1977
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe process of cortex formation in the apical meristems of normally elongating crown roots of rice plants was studied by observing cell arrangement and cell divisions. All longitudinal cell files in cortex of a root branched from the endodermal cell file (Fig.2). The branchings mostly occurred within 200 μm of the meristem tip (intersecting point of root axis with cap boundary). Consequently, the number of cortical cell layers decreased toward the meristem tip. Cortical cells dividing transversely were found as far as about twice the root diameter from the meristem tip (Fig. 7). The frequency of transverse cell divisions decreased gradually toward the meristem tip, from the 150 μm level in roots thicker than 600 μm in diameter and from the l00 μm level in thinner roots (Fig. 8). In thicker roots, no transverse division was seen in parts more distal than 50 μm. Periclinal cell divisions occurred only in endodermal cells near the meristem tip where transverse division frequency and layer number of cortical cells decreased (Fig.11). Most endodermal cells dividing periclinally are those from which cortical cell files are branched in a basal direction (Fig. 9). In thicker roots, periclinal divisions occurred in endodermal cells 50 μm-200 μm distant from the meristem tip; and in thinner roots, in those within 150 μm (Fig. 8). The transverse cell divisions in the most distal part of cortex with less number of cell layers are considered to decrease the number of cortical cell layers by sending this part in the basal direction. Thus, thicker roots with less frequency of transverse cell division in distal part of meristematic cortex tend to maintain their layer numbers in comparison with thinner roots. The periclinal cell divisions in endodermal cells act as if they compensate for the decrease in the number of cortical cell layers.View full abstractDownload PDF (1834K) -
Yoshimasa UEMURA, Akira MIYASAKA1977 Volume 46 Issue 3 Pages 414-422
Published: September 30, 1977
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn some cases of direct sowing culture (direct sowing of paddy rice under upland condition) in the Kanto district, there is observed a year by year decrease in yield. The purpose of this experiment is to find a counterplan to the rice yield decrease due to the continued culture of direct sowing. This paper deals with the effect of alternation of direct sowing and transplanting on the growth and yield of direct sowing rice. 1. Better growth and better yield were given in the first year of direct sowing culture in the converted plots (converted to direct sowing culture after one or two years of transplanting one), than those in the continued direct sowing plots (direct sowing was continued more than ten years). These tendency was more apparent in well drained paddy field than in ill drained one. 2. No significant differences in the growth and yield of direct sowing rice could be found between the second year plots after converted from transplanting culture and the continued direct sowing plots. 3. Increased amount of total inorganic available nitrogen but decreased amount of nitrate nitrogen in the soil were given in the early stage of upland condition of the first year of direct sowing culture by the conversion from the transplanting culture. 4. The soil in the direct sowing paddy fields (after harvesting) was easier not only to drain but also to harrow and was favoured more porosity than in those of transplanting. Such physical properties of soil in direct sowing field was acquired in the first year after the conversion. 5. From above facts, the alternation of direct sowing and transplanting was concluded to be a promising counterplan to the rice yield decrease due to the continued direct sowing culture.View full abstractDownload PDF (958K) -
Shin-ichiro KAWATA, Jiro HARADA1977 Volume 46 Issue 3 Pages 423-430
Published: September 30, 1977
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe process of diameter increase in crown root primordia was investigated in the successive developmental stages of the primordia in rice plants. The diameter of lower (basal) root primordia formed in a "shoot unit" is mostly-determined during the period from Stage 8 to Stage 12 (Fig. 2). The rapid increase in the diameter of primordia at this period is due rather to the rapid increase in the thickness of the cortex than to the slow increase in the diameter of the stele (Fig. 2). Such rapid increase in the thickness of cortex is based chiefly on the increase in the number of cortical cell layers during the period from Stage 8 to Stage 10 (Fig. 3). During the following period, from Stage 10 to Stage 12, this is based chiefly on the increase in the radial diameter of cortical cells (Fig. 3). The diameter of upper (apical) root primordia formed in a "shoot unit" does not increase so rapidly during the period from Stage 8 to Stage 10 as does that of lower primordia of the same "shoot unit". Therefore, the diameters of upper and lower primordia of a "shoot unit" show a difference after this period (Fig. 4). And such slower increase in the diameter of upper primordia at the period from Stage 8 to Stage 10 corresponds to the slower increase in the thickness of the cortex (Fig. 6). Furthermore, this slower increase in the thickness of the cortex is based on the slower increase in the number of cortical cell layers during this period (Fig. 8). Consequently, it is assumed that the increase in the number of cortical cell layers during the period from Stage 8 to Stage 10 have the most important influence on the determination of the diameter of crown root primordia.View full abstractDownload PDF (929K)
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