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Mitsugu INOUE, Eizo MAEDA
1980 Volume 49 Issue 2 Pages
167-174
Published: June 30, 1980
Released on J-STAGE: February 14, 2008
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Kunio ARAI, Yasuhiro KONO
1980 Volume 49 Issue 2 Pages
175-183
Published: June 30, 1980
Released on J-STAGE: February 14, 2008
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Translocation and distribution of nitrogen top-dressed at early ripening stage in rice plant (Oryza sativa L. cv Chyukyoasahi) were studied by using
15N as a tracer. The plants cultured in Kasugai nutrient solution were top-dressed with
15N-labelled ammonium sulfate at 7 days after heading. Heading was designated as the flower-opening day of the uppermost spikelet on the panicle. Incorporations of
15N were detected in culms, leaf sheathes and panicle at 3 hr after top-dressing, whereas in leaf blades it was detected 3 hr later. The amount of
15N in these organs increased markedly up to 48 hr after top-dressing, then began to decrease after 48 hr in culms, after 72 hr in leaf shcathes and after 96 hr in leaf blades. The amount of
15N in panicle continued to increase during experimental periods. These results imply that rctranslocation of incorporatcd
15N into leaf blades began to take place from 96 hr to 120 hr after top-dressing. Therefore, it is likely that the amount of
15N in panicle at 72 hr after top-dressing, accounting for about 25% of total nitrogen, was not transported from leaf bladcs but directly transported from roots. Much of
15N was distributed to early developing grains on each primary branch. This distribution patten was coincident with the differentiation order of spikelet on the inflorescence. In the grains on top and middle primary branches, incorporations of
15N were detectcd at 3 hr after top-dressing, while the grains on the bottom primay branch incorporated
15N at 6 hr after top-dressing. There were little differences in
15N percentages of total nitrogen translocated to the grains on all primary branches till 120 hr after top-dressing, but after that time
15N percentage of newly incorporated nitrogen was decreased in the grains on bottom primary branch. These results seem to be difficult to explain by the vascular bundle connection of each primary branches at the node of the flag leaf and penultimate leaf. The concentrations of
15N in the grains were lower than that of the whole panicle about 10 to 15% during a period when active absorption and translocation of top-dressed nitrogen was occurring. Moreover, increasing rate of
15N in whole panicle exceeded that in the grains during early stage. These results suggest that some of the nitrogen directly transported to panicle from roots is once incorporated into rachis, rachis-branches and husks and then retranslocated to growing grains.
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Hiroharu BANBA, Takahiro OHKUBO
1980 Volume 49 Issue 2 Pages
184-190
Published: June 30, 1980
Released on J-STAGE: February 14, 2008
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This experiment was conducted to clarify that the root distribution of upland-cultured paddy rice (var. Myojoo) and upland rice (var. Norin No. 21) in the soil was influenced by soil temperature. To obtain the different soil temperature, two mulching methods, three seeding times and two plant densities were adopted. The soil temperature was raised by transparent-polyethylene mulch and was lowered by aluminium-foil mulch and it was also lower in the early seeding than the late seeding and in the dense planting than the sparse planting. The results obtained are as follows. 1. The roots of upland-cultured paddy rice were distributed shallow in the soil at high soil temperature and deep in the soil at low soil temperature. 2. The root distribution of upland rice was not influenced by soil tempcrature because upland rice has genetically deep rooting in thc soil. 3. Seeding times grcately influenced the root systems of upland rice. The roots of upland rice in the rainy season (May 28) penetrated into the shallow layer of soil because of high soil moisture. Otherwise, that in the dry season (June 29) penetrated into the deep layer of soil because of low soil moisture. 4. The roots of upland-cultured paddy rice and upland rice in sparse plant density penetrated into the deep layer of soil, otherwise that in dense plant density penetrated the shallow layer of soil. 5. The top weight and the root weight of upland-cultured paddy rice were enhanced at high soil temperature.
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Seok Weon SEO, Toshiro HAYAKAWA
1980 Volume 49 Issue 2 Pages
191-198
Published: June 30, 1980
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1. Shape of opaque part of white belly kernels. Most of the opaque part of the white belly kernels of this variety extended near the dorsal side. In this variety, white belly and white milky occurred in the kernel at the same time. 2. Starch granules on the ventral and dorsal sides in developing rice kernel of Chosaeng Tongil were observed using scanning electron microscope. In this study, the observed points were 250 μm to 300 μm interior from pericarp. (a) On the dorsal side: 8 days and 12 days after flowering, small and large starch granules were observed. Their shapes were irregularly spherical, and air-spaces were observed among the granules. 16 days after flowering, the air-spaces were not observed, and starch granules showed sharp edges. And on the surface of the starch granules, the pits due to protein body were observed. (b) On the verltral side: In spite of the passing of the time after flowering, at least after 8 days after flowering, starch granules almost never developed, and their diameters were 2 to 5 μm 30 days after flowering. After 16 days, on the surface of the starch granules, the pits due to enzymes in kernel were observed. But the pits due to protein body were not observed. Their shapes were irregularly spherical, and air-spaces were observed among the starch granules during the whole ripening period.
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Seok Weon SEO, Shugo CHAMURA
1980 Volume 49 Issue 2 Pages
199-204
Published: June 30, 1980
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1. Among the varieties, the earlier heading varieties made smaller yields and their percentages of protein, phosphorus, and potassium content in brown rice were higher. 2. Among the varieties, there was high positive correlation between percentages of protein, phosphorus, and potassium content in brown rice and the temperature during ripening period. 3. Varietal differences in the percentage of these in brown rice observed under the same temperature during the ripening period, Low (day: 21°C, night: 19°C) and High (day: 29°C, night: 26°C). The percentage of these in brown ricc was higher in earlier heading varieties not only under low temperature but also under high temperature. 4. Percentages of protein, phosphorus, and potassium content in brown rice were higher in the mutant than in the original varicty "Koganemochi". 5. By shading treatment during the ripening period, the percentage of protein, phosphorus, and potassium in brown rice became higher. The rate of the increase was larger in protein than in phosphorus and potassium content.
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Harue TAIRA, Hirokazu TAIRA, Isao MATSUKAWA, Takashi SANBUICHI, Masaki ...
1980 Volume 49 Issue 2 Pages
205-218
Published: June 30, 1980
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In order to know the influcncc of fertilizer and planting density on the chemical composition of soybean seeds, 2 kinds of field experiment were performed on 2 varieties and 2 lines in 1975 and 2 varieties and 1 line in 1976 at Hokkaido Prefectural Central Agricultural Experiment Station (Experiment 1) and on 3 varieties and 9 lines in 1975 at Hokkaido Prefectural Tokachi Agricultural Experiment Station (Experiment 2). Among the varied fertilizer conditions, significant difference was not observed in experiment 1 and 2. On the planting density, close planting significantly increased protein content and significantly decreascd oil, carbohydrate, and ash content in experiment 1. On the other hand, significant differene was only observed on ash content in experiment 2. The varieties in experiment 1 and 2 differed significantly on all chemical compositions. On the significant interactions, there were fertilizer × planting density on ash content, density × variety on protein and ash content, and fertilizcr × variety on oil, carbohydrate, and ash content in l975 (Experiment 1), and variety × density and fertilizer × density on ash content (Experiment 2). On the correlation between chemical component content and growth habit, weight of 100 seeds or yield, protein content was positively correlated with the length of main stem, weight of 100 seeds or yield, and negatively with the number of branches per plant or number of ripe pods per plant. Oil, carbohydrate, and ash content was positively correlated with number of branches per plant or number of ripe pods per plant, and negatively with length of main stem, weight of 100 seeds, or yield.
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Kikuo ISHIDA, Koki KOBAYASHI
1980 Volume 49 Issue 2 Pages
219-225
Published: June 30, 1980
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This experiment was undertaken to analyse the influence of shading on growth and fiber yield of Mitsumata, Edgeworthia papryifera Sieb. et Zucc. under pot cultured conditions from 1973 to 1978. The results obtained are summarized as follows; 1. The plant height increased very markedly with decrease of sunlight. While the thickening growth of stem was not affected by shading. The leaf growth increased in area by shading. 2. The relative growth rates (RGR) increased with increasing light intensity in the early stage of the experiment. While, in the late stage, the RGR was a little higher in most heavy shading plot than in full sunlight. 3. The net assimilation rate (NAR) generally decreased with increasing degree or shading. As the plants grew, the NAR reduced progressively in all the plots. The leaf area ratio (LAR) increased with decreasing light intensity. 4. In early stage, the distribution ratio of producted dry matter to leaf was larger than to the other organs. While, in late growth stage, it was larger to root than leaf. Consequently, T/R ratio and stem weight/totatl plant weight ratio has rised according to the shading. 5. Total plant weight gradually increased with increasing degree of shading. The highest growth was observed in 40% shading. Stem weight and fiber yield per plant was the highest in 40% shading too. But thc highest fiber rate was obtained in 80% shading. 6. Thus, the influence of shading on growth and fiber yield of Mitsumata plant was observed very markedly. The optimum shading on its growth is considered to be about 40% of full sunlight.
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Shigeru INUYAMA
1980 Volume 49 Issue 2 Pages
226-231
Published: June 30, 1980
Released on J-STAGE: February 14, 2008
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This experiment was conducted to evaluate the effect of the amount of irrigation water on growth and grain yield of grain sorghum during drought stress period and to make efficient use of irrigation water under four treatments : 0, 1, 2 and 3 irrigations per week. Twenty millimeters of water was applied at each irrigation time. Irrigation water was applied from July 12 to Augllst 2, when grain sorghum was heading time through milk stage. Leaf water potentials measured by pressure chamber (Daiki Rika K.K.) were affected by the quantity of irrigation water and lowered by less amount of irrigation water. The recovery of leaf water potential by irrigation was 2 to 3 bars and the difference of leaf water potential between well irrigated treatment (3 irrigations per week) and others was enlarged when drought stress was accelerated. Two irrigation treatment never became lower than - 19 bars which is a critical point of grain sorghum when stomata close. Leaf diffusive resistance measured by porometer (Lambda Instruments Corp.) was high in no and one irrigation treatments. However, it was low in two and three irrigation treatments and no difference was recognized between them. Top growth of grain sorghum was slowered and stopped by drought stress and its recovery after drought was small. Stressed top growth was mainly due to slow development of grain head and decay of lower leaves. Grain yields decreased as the amount of irrigation water decreased, but no statistical difference was recognized between well irrigated and two irrigation treatments. Reduced grain yields were attributed to low 1, 000 grain weight. From the results of grain yield and difference between evapotranspirations and the amounts of irrigation water during drought stress period, drought damage will be reduced by irrigation of about 40 millimeters of water a week.
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Tohru YAMAGISHI, Kensuke OKADA, Tetsuji HAYASHI, Atsuhiko KUMURA, Yosh ...
1980 Volume 49 Issue 2 Pages
232-242
Published: June 30, 1980
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Kanoe SATO, Jong Man KIM
1980 Volume 49 Issue 2 Pages
243-250
Published: June 30, 1980
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To understand the life of rice plant more actually, photosynthetic and respiratory rates of individual leaf of different age were measured for 7-8 days continuously at each of the 3 growth stages (panicle formation stage, boot stage and ripening stage) under field conditions and their relationships with the environmental conditions were discussed. 1. The ambient CO
2 concentrations at 3 layers (80, 50 and 20 cm from the ground level, respectively) in the canopy were high during night, probably being relatcd with the very low wind speed. During daytime, CO
2 concentration of middle and low layers was lower than that of the upper layer as much as 25 ppm, but all the layers showed almost similar changing patterns of CO
2 conccntration in different days or different seasons, probably due to adequate influx of air into the canopy. 2. Daily or seasonal differences in air temperature were great, but diurnal changes during active photosynthesis (8:00-17:00) were small (about 2-5°C). Dark respiration was very closely related with night temperature. 3. Both on fine and cloudy days, photosynthetic rate changed with light intensity, but responses were less sensitive in lower leaves. However, on clear days, photosynthesis remained almost constant during 9:00 to 14:00, irrespective of the light intensity, excluding its sudden drop by cloud. The photosynthesis of the uppermost leaf was saturated at the incident light intensity of 70 klx ca., the lower leaves at 50 klx ca. and the middle leaves at the intermediate intensity. 4. The middle and lower leaves photosynthcsized ca. 60-70% and ca. 35-50% of the amount for the uppermost leat respectively, and the percentages were a little higher on cloudy days than on fine days. During night, they respired 80-90% and 50-60%, respectively, compared with the uppermost leaf (100%). The ratios of dark respiration to photosynthesis were about O.1 on clear days; but they were a little higher on cloudy days and for the lower leaves. The lowest leaves at the ripening period which were just prior to dying consumed during night less than half of the photosynthate produced during daytime even on cloudy days, suggesting that even those old leaves under strong shade may not be "parasitic" in the sense of consuming more than production.
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Kanoe SATO, Jong Man KIM
1980 Volume 49 Issue 2 Pages
251-256
Published: June 30, 1980
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This experiment was carried out to know the effects of air temperature on photosynthesis and dark respiration of individual leaf of different position. 1. In each of continuous temperature treatments (30°C, 25°C and 20°C day temperature; night temperature was 5°C lower, respectively), the photosynthetic rate of the 10th leaf (the uppermost expanded leaf) was not changed remarkably for the first 6 days; then gradually declined, but those of the lower leaves decreased during that period and became smaller as their positions lowered and they declined earlier than the upper leaf. 2. The photosynthetic rate at 17°C decreased markedly and that at 30°C increased a little comparing with that at 25°C. The 8th leaf was especially sensitive to low temperature and the difference of photosynthetic rate between the 8th and the upper leaves became greater with time of the temperature treatments. 3. Photosynthetic recovery of the leaves which received stress at 17°C for 1 day or 3 days and transferred to 30°C or 25°C was more rapid, as shorter the cool temperature duration and higher the transferred temperature. Older leaves recovered more slowly from temperature stress. 4. The respiration rates increased with increase of temperature, but changed to a small extent. The decreasc of respiration rate at low temperature was greater than that of photosynthetic rate. The ratio of respiration rate to photosynthetic rate of the 8th leaf was somewhat higher than the upper leaves.
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Kanoe SATO, Jong Man KIM
1980 Volume 49 Issue 2 Pages
257-262
Published: June 30, 1980
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Changes of photosynthetic and respiration rates of leaves of different position under full light and shading conditions and of their recovery processes from shading to full light were investigated. 1. The photosynthesis under shading (about 95% shaded; maximum light intensity under shading was about 6 klx) was about 20% of that under full light, and the ratio of photosynthetic rate under shading to full light condition was higher at the low leaf than at the upper or middle leaf, and it declined in all leaves with time of treatment. 2. There was no remarkable after-effect of shading when plants were shaded one or two days and then transferred to full light, but 3 or 5 days' shading retarded the recovery and such a retardation was marked in the low leaf. 3. Respiration rates decreased by shading. The ratios of respiration rate to photosynthetic rate were 8-12% under full light, being larger as the leaf position was lowered, and they were about 26-33% and 36-40% at the upper leaves and the lower leaf, respectively, under shading. In general, respiration rate changed in parallel with the change of photosyntlletic rate under full light condition, and also under shading although to a smaller extent. Even the lowest leaf may not be "parasitic".
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Kanoe SATO, Jong Man KIM
1980 Volume 49 Issue 2 Pages
263-269
Published: June 30, 1980
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To understand the contribution of each positional leaf to the dry matter production in rice populations or individual plants, net photosynthetic and dark respiration rates of individual leaves of different position and age were measured at four growth stages (reduction division stage, boot stage, heading stage and ripening stage) under full light and mutual shading conditions in the paddy field where different fertilization (high fertilizer, 1 kg/a of each of the three main elements; low fertilizer, 0.2 kg/a of the same elements) and plant spacing (wide spacing, 30 × 22.5 cm; close spacing, 30 × 7.5 cm) were given. 1. The maximum rate of photosynthesis of the uppermost leaf was considered to show the full capacity of production, and the ratio of the photosynthetic rate of each individual leaf to that of the uppermost leaf under the full light condition was regarded to indicate its relative vitality, while the decrease in the photosynthetic rate under mutual shading compared with that under full light was thought to be caused by the external factors. 2. At reduction division stage, the relative vitality of middle and lower leaves to the upper leaf were 80% ca. and 60% ca., respectively; and the external factors lowered the photosynthetic rates under mutual shading by 20% ca. and 35% ca. in the middle and lower leaf, respectively, compared with those under full light. Photosynthetic rate decreased as the time progressed, and the heavily fertilized plants had more efficient leaves in photosynthesis than those lightly fertilized during all the experimental period, but there was no significant difference between those of different plant spacing. In general, photosynthetic rates of individual leaves both under full light and mutual shading conditions decreased about 20% by each descend ofleaf position from the top. 3. Dark respiration rates decreased proportionally to photosynthetic rates during the aging processes of the leaves. The dark respiration rate of the lowest leaf did not exceed 30% of its net photosynthetic rate under mutual shading. Therefore, even the lowest leaf did not seem to be so-called parasitic.
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Kanoe SATO, Jong Man KIM
1980 Volume 49 Issue 2 Pages
270-275
Published: June 30, 1980
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1. Total sugar concentration in leaf blade decreased with time from meiosis stage to ripening stage, the maximum being 7% and the minimum 5.0-5.5% at the meiosis stage. Leaf positional differenccs of concentration were small (1.5-2.0%) during all the experimental period. Crude starch concentration increased until heading stage, but declined to a halh at the ripening stage. The leaves which showed maximum concentration were the 2nd or the 3rd leaf inl total sugar and the 1st or the 2nd leaf in crude starch. 2. Nitrogen concentration was the highest in the uppermost leaf during all the experimental period, and higher with the high level than with the low level of fertilization. The pattern of seasonal and leaf positional change of nitrogen content per unit leaf area was similar to that of concentration and the nitrogen content of each leaf changed parallel to the rates of photosynthesis and respiration. Concentration of potassium changed to a small extent, being 2.O-2.5% during all the experimental period, although that for upper leaves was somewhat higher. Content of potassium per leaf area decrcased as the leaf position descended and gradually decreased as the stage progresscd. In general, contents of carbohydrates, nitrogen and potassium were higher in plants with wide spacing than those with closc spacing, except meiosis stage. 3. Photosynthetic rates ran almost parallel with nitrogen content at each leaf, but showcd no relationship with the contents of other components, and the C/P ratios (ratios of the contents of each component to photosynthetic rate) excluding nitrogen became greater as the leaf position was lowered.
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Kosei TSUNODA, Kumiko KARIYA, Hiroyasu MACHIDA
1980 Volume 49 Issue 2 Pages
276-280
Published: June 30, 1980
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Responses of the growth, yield and its components in rice plants to the irregular disposition of planted hills under broadcasting condition were examincd by setting up ten kinds of treatment-plots differing in the coefficient of variation (CV) of the number of planted hills among four small sections in a plot. 1. The larger the CV of the number of planted hills among small sections was, the larger the degree of decrease in yield becamc, and the high correlation could be recognized between these two factors. The result was directly due to the shortage of yield compensating of plants in the dense planting sections for the decrease of yield in the sparse planting sections. 2. The bad effects of irregular disposition on the yield was considered to consist or three factors, namely, (1) the percentage of missing plant area to the total one, (2) the difference in the number of hills among the planted sections and (3) the arranged condition of planted sections in a small area. These three factors affected severely in the order of (1) > (2) > (3) on the yield. 3. The grain yield was influenced mainly by the number of panicles and the bad effect of irregular disposition upon the number of tillers and panicles was clearly seen after maximum tillering stage.
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Aogu NAKAYAMA
1980 Volume 49 Issue 2 Pages
281-285
Published: June 30, 1980
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Differentiating process of stomata in tea leaves was studied with the helps of paradermal sections of immature and mature leaves. The guard cell mother cell and three subsidiary cells were produced from a protodermal cell by three times of unequal divisions of abaxial side in immature leaves, and the guard cell mother cell divided vertically forming two equal-shape guard cells. Normally, the mature stomata in tea leaves was anisocytic type. But, sometimes, the subsidiary cells surrounding the guard cell were increased by anticlinal divisions following the unequal divisions. Especially, a small numbers of stomata, maybe differentiated before leaf unfolding, were surrounded by 5-8 neighbouring subsidiary cells. Differentiation of stomata, however, began mostly from the leaf unfolding stage, and these completed at 12 days after unfolding.
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Katsumi INADA
1980 Volume 49 Issue 2 Pages
286-294
Published: June 30, 1980
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Hiroaki NAKABAYASHI, Masami IWASAWA, Kunio MIURA
1980 Volume 49 Issue 2 Pages
295-300
Published: June 30, 1980
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Because high yield of oil seed rape is generally attained by increasing number or pods, changes in the number of flower buds differentiated, and their development into flowers and pods according to the growth stages were investigated. Results obtained are as follows: 1. Greater part of flower buds in the plant were differentiated on the secondary branches. The ratio of the number of flower buds on the main stem, primary, secondary and tertiary branches to the all buds were 1.5, 25.0, 63.0 and 10.5%, respectively. 2. Greater part of flowers were also developed on the secondary branches. The ratio of the number of flowers to total flowers on the main stem, primary and secondary branches were 34.7, 58.6 and 6.7%, respectively. All of flower buds on the tertiary branches failed to bloom. 3. The ratio of the number of flowers to flower buds differentiated on the main stem differed considerably with those on branches, the ratio on the main stem, primary and secondary branches being 75.9, 40.8 and 9.6%, respectively. 4. On the main stem and primary branches, almost all flower buds in which ovule protuberances became visible on the inner wall of pistil just before flowering stage of the plant, developed into flowers. On the secondary branches, however, the rate of developing to flowers was only 58.0%. 5. Greater part of pods in the plant were produced on the primary branches. The ratio of the number of pods on the main stem, primary and secondary branches to total pods were 12.9, 76.9 and 10.9%, rcspectively. 6. On the main stem and primary branches, greater part of flowers developed into pods. The rate of the number of pods to number of flowers on the main stem and primary branches were 76.0 and 61.0%, respectivcly. But, on the secondary branches, the rate was only 16.3%.
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Shin-ichiro KAWATA, Manabu KATANO, Koou YAMAZAKI
1980 Volume 49 Issue 2 Pages
301-310
Published: June 30, 1980
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The growing direction of rice roots and their geotropic responses were examined using the "leaf-cutting method), i.e. a method of culturing one or more "shoot units" of a stem in water or agar media, thus making the direct observation of the growth of the emerging crown roots possible. The results obtained were as follows: All the upper roots of each "shoot unit" grew horizontally, and the lower ones in various directions, while those of the prophyll "shoot unit" located at the base of each tiller grew vertically, irrespective of the position of the tillers on the parent stems. Among the lowcr roots of each "shoot unit", those which emerged in the vegetative phase of the plants grew obliquely-downwards or vertically, while those emerged after the panicle initiation stage of the plants grew horizontally. These findings coincides with those obtained previously in the field or pot cultured plants. The experiments of laying sideways of the culture vessels, while roots were growing in agar media, revealed that the roots originally growing more vertical responded more to the newly imposed geotropic stimuli. These results mentioned above suggest that the rice crown roots are endowed with a specific geotropic responsiveness which is determined by the positions on stems on which they appear.
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Shin-ichiro KAWATA, Manabu KATANO, Koou YAMAZAKI
1980 Volume 49 Issue 2 Pages
311-316
Published: June 30, 1980
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The root system development of rice plants grown in the worked-and the sub-soils was investigated in a farmer's paddy field located in Akita Prefecture. After a soil monolith (10 × 10 cm with a depth of 40 cm, including a hill of rice plants) had been taken, the crown and lateral roots, which appeared in the 10 × 1O cm horizontal quadrate made at every 2.5 cm depth from 7.5 to 30.0 cm from the soil surface, were plotted. It was found that the numbers of crown and lateral roots appcaring in each horizontal quadrate gradually decreased from the depth of 7.5 cm downwards, and that the numbers of roots, especially those of lateral ones decreased markedly in the subsoil. In the compact subsoil demarcated from the worked-soil by a ploughsole (16 cm depth), both crown and lateral roots seemed to grow along the tube-shaped soil pore, and a case was found in which a crown root as well as lateral roots penetrated into other crown root in the same pore. These findings suggest the importance of soil structure in the compact subsoil for the growth of rice roots.
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Koou YAMAZAKI, Manabu KATANO, Shin-ichiro KAWATA
1980 Volume 49 Issue 2 Pages
317-322
Published: June 30, 1980
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The relationship was examined between the number of ears and the number of crown roots grown above 5 cm in length on a hill of rice plants. Total 92 hills were gathered from paddy fields of farnlers ahd of the experimental stations in Japan, as well as from experimental frames and pots in the university field. A positive close correlation (r= +0.819) was found between the number of ears (Y) and the number of grown crown roots (X) of a hill of rice plants with a regression formula of Y=28.3X+107.
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Ryuhei TAKAHASHI, Koshi OGAWARA
1980 Volume 49 Issue 2 Pages
323-329
Published: June 30, 1980
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This study was conducted for obtaining information about the seed germination of Coptis japonica MAKINO, a species which is endemic to Japan and cultivated as one of the important medical plants in north central part of Japan. The seeds of this plant are known to be dormant at the time of maturity and require a period of storage in imbibed state for after-ripening. Our storage experiment has shown that when the freshly harvested seeds were buried in June in the soil until November at natural temperature condition under eaves, they could become well germinable, but those which were stored under constatnt temperatures of 6°, 10°, 15°, 20° and 25°C with moist sand have entirely lost their germinating power. The optimum temperature for germination of after-ripen seeds of this plant proved to be about 5°C, although about four months were needed for full germination when sown in early December. At 10°C or higher temperatures its germination was markedly retarded. Gibberellin was known to be very effective in promoting germination and also in weakening inhibitory effect of high temperature. KNO
3 was also found to promote germination, though not so markedly, but kinetin and IAA were entirely ineffective on germination. When the seedlings just after sprouting in early spring were planted in a green house, they could develop 10 to 11 leaves by August and a part of them flowered in the following early spring.
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Harunosuke KAWAHARA, Toshiaki MATSUDA, Nobuo CHONAN
1980 Volume 49 Issue 2 Pages
330-339
Published: June 30, 1980
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The phloem of rapidly elongating crown roots of rice plants, cultured in water or paddy, were observed by an electron microscope. The intact crown roots were fixed as follows, 1) glutaraldehyde and post osmic acid, 2) ice-cold acrolein-glutaraldehyde and post osmic acid after freezing in aqueous nitrogen, 3) freeze-substutution and post osmic acid. The ultra-thin sections were stained with uranium and lead. The sieve elements of protophloem, having P-plastids, differentiate 300 μm and mature 700-800 μm apart from the growing point. Small vacuoles of the immature sieve elements of protophloem do not participate in the degeneration of cytoplasm. On the other hand, the vacuoles of the sieve elements of metaphloem are expanded in the rapidly elongating zone-1 mm-1 cm apart from the growing point, and the destruction of the tonoplast participates in the degeneration of cytoplasm. The fibillar P-protein and the strand of cytoplasm could not be found in both the immature and the mature sieve elements of proto-and metaphloem. The sieve elements of metaphloem mature about 5 cm apart from the root tip, and just soon after, lateral roots appear. Therefore, on the view point of morphgenesis, the root tissues of 5 cm from the root tip are supported by the sieve elements of protophloem, and the sieve elements of metaphloem support the tissue formation of the basal part of the main root and the elongation of the lateral roots. The sieve elements of proto-and metaphloem have plasmodesmata in the walls facing to pericycle cells and fundamental parenchyma cells as well as to companion cells. These plasmodesmata are thought to be a characteristic of the sieve elements functioning in both sink and long distance transport. The root tissues from 0.5 mm to 2 cm from the growing point are rich in mitochondria, Golgi apparatus and rough endoplasmic reticulum. These cell activities have to be studied in relation to not only morphogenesis, but ion absorption and biochemical synthesis.
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Harunosuke KAWAHARA, Toshiaki MATSUDA, Nobuo CHONAN
1980 Volume 49 Issue 2 Pages
340-348
Published: June 30, 1980
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Root caps of rapidly elongating roots of rice plants, grown in water or paddy, were fixed with glutaraldehyde and post osmic acid, and were embedded in Spurr's resin. Ultra-thin sections were stained with uranium and lead to be observed by an electron microscope. Aspects of cell organelles of the rice root caps resemble closely to those of Zea mays. The cells in the peripheral part of the rice root cap have abundunt mitochondria, rough endoplasmic reticulum and Golgi apparatus. The forming dictyosome cisterna of the Golgi apparatus is composed of branched tubules, carrying sometimes the primary vesicles. These primary vesicles are thought to be produced on the smooth membrane side of rough endoplasmic reticulum near the forming face of dictyosome. The maturing cisternae manufacture large Golgi vesicles (secretory vesicles). The endoplasmic reticulum connect with the forming cisterna tubules and the transitional cisternae. Some terminal sacks of the endoplasmic reticulum accumulate dense materials, which are delivered to plasma membrane as well as the Golgi vesicles, and the contents of these vesicles are secreted out of the plasma membrane by exocytosis. Besides, the endoplasmic reticulum connect directly with plasma membrane and may be thought to secrete some materials. The fibrillar secretory materials precipitate in both sides of the cell walls and thereafter disperse out to mucilage. A scheme is drawn based on the observations of the rice root caps, and a transfer mechanism is speculated by confering the reports of Zea mays.
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Jiro TATSUMI, Yasuhiro KONO
1980 Volume 49 Issue 2 Pages
349-358
Published: June 30, 1980
Released on J-STAGE: February 14, 2008
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Masayoshi MAKAYAMA, Yasuo OTA
1980 Volume 49 Issue 2 Pages
359-365
Published: June 30, 1980
Released on J-STAGE: February 14, 2008
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Studies have been planned to estimate the effect of ethylene in rhizosphere on root growth. This experiments were carried out to determin the ethylene production from soil as affected by application of water, compost and methionine, an ethylene precursor in plant. The results obtained are summarized as follows: 1. The rapid evolution of ethylene was caused within one day by the application of water to the dry soil. The larger the application of water to the dry soil, the greater was the ethylene evolution from the soil. 2. The peak of ethylcne production was seen during five days after soil submergence, although the pattern of ethylene production was different depending on the condition of the soil. Ethylene production from the soil in submerged condition was greater in five to seven times than that from the soil in upland condition. 3. From the soil sterilizing test, it seems that ethylene production in submerged condition might be mainly occurred by an action of micro-organisms, whihe in upland condition non-micro-organic evolution of ethylene might be mainly occurred. 4. Compost was found to produce one hundred to five hundred times much more ethylene than dry soil. Ethylene production from soil was closely related to the amount of compost applied to the soil. 5. The production of ethylene from the soil was greatly stimulated by methionine application. As results of above, it is quite possible that ethylene in rhizoshere may act directly to root growth, and ethylene production in soil can be controlled by such as application of water, compost and methionine.
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Masayoshi MAKAYAMA, Yasuo OTA
1980 Volume 49 Issue 2 Pages
366-372
Published: June 30, 1980
Released on J-STAGE: February 14, 2008
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Effects of hydrocarbons, such as methane, ethane, ethylene, propane and propylene, on the root growth of soybean (Glycine max Merr. cv. Enrei) and rice (Oryza sativa L. cv. Nihonbare) seedlings were examined. The results obtained are summarized as follows: 1. When roots of soybean were exposed to 1, 000 ppm of hydrocarbons, ethylene was most effective to inhibit the root growth with promortion of root-hair formation and increase of stem-diameter. The activity was decreased in the order of propyelene, propane, ethan and methane. Inhibitory activity of propylene on root growth was one hundredth of ethylene, and 50% inhibition of soybean root growth was obtained with 1 ppm ethylene. 2. In rice seedling, seminal root growth was stimulated with both of 1, 000 ppm ethylene and propylene, whereas the growth of first crown roots was inhibited greatly as well as the soybean roots. 3. Effect of ethylene on the growth of seminal root of rice seedling was examined in the range of concentrations from 0.1 to 10, 000 ppm. The most effectivc promotion was obtained at 0.1 to 1 ppm. On the other hand, the growth of first crown roots was promoted with 0.1 ppm ethylene, whereas concentrations higher than 10 ppm inhibited the growth greatly. 4. Effect of ethylene on rooting of rice seedlings was examined and promotion of new roots elongation was observed at 0.1 ppm of ethylene, whereas increase in number of new roots was observed at 10 ppm of ethylene. These results strongly suggest the view that ethylene in the rhizosphere may have direct effect on the growth and development of roots.
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Kanoe SATO, Yusuke GOTO
1980 Volume 49 Issue 2 Pages
373-379
Published: June 30, 1980
Released on J-STAGE: February 14, 2008
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Using clones of Italian ryegrass and perennial ryegrass, the tillering patterns were compared from April to June to know the cause of annuality or perenniality of grasses, with special reference to axillary buds behavior of heading shoots. 1) The relative tillering rate of Italian ryegrass steadily decreased with its development, while that of perennial ryegrass remained almost constant throughout the experimcnt period. 2) In Italian ryegrass not only most tillers that emerged early or late but also the axillary buds formed at the lower nodes of heading shoots turned to reproductive growth at almost the same time, resulting in many heading tillers of different plant height and in small number of vegetative tillers or buds, thus decreasing the relative tillering rate. This situation may promote the seed production and have a keen relation to its annuality. 3) In perennial ryegrass, on the contrary, tiller buds elongated regularly according to a rule, and only a part of tillers which emerged earlier and elongated to a larger height with a greater number of leaves produced heads, remaining the most tillers and tiller buds in vegetative growth stage, which continued to produce new tillers regularly, thus maintainjng its relative tillering rate almost constant, resulting in a greater persistency or perenniality.
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Nobuo CHONAN, Harunosuke KAWAHARA, Toshiaki MATSUDA
1980 Volume 49 Issue 2 Pages
380-384
Published: June 30, 1980
Released on J-STAGE: February 14, 2008
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The lipid globules and vacuolar granules in the mesophyll cells of ricc plants were observed by electron microscope at intervals of 10 days after leaf expansion. When the leaves had just fully expanded, many small lipid globules appear in the cytoplasm around nucleus, and afterwards they coalesce into one or several larger globules. After leaf expansion the lipid globules rapidly increase in diameter, but with the progress of leaf senescence the rate of increase gradually becomes slower and the diameter reach above 5 μm. The lipid globules remain in the dead leaf without remarkable destruction. On the other hand, soon after leaf expansion the electron dense granules appear in the vacuoles of mesophyll cell and increase in diameter by adhesion of the flocculent particles. The electron micrographs of the vacuolar granules show a spherical, rough-surfaced structure. Both the granules and flocculent particles in vacuole probably consist of protein. Increasing process in diameter of the vacuolar granules is the same as the lipid globules. As the leaf color changes to yellow, the vacuolar granules decrease in electron density and in the yellow leaf the disintegrating granules are observed.
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Shigekata YOSHIDA
1980 Volume 49 Issue 2 Pages
385-386
Published: June 30, 1980
Released on J-STAGE: February 14, 2008
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Jiro HARADA, Koou YAMAZAKI
1980 Volume 49 Issue 2 Pages
387-388
Published: June 30, 1980
Released on J-STAGE: February 14, 2008
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Toshiro HAYAKAWA, Seok Weon SEO
1980 Volume 49 Issue 2 Pages
389-390
Published: June 30, 1980
Released on J-STAGE: February 14, 2008
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