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Volume 51 (1982)
- Issue 4 Pages 439-
- Issue 3 Pages 271-
- Issue 2 Pages 151-
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Volume 51, Issue 4
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Satoshi AOKI1982 Volume 51 Issue 4 Pages 439-444
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
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Yasuhiro KONO, Kozo NAKATA, Jiro TATSUMI1982 Volume 51 Issue 4 Pages 445-454
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
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Yeong-Chyn WANGZ, Kiichi HANADA1982 Volume 51 Issue 4 Pages 455-461
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSA defoliation experiment was carried out in an attempt to clarify the interrelation in growth among the main stem and primary tillers and to determine whether or not the compensatory translocation of assimilate would occur when the leaves of main stem or some tillers were injured, in rice seedlings. The experimental material used was cultivar, Nihonbare. Plants were sown and grown in 1/5, 000 a Wagner pots outdoors at University of Tsukuba. Defoliation was carried out when the plants reached a leaf age of 7.5, at which time the tillers on the second, third, and fourth nodes (refered to hereafter as tillers II, III, and IV) had already emerged from the leaf sheaths of the subtending leaves of the main stem. Sixteen types of defoliation were performed. Leaf blades which had expanded completely were excised with a pair of scissors at the auricles, and the leaves which were still expanding were left untreated. The increment in dry weight in the main stem and each tiller for 4 days after defoliation was used as a measure of the growth. The results are summarized as follows: 1. It was assumed that the translocation of assimilate from tillers to main stem or from main stem to tillers would take place when the leaves of thc main stem or the tillers were lost, respectively, and that this kind of compensatory translocation would also occur among tillers when the leaves of a tiller were lost. 2. The fact that growth of tillers was inhibited by defoliation of the main stem and that the inhibition was severer in the upper node tillers, suggested that the growth of the upper node tiller was more closely associated with the main stem. However, tiller, II, a lower node tiller, which was considered to be at its autotrophy, might be associated with the main stem when the tiller was defoliated. 3. Considering the effect of the defoliation, growth of a tiller was influenced most by the main stem and next by the tillers below. And it was assumed that when leaves of the main stem were lost, tiller II would take the role of main stem to some extent in taking care of the other tillers, and, moreover, tiller III would take this role when both of the main stem and tiller II were injured.View full abstractDownload PDF (783K) -
IWA0 NISHIYAMA1982 Volume 51 Issue 4 Pages 462-469
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
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Shuji SHIBATA, Kanoe SATO1982 Volume 51 Issue 4 Pages 470-475
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDeposition and development of calcium oxalate crystals were observed with the development of coleoptile and several leaves in a japonica rice seedling (cv. Sasanishiki). The results are summarized as follows: 1) Prismatic crystals first deposited in the parenchyma cells of coleoptile when the 2nd leaf emerged (Figs. 1, 2, 3) and then slightly increased their size as aging of seedling proceeded. 2) In leaf blade before emerging from the previous leaf sheath, small crystals deposited in bundle sheath cells, but not in chlorenchyma cells. When the leaf blade began to emerge and unfold, the bundles of crystals abundantly deposited in chlorenchyma cells (Figs. 4, 6, 7) and thereafter they increased size and number per cell with aging of the leaf. The size and number of crystals and thus the volume percentage of them to the cell which contained them tended to be greatest at the upper part and smallest in the basal part of leaf blade (Fig. 9). There was positive correlation between the cell size and the crystal size (Table 1). 3) In leaf sheath the crystals deposited initially in the parenchymatous cells including bundle sheath and then in the chlorenchyma cells (Fig. 8). Their length, width, volume and volume percentage to the cell also increased with aging of the sheath, although their amount was less than in the leaf blade.View full abstractDownload PDF (844K) -
Kanoe SATO, Shuji SHIBATA1982 Volume 51 Issue 4 Pages 476-482
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn order to discuss the physiological significance of the existence of Ca oxalate crystals at the pulvinus of rice plants, the amount of Ca oxalate or Ca was estimated anatomically or chemically at different leaves, and different parts of each leaf with their development. The results are summarized as follows; 1. Many types of Ca oxalate crystals which differed in shape and water content were observed at the pulvinus. Among them the tetragonal dihydrate crystal was of the abundant type (Fig. 1). 2. Crystals at the pulvinus of upper and more active leaf were more abundant and larger than those at the pulvinus of basal leaf (Fig. 3-5). 3. Calcium oxalate crystals seems to start its deposition at the pulvinus of leaf when it emerged from the previous leaf sheath, after that their number and size increased rapidly with the expansion of the leaf, and then gradually decreased with a deformation of the crystals of tetragonal type as the leaf senescenced (Fig. 2-5). 4. The concentration of HCl soluble Ca of the basal part of leaf sheath containing pulvinus gradually decreased as the leaf age proceeded (Fig. 7). 5. It was suggested from these results that at least one of roles of Ca oxalate at pulvinus may be a temporary storage of Ca and/or oxalic acid rather than the exclusion of the toxic effect by oxalic acid.View full abstractDownload PDF (1046K) -
Yeong-Chyn WANG, Kiichi HANADA1982 Volume 51 Issue 4 Pages 483-491
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe following experiment was conducted to evaluate the translocation of 14C-assimilate among main stem and tillers at tillering stage in rice plants. Rice plants, cv. Nihonbare, were grown outdoors in 1/5000 a Wagner pots. When the plants reached a leaf age of about 10, leaf blades of the upper two to four leaves on the main stem, tiller II, III, IV, V or tiller VI (the tiller on 2nd, 3rd, 4th, 5th or 6th node of main stem, respectively) were exposed to 14CO2 for 30 min. each, in a growth chamber at 30°C and 30 klx of light. The plants were harvested at 24 hours after exposure and radioactivity in the main stem and each tiller was determined. For a better understanding of the compensatory translocation of assimilate which may occur when leaves of tiller and/or main stem are lost, some plants were defoliated in various ways on main stem and tillers 1 day prior to 14CO2 exposure. The results are summarized as follows: 1. The 14C-assimilate from the exposed leaves was distributed in the largest quantity to the other parts of the exposed tiller (or main stem) itself. And the contribution of the 14C-assimilate to the exposed tiller itself showed larger in the upper node tiller than in the lower node tiller. 2. The main stem supplied much more assimilate to the primary tillers than to the secondary tillers. Among the primary tillers, the upper node tiller received more assimilate from the main stem than did the lower node tiller. On the contrary, in the secondary tillers which were on the same primary tillers, the lower node secondary tiller received more assimilate from the main stem than did the upper node secondary tiller. And this suggested that more 14C-assimilate was translocated to the tillers nearer the source leaves of the main stem. 3. The translocated 14C-assimilate from the exposed tiller (mother stem) was distributed mostly in the secondary tillers (daughter tillers) on the exposed tiller itself. The distribution of 14C-assimilate from the mother stem decreased as the daughter tillers became more developed, and those tillers which had 3 or more expanded leaves received only a small part of the 14C from the mother stem. 4. Translocation of the 14C-assimilate from the primary tillers to the main stem was observed. It was found that the nutritional contribution to the main stem was larger from the lower node tiller than from the upper node tiller. In addition, the translocation of 14C-assimilate among primary tillers was also observed. As determined by dpm/mg dry weight, a higher concentration of 14C was transported to the upper node tiller, especially to the 2nd tiller above the exposed tiller, than to the lower node tiller. 5. Translocation of 14C-assimilate from the exposed tillers toward the youngest primary tillers increased when the main stem and all the tillers below the exposed tiller were defoliated. However, at the same time, translocation toward the defoliated tillers decreased.View full abstractDownload PDF (864K) -
Yoshio INOUE, Tsutomu MORIWAKI, Hiroshi KURIHARA1982 Volume 51 Issue 4 Pages 492-499
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThis experiment was undertaken to study the influence of method of fertilizer application on root system, root-shoot relation and roles of root system in yield determining process. Paddy rice cv. Nipponbare was grown by water culture, and development of root system and distribution of nitrogen were investigated using a root-dividing method and 15N tracer technique. The results obtained are summarized as follows: 1. The total nitrogen content was remarkably reduced by the low concentration treatment before and after the panicle initiation stage. Inspite of the reduction of dry matter production, those roots elongating or emerging during this period showed marked development (Table 2). 2. At the heading stage dry weights of panicle, upper leaves and upper internodes in low concentration plot (L plot) were lager than those in high one (H plot). On the contrary dry weights of lower leaves and lower internodes in L plot were smaller than those in H plot although there was no difference of total dry weight between the two plots (Table 2). There also seemed the same trend about the nitrogen content in each part (Table 2). At the maturity stage weight of panicle in L plot was larger than that in H plot (Table 5). 3. Nitrogen uptaken during the 15N feeding treatment in L plot was larger than those in H plot, and it was distributed more into panicle, upper leaves and upper internodes, and lesser into lower leaves and lower internodes in L plot than in H plot (Table 3). In L plot labeled nitrogen existing in each part was transported from the root group (emerged during the 13th-16th leaf stage) at relatively high percentage. There was a lot of nitrogen left in a root group which was uptaken from the very root group (Table 4). 4. According to the distribution pattern of labeled nitrogen, difference of absorbing parts in root system did not have any effect on the distribution of nitrogen in a rice plant irrespective of the concentration treatment: H and L (Fig. 3).View full abstractDownload PDF (827K) -
Jen-Hsien WENG, Tomoshiro TAKEDA, Waichi AGATA, Susumu HAKOYAMA1982 Volume 51 Issue 4 Pages 500-509
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe assimilation products reserved in rice grain during the ripening period is considered to consist of two parts. One part is the assimilate reserved in the rice plant until heading stage (C), which is transferred into the grains during the ripening period; the other part is the assimilate produced during the ripening period (ΔW). This study was carried out to elucidate the effect of these two parts on grain yield. Several long culm and short culm varieties of Japonica and Indica types cultivated in Japan, Taiwan and the U.S.A. were used (Table 1). Moreover, planting density, top- dressing and thinning treatments were conducted as shown in Table 2. The results obtained are summarized as follows: 1. The increase in ear weight during the ripening period (ΔE) showed significant positive multiple-correlation with ΔW and C. However, the correlation between ΔE and ΔW was significant only when the range of variation of C was very small. On the contrary, there was significant positive correlation between ΔE and C at any values of ΔW (Fig. 1). 2. When C/(C+ΔW) value was high, the assimilate was efficiently transferred into the grains (Fig. 2). 3. Both C and ΔW per grain increased the percentage of ripened grains, but C was more effective than ΔW in producting this increase. 4. The results mentioned above suggest that C influences the increase of ΔE by means of promoting of the accumulative ability of the assimilation product in grain. Therefore, the increase of C is very important for high grain yield. 5. The range of variation of C differed more according to varieties than cultivation conditions, and C in recently improved varieties was larger than in the old varieties (Table 3 and Table 4).View full abstractDownload PDF (997K) -
Jen-Hsien WENG, Tomoshiro TAKEDA, Waichi AGATA, Susumu HAKOYAMA1982 Volume 51 Issue 4 Pages 510-518
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo investigate varietal differences in dry matter productivity before the heading stage, several long culm and short culm varieties, the same used for the experiment in paper I, and several recently improved Japanese and Korean varieties were studied. Growth analysis of these varieties was conducted. The results obtained are summarized as follows: 1. Varieties with taller plant height and more productive tillers had a higher total dry matter weight at the heading stage when they had approximately the same heading date (Fig. 1 and Table 2). 2. The optimum leaf area index (LAIopt) showed a significant positive correlation with the total dry matter weight at the heading stage and the maximum crop growth rate (Fig. 4). Varieties with tall plant height and more productive tillers also showed higher LAIopt (Fig. 5).View full abstractDownload PDF (886K) -
Jen-Hsien WENG, Tomoshiro TAKEDA, Waichi AGATA, Susumu HAKOYAMA1982 Volume 51 Issue 4 Pages 519-528
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn order to analyze the causes of varietal differences in dry matter production before the heading stage, the same varieties used for the experiment, in paper II were examined. The photosynthetic rate of a single leaf (Po), the respiratory rate of each plant organ and the specific leaf area were determined. The extinction coefficient, leaf inclination and the horizontal distribution of leaves in the canopy were also determined. The results obtained are summarized as follows: 1. Varieties with a higher optimum leaf area index showed a smaller value in the decreasing rate (b) of NAR with LAI increase (Fig. 3). 2. All of the variables examined, Po, the mean leaf inclination, the variation coefficient of horizontal leaf distribution in the upper half of the canopy, and the respiratory rate, showed significant positive correlations with b (Table 3 and Table 4). On the other hand, specific leaf area showed a significant negative correlation with b (Table 3). 3. Varieties with a taller plant height and more productive tillers showed thinner leaf blades, a higher leaf area expansion speed, a low Po and lower respiratory rates (Table 4, Table 5, Fig. 5 and Fig. 6). NAR of these varieties was low at the small LAI stage of the canopy, but the decreasing rate (b) of NAR with increase of LAI in the canopy was small. Therefore, dry matter productivity at the increased LAI stage of canopy was high in these varieties (Fig. 2). 4. Varieties with taller plant height and somewhat inclined leaf blades were characterized by a uniform leaf distribution in the upper half of the canopy, so that the b value became smaller (Table 5).View full abstractDownload PDF (1043K) -
Seok Weon SEO, Yasuo OTA1982 Volume 51 Issue 4 Pages 529-534
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSWater loss in hull and the effect of aerial humidity on the development of kernel were investigated. The results obtained are as follows: 1. The rate of water loss in the hull after detaching from panicle decreased, as ripening proceeded in both fertile and sterile grains. 2. The rate of water loss differed among sterile, fertile grains, and hull of fertile grains, being higher in the following order: sterile grain>hull of fertile grain>fertile grain. 3. The rate of water loss was much lower in normal than in malformed grain. 4. The water loss in panicle was affected by SiO2 application and it was higher in detached panicle in plots without SiO2 application. 5. By glume top clipping, the development of the kernel was inhibited very severely. But even though the top of glume was clipped, the development of kernel was not prevented so severely under high aerial moisture conditions. And even under the same moisture conditions, when the glume-top-clipped kernel was covered with a parafilm bag, the development of the kernel was better than that without covering of parafilm bag. From these results, it was shown that in the ripening of rice plant, the hulls play an important role in keeping high moisture condition in grain, thus enabling the kernel to achieve a normal development.View full abstractDownload PDF (617K) -
Yasuhiro KONO, Takeru MIZOGUCHI1982 Volume 51 Issue 4 Pages 535-541
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
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Il-Doo JIN, Hiroyuki TERAO, Jun INOUYE1982 Volume 51 Issue 4 Pages 542-545
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSUsing 10 aman varieties, 11 aus varieties, 6 boro varieties, 8 bulu varieties, 8 tjereh varieties, 100 Korean paddy rice varieties and 16 Japanese paddy rice varieties, degree of grain shedding (breaking tensile strength) and morprology of abscission region in longitudinal sections of pedicel at harvest time were examined. The results obtained were summarized as follows. 1. Breaking tensile strength was weakest in both aus and boro, followed in ascending order by aman, tjereh, Korean paddy rice, Japanese paddy rice, and bulu (Table 1). 2. All the varieties belonging to aman, aus, boro, bulu and tjereh had abscission layer. In aman, aus, boro and tjereh varieties, parenchymatous cells presented in the abscission layer had completely cracked (Table 2 and Fig. 1-A). The parenchymatous cells of bulu varieties, however, had not cracked (Table 2 and Fig. 1-C). On the other hand, in both Korean and Japanese paddy rices, one group of varieties had abscission layer of bulu type and the other had not abscission layer (Table 2 and Fig. 1-C and D). Therefore, from the viewpoint of cracking of abscission layer, bulu varieties appeared to be situated closely to Korean and Japanese paddy rices.View full abstractDownload PDF (776K) -
Kanoe SATO, Takeshi IKEDA1982 Volume 51 Issue 4 Pages 546-552
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe soybean plants (cv. Miyagishirome) were grown in the phytotrons under natural light at day/night temperatures of 30°/25°, 24°/19°, 17°/12° and 9°/9°C. The 6th trifoliate leaf (numbered from the base) which was fully expanded at the start of temperature treatment was sampled two times at weekly intervals during the treatment, and the young developing 11th leaf which was ca 0.5 cm long at the start was sampled three times: at the time when it elongated 1.0-1.5 cm long, when it elongated ca. 3.0 cm long, and fully expanded at respective temperature treatment. The samples were embedded in spurr resin and observed under both light- and electron microscopes. The results are summarized as follows: 1. Starch accumulation in the 6th leaf plastids was most abundant at 17°/l2°C'and decreased in the order of 24°/19°, 9°/9° and 30°/25°C, showing a tendancy to deposit most in the 2nd layer of palisade mesophyll and then at the inner layer of spongy mesophyll (Figs. 1-4). 2. The 11th leaf at the start consisted of six cell layers except around the vascular bundles (Fig. 5). When it elongated to ca 3.0 cm. long, the paraveinal cells began to expand and vacuolate ahead of the palisade and spongy cells (Figs. 9, 10), and at this time chloroplasts were scattered in the cytoplasm. In the fully expanded 11th leaf the starch accumulation under each temperature was almost similar to that of the 6th leaf (Figs. 11-13). 3. In the 11th leaf, starch accumulated most abundantly at 17°/12°C during all its developmental phases. It was observed that epidermal cells including trichomes and subepidermal mesophyll cells contained more starch granules than the inner cells when it was 1.0-1.5 cm long, but the cells of all layers contained them rather uniformely when it elongated to ca 3.0 cm long (Figs. 6, 9). When it fully expanded, starch granules disappeared in the epidermal and paraveinal cells, and thereafter new starch granules accumulated in all the mesophyll cells except vascular bundles. 4. The fine structure of chloroplasts of the 6th leaf was little affected by 17°/12°C, while at 9°/9°C after one week treatment an abnormal swelling of thylakoids and many vesicles appeared in the chloroplast, the tendency becoming more clear after two weeks. (Figs. 14-16, 21-23). The 11th leaf didn't expand after 3 days of treatment at 9°/9°C and its chloroplasts remained without development, although those at the other treatments formed thylakoid and grana faster the higher the temperature. 5. Starch accumulation in the chloroplast seemed to be more abundant during daytime than during nighttime (Figs. 24, 25 and Table 1).View full abstractDownload PDF (2094K) -
Shigeo NISHIMURA, Eizo MAEDA1982 Volume 51 Issue 4 Pages 553-560
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
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Toshiaki MATSUDA, Harunosuke KAWAHARA, Nobuo CHONAN1982 Volume 51 Issue 4 Pages 561-569
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSHistogenesis of the 4th internode from the top of rice culm, var. Koshihikari, was observed in the rapidly elongating stage with light and electron microscope. The materials, for preparation to electron microscope, were fixed with 2-4% glutaraldehyde, postfixed with 1-2% osmium tetroxide, and embedded in Spurr's resin. Meshes were stained with uranium and lead. Proliferation and enlargement of the tissues at the base of internode bring approximately 30% increase in diameter, reduction by half in thickness of the fundamental parenchyma and duplication in total thickness of the epidermis and cortical fibers (Fig. 1). Epidermal cells, just above the intercalary meristem, differentiate to long and short cells (Fig. 3). The short cells again differentiate to silica cells, cork cells and trichomes (Figs. 4 and 5). The long cells elongate in the range of 35 mm above the intercalary meristem and attain a length of about 200μm. Cortical fiber cells divide anticlinally, periclinally and radially in the zone of intercalary meristem, and in the range of 35 mm above it, they elongate rapidly to a length of average 1.2 mm (Figs. 6-9). Meanwhile, the number of periclinal rows in cortical fibers increases from 3 to 5-7, and the cell arrangement falls into disorder by intrusive growth. The intercalary meristematic cells have dense cytoplasm, and contain a number of starch grain and osmiophilic globules, which decrease during cell elongation. Dense cytoplasm, a large number of mitochondria and ribosomes are represented by the tips of the cortical fiber cells growing intrusively (Figs. 10-13). We think, therefore, that the developmental activities of the cortical fibers are reflected in the tissue thickness, the number of periclinal rows, the degree of rows irregularity and the cell length.View full abstractDownload PDF (2738K) -
Seok Weon SEO, Yasuo OTA1982 Volume 51 Issue 4 Pages 570-576
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe distribution of 14C in panicles assimilated through leaves and stems at heading stage was investigated in plants with completely and partially sterile panicles, with focusing on hulls of grains. The results are as follows. 1. Photosynthetic activity was much lower in hulls than in rachis and rachis-branches. 2. In the completely sterile panicles, 14C translocated from the grains on the lower branches to those on upper branches, and from the grains in the lowest position to those in highest position on the same branches. When all the grains became sterile and kernels were not formed, 14C assimilated through leaves and stems translocated and accumulated from the grains in the lowest position to those in the highest position. These results suggest strongly that the translocation of carbohydrates proceeds through the gradient of sugars4) content in the plant organs. 3. On the other hand, impartially sterile panicles, there was a great difference in the ammount of 14C translocated from leaves and stems to the hulls between sterile and fertile grains. Namely, in hulls of fertile grains 14C amount increased rapidly one day after flowering (i.e. the day after 14C assimilation treatment) and there was a peak in the amount of 14C in hulls (9490 dpm/grain) 4 days after flowering. Thereafter the value was almost constant until 17 days after flowering, and then it decreased. In contrast, in the hulls of sterile grains the amount of 14C translocated was much smaller, with a peak (2684 dpm/grain) one day after flowering. Thereafter 14C flowed out of the hulls. 4. In fertile grains, at the very early stage of ripening when the development of kernel was very small, 14C translocated much more in hulls than in kernels. From these results, it was concluded that the hulls of fertile grains absorb carbohydrates much more actively than those of sterile grains after flowering, that this function takes place through fertilization, and that hulls play an important role in pooling the carbohydrates to be translocated into kernels at the very early stages of ripening.View full abstractDownload PDF (738K) -
Naotsugu UCHIDA, Yoshiharu WADA, Yoshio MURATA1982 Volume 51 Issue 4 Pages 577-583
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSPhotosynthetic activity measured by O2 evolution and other physiological characteristics such as the content of total nitrogen, soluble protein, fraction I protein and chlorophyll (a+b) were investigated in the senescing 5th, 7th, 8th and flag leaf of rice grown under different nitrogen supply. The results obtained are as follows: 1. Nitrogen deficiency given during leaf senescence immediately decreased photosynthetic activity as well as the content of soluble protein, fraction I protein and chlorophyll (a+b). The older 5th leaf was affected more severely as compared with the upper and younger leaves (Table 1). 2. Photosynthetic activity, which was affected heavily by nitrogen deficiency, declined with age of the leaf more rapidly in its value measured under a high light intensity (70 klx) than in that measured under a low light intensity (10 klx) (Fig. 1). 3. The content of fraction I protein which was influenced most severely by nitrogen deficiency among various leaf constituents, decreased most rapidly with the progress of leaf senescence (Table 1, Fig. 1). 4. A close, curvilinear correlation was observed between the photosynthetic activity and the content of fraction I protein of rice leaves at vegetative stage (Fig. 2). Thus, the content of fraction I protein which declined most rapidly during leaf senescence, seems to be the most important limiting factor for the photosynthetic activity of senescing rice leaves at vegetative stage. 5. The regression curve for the control plant differed from that for the no nitrogen supplied plant, although a fairly close correlation was found in both cases between the photosynthetic activity and the content of fraction I protein (Fig. 3). This disagreement suggests the existence of other limiting factors than the content of fraction I protein for the photosynthetic activity of a flag leaf.View full abstractDownload PDF (677K) -
Koou YAMAZAKI, Naganori KAERIYAMA1982 Volume 51 Issue 4 Pages 584-590
Published: December 05, 1982
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe number, the diameter and the growing direction of primary roots (main nodal roots) on successive "shoot units" of corn grown under field conditions were investigated. The number and the basal diameter of primary roots of each "shoot unit" remained almost constant in the lower "shoot units", then increased remarkably towards the higher "shoot units". Such tendencies were also found in case of the stem diameter and the internode length along successive "shoot units". In any "shoot unit", therefore, there were close correlations among the root diameter, the stem diameter and the internode length. The primary roots were classified into the following three types according to their growing directions: 1) The primary roots of lower "shoot units", which emerged at the earlier growing stages, grew horizontally or somewhat obliquely. 2) The primary roots of the middle "shoot units" grew obliquely at first, then turned their direction vertically near the interface of top- and sub-soil, and finally reached the deepest soil layer. 3) The primary roots from the upper "shoot units", which emerged in the later growing stages of the plant, grew vertically, however, they did not reach as deep layer as the roots of the type 2. From these results, it is inferred that a growth correlations might exist among the morphological characters of primary roots, growing directions of them and stem characters in successive "shoot units".View full abstractDownload PDF (758K)
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