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Volume 57 (1988)
- Issue 4 Pages 599-
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- Issue 2 Pages 263-
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Volume 57, Issue 4
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Katsuya MATSUBA1988 Volume 57 Issue 4 Pages 599-607
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn order to clarify the regularity of shoot development in an individual rice plant, the nodal position of the last tiller on each stem was investigated for four year period using 6-10 plants individually potted. The results disagreed with the generally accepted theory of "synchronous development of leaves and tillers" (Katayama, 1951), which proposes a "standard" plant and indicates the theoretical nodal positions of the last tillers. Our data rather coincided with the assumption by Yatsuyanagi et al (the left collums of Table 2 and 3) in principle, but differed from the "standard" plant, with a certain regularity regarding Katayama's theoretical nodal positions of the last tillers (the right collums of Table 2 and 3); the actual position of the last secondary tiller was higher by one node, that of the last tertiary tiller by two or one nodes and that of the last quaternary tiller by three or two nodes. Thus we conclude that the nodal positions of the last tillers coincide, in principle with the positions assumed by Yatsuyanagi et al. The maximum number of tillers (T max.) obtained on the basis of their assumption can be expressed in a formula, T max.= 2n, where n is the nodal position of the last primary tiller. Those maximum numbers are found to be about twice as large as the maximum numbers based on the "standard" plant.View full abstractDownload PDF (872K) -
Hide SAWAHATA1988 Volume 57 Issue 4 Pages 608-613
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSInvestigation on the storage root yield of sweet potato was carried out under different underground conditions by utilizing gravel culture. Roots were divided into three different functional parts: storage roots, roots developed from the stem (RA), and roots from the storage roots (RC). Different kinds of soil and soil moisture levels were applied to storage roots and different concentrations of culture solution were applied to RA and RC. These treatments were given during the thickening stage of storage roots. 1) Material plants grown by the gravel culture method exhibited normal growth. The yield in the control plot was higher than the yield obtained under the ordinary field conditions. 2) Application of a culture solution to RA and RC was more effective on storage root yield. On the other hand, the effect of soil and its moisture contents of storage roots was comparatively small on their yield and dry matter content. 3) The research results suggested that the direct effects of soil and its moisture contents on storage root were smaller than the effects of nutritional treatments on rootlet.View full abstractDownload PDF (822K) -
Katsuya MATSUBA1988 Volume 57 Issue 4 Pages 614-620
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn order to clarify the regularity of shoot development in an individual rice plant, the relationship between the total number of leaves on each tiller and that of leaves on the main stem was investigated for four year period using 6-10 plants individually potted. The results disagreed with the generally accepted theory of "synchronous development of leaves and tillers" (Katayama, 1951). The total number of leaves on the main stem often varied by one leaf in the same plot. When compared with Katayama's theoretical total number of leaves on tiller [deduced using the smaller total number of leaves on the main stem (expressed as N-1, where N is the larger total number of leaves on the main stem], the actual total number of leaves on each tiller of different orders showed an increase with certain regularity; the number increased by 0 to 1 on the primary tillers, 1 to 2 on the secondary, 2 to 3 on the tertiary and 3 to 4 on the quaternary tillers, respectively. The present study suggests the existence of a certain regularity in the relationship between the total number of leaves on each tiller and that of leaves on the main stem. Accordingly, on each primary tiller (expressed as n1) and on each secondary tiller (expressed as n1 n2), the maximum total number of leaves (referred to as L max.) -excluding prophyll-in the same plot, can be expressed as: L max. (n1) = [(N-1) -1] -n1 and L max. (n1n2) = [(N-1) -2] - (n1+n2). In these formulas, both n1 and n2 are numbered according to the nodal position counted acropetally.View full abstractDownload PDF (816K) -
Shigeki NAKAMURA, Hide SAWAHATA1988 Volume 57 Issue 4 Pages 621-626
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThis investigation was conducted to clarify varietal differences of the ratio of stem weight to root weight (RSR) and to explain the relationship between RSR and some other characteristics by measuring dry matter weight of the stem and the root of a number of soybean cultivars. Due to the environmental factors during the growing season, stem weight and root weight varied greatly; in contrast RSR was rather stable. It was therefore, concluded that RSR is more stable than stem weight and root weight (Table 2, 3). The highest RSR measured was more than twice as large as the lowest RSR and marked varietal differences were recognized in the RSR (Table 1, 2, 5). A significant positive correlation was recognized between RSR and the length of growing period and also between RSR and seed yield, but except the effect of the length of growing period, no significant positive correlation was found between RSR and seed yield in early cultivars (Table 4, 5). It was also recognized that the stem weight and root weight of many new cultivars became greater year by year, but the increase of stem weight was less than that of root weight. Thus, RSR is gradually decreasing each year (Fig. 2, Table 6). In order to obtain higher seed yield, it is very important to develop a breeding method or cultivation method by which stem diameter and branching are increased.View full abstractDownload PDF (717K) -
Tomomi NAKAMOTO, Hiroyasu MACHIDA, Akio MATSUZAKI1988 Volume 57 Issue 4 Pages 627-630
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe relationship between the difference of date of anthesis (Δt) and that of final grain weight (Δw)was studied by observing pairs of spikelets at various positions on the panicle of rice cultivers, 'Nipponbare' and 'Musashikogane'. A high negative correlation was found between the deviation of Δt (Δt-Δtmode ; Δtmode was the most frequently observed Δt) and that of Δw (Δw-Δwmode ; Δwmode is the Δw when Δt = Δtmode), in all pairs of spikelets both on the same (Fig.2) and on different (Fig.3) primary rachis branches. Thus, the results suggest that early flowering spikelets bear larger grains than later flowering spikelets on the corresponding position of primary rachis branch. This fact is probably because early flowering augments nutritional distribution.View full abstractDownload PDF (517K) -
Takashi OHTSUKA, Hitoshi SAKA1988 Volume 57 Issue 4 Pages 631-635
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIsoprothiolane (diisopropyl-1, 3-dithiolan-2-ylidenemalonate, IPT) has been used as an agent controlling not only rice blast but also non-parasitic damping-off (MURENAE disease) of rice seedlings. It also accelerates the development of rice roots at the seedling stage. To study the plant hormone-like action of IPT, interactions between IPT and phytohormones with some biological assays were investigated. IPT stimulated the activity of auxin (IAA) -induced lamina inclination in the etiolated rice seedlings at high concentrations above 1O-4M. As for the chlorophyll-retention in rice leaf disc system, IPT was more active than benzyl adenine, especially at high concentration. Though IPT suppressed both the shoot elongation of rice seedlings at 10-4M and the proliferation of rice callus tissues, it enhanced the ethylene production both in seedlings and callus of rice. There was no interaction between IPT and GA on the growth of rice seedlings (cv. Tan-ginbouzu or Nipponbare) by the immersion method. These results indicate that IPT remarkably affects the growth process of rice seedlings through the enhancement or the modification of auxin activity, cytokinin activity and ethylene production system.View full abstractDownload PDF (600K) -
Makoto TSUDA1988 Volume 57 Issue 4 Pages 636-642
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe objective of this study was to examine whether the ripening period is affected by water stress during early stages of panicle development in rice. Sixteen seedlings of a paddy field rice cultivar Koshihikari were transplanted in a 4l pot containing sandyloam soil, and pots were kept flooded. Tillers being removed weekly, only main culms were exposed to 10 different soil moisture stress started either at the primary rachis branch or the floret differentiation stage. The time from sowing to heading increased by water stress. The panicle growth after heading was lowered by water stress and the ripening period was shortened when water stress became severe. As a result, the growth period varied only slightly under water stress. Although a proportional relation existed between the time from sowing to heading and water stress duration, this was not so chose as to cumulative water stress (CWS). It is therefore concluded that the ripening period of rice is shortened under water stress during early stages of panicle development, while the time to heading increases with increasing CWS. The causes of shortening the ripening period and its contribution to grain production were discussed.View full abstractDownload PDF (723K) -
Hironori MIMOTO, Toichiro INANO, Hiroyuki DAIMON, Hiroyoshi CHUJO1988 Volume 57 Issue 4 Pages 643-649
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSApplication of Italian ryegrass (top) to the paddy field remarkably inhibited the growth and nitrogen absorption of rice plants from the transplanting to the rooting stage. The degree of the inhibition was closely correlated to the intensification or rapid reduction of soil due to decomposition of the Italian ryegrass but not to the amount of applied nitrogen fertilizer. From the rooting to the active tillering stage, the rice growth and nitrogen absorption were also inhibited. However, during this period, no correlation was found between the degree of inhibition and the intensification of soil reduction or the amount of nitrogen fertilizer applied. From the active tillering to the maximum tiller number stage, tendency towards restricted nitrogen absorption was no longer observed. However, the number of tillers at the maximum tiller number stage was decreased due to the effect of earlier inhibition. A high nitrogen content in rice plants was maintained after the panicle formation stage, and this induced a reduction in the number of non-productive tillers. But the number of grains, percentage of ripened grains and 1000-grain weight increased.View full abstractDownload PDF (836K) -
Hironori MIMOTO, Toichiro INANO, Hiroyuki DAIMON, Hiroyoshi CHUJO1988 Volume 57 Issue 4 Pages 650-654
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe process of nitrogen uptake in rice plants from applied Italian ryegrass (top), fertilizer, and soil was investigated using 15N as a tracer in a paddy field. At the rooting stage, rice plants absorbed an extremely small amount of nitrogen, and the recovery rate of nitrogen from the fertilizer was below 1%. The fertilizer-nitrogen had a very minor effect on the growth of rice plants at this stage. Due to decomposition of the Italian ryegrass, fertilizer-nitrogen was preferentially consumed after the rooting stage, therefore the ratio of the absorption of fertilizer-nitrogen to that of total nitrogen by rice plants was reduced. It was found that nitrogen from the decomposed Italian ryegrass was simultaneously absorbed by rice plants from this early stage. At the most active tillering atage, the applied Italian ryegrass maximized the inhibitory effect on fertilizer-nitrogen absorption. But the contribution ratio of nitrogen originated from the Italian ryegrass increased to the maximum amount at this stage. The nitrogen content in rice plants after heading was maintained at a high level by the combination of the late-effect of soil- and fertilizer-nitrogen and the additive effect of nitrogen from the decomposed Italian ryegrass. The maintenance of nitrogen content at a high level remarkably contributed to the active growth of rice plants at the ripening stage.View full abstractDownload PDF (647K) -
Takashi ORITANI, Eiichi MATSUMOTO1988 Volume 57 Issue 4 Pages 655-665
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe proper combination of N-level of basal dressing and N-topdressing was effective for increase in the cutting yield but N-topdressing under large-N condition brought about not only reduction in the cutting yield but also an increase in cyanide content harmful to domestic animals. These N-reactions were strongly developed especially under large-N condition lacking in K or P. The proper topdressing quantity of N in the field was considered to be 5-10 kg/10a. Further, the concentration of P in the bleeding sap was also markedly reduced especially when K or P was deficient under large-N condition. It was considered that abnormal metabolism, such as the increase and accumulation of free amino acids in vivo, brought about a marked increase in cyanide or nitrate-N in the leaf blade and stem. The increase of asparagine in the bleeding sap and stem was especially marked as a result of the N-reaction in the sorgo plant accompanied by a rise in the N-level of basal dressing. From this, the purpose in the nutritional diagnosis of the sorgo plant can be achieved by the simple detection of asparagine in the bleeding sap.View full abstractDownload PDF (1022K) -
Tomomi NAKAMOTO, Koou YAMAZAKI1988 Volume 57 Issue 4 Pages 666-670
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSQuantitative relationship between leaves and primary roots was investigated on the main stems of field grown millets, i.e. Setaria italica. Sorghum bicolor, Pennisetum typhoideum, Panicum miliaceum, Echinochloa frumentacea, Eleusine coracana, and Coix lacryma-jobi. 1. The values of 'total leaf area/total cross sectional area of primary roots' at the maturing stage are nearly identical among the millets examined, except Eleusine coracana (Table 2). This means a common quantitative relationship exists on the main stem between total leaf area and total cross sectional area of primary roots. In the early growing stage, the total leaf area increased more rapidly than the total cross sectional area of primary roots. In later growing stage, the increase of total cross sectional area of the primary roots considerably surpassed that of the total leaf area (Fig. 1). Relationship between these two areas throughout plant growth varied quantitatively among species. In the early growing stage Setaria and Sorghum showed high values and Coix and Echinochloa showed low values of 'total leaf area/total cross sectional area of primary roots'. 2. The value of 'total cross sectional area of. vascular bundles at the base of leaf blades/total cross sectional area of steles at the base of primary roots' differed only slightly among species (Table 2). Total cross sectional area of steles in primary roots increased more rapidly than the total cross sectional area of vascular bundles in leaves (Fig. 2). This means that conductive tissue formation of primary roots gains increasing predominance over that of leaves. 3. The implications of quantitative relationship between roots and leaves was discussed from the view point of safety from environmental stresses.View full abstractDownload PDF (659K) -
Tetsuya SUGA, Koou YAMAZAKI1988 Volume 57 Issue 4 Pages 671-677
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSPaddy rice ( Oryza sativa L.) root mass was analyzed from the viewpoint of developmental changes in quantitative characters and growth correlation with leaf mass. The total root length was expressed as (primary root number)×(average primary root length)×("coefficient of branching"), or (total primary root length)×("coefficient of branching"), where the "coefficient of branching" is the ratio of the total root length to the total primary root length. The average primary root length and the "coefficient of branching" increased linearly, while the primary root number, the total primary root length and the total root length increased exponentially with plant age in leaf number. To the increase in the total root mass, the increase in the primary root mass contributed much more than in the degree of primary root branching. The allometric formula : log (root mass) = k·log (leaf area) + b was calculated in earlier and Later growth periods separately. The coefficient of allometry, k, was smaller than l during the earlier period when the main stem leaves emerged quickly, while the value of k exceeded l after the leaf emergence speed became slower. This showed there might be two developmental stages before heading in rice plants, probably corresponding to the conversion of growth phase. Such a switching was presumably regulated by the changes in the primary root mass rather than in the degree of primary root branching.View full abstractDownload PDF (827K) -
Ho ANDO, Ken ADACHI, Makoto MINAMI, Naoki NISHIDA1988 Volume 57 Issue 4 Pages 678-684
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSField and growth cabinet experiments were carried out to clarify the relationship between the number of tillers at early growth stage (NT) and the amount of NH4-N in soil and soil solution. In the growth cabinet experiments, zeolite was added to the soil at the rate of 0%, 1%, 2% and 10% of soil weight to modify CEC values of the soil. In field experiments, two fields with different CEC values were used. 1) In growth cabinet experiment, results revealed that with zeolite treatment, there is no difference in exchangeable NH4-N in soil. However, big differences were noted in content of NH4-N in soil solution (CAS) before transplanting, i.e., 17ppm, 7ppm, 3ppm and 0ppm in 0%, 1%, 2% and 10% zeolitetreated plots, respectively. The NT is not affected by CAS under high temperature condition (25°C, daytime ; 15°C night time). However, under low temperature condition (20°C/10°C), NT is in this order : 0%>1%=2%>10% zeolitetreated plots. 2) Results of the field experiments showed no difference in the amount of exchangeable NH4-N between the two fields. However, higher CAS is observed in field with low CEC while relatively lower CAS in field with higher CEC. Higher NT was noted in low CEC than in higher CEC field in 1986 probably due to low temperature (13.8°C) during early tillering stage. In 1987, however, no difference in NT between the two fields was observed which can be attributed to high temperature (16°C) during early tillering stage. 3) In 1986, a negative correlation coefficient (r=-0.691*) between CEC and NT of different paddy fields in Shonai area was observed, while no relationship was observed in 1987 (r=0.264, ns). The CAS (or CEC) can affect NT only in the year where relatively low temperature at early growth stage of rice plant.View full abstractDownload PDF (749K) -
Yusuke GOTO, Kiyochika HOSHIKAWA1988 Volume 57 Issue 4 Pages 685-691
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTillering behavior of rice plants (1 plant/pot) of three cultivars was investigated. In a rice plant, there are differences (D) in growth speed between the main stem and each tiller. In the previous paper, we prescribed a relative tiller age (RA) to the individual tillers, and compared the ages of every tiller with each other. In this paper, we investigated the relationship between D and the increasing pattern of tiller number. If there is no D, we can make a curve called a synchronous growth curve indicating the increasing pattern of tiller number when leaves of each tiller and leaves of the main stem expanded synchronously (synchronous growth). Using three cultivars, we analyzed the pattern of synchronous growth curves and discussed the differences in the tiller behavior among the cultivars. We simulated the synchronous growth curve when every tiller appears in a rice plant. Assuming the value of D, we also simulated the growth curve when every tiller appears. Compared the curve with the synchronous growth curve, we discussed the relationship between D and the increasing pattern of ti1ler number.View full abstractDownload PDF (833K) -
Sachio MARUYAMA, Koichi TAJIMA1988 Volume 57 Issue 4 Pages 692-698
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSField experiments on the growth response to nitrogen were conducted for three years (1983-1985) using 49 rice varieties including japonica, indica and japonica-indica hybrid. Rates of increase in culm length and lower internodes as a result of nitrogen fertilization to japonica, japonica-indica hybrid and semidwarf indica were large, intermediate and small, respectively. The rate of decrease in dry weight of the leaf sheath and culm per unit culm length was larger in japonica than that in japonica-indica hybrid and semidwarf indica. The ratio of leaf area to the spikelet number was obviously smaller in japonica-indica hybrid and semidwarf indica compared to that in japonica. However, the ratio of the rate of increase in leaf area to that in the spikelet number due to nitrogen fertilization was larger in these groups than that in japonica. Furthermore, the rate of increase in single leaf area and specific leaf area of japonica-indica hybrid and semidwarf indica were larger than those of japonica. The obtained results suggested that one of the reasons of higher lodging resistance of japonica-indica hybrid and semidwarf indica was ascribed to a little changes in the culm length due to nitrogen fertilization compared to that of japonica. It was also suggested that these groups had a tendency of over-luxuriant growth due to nitrogen fertilization compared to japonica. This characteristic should be improved for breeding high-yielding varieties by using japonica-indica hybrid or semidwarf indica as genetic resources.View full abstractDownload PDF (807K) -
Koji ITO, Shinobu INANAGA1988 Volume 57 Issue 4 Pages 699-707
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe effect of temperature on growth and subsequent growth variations in Napiergrass (Pennisetum purpureum cv. Merkeron) pretreated with low temperatures were investigated mainly by leaf growth and dry matter production. Three groups of plants were, at first, grown separately in three controlled environments with day/night temperature of 15/12, 23/20 and 30/27°C for 15 days. Subsequently, plants from each controlled condition were grown for 33 days under a single condition in a glasshouse with 32/26°C in average. In the controlled environments, the plant growth was greatly restricted under the lowest temperature, while it was maximized under the highest temperature. In the glasshouse, relative growth rate was higher in plants pretreated with lower temperatures. This compensatory growth was brought about by the after effect of low temperatures on leaf area enlargement and net assimilation rate. The folded leaf. numbers and the total non structural carbohydrate concentration in the stem under the controlled environments were inversely related to temperature. It can be inferred that such results contributed to a more rapid increase in unfolded leaf numbers in the glasshouse, leading to a higher rate of leaf area enlargement and the higher net assimilation rate in plants pretreated with lower temperatures.View full abstractDownload PDF (980K) -
Teruhisa UMEZAKI, Shiho MATSUO, Shigeo MATSUMOTO, Itaru SHIMANO1988 Volume 57 Issue 4 Pages 708-714
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo demonstrate the effects of dwarf characters of the soybean on flowering and fruiting, which are closely related to the yield, cultivar Hyuga and its dwarf mutant Hyuga-dwarf line were used in this experiment. The results obtained are summarized as follows: 1. Anthesis of Hyuga-dwarf line concentrated almost in the beginning of flowering season similar to Hyuga, although the flowering period of Hyuga-dwarf line was shorter than that of Hyuga. 2. Hyuga-dwarf line exhibited a similar pattern of flowering and fruiting habits as Hyuga, i.e., percentages of flowering and fruiting were much higher on branches than on the main stem. In particular, this tendency was clearly observed in the branches elongated from the lower nodes of the main stem in Hyuga-dwarf line. 3. The total number of flowers of Hyuga-dwarf line was one-half of that of Hyuga. This was not due to the total node number, but to the number of flowers per node. 4. Since no difference in the number of pods per node between Hyuga-dwarf line and Hyuga was observed, it is indicated that the capacity of podding in a phytomer is limited. 5. Since the number of pods per unit stem weight showed the same tendency as the node number per unit stem weight, the high seed-stem weight ratio in Hyuga-dwarf line is considered attributable to a reduction in phytomer size. In conclusion, these results indicate that the number of flowers produced is limited by the amount of vegetative growth until the flower bud differentiation, and that the fruit percentage is limited by the vegetative growth increment after flowering and the number of pods per phytomer. In dwarf lines, the former seemed to be disadvantageous, whereas the latter seemed to be advantageous to crop production.View full abstractDownload PDF (694K) -
Yuji HAMACHI, Masahiko FURUSHO, Tomohiko YOSHIDA, Masamitsu ITO1988 Volume 57 Issue 4 Pages 715-721
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe objective of this study was to find high wet endurance cross parents for a malting barley breeding program. Barley cultivars containing newly developed malting barley cultivars were grown under an excess soil moisture treatment (irrigated condition) at the internode elongation stage. Principal Component Analysis (PCA) was applied for two barley populations; 78 two-rowed barley cultivars and 51 late-maturing cultivars. Characters for PCA were the reduction ratios of culm length and four yield components (number of kernels per ear, number of ears per plant, seed fertility and 1000 kernel weight) by the treatment. The reduction ratios was calculated as (the mean value of excess soil moisture plots/that of control plots)×100. Component l by the PCA was considered to be a reliable index for wet endurance of barley cultivars. Among 78 two-rowed and 51 late-maturing barley cultivars tested, several cultivars were less-damaged under the excess soil moisture condition and were selected as the wet endurance cross parents in a malting barley breeding program.View full abstractDownload PDF (771K) -
Takashi OHTSUKA, Hitoshi SAKA1988 Volume 57 Issue 4 Pages 722-727
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSConditions for undestructive assay system of acid phosphatase in the intact roots of rice ( Oryza sativa L.) seedlings as a marker of physiological activity of roots using p-nitrophenyl phosphate as a substrate were investigated Phosphatase activity was linear up to 3h at the concentrations from 0.5 to 10mM. Optimum acid phosphatase activity was obtained between pH 3 and 6 at 25-30°C. The enzyme activity of the whole roots including seminal and crown ones at the 4th leaf stage plant was higher than that at younger or older seedling stage. Using this method, we also investigated the effect of isoprothiolane (IPT), which is known as a plant growth regulator, on acid phosphatase activity in roots of rice seedlings. This compound promoted acid phosphatase activity in rice roots.View full abstractDownload PDF (627K) -
Tetsuro TANIYAMA, Katsuhiko IKEDA, S.V. SUBBAIAH, M.L.N. RAO, S.K. SHA ...1988 Volume 57 Issue 4 Pages 728-732
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe grain yield and the yield components of Indian rice cultivars grown in 1985 wet season were studied. The results revealed that the yield was largely dependent on the number of spikelets per panicle and percentage of ripened grains. The number of spikelets per panicle was not correlated with the number of panicles per hill. One thousand-grain weight, length of panicle and leaf area of the four uppermost leaves seemed to have no significant effect on grain yield. The highest grain yield of 'Vijayamahsuri' among cultivars tested attributed to the greatest number of panicles per hill, a relatively great number of spikelets per panicle and a high percentage of ripened grains. The second highest yield was obtained with 'Sonamahsuri'. Both cultivars showed the same length of panicle as well as the first internode and the lower the internode, the shorter the length with similar tendency. Between two scented cultivars, 'HR 59' produced a higher yield than 'Basmati' at normal planting depth of 8-9 cm, 'Basmati', however, produced higher grain yields when transplanted at a shallow depth (2-3 cm). Although the number of panicles were nearly the same in both scented cultivars, the leaf area was larger in 'HR 59' than in 'Basmati'. Lodging in 'Mahsuri' and 'HR 59' were observed due to the elongation of lower internodes.View full abstractDownload PDF (636K) -
Eizo MAEDA, Kazuko MAEDA1988 Volume 57 Issue 4 Pages 733-742
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe structure of hydathode in the leaf tip of indoor-grown and outdoor-grown rice plants was examined by light and transmission electron microscopy. Terminal ends of large-sized vessel elements are in direct contact with some cells of the epidermis covering the extreme tips of. the leaves. Expanded intercellular spaces directly adjoin thin cell wall of the large vessel elements. The cell wall of vessel elements exhibited a secondary thickness in places. Intercellular spaces are occasionally occupied with numerous bacteria. Mesophyll parenchyma cells surrounding the vessel elements characteristically have cell wall ingrowths developed slightly. The mesophyll cells sometimes contain electron dense deposits which are tightly packed between cell wall and plasmamembrane. Microbodies are often present in the mesophyll cells. From these results, it was elucidated that rice leaf hydathode principally consists of large-sized vessel elements, the adjoining expanded intercellular spaces and water pores.View full abstractDownload PDF (2707K) -
Makie KOKUBUN, Hideyuki MOCHIDA, Yukimitsu ASAHI1988 Volume 57 Issue 4 Pages 743-748
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn a field experiment using 17 soybean cultivars and lines with a diverse variation of seed yield within each maturity group (early, middle and late), the association of apparent photosynthetic rates per leaf area (AP) with seed yields was examined. AP was measured of intact leaves of most actively working at three growth stages :vegetative (VT), pod formation (PF), and seed development (SD). Significant cultivar differences in AP within maturity groups were observed at VT and PF of early maturing, at all the three stages of middle maturing, and at SD of late maturing cultivars, respectively. AP tended to increase with growth stage, being accompanied by a variation of' cultivar ranking. Across cultivars and lines in each group, AP tended to be correlated negatively with single leaf area, and positively with specific leaf weight (SLW) and chlorophyll content at VT, but the tendency became ambiguous at later stages. APs measured at VT and PF did not bear significant correlations with crop growth rates (CGR) or net assimilation rates (NAR) determined between the two stages. Seed yields were positively correlated with APs measured at SD in the late maturing group, but no significant correlations between them were observed at other growth stages, or in the early and middle maturing groups. We presumed that greater sink demand by high-yielding cultivars were responsible for a higher AP, not that a higher AP contributed to an increased seed yield.View full abstractDownload PDF (689K) -
Tetsuya SUGA, Keisuke NEMOTO, Jun ABE, Shigenori MORITA1988 Volume 57 Issue 4 Pages 749-754
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSA model is proposed to analyze root system morphology using simulated root length densities. A crop population with fibrous root systems is imagined, and three simple assumptions are set : (1) uniform elongation of primary roots, (2) homogeneous branching and (3) hemispheric rooting zone. The assumptions give mathematical descriptions of root length densities (p) so that the variable p can be expressed as a mathematical function of the position in the soil. Simulation of. p is conducted with a computer program which includes five parameters : distance between hills (a), distance between rows (b), hill size ('hill radius' ; ro), size of a rooting zone ('rooting zone radius' ; rmax) and degree of root branching ('root length density constant' ; k). The values of k and rmax were evaluated so that simulated root length densities (pmodel) fit actual densities (pactual). Indices of root system morphology were algebraically derived from the simulation parameters. The indices correspond to important characters that are difficult to be estimated from usual field studies. Part II will cite examples of analysis on rice (Oryza sativa L.) root systems using this model.View full abstractDownload PDF (626K) -
Shigenori MORITA, Tetsuya SUGA, Keisuke NEMOTO1988 Volume 57 Issue 4 Pages 755-758
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe root system morphology of rice plants (cv.: Koshihikari) grown under control and shaded conditions was analyzed by the root length density model proposed in Part I . The root length densities were simulated under various combinations of the 'root length density constant'(k) and the 'rooting zone radius' (rmax) in the model, and the most suitable values of both parameters were selected so that the simulated root length densities should fit the actual densities. The values of k and rmax thus obtained and other observed data made it possible to calculate the indices relating to the root system morphology, i.e. 'model primary root length', 'coefficient of branching', 'hill primary root length', 'hill total root length', 'area primary root Length', and 'area total root length', which are hardly accessible in field studies. The comparison of these parameters and indices between experimental plots suggested that the root system development was clearly poorer in the shaded plot as had been expected. The simulated root length densities were substantially closer to the actual densities. Although the model was based only on three simple assumptions, the results mentioned above well support its validity.View full abstractDownload PDF (455K) -
Kazuto IWAMA1988 Volume 57 Issue 4 Pages 759-764
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSKnowledge of the fertilizer effect on the roots of potato plants is surprisingly limited and not definitive. In order to obtain more detailed information, root dry weight (DW), root length, root morphology and root activity were investigated under field conditions at different fertilizer rates (0, 75, 150 and 300 kg/ha in each component of N, P2O5 and K2O). The roots were sampled 28 days and 56 days after sprouting with a monolith of 5 cm in width, 30 cm in length and 30 cm in depth. Root activity was identified by root respiration rate per unit root length (ULRR). The ratios of lateral root length to total (nodal+lateral) root length and of root length to root DW were relatively constant regardless of the fertilizer rates. The root length showed similar changes such as root DW, depending on the fertilizer rates. The increases of root DW and root length were suspended and the decay of the roots started earlier at the lower fertilized plot. In addition, ULRR increased significantly with the increase of the fertilizer rates at both sampling times. Its differences were much larger at 56 Days. These results suggested that an increase of the fertilizer rates would result in the increased nutrient absorption ability of the roots especially after the initial flowering stage, depending mostly on the differences in root activity per unit root mass.View full abstractDownload PDF (692K) -
Issirep SUMARDI, Tiemi NAKAMURA, Takeshi TANIGUCHI, Eizo MAEDA1988 Volume 57 Issue 4 Pages 765-772
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSInitial callus was primarily formed on the cut ends and occasionally on the abaxial surface of sugarcane immature leaf explants. The growing callus became nodular and purple in colour. Some specimens became white. Subsequent growth of callus led to the breaking through callus surface. The newly formed cells emerged from the breakages and grew into oval and hairy, elongated shapes ; this led to the formation of soft callus masses on the explants where spherical structures developed consisting of meristematic cells.View full abstractDownload PDF (1249K) -
Shuichi MIYAGAWA, Toshiro KURODA1988 Volume 57 Issue 4 Pages 773-781
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSRelationship between rice yield and several factors which would be concerned with variability of rice yield for rain-fed paddy field in Don Daeng village in Northeast Thailand was discussed. In 1981, a drought year, the mean value of yield of the upper topographically paddy field was only 63% compared to that of lower paddy field. Water condition was the most dominant factor affecting rice yield. Three factors, water condition, soil fertility and varieties cultivated, explained 45% of yield variation among paddy fields in evaluation using quantification scaling type I. In 1983, a bumper year, two factors, fertilizer application and crops in the former year, and above 3 factors could explain only 17% of grain yield variation. On the other hand, these five factors could explain 47% of variation of straw weight per unit area. Partial correlation coefficient between soil fertility and straw weight was the highest value among those between other factors and straw weight. Adoption of improved variety may be usefull for increasing yield, as well as establishment of irrigation facilities.View full abstractDownload PDF (906K) -
Kimio NAKASEKO1988 Volume 57 Issue 4 Pages 782-789
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSAs an attempt for better understanding the relationship between canopy architecture and seed production, the upper portions of the canopy, cv. Kitahomare, were mechanically stimulated during the period from the fifth trifoliolate leaf stage to the young pod stage, and its effect and after effect on morphology, canopy structure, light penetration, growth and yield was investigated. Mechanical stimulation inhibited growth of the main stem, but promoted that of the lateral branches ; the main stem-branch ratio of dry matter in each part was 1:1 in unstimulated control plants, but 1:2 or more in stimulated plants at the end of the treatment. Morphologically, stimulated plants had 1) shorter, thicker and sturdier stems, 2) smaller and thicker leaves with shorter petioles, and 3) greater a number of branches when compared with the controls ; thus modified to a typical dwarf type form. After the treatment has finished, stimulated plants showed a typical table type canopy throughout the pod filling period, but their light extinction coefficients were smaller than those of controls. The pod development was retarded by the treatment during the flowering stage. Stimulated plants, however, showed higher net assimilation rates and pod filling rates, and produced more pods than controls, resulted in 38% greater seed production at maturity, because of a greater increase in branch quantity. A plant form such as dwarf type with smaller sized leaves may be advantageous for high yielding under high population densities that cause a severe mutual shading and risks of lodging.View full abstractDownload PDF (983K) -
Akihiro ISODA, Kimio NAKASEKO, Kanji GOTOH1988 Volume 57 Issue 4 Pages 790-791
Published: December 05, 1988
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (324K)
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