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Volume 63, Issue 1
Displaying 1-26 of 26 articles from this issue
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Tatsuhiko SHIRAIWA, Ushio HASHIKAWA, Shingo TAKA, Ayako SAKAI1994 Volume 63 Issue 1 Pages 1-8
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe amount of dry matter produced per photosynthetically active radiation (PAR) intercepted by the canopy (EPAR) and factors which might affect EPAR were determined for various soybean cultivars, and their relationships were also analyzed in two field experiments. In 1989 and 1990, 11 cultivars and 27 cultivars respectively, were grown on an experimental field in Shiga Prefectural Junior College. Changes of intercepted PAR, top dry matter weight, light extinction coefficient (KPAR), nitrogen content per leaf area (SLN) and nitrogen accumulation in the top (1990 only) were measured. EPAR averaged for all the cultivars was 2.48g MJ-1 in both years and its coefficient of variance among cultivars was ±9% in 1989 and ±17% in 1990. In general, recent cultivars showed greater EPAR than older ones. The correlation coefficients between SLN and EPAR were 0.548 in 1989 and 0.651 in 1990, while there was no correlation between KPAR and EPAR. Since SLN showed close correlation with SLW (r=0.954 in 1989, r=0.710 in 1990), the difference in EPAR between old and new cultivars was considered to be attributable mainly to the improved leaf morphological trait and consequently greater leaf photosynthesis of newer cultivars. SLN further correlated with total top nitrogen content (r=0.736 in 1990) thus seemed to be limited by nitrogen accumulation.View full abstractDownload PDF (861K) -
Morio MATSUZAKI, Tomoyoshi HASHIMOTO, Tadao KON, Masakazu TOYODA1994 Volume 63 Issue 1 Pages 9-14
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSCropping surveys were conducted on three soil types (each point was 120 ha in area) in the central region of Tokachi district over a period of 8 years. In each point, survey maps for every year were divided to sections that had only one cropping sequence. Each section's data (area, cropping sequence, etc.) were input into a data base. Cropping sequences in the data base were divided into cropping sequences with three crops (CS3), which had twin rotation units. The observed area ratio of each CS3, which was denoted by a percentage based on the surveyed area, was determined six times. The mean value and coefficient of variation of the CS3's observed area ratio and the observed frequently of CS3 were determined from the six observed area ratios. Using the coefficient of variation, the major cropping sequences with three crops (MCS3), which were typical CS3, were classified. MCS3 consisted of only field crops, and they were observed over a large area and at a high frequency. In each surveyed point, only 10 or 12 types of MCS3 were observed, but their observed total area ratios were from 21 to 53%. Two MCS3 were observed to have the same rotation unit B→C (A→B→C and B→C→A). Therefore these MCS3 can link by overlapping the common rotation unit B→C, and the cropping sequence A→B→C→A was identified. Repeating this process, typical cropping sequences with many crops or crop rotations could be identified.View full abstractDownload PDF (606K) -
Morio MATSUZAKI, Tomoyoshi HASHIMOTO, Tadao KON, Masakazu TOYODA1994 Volume 63 Issue 1 Pages 15-20
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSMajor cropping sequences with three crops (MCS3) were classified in the previous report. In this report, crop rotations were identified by means of linking with MCS3, and the observed area ratios of the identified crop rotations were determined. Three crop rotations for light-colored andosols were identified : 1) sugar beet→potato→wheat (the observed area ratio was 11.4%), 2) sugar beet→potato→sweet corn→wheat (24.0%), 3) sugar beet→potato→wheat→wheat (11.6%). Two crop rotations for andosols were identified, and they were 4) sugar beet→potato→wheat→wheat (23.6%), 5) sugar beet→potato→sweet corn→wheat→wheat (7.5%). The identified crop rotations coincided with the cropping intervals of the major crops observed in these crop rotations, and the identification method in these reports was effective for numerical analysis to crop rotations. The identified crop rotations were regulated by the cultivated area ratio of each crop and cropping season of winter wheat.View full abstractDownload PDF (683K) -
Tsuguhiro HOSHINO, Seiji ITO, Yoshinori TANIGUCHI, Akiko SATO1994 Volume 63 Issue 1 Pages 21-25
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe relationships between grain size and quality in wheat were investigated with Koyukikomugi from 1989 to 1991. In 1990/1991 experiment, Koyukikomugi was harvested at maturity by combine, and grains were dried in a layer type dryer until about 11% moisture content was achieved. The grain samples were separated into nine size classes using a sieve every 0.2 mm for seed size from above 3.0 mm to below 1.6 mm in diameter. The grains and 60% extraction flour by Buhler experimental mill in each grain size were analyzed for crude protein and ash content. The dough characteristics were assessed using Brabender machines. The 1, 000 grain weight was increased with an increase in seed size, while the crude protin content of grain and 60% flour in 1990/1991 were constant. The ash content was the highest in 2.4 mm-sized seeds in the 1989/1990 and in 2.6 mm-sized seeds in 1990/ 1991. The milling yield was increased with an increase in seed size and the differences among seed sizes were statistically significant at the 1% level. The values of the whiteness (R455) and brightness (R554) of flour color were higher in the flour made from larger grain, but the values of the grain with yellowish pigmentation (log R554/R455) were the inversely related to them. The farinogram characteristics and amirogram MV showed no significant differences among seed sizes. The area and resistance (R) of extensogram characteristics had also statistically significant differences, while the differences in extensibility (E) and R/E were not significant among seed sizes. It is concluded that the grains with larger seed size were superior with regard to flour yield and flour color but were slightly inferior with regard to Bartender characteristics.View full abstractDownload PDF (619K) -
Daisuke HIROSE, Jiro TATSUMI, Hyoe TSUGAWA, Kin-ichi NISHIKAWA1994 Volume 63 Issue 1 Pages 26-33
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSWe investigated the growth, uptake and partitioning of nitrogen (N) in alfalfa seedlings grown in the pot soil where 15N-labelled combined N was applied as nitrate-N or ammonium-N by means of basal dressing or topdressing. Dry weight, N content, and 15N recovery, in the plant were greater when N was applied as ammonium-N than nitrate- N in both basal dressing and topdressing. Elongation of the roots was more strongly promoted by ammonium-N than nitrate-N, and this was associated with increased uptake of 15N from labelled fertilizer topdressed in ammonium form. Absorbed 15N was more preferentially allocated to the roots than the stem in the plant when ammonium-N was topdressed, while a reverse trend was found in the plant to which nitrate-N was topdressed. These results indicate that ammonium-N is more effective source of N for the growth of alfalfa seedlings as compared with nitrate-N.View full abstractDownload PDF (874K) -
Kazuo TERASHIMA, Takefumi OGATA, Shigemi AKITA1994 Volume 63 Issue 1 Pages 34-41
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe dry weight of each organ including root in topsoil, root density in each soil layer and root morphology of rice plant (Oryza sativa L.) were compared among USA cultivars, semi-dwarf (panicle weight type) Indica cultivars and Japanese cultivars which have different magnitude of tolerance to root lodging, to investigate the eco-physiological basis of root lodging tolerance. Total dry weight of medium grain USA cultivar and Japanese cultivar with similar growth duration were comparable throughout the growing period. Long grain USA cultivar showed less total dry weight than Japanese cultivar. Root dry weight at full heading stage were larger in USA cultivars than Japanese cultivars when compared between groups with the same maturity. The ratio of root to total plant in the dry weight basis at full heading stage was higher in all USA cultivars examined in this experiment than in Japanese cultivars. Larger dry weight of semi-dwarf Indica cultivar resulted in larger root dry weight of root at full heading stage without significant difference in the ratio of root to total weight. Tolerant cultivars to root lodging, including USA and semi-dwarf Indica cultivars, developed more roots in deeper soil layers than susceptible Japanese cultivars.View full abstractDownload PDF (893K) -
Makoto NAKATANI, Sigeto KAWASHIMA1994 Volume 63 Issue 1 Pages 42-47
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe estimation of the chlorophyll content of leaves of wheat, barley and rye was attempted using an 8 mm video camera and a personal computer system. First, we took video images of a color chart for rice leaf from various directions outdoors, and the variation of R (red), G (green), and B (blue) signals of the images was investigated. The signals varied extremely with every direction of the camera in fine weather, but were relatively stable in cloudy weather. For this reason, the estimation of chlorophyll contently video image was examined in cloudy weather. The images of wheat, barley and rye were gathered on five cloudy days. The relationships between the signals from the image and the chlorophyll contens were examined. Among the several functions of the signals, the highest correlation (r=-0.84 to -0.96) was found in R-B or G-B within the day of each investigation. However, the highest correlation (r=-0.81) was found in (R-B)/(R+B), when all results were combined. Moreover, almost the same regression line was obtained for (R-B)/(R+B) regardless of the investigation day and the species. From these results, the possibility of the assessment of leaf color by video image was discussed.View full abstractDownload PDF (666K) -
Yusuke GOTO, Mitsuo SAITO, Kan HASEBE, Satoshi NAKAMURA, Masamichi OHE ...1994 Volume 63 Issue 1 Pages 48-54
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe rice plants cv. Sasanishiki (3 plants/pot) were moved into the controlled growth chamber at 9°C when half of the leaf blade (LB) of the 7th leaf (L7) was emerged (H plot) or when the whole 7th leaf blade (LB7) was fully emerged (W plot). The plants were kept at that temperature for 1, 2, 4, and 8 days. Plant did not grow during the treatment and began to continue the growth after treatment. In the 8-day treatment plots (H8 and W8 plots) plants sustained heavy damage and at 1 or 2 weeks after the treatment about 30% of plants had died. The effects of the treatments on the leaf length or on the tillering behaviour are as follows. 1) the length of LB and the leaf sheath (LS) treated at rapid elongating stage (LB7, LS7, LB8 of H plots and LS7, LB8 of W plots) were shorter than that of untreated plants, but on the other hand the length of LB or LS treated just before the rapid elongating stage (LS8, LB9 of H plots and LS8, LB9, LS9, LB10 of W plots) were longer than that of untreated plants. Tiller growth of the treated plants was slower than that of untreated plants. The percentage of emerged tillers at expected nodes after treatment was smaller than that of untreated plants. The percentage of emerged tillers and the tiller growth rate indicated the rate of the damage that plants sustained. In this study, there were no reason to say that a tiller bud was sensitive to low temperature in the specific developmental stage.View full abstractDownload PDF (794K) -
Osamu KUSUDA1994 Volume 63 Issue 1 Pages 55-62
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSLeaf area of rice plant is an important character for survey to elucidate its characteristics of dry matter production. However, it requires much time and labor to precisely estimate the leaf area, which makes the survey difficult. Accordingly, it is necessary to establish a survey method effective in laborsaving while maintaining precision of a definite level or above. In this report, the effectiveness of a method by means of the double sampling and ratio estimate which were partially applied to the estimation of leaf area was examined, using investigational analysis of its precision and time required. When only the leaf area was surveyed, the above method enabled us to shorten the time required to obtain an estimation with the desired precision to 44 and 63% of those for simple random sampling, principle of sample survey at maximum tiller number and full heading stages, respectively, compared with 30 and 75% when dry weight was surveyed in addition to leaf area.View full abstractDownload PDF (897K) -
Noriyuki TANAKA, Minoru MIHARA, Susumu ARIMA, Jiro HARADA1994 Volume 63 Issue 1 Pages 63-67
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe applicability of the pipe model to the structure of soybean (Glycine max Merr.) root system grown under various underground water levels or depths of plow sole were investigated. The form, distribution and quantity of root systems changed with the growth conditions. However, cumulative root dry weight of thin roots showed a linear regression with dry weight of thick roots irrespective of soil layer or treatment. Also, in the case of roots whose diameter was over 0.25 mm, negative linear regression was seen between the diameter classes and their cumulative length. Therefore, the structure of the root system was considered to correspond to the pipe model. Meanwhile, as a result of further detailed analyses by using the "Ideal pipe" concept that we have introduced, the range of the soybean root system to which the pipe model is applicable is more than about 1 mm in diameter. The length of thin roots whose diameter are less than about 1 mm was considerably larger than that predicted by the model.View full abstractDownload PDF (594K) -
Kuniyuki SAITOH, Ryuzi INAMURA, Kuni ISHIHARA1994 Volume 63 Issue 1 Pages 68-74
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe occurrence of leaf movements during the daytime is widely known in the leguminous plant canopy. We observed in the soybean field that leaflets moved not independently but that the trifoliolate compound leaf moved as a unit in response to the direction and the intensity of sunlight. Time course changes in trifoliolate leaf movements of soybean, grown in the pot and the field, was investigated by measuring the area of the triangle which connects the three leaflet tips (ΔT), the distance between left and right leaflet tips and terminal leaflet inclination angle. In the early morning, leaflets were already inclined upward, and ΔT reached a minimum value at 10 a.m., followed by a gradual increase in ΔT. As the leaflets became horizontal at dusk, ΔT reached nearly 100%. At the onset of darkness, every leaflet dropped their tips, and ΔT decreased rapidly with the downward (nyctinastic movement). In spite of the darkness, leaflets began to rise in the middle of the night, and turned upward at predawn. The tip of the terminal leaflet, which was oriented north, moved along with the sun movement in a circle from east to west. By measuring the changes in ΔT described above, both heliotropic and nyctinastic movement during the daytime and nighttime could be quantitatively determined. Further, decrease in ΔT within the upper layer of soybean canopy meant that more sunlight penetrated to the lower layer.View full abstractDownload PDF (763K) -
Tadashi TAKAHASHI, Naoyuki TSUCHIHASHI, Kimio NAKASEKO1994 Volume 63 Issue 1 Pages 75-80
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe dry weights and water soluble sugar contents (WSC) in grain, ear, culm and leaves of the field grown spring wheat (cv. Haruyutaka) were measured every morning and evening throughout the grain filling period to determine the physiological and morphological mechanisms of grain filling. Many of these plant organs increased or decreased linearly during each grain filling phase, divided on the last report : (1) initial grain filling phase, (2) early grain filling phase, (3) late grain filling phase and (4) final grain filling phase. They were, therefore, analyzed by linear regression against the days after anthesis to determine the difference in dry matter accumulation among these four phases and the difference between daytime and night. The regression slope, increasing rate, in total biomass declined with growth and was almost zero during the final phase when canopy did not photosynthate. The slope in grain dry weight peaked during the late phase (60 mg pl-1 day-1). The WSC in the culm increased during the initial and early phase (22 and 11 mg pl-1 day-1, respectively), while it decreased during the late and final phases (-15 and -19 mg pl-1 day-1). In addition, the grain increased similarly between daytime and night during the initial, early and final phases, although its increasing rate in the daytime (45 mg pl-1 day-1) was threefold greater than at night (16 mg pl-1 day-1). During the early phase, the WSC in the culm increased during the daytime (18 mg pl-1 day-1), but decreased during the night (-8 mg pl-1 day-1). Therefore, this suggests that the WSC is accumulated in culm during the daytime and that it is translocated into the grains at night.View full abstractDownload PDF (643K) -
Tadashi TAKAHASHI, Kimio NAKASEKO1994 Volume 63 Issue 1 Pages 81-88
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSSpring wheat varieties, early Haruyutaka and late Selpek, were grown under field conditions to find the relation between leaf emergence rate and temperature. Fourteen sowings were made at two week intervals from March 17 (S1) to September 13 (S14). Leaf expanding degree (Haun's scale) were measured daily, and shoot apices were checked every day to determine the date double ridge stage (DRS) appeared. Final leaf numbers differed by only one, although the first nine sowings ranged over four months from March (S1) to July (S9). Late variety Selpek always had one more leaf than early variety Haruyutaka for S1∼S9, suggesting that the final number of leaves was closely related to the earlobes of varieties. Leaf emergence rates with accumulated temperature (AT) were higher before than after DRS, and those before DRS decreased with delay in sowing time. The leaf expanding degree at DRS did not vary greatly among sowing times, but were synchronized with phenology. We established regressions before and after DRS for the relation between leaf expanding degree and AT. The coefficients (a) before DRS were higher than those after DRS for both varieties. In addition, their standard deviation was large so that inclinations of regressions before DRS differed with sowing time. We concluded that leaf emergence rate has a squared relation with mean temperature before DRS and a linear relation with mean temperature after DRS.View full abstractDownload PDF (701K) -
Fumitake KUBOTA, Kazuyoshi NADA, Waichi AGATA1994 Volume 63 Issue 1 Pages 89-95
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSRubisco (ribulose 1, 5-bisphosphate carboxylase/oxygenase) activity is the prime determinant for CO2 exchang rate (CER) at the beginning of the photosynthetic reaction, and hence the rubisco activity in a leaf can be deduced from the initial rise of CER. The activity of rubisco is also regulated by two main internal factors, the activation state of rubisco and the availability of RuBP (ribulose 1, 5-bisphosphate). A peeled leaf (Ipomoea batatas, cv. Koganesengan) without stomatal resistance was preilluminated in PAR of 900 μ mol m-2 s-1 at CO2 concentration ([CO2]) of 20, 60 or 350) μmol mollt;-1>. Directly after the dark interruption following preillumination, the response of CER of a peeled leaf (CERP1) to reillumination (PAR of 900 μmol m-2 s-1) was measured at [CO2] of 350 μmol mol-1. The dark time affected the response of CERP1. The light-activated state of rubisco, which was deduced from the response of the initial rise of CERP1 (IR-CERP1), could remain constant for at least 5 min in the dark. The leaves preillluminated at different [CO2] levels had no or little difference in IR-CERP1 which was determined after the dark interruption of 2.5 min. This is an evidence that rubisco in the intact mesophyll tissues was substantially light-activated even at such a low [CO2] level as 20 or 60 μmolmol-1] and the rubisco activity was primarily determined by the activation state of rubisco but was independent of the RuBP pool level. IR-CERP1 can be proposed as an indicator for the rubisco activation state in vivo or the rubisco activity unrestricted by RuBP availability.View full abstractDownload PDF (796K) -
Akio SUMI, Tadao C. KATAYAMA1994 Volume 63 Issue 1 Pages 96-104
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo compare the growth, yielding ability and water consumption in the two cultivated rice specks, Oryza sativa L. and O. glaberrima Steud., the respective six strains of O. sativa and O. glaberrima collected in West Africa were examined. O. glaberrima tended to be larger in leaf area at heading time than O. sativa. In some strains of O. glaberrima, the vegetative growth was expanded notably under manuring, and also the panicle number per hill was significantly larger and the one-grain weight significantly smaller than in O. sativa. These two significant differences are correlated with the fact that many strains of O. sativa had long culm and that all strains of O. sativa belong to the javanica type with a large grain. No difference was observed in the grain number per head and the percentage of ripened grains between the two species. The grain yield tended to be larger in O. glaberrima than in O. sativa. On the other hand, O. glaberrima was found to have smaller water use efficiency with greater water consumption.View full abstractDownload PDF (859K) -
Akio SUMI, Tadao C. KATAYAMA, Waichi AGATA1994 Volume 63 Issue 1 Pages 105-110
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo compare the time courses of dry matter increase and water consumption in the two cultivated rice species, Oryza sativa L. and O. glaberrima Steud., six strains each of O. glaberrima and O. sativa collected in West Africa and Nipponbare, a Japanese leading cultivar, were examined. The six strains of O. glaberrima showed a vigorous growth around the heading time but afterward the dry matter increase stopped promptly, while all strains of O. sativa showed a slower but longer dry matter increase. The decline of leaf area after heading was slower in strains of O. sativa than in those of O. glaberrima. The root/top weight ratio increased after ripening again in O. sativa, but no such phenomenon was observed in O. glaberrima. These differences between the two species are presumed to be caused by the genetic differences in their progenitors, i.e., whether they are perennial or annual. The water use efficiency (WUE) estimated on the basis of dry matter was smaller in O. glaberrima than in O. sativa, and decreased with the advance of growth stages. The decline was closely, correlated with the decrease in the leaf area ratio (LAR) which accompanies the advanced growth stages. Although vigorous leaf development is one of the characteristics of O. glaberrima, and this is resulted in a large water consumption, the leafy posture seemed to be beneficial for WUE. The ratio of panicle dry weigh to total transpiration was equal both in O. glaberrima and O. sativa.View full abstractDownload PDF (640K) -
Tatsuhiko SHIRAIWA, Thomas SHINCLAIR, Ushio HASHIKAWA1994 Volume 63 Issue 1 Pages 111-117
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSVariability in nitrogen fixation activity among soybean cultivars was examined under well-managed field conditions. Four and 15 soybean cultivars were grown in 1989 and 1991, respectively, along with the non-nodulating cultivar T201. Top dry weight, total top nitrogen content and nodule dry weight (1991 only) were determined on three or four dates. Nitrogen fixed by each cultivar was estimated with the difference method. In both years, daily nitrogen fixation rate (DNF) increased until roughly stage R5, showing a close linear relationship with top dry weight. dDNF/dTOPDW calculated combining all cultivars was 1.62 mg day-1g-1 (r2=0.91)in 1989 and 1.69 mg day-1g-1 (r2=0.92) in 1991. At the same time, calculation of dDNF/dTOPDW for individual cultivars before R5 showed a substantial difference among cultivars ranging from 1.29 mg day-1g-1 (r2=0.47) of Harosoy in 1991 to 2.23 mg day-1g-1 (r2=0.93) of Fusanari in 1991. Calculated nodule specific activity (DNF/NDW, mg day-1g-1) in 1991 increased for all cultivars during vegetative growth, while the ratio of module dry weight to top dry weight (NDW/TOPDW, g g-1) decreased. The highest DNF of cultivars which occurred near stage R5 ranged approximately from 0.3 g m-2day-1 to 0.5 g m-2day-1. During pod filling, DNF was observed generally to decrease, and old cultivars showed rapid declines in DNF just after R5 compared to more modern cultivars.View full abstractDownload PDF (747K) -
Si-Yong KANG, Shigenori MORITA, Koou YAMAZAKI1994 Volume 63 Issue 1 Pages 118-124
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe development of rice root system has been studied in Japonica-Indica hybrid cultivars (J-IH), Milyang 23 and Suweon 264, and Japonica type cultivars (JT), Nipponbare and Koshihikari, grown in a paddy field. Soil cores were taken below (and between) hill(s) at the panicle initiation, the heading and the grain-filling stages. After the soil cores were divided into layers by soil depth and the roots were washed out, length and weight of the roots in each soillayer were measured to calculate root length density (RLD) and root weight density (RWD). At the panicle initiation stage, there were no significant differences in RLD and RWD in the 0-25 cm soil layer below hill of each cultivar. Thereafter, RLD and RWD markedly increased, especially in J-IH, and at the grain-filling stage RLD and RWD of J-IH both below and between hills were significantly larger than those of JT. Such increases of RLD and RWD in J-IH after the panicle initiation stage occurred mainly in shallow soil layers. The soil depth of the maximum value in RLD and RWD below hill were different from each other ; the 0-5 cm soil layer in RLD and the 5-10 cm soillayer in RWD. The specific root length in 5-10 cm soillayer below hill was smaller than those in the other soil layers below and between hills, especially in the later growth stage, which might depend on the distribution of root diameter and branching.View full abstractDownload PDF (746K) -
Kunio OKANO, Shinya KOMAKI, Kiyoshi MATSUO1994 Volume 63 Issue 1 Pages 125-130
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSUptake, distribution and redistribution of 15N-nitrogen in young tea plants were examined during the first flush season in order to know the seasonal changes in nitrogen uptake and the origin of nitrogen in sprouting shoots. Rate of nitrogen uptake was kept at relatively lower levels before bud break, while it rose 1.5-fold after the bud break. Most nitrogen absorbed before bud break was distributed to stem and roots, and after the bud break they retranslocated to the sprouting shoots. More than 75% of nitrogen absorbed after the bud break was partitioned to the sprouting shoots. Both the nitrogen balance and isotope dilution methods indicated that approximately 30% of nitrogen accumulated in sprouting shoots was newly absorbed and remaining 70% was retranslocated from the vegetative parts. The retranslocated nitrogen would play an important role for the growth of sprouting shoots both in quantity and in quality.View full abstractDownload PDF (660K) -
Makoto TSUDA, Tetsuya FUJIKAWA, Katsuhiko IKEDA1994 Volume 63 Issue 1 Pages 131-136
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSMany water droplets adhere to the surface of a rice panicle located inside the protective sheath of flag-leaf at the booting stage. Since the adhering water is formed by the exudation of liquid water from the plant, we can expect that the amount of adhering water varies diurnally with the change of root pressure. To test this hypothesis, we examined the amount of the adhering water and the bleeding sap from the cut surface of the stub for 24 hours. Wetland rice cultivars, Akenohoshi and Ukonnishiki, were grown under submerged and water stressed soil conditions. The amount of adhering water changed diurnally in response to the potential evapotranspiration : the amount increased during the night and decreased during the day. A similar trend was also found in bleeding rate, except under drought conditions where both bleeding and adhering water were negligible. Furthermore, the adhering water increased proportionally with the increase of bleeding sap during the night. Bleeding occurs when root pressure develops. These results suggest that the adhering water is formed through the efflux of water under root pressure during the night, and is lost by transpiration during the day.View full abstractDownload PDF (634K) -
Katsuya YANO, Hiroyuki DAIMON, Hironori MIMOTO1994 Volume 63 Issue 1 Pages 137-143
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSEffect of summer legumes incorporated as green manures, sunn hemp (cv. Kobutoriso) and peanut (cv. Chiba-handachi), was examined for nitrogen contribution to the succeeding wheat (cv. Norin 61). The dry weight of sunn hemp, of which the stem occupies the largest proportion, was higher than that of peanut at time of incorporation. Total nitrogen content was higher in peanut compared with sunn hemp. The amount of nitrogen fixed by each legume was estimated by the 'difference method' with non-nodulating peanut (cv. Tarapoto) as a reference crop. In peanut, 18 g N per m2 was calculated as the amount of nitrogen fixed at the late maturity stage. The percentage of nitrogen fixed to the total nitrogen was 60-70% in both legumes. On the yield and nitrogen uptake of the succeeding wheat, the peanut plot was superior to the sunn hemp plot. The percentage contribution of nitrogen accumulated by each legume to total nitrogen of the succeding wheat was 11.2% on the peanut plot and 9.4% on the sunn hemp plot. In peanut, the C-N ratio was approximately 20 at time of incorporation. In sunn hemp, it was 40, and the decomposition rate was found to be slower than that of peanut by a modified method using glass fiber filter papers. The results indicated that peanut crop contributed more nitrogen to the succeeding wheat compared with sunn hemp.View full abstractDownload PDF (754K) -
Tiemi NAKAMURA, Takeshi TANIGUCHI, Eizo MAEDA1994 Volume 63 Issue 1 Pages 144-157
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSA histological and ultrastructural study of somatic embryogenesis in coffee embryos was made by light microscopy and transmission electron microscopy. A comparative study on somatic and zygotic embryos of coffee was also performed. The cells in the suspensor region of somatic embryos were filled with large-and small-sized granules containing polyphenol substances stainable in black. The granule size increased until the elongated-embryo stage and thereafter it decreased with embryo development. Such granules were very small in cotyledonary embryo cells. The continuous and discontinuous cuticular layers were detected on both the somatic, globular embryos and the zygotic proembryos by treatment of iodine/potassium iodide-sulfuric acid-silver proteinate. This preparation also permitted the identification of the deposition of fine silver particles inside the polyphenol granules. In addition the plastids were filled with several starch grains of large and small sizes. Similarly, cells of the zygotic proembryos and young embryos were also filled with polyphenol granules and plastids containing starch grains. It is interesting to note that mucilaginous materials cover the surface of both the embryogenic callus and the suspensor region of somatic embryos and are also present in the intercellular spaces of these tissues. These materials were also covering zygotic embryos situated in the embryo cavity of seeds. These observations led to the conclusion that the somatic and zygotic embryos have several similarities at the ultrastructural level.View full abstractDownload PDF (3551K) -
Makoto NAKATANI1994 Volume 63 Issue 1 Pages 158-159
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (393K) -
Yoshiaki WATANABE, Shigehito TAKENAKA1994 Volume 63 Issue 1 Pages 160-161
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (329K) -
Tatsuro HIROSE, Michio IKEDA, Takeshi IZUTA, Hiroshi MIYAKE, Tsumugu T ...1994 Volume 63 Issue 1 Pages 162-163
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (331K) -
[in Japanese]1994 Volume 63 Issue 1 Pages 164-168
Published: March 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (670K)
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