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Volume 64, Issue 3
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Haruhiko YAMAMOTO, Yoshinori SUZUKI, Masanori IWANO, Seiji HAYAKAWA1995 Volume 64 Issue 3 Pages 467-474
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSA remote sensing of leaf temperature of rice blast disease was made using an infrared radiative thermometer. The severity of rice blast disease of Hiyokumochi (sensitivity cultivar) was not confirmed by photographs of the visible range taken 19 days after eclosion. The leaf temperature of Hiyokumochi was 1.1°C higher than Reiho (resistant cultivar) using an infrared radiativethermometer. Thus, the severity of rice blast disease of Hiyokumochi was confirmed by infrared thermal image. The leaf temperature difference and disease severity were proportional. The disease severity of rice blast disease (%) = 10.56X2+0.582X-0.295(r=0.999***). Where X was the difference of leaf temperature.View full abstractDownload PDF (1054K) -
Dong-Ha CHO, Haruto SASAKI, Ryuichi ISHII1995 Volume 64 Issue 3 Pages 475-482
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSReduction of relative growth rate (RGR) due to the NaCl treatment was examined in the seedlings of six Korean rice cultivars which had been reported to be different in salt tolerance on the level of grain yield. On the level of RGR, three of the cultivars were identified as salt tolerant, and the remaining three were identified as the sensitive cultivars. Further analysis of RGR indicated that the reduction of RGR by NaCl treatment was attributed in large part to the reduction of the net assimilation rate (NAR) rather than to that of the leaf area ratio (LAR). Leaf photosynthesis which is closely related with NAR, was also reduced by NaCl treatment in salt sensitive cultivars to a greater extent than tolerant cultivars. Ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) content was determined in a tolerant cultivar, Han-Kang-Chal, and a sensitive one, Dong-Hae. Han-Kang-Chal showed a smaller decrease of Rubisco content per absorbed Na in the NaCl-treated leaves. This indicates that degradation of Rubisco by absorbed Na is slower in tolerant cultivars than in sensitive cultivars. Moreover, Han-Kang-Chal showed a larger decrease in osmotic potential in the NaCl treated leaves, suggesting that osmotic adjustment was developed under salt stress conditions in a tolerant cultivar.View full abstractDownload PDF (861K) -
Yukindo TSUNO, Takeshi YAMAGUCHI, Junichi NAKANO, Osamu OMOCHI1995 Volume 64 Issue 3 Pages 483-491
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSEven though the nitrogen content (mgNdm-2) of rice leaves is the same, a large difference in the net photosynthetic rate (Pn) has been recognized. To determine the reasons for the difference, leaf xylem water potential (Wp), leaf position on stem, days after fully expanded and root respiration of plant having sample leaves were studied. Throughout the period from the booting stage to the middle ripening stage, Wp was measured by the pressure chamber method in the leaf of potted rice plant, cv. Yamabiko and Ochikara immediately after measuring Pn under the conditions 25°C air temperature and 45-50 Klx artificial light. The correlation between mgNdm-2 and Pn in both cultivars is shown for each group of first leaves at the top of the stem, and for the second leaves and third leaves, but not the fourth leaves. In the case of young first leaves at the top of the stem and also second leaves, showing the higher Pn (i.e., higher rate of transpiration), a positive correlation was seen between Wp and Pn. Otherwise, old leaves positioned third and fourth, existing a short distance from the roots, had a negative correlation between Wp and Pn. It seemed that the relationship between mgNdm-2 and Pn in the lower leaves was altered by Wp. The lower leaves of the plants which had a high respiratory rate in the roots were maintained at a comparatively high Pn until Wp decreased below -1.4MPa. The lower leaves of a plant having poor root activity were specialized as lower Pn and higher Wp; possibly because of the lower degree of water transport resistance from the root system to the leaf.View full abstractDownload PDF (957K) -
Yukindo TSUNO, Osamu OMOCHI, Takeshi YAMAGUCHI, Junichi NAKANO, Satomi ...1995 Volume 64 Issue 3 Pages 492-499
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe photosynthetic rate and the water content in the rice leaf of potted plant, cv. Yamabiko, Ochikara and Araki, were measured simultaneously by the assimilation chamber method and by β-ray transmittance of 99Tc-source through the leaf blade. During measurement, leaf was excised from its leaf sheath and the measurement was continued until the photosynthetic rate reached a minimum. Within one minute after leaf excision, the photosynthetic rate increased quickly with a concomitant decrease in leaf water. This phenomenon was clearly recognized in the leaf with a lower rate of photosynthesis and higher water content except for leaf showing a higher rate of photosynthesis and yellowy old leaf. It could generally be expressed by following formula. ΔPn=4.950exp (-0.06Pn*)·ΔI/I0 r=0.965** Where, ΔPn is the difference between the rate before excision (Pn*) and the maximum rate of photosynthesis induced by leaf excision. ΔI/I0 is the difference in β-ray transmittance between before excision and when the maximum photosynthetic rate was induced by leaf excision. It is considered that photosynthesis of the leaf in which the stomata was insufficiently opened had been depressed by excess leaf water due to intercepting CO2 exchange between the intercellular space and mesophyll tissue. This postulation was supported by the experimental finding that the temporary increase in photosynthesis did not change with the stomatal aperture, and the air amount in the leaf blade had a negative correlation with leaf water content. Depression of photosynthesis by the excess water content in leaf was recognized with outdooor measurement under conditions at early morning and in the daytime on cloudy days.View full abstractDownload PDF (912K) -
Hajime WATANABE, Kiyoshi TAKAHASHI1995 Volume 64 Issue 3 Pages 500-508
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe characteristics of mesocotyl and internode growth of rice cultivars (Oryza sativa L.) and wild taxa of Oryza were investigated using the following cultivars and strains : (1) 260 IRRI's core colletion and 2 Japanese cultivars (Sasanisiki and Koshihikari), (2) 9 Panama cultivars (6 used for shifting cultivation system and 3 as improved cultivars) and (3) 6 wild taxa of Oryza. Sterilized brown rice grains were cultured on 0.8% agar medium, and maintained at 30°C in the dark for 14 days. The lengths of the mesocotyl, first internode and second internode were examined. Based on the measurements of mesocotyl and internode length, the cultivars (Oryza sativa) were classified into 3 main types. Two of them, type 5 and type 6, had the longest second internode, while another one, type 0, had only mesocotyl and undeveloped internodes ; We refer to this type as "MC type". The frequencies of appearance of the two former types were 79.7% and the latter one was 14.4%. Most of the MC type cultivars were found in cultivars originated from the Indian subcontinent : Bhutan, Bangladesh, Nepal, India, and Iran. Two ancestral species of O.sativa, O.rufipogon and O.nivara, contained lots of MC type compared with those of cultivated species. The cultivars for shifting cultivation system in Panama had many MC types compared with those of improved cultivars. It is suggested that the occurance of MC type was related to the cultivation system.View full abstractDownload PDF (942K) -
Fumihiko ADACHI, Tohru KOBATA, Masayuki ARIMOTO, Tadashi IMAKI1995 Volume 64 Issue 3 Pages 509-515
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe transpiration rate is affected not only by meteorological but also by physiological and structural factors of the crop. Our objectives were to develop a method of estimating the transpiration rate (T) of paddy rice (Oryza Sativa L.) using meteorological and physical data of the crop without continuous direct measurement of T in the field. We measured following parameters at the Experimantal Farm of Shimane University, Matsue : net radiation, relative humidity, air temperature and wind speed during the whole growing season, diurnal changes of stomatal conductance (gs) of fully expanded leaves near the canopy surface on several dominant growth stages, and plant height, leaf area index (LAI) of paddy field rice at 2-week intervals. Evapotranspiration (ET) and the evaporation rate from soil surface (E) were measured with a microlysimeter during the rice planting season. When three methods to calculate estimated evapotranspiration rate (Ec)(the Penman, Van Bavel and Penman-Monteith methods) were applied, the fitness of regression between Ec from the Penman-Monteith method and ET was highest. The fitness was improved further when canopy resistance was corrected by the ratio of irradiated to total leaf area calculated empirically from LAI. T was good assumed from the product of ET and T/ET which is calculated from the empirical equation14) as a function of LAI. We concluded that the transpiration rate of paddy rice can be more strictly estimated from Ec by the Penman-Monteith method with minor modification that canopy resistance is corrected by illuminated leaf area and soil evaporation is assumed by LAI. This method is available for comparison of transpiration rate where continuous measurements of transpiration rate for long intervals is very difficult.View full abstractDownload PDF (836K) -
Naoaki TACHIBANA, Shigehiko YOSHIKAWA, Katsuhiko IKEDA1995 Volume 64 Issue 3 Pages 516-522
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSWe surveyed the actual levels of nitrogen application in the productive region of green tea in northern Mie prefecture and investigated the physico-chemical properties of the soils and root growth in the tea fields. The annual quantity of nitrogen supplied ranged from 5.8 to 28.3kg a-1, giving 14.7kg a-1 on average. The annual quantities of phosphoric acid and potassium were 5.7 and 4.6kg a-1 on average, respectively. More than 20kg a-1 of nitrogen had been applied annually for 11% of the surveyed tea fields. White roots in the topmost layer(0∼20cm) of inter-row soil were considerably reduced when nitrogen exceeding 14.0kg a-1 was applied and were not found when the amount of nitrogen exceeded 18.0kg a-1. The soil acidity (H2O) in the inter-row decreased from pH 5.9 to 2.9 with an increase in the amount of nitrogen applied. The topmost layer of inter-row soil was highly acidic lower than pH 4.5. Anions in the soil solution collected in the inter-row were mainly composed of NO3- and SO42- and the concentration of anions exceeded that of cations. The soil acidity was kept at pH 3 when alminium inos were available to compensate for the lack of cations.View full abstractDownload PDF (889K) -
Naoaki TACHIBANA, Shigehiko YOSHIKAWA, Katsuhiko IKEDA1995 Volume 64 Issue 3 Pages 523-528
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSWe investigated the behavior of nitrogen heavily applied to inter-row spaces of the fields and the deterioration in amino acid contents caused by the reduction in nitrogen. The concentrations of inorganic nitrogen in soil solution collected from inter-row soil layers at different depths showed the maximum level in August. A high correlation was found between the amount of nitrogen applied and the concentration of inorganic nitrogen in soil solution. The average concentration of inorganic nitrogen in soil solution collected from inter-row soil layers and under canopy edge was significantly high at 495 ppm, while that in the soil solution collected under the canopy ranged from 30 to 100 ppm. A reduction in the amount of nitrogen supplied resulted in a decrease in the amino acid content in green tea leaves in the first year, regardless of the amount of nitrogen applied. However, the total content of amino acids in lower application plots recovered to almost the same level as that in the heavy application plot in the second year. This deterioration in the amino acid content in the first year after reduction in nitrogen application seems to mainly attributable to a growth disorder of roots caused by the preceding heavy application of nitrogen.View full abstractDownload PDF (749K) -
Takeshi YAMAGUCHI, Yukindo TSUNO, Junichi NAKANO, Reiko MANO1995 Volume 64 Issue 3 Pages 529-536
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSRice plants were given various treatments, such as organic matter application, a large amount of nitrogen as topdressing and light shading of 75%, and ammonium (NH3), silica (SiO2) and calcium (Ca) in bleeding sap were then measured from young panicle formation to ripening stage. The average NH3 concentrtation in bleeding sap of shading plants was remarkably higher (8.3ppm) than those of other treatments and shading plants had shown the lowest content of total sugar in roots during ripening. High NH3 concentration in bleeding sap from the stem was accompaied by low total sugar content in the roots. The SiO2 concentration in bleeding sap gradually decreased, essentially in parallel with root respiration, according to plant aging. The Ca concentration in bleeding sap was generally constant from young panicle fromation to the ripening stage. The SiO2 concenttration and/or amount per stem in bleeding sap was shown to be highly positively correlated with root respiration. The SiO2/Ca ratio in bleeding sap was proprtional with root respiration ; SiO2/Ca ratio in bleeding sap from the stem had active root in respiration was being higher. Therefore, it supported that the plants which had high root respiration realized to be higher SiO2 concentration in their leaves.View full abstractDownload PDF (909K) -
Tokihide NAGOSHI, Sakae KAWASHIMA1995 Volume 64 Issue 3 Pages 537-544
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe purpose of this study was to clarify the effects of triacontanol (TRIA) on the roots growth and the appearance stage of the effects, and to clarify the relationship between root development and hulled rice weight. The cultivar used was Koshihikari. This experiment was conducted to investigate the development of roots in the main. Root dry weight increased in TRIA-treated plots 2 weeks after application, and the effects continued until the maturing stage. In TRIA-treated plots at the late growth stage, root dry weight increased, and the ratios of root weight to top weight and to leaf area (R/T ratio and RW/LA ratio) were higher than in non-treated plot. Root respiration and total sugar content in root increased by TRIA-application. In particular, the rate of increase of hulled rice weight was enhanced by application at heading time and by application in three stages (tillering stage, young panicle formation stage and heading time). The weight of hulled rice was correlated positively with the R/T and RW/LA ratios at heading time and at the maturing stage, respectively. From these results it was inferred that TRIA application enhanced the growth of roots and enlarged the stomatal aperture owing to higher water absorption ability in roots, which increased to the hulled rice weight by maintaining a high photosynthetic rate to the maturing stage.View full abstractDownload PDF (825K) -
Yulong WANG, Yoshinori YAMAMOTO, Youji NITTA1995 Volume 64 Issue 3 Pages 545-555
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESS9004 (L9), which is a high yielding japonica type glutinous rice line developed in Jiangsu province, China, was cultivated under different combinations of nitrogen (N) application with or without phosphoric acid (P) as topdressing at the ear formation stage, to analyze the factors of high yielding ability for its line, using a Japanese non-glutinous variety with almost the same heading time, Koganemasari (KM), as a control. Both cultivars had the highest borwn rice yield in the plot applied high N + P through the large number of spikelets per area based on the number of spikelets per ear, in the ranges 675-820 g m-2 for L9 and 568-64l g m-2 for KM, respectively. Strong positive correlations were observed between brown rice yield and the grain-straw ratio, and between the grain-straw ratio and sink capacity (spikelet number per m2 × a grain weight). The yield of both cultivars was increased in the plots applied P due to the prevention of the reduction of the percentage of ripened grains that should occur as a result of the increased number of spikelets per ear. In this regard, larger increases were seen in L9 than in KM, and in high N than in low N application plots. P application with N improved leaf color and NAR compared with N application alone, and also resulted in more dry matter production during the ripening period. On the other hand, the difference of ca. 150 g m-2 in average yield between L9 (735 g) and KM (588 g) is mainly due to the difference of 1000-grain weight (27.7 g : L9, 23.8 g : KM). A significant difference in hull weight and ripening period between L9 and KM could not be detected, but L9 showed a faster dry matter accumulation rate per grain than KM during the first half of the ripening period. The difference of 1000-grain weight between L9 and KM was based on the high sink activity of L9 due to the high moisture percentage in a grain, and because preserves a lot of storage carbohydrate in stems and leaf sheaths, and moreover its vascular bundle system from stem to ear is superior to that of KM.View full abstractDownload PDF (1173K) -
Yoshinori YAMAMOTO, Akihiko IKEJIRI, Youji NITTA1995 Volume 64 Issue 3 Pages 556-564
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSEleven kinds of rice seedlings with different plant age in leaf unmber in the range 0-7.2 (counting the incomplete leaf as the first leaf), raised under the same condition, were grown in the phytotron-controlled day/night temperature (25/20 or 20/15°C) with natural light to clarify the characteristics of rooting and leaf emergence rate after transplanting, and also the difference of earfy growth and heading date. Both the number of new roots and total new root length at 7 days after transplanting (TP) were higher in the seedlings with more leaves due to the nodal position of emerged new roots. The reverse relation was observed in the leaf emergence rate during that period due to the difference in average leaf blade length. Transplanting injury, indicated by the leaf emergence rate during 3 days after TP, increased in proportion to the number of leaves of the seedling, and was not observed in the youngest seedling without foliage leaf. The number of new roots showed a highly significant negative or positive correlation with leaf emergence rate or leaf elongation rate from the leaf sheath, respectively. Each of the growth parameters at 21 days after TP was superior in proportion to the number of leaves of seedlings, but the difference of each parameter among the seedlings decreased in order of: (1) plant length and age in leaf number, (2) number of tillers and roots, and (3) dry weight over time after TP due to the faster growth rate of seedlings with fewer leaves. Although the number of leaves on the main culm was almost the same among the seedlings (range 15.6-16.5), the dates of flag leaf emergence and heading were delayed proportionally in the seedlings with fewer leaves.View full abstractDownload PDF (987K) -
Yushi HIDA, Tadashi HIRASAWA, Kuni ISHIHARA1995 Volume 64 Issue 3 Pages 565-572
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSCrop plants suffer water deficits when soil moisture is depleted significantly throughout the rhizosphere and even when only surface soil moisture decreases rapidly after they have been grown under humid conditions. For breeding drought-tolerant varieties, it is necessary to clarify the physiological, ecological and morphological characteristics of the varieties which can attain a high and reliable yield under both conditions. We compared dry matter and grain production among 34 soybean cultivars under conditions where soil moisture was depleted gradually after the emergence of seedlings in the field. The decrease in dry matter and grain productions was less in the early maturing cultivars than in the late maturing cultivars. Significant differences in the decrease were also observed among the cultivars classified into the same ecotype or maturity group. Then, cultivars, classified into the same ecotype and growth habit but different in the decrease, were grown in a row alternatively under deficient soil moisture conditions. The reductions in leaf xylem water potential and photosynthetic rate during the daytime were less and leaf expansion was less suppressed in the cultivars, which attained less decreased dry matter and grain productions. These cultivars were expected to have developed expansive root systems from the results of higher pre-dawn leaf xylem water potentials. Expansive root system development might be a common characteristic in drought-tolerant cultivars.View full abstractDownload PDF (936K) -
Yushi HIDA, Tadashi HIRASAWA, Kuni ISHIHARA1995 Volume 64 Issue 3 Pages 573-580
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn the previous paper, it was clarified that the decrease in dry matter and grain productions under deficient soil moisture conditions differed between cultivars classified into the same ecotype, and it was suggested that root system development might be responsible for the varietal differences. To investigate causal factors of the differences in dry matter production and yield between the cultivars, ecophysiological characters and root system development were compared between the populations of Enrei and Tachinagaha in the field. The net assimilation rate was high in Tachinagaha compared with Enrei because of the high leaf xylem water potential and low leaf diffusive resistance during the daytime, and the less decrease in the photosynthetic rate with senescence. This resulted in high dry matter production and high grain yield in Tachinagaha. Root length density measured by the core sampling method and root length measured by the minirhizotron method were both larger, especially in the deep soil layers, in Tachinagaha. The amount of soil water depletion was also larger, especially at the deep soil layers in Tachinagaha, probably due to greater water absorption by the plants. These results indicated that the root system was well developed in the deep soil layers in Tachinagaha compared with Enrei as soil moisture was depleted. The root system development might be responsible for the differences in the ecophysiological characters between Enrei and Tachinagaha.View full abstractDownload PDF (889K) -
Hajime WATANABE, Kiyoshi TAKAHASHI1995 Volume 64 Issue 3 Pages 581-586
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo clarify the morphological features and internal structure of shoot apex of MC seedlings, one of the rice seedlings type, in relation to agricultural significance, an Indian rice cultivar, Basmati 217, was used. Sterilized brown rice grains were cultured on 0.8% agar medium and maintained at 30°C in the dark for 14 days. The lengths of mesocotyl, coleoptile, first leaf and second leaf were examined. The M/C ratio (mesocotyl length/coleoptile length) was also calculated. Based on the existence of coleoptilar node root, 2 types of frequency distribution of the coleoptile final length and MC ratio were observed. One type belonged to the MCN (MC seedlings with no nodal root), and the other one to the MCR (MC seedlings with nodal root). The mean length of coleoptile and mean M/C ratio of MCN were 8.3±0.5mm and 16.6±0.9 whereas those of MCR were 35.2±1.4mm and 2.8±0.3 respectively. The correlation coefficient for mesocotyl length versus coleoptile lengh of the MCR was significantly negative (r=-0.537**) whereas that of the MCN was positive and not significant (r=+0.032). It was observed that the number of leaf primordia of MCR was 0.6 higher than that of MCN. The shoot apex of MCR was more developed than that of MCN. From these results, we identified three types of rice seedlings based on the emergence of the first leaf, coleoptile length and the existence of coleoptilar node root as follows : MCN, MCR and non-MC seedling.View full abstractDownload PDF (942K) -
Hengji CUI, Yoji TAKEOKA, Tomikichi WADA1995 Volume 64 Issue 3 Pages 587-592
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe effect of salinity stress on external shoot morphology in relation to panicle development was studied. Three rice cultivars, Nipponbare, as a Japonica-type rice, Blue bonnet as a Javanica-type, and Konosuke, a Japonica-type sensitive to soil stress were used and were grown in pots by sand culture method with various concentrations of sodium chloride. Injury symptoms in different cultivars were expressed in various ways. Treatment during the young panicle formation stage caused green leaves to become pale yellow followed by browning, starting from leaf tip to base, and the lowermost leaf was affected first, followed by younger upper leaves on the same culm. Under conditions of increased salinity and with prolonged duration of treatment, flag leaf burning became more pronounced. The injury symptom during late panicle growth period was expressed as a reduction in culm length, and a number of late-grown tiny tillers came out on upper nodes in some plants. Heading time was so remarkably delayed that the period of heading was prolonged. Under higher salt conditions, basal part of the panicle started to emerge earlier, while the tip remained inside the leaf sheath. The similarities in effects of salt stress on shoot morphology with those of other adverse environmental conditions are discussed.View full abstractDownload PDF (830K) -
Hengji CUI, Yoji TAKEOKA, Tomikichi WADA1995 Volume 64 Issue 3 Pages 593-600
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo provide new information on salt stress in rice plant based on developmental morphology, structural changes of panicle and spikelet were investigated. As the salt concentration increased, growth and development of the rachilet was progressively reduced. This resulted in a decrease in the number of primary and secondary rachilets and also decreased grain numbers in the panicle. Additionally, the percentage of fully ripened grains decreased as the salt concentration increased. Salt treatment caused morphological variations in rachilla, spikelet and leaf structures. Degenerated primary rachilets were decreased in size or abruptly reduced, although there was a wide range of variations in degree of the degeneration among different cultivars. These morphological changes in panicle and spikelet in rice plants under salt stress conditions are compared with those under other environmental stresses. There are many similarities in morphological variations under different stresses, which finally led to the inhibition of growth of rice plants. The common processes in morphogenesis of panicle and spikelet in response to these environments was discussed together with the previous knowledge.View full abstractDownload PDF (933K) -
Yuji MATSUE, Koji ODAHARA, Michikazu HIRAMATSU1995 Volume 64 Issue 3 Pages 601-606
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe amylose content, amylographic characteristics and storage proteins of milled rice grains on the primary and secondary rachis branches were investigated. The amylose content of grains on the primary rachis branches with superior palatability was higher than that on the secondary rachis branches. Grains on the primary rachis branches showed higher maximum viscosity and breakdown values, and lower gelatinization temperature than those on the secondary rachis branches. These results suggested that the palatability of cooked rice of grains with high amylose content and amylogram values was superior to that with low amylose content and amylogram values within a cultivar under the same cultural conditions. In terms of protein fraction in the starchy endosperm, there was little difference in prolamin content and in albumin + globulin content between grains on primary and those on secondary rachis branches, whereas total protein content and glutelin content of grains on the primary rachis branches were noticeably lower than those on the secondary rachis branches for all the cultivars. Total protein, glutelin and prolamin content of a good palatability cultivar, Koshihikari were lower than those of moderate palatability cultivars Nipponbare and Reihou. These results indicate that, among storage proteins, glutelin and prolamin play important roles in rice palatability and that it is possible to use glutelin as an indicator of palatability within a single cultivar and prolamin as an indicator of palatability among cultivars.View full abstractDownload PDF (648K) -
Shinya OBA, Noriko SUMI, Fumihiro FUJIMOTO, Tasuke YASUE1995 Volume 64 Issue 3 Pages 607-615
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSRice garin shattering habit is closely associated with the abscission layer formed at the base of sterile lemmas (empty glumes). In the current study, the character expression of sh-2, one of the representative shattering genes, was investigated by comparing some agronomic parameters among Norin 29, a Japanese non-shattering cultivar, and its shattering near-isogenic line SH-AJNT, as well as Dee-geo-woo-gen, a shattering indica cultivar. After observation of longitudinal sections of sterile lemmas bases, the abscission layer was not found at the spikelet differentiation stage. However, at the reproductive cell formation stage, SH-AJNT faintly formed the abscission layer. No abscission layer, on the other hand, appeared in Norin 29 throughout the stage of panicle development. The breaking strength at the base of sterile lemmas was measured to compare the threshability among materials. Until 19 days after heading, both threshability on Norin 29 and SH-AJNT exhibited similarly high values, indicating non-shattering conditions. At 21 days after heading, the garin of SH-AJNT dropped more easily than those of previou stages, while Norin 29 kept its persistent character. This difference is important for the evaluation of SH-AJNT and Norin 29, shattering and non-shattering cultivars, respectively. The progressive decline in the breaking strength of SH-AJNT was thought to be associated with the ripening of the grain.View full abstractDownload PDF (1092K) -
Naoko NAKAJIMA, Susumu TOYAMA1995 Volume 64 Issue 3 Pages 616-621
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSExogenous epibrassinolide (EBR) treatment promoted elongation of cucumber epicotyls and at the same time, enhanced sugar accumulation in the epicotyls. This accumulation was concomitant with the elongation. Accordingly, it was suggested that the sugar accumulation is closely related to the promotion of elongation. Furthermore, the components of the soluble sugar were researched. By EBR treatment, the amount of glucose was remarkably increased, although sucrose was not affected. The amount and transport of 14C-assimilates in EBR-treated cucumber were analyzed. EBR treatment had no effect on the amount of 14CO2 assimilation but they promoted the transport of 14C-photosynthates to epicotyls. In addition, the amount of 14C-labeled glucose transported to epicotyl was remarkably increased. In conclusion, these changes enhanced by EBR seem to be a cause of glucose accumulatilon in cucumber epicotyls.View full abstractDownload PDF (701K) -
Yasuhiro IZUMI, Yasuhiro KONO, Takanori AOSHIMA, Akira YAMAUCHI, Morio ...1995 Volume 64 Issue 3 Pages 622-628
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTissue culture of excised root is a useful method with which genetic variation of plant root itself can be determined without the influence of shoot. We aimed to determine the effects of age and elongation rates of the seminal root axis of rice on subsequent growth in a culture medium. Taichung Native 1 (indica type) and Yukara (japonica type) were used in the experiments. The seminal root tips (1-cm-length) were sampled every day after bedding on agar and their morphological and physiological characteristics were monitored by recording the persence of lateral roots and primordia, dry weight and C·N content. Root tips with different ages or elongation rates were then cultured, and subsequent growth was observed after three week culture. Root tips which were older and had lower elongation rates showed inferior root growth in both cultivars. When a more than three-day-old seminal axis on which lateral roots started to emerge was excised, less L-type first order lateral roots was produced than that grown on the two-day-old axis, and this affected the total root number and length. The dry weight or C·N content of excised segments decreased as the excision day, and these characteristics showed a close correlation with the subsequent root growth. Thus, we concluded that the excision of root tip segments at an earlier stage ensures excellent development of seminal root system in vitro.View full abstractDownload PDF (750K) -
KWAK Kang Su, Morio IIJIMA, Akira YAMAUCHI, Yasuhiro KONO1995 Volume 64 Issue 3 Pages 629-635
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe allocation pattern of carbon (C) and nitrogen (N) with aging among several organs of rice seedling was investigated with particular attention to the difference in seminal root axis (SRA) and concomitant lateral roots (LR). Rice (Oryza sativa L. cv. Aichiasahi) was grown in root boxes under submerged conditions for 35 days after sowing (DAS). Overall C and N concentration of LR were higher than those of SRA, and the difference was more pronounced in N concentration. In the seminal root portion of the same age, C and N content decreased in both SRA and LR with progression of age, however a trend of declining N content in LR was alleviated by the rooting of higher (2nd order) LR. The ratios of root length to C content and dry weight in LR were 27 times that of SRA, and the ratio of root length to N content in LR was 12 times that of SRA after Day 21. These results suggest that the aging patterns of LR and SRA are different, and LR plays a more important role in controlling the metabolic activity of the whole root system than SRA. Moreover, increase in N content in SRA after Day 12 and the increase in the number of LR up to 35 DAS suggested that the seminal root of rice was alive and maintained its metabolic activity for at least 35 DAS.View full abstractDownload PDF (758K) -
Yasuhiro IZUMI, Yasuhiro KONO, Akira YAMAUCHI, Morio IIJIMA1995 Volume 64 Issue 3 Pages 636-643
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe development of cultured seminal root system of rice was analyzed to determine the most appropriate culture period for the characterization of root system morphology. Excised seminal root tips of Taichung Native 1 (TN-1, indica type) and Yukara (japonica type), were cultured for six weeks with the conventional tissue culture method, and their growth was evaluated with developmental, topological and fractal analyses. Developmental root growth parameters, such as the number and length of each root system component, reached almost maximum values at the fourth week in TN-1, and the third week in Yukara. On the other hand, it was possible to characterize the root system morphology by the branching densities of L- and S-type first order lateral roots and the average length of S-type first order lateral roots at the third week. In the timecourse changes of a topological parameter (log a/log μ), which indicates the branching pattern, the difference between cultivars became clear at the third week. The fractal dimension (D), which indicates the complexity of root morphology, was higher in Yukara than in TN-1 throughout the experimental period. This suggested the possibility for characterizing the root system morphology of each cultivar by the D value. Therefore, we concluded that the most appropriate sampling time for the morphological research of cultured seminal root system was three weeks when the conventional excised root culture method is used.View full abstractDownload PDF (836K) -
Hideki OHDAN, Hiroyuki DAIMON, Hironori MIMOTO1995 Volume 64 Issue 3 Pages 644-649
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSAllelopathic effect of aqueous extracts of six Crotalaria species on wheat root growth at early growing stage was examined by using a seed pack growth pouch. There was a significant difference in total root length of wheat with application of the extract of each species compared with control at 21 days after planting. C. juncea and C. pallida suppressed the length by approximately 40% based on the control. Remarkable suppression of root growth could be clarified by image-processing of the root system which appeared on the surface of the pouch. A significant reduction in the length of the longest root was also observed, and C. juncea and C. spectabilis showed severe reduction. Definite inhibition was observed with the leaf extract compared with the stem extract in C. spectabilis, and the inhibition was remarkable as the concentration of the extracts increased. Dry weights of both top and root of wheat were not influenced by application of C. brevidens, C. juncea, C. lanceolata and C. pallida. With application of C. spectabilis, however, top dry weight was restricted to a low value compared with the control. Fractal dimension of the profile of root system ranged in value from 1.27 to 1.35, and it was not necessarily influenced by the application of extract of each species. These results indicated that wheat root growth was inhibited by application of the aqueous extract of Crotalatia, and the seed pack growth pouch techique might be applied to the evaluation of allelopathy.View full abstractDownload PDF (660K) -
Hiroyuki DAIMON, Masahiro MII1995 Volume 64 Issue 3 Pages 650-655
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn Rudbeckia hirta L., an antagonistic plant to nematodes, hairy roots were induced by infection with a wild strain (A-5) of Agrobacterium rhizogenes. Hairy roots cultured in half-strength MS agar medium without phytohormones showed vigorous growth and extensive lateral branching. Mikimopine (opine) was detected in the extract of hairy root by paper electrophoresis. Adventitious shoots were induced on the surface of hairy roots after 30 to 50 days of transfer to half-strength MS agar medium supplemented with BAP at 0.5-10.0 mg/l. The highest frequency of shoot formation was obtained at 0.5 or 1.0 mg/l BAP in combination with 0.1mg/l NAA. Plants regenerated from hairy roots showed morphological alterations such as wrinkled leaves, small size of flowers and abundant lateral branching of roots. A nematocidal compound, α-terthienyl, was detected in the extract from lateral roots of the regenerant.View full abstractDownload PDF (836K) -
[in Japanese]1995 Volume 64 Issue 3 Pages 656-662
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (749K) -
[in Japanese]1995 Volume 64 Issue 3 Pages 663-667
Published: September 05, 1995
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (562K)
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