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Volume 62, Issue 4
Displaying 1-25 of 25 articles from this issue
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Yoshitaka YAMAMOTO, Sachio KAWAGUCHI, Wataru TAKAHASHI1993 Volume 62 Issue 4 Pages 485-490
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSEstimation of the developmental stages of paddy rice by temperature (DVS method) was conducted during different cropping seasons and areas for the rice variety Koshihikari. The DVS method was applied to cases of transplantion from April 20 to June 1. During this period, the standard deviation of estimated error was 1.21, 1.48, and 1.45 days for the young panicle formation stage, heading stage, and maturing stage, respectively. However, the DVS method could not be used for transplanting on June 15, and the estimated developmental stages were somewhat behind actual growth rates. The developmental stage that appears to possibly be affected by the length of the day, and accelerated development was noted for short days. This method could be used in Nyuzen town, Tateyama town and Tonami city, all in Toyama prefecture, using temperature data from AMeDAS. Standard deviation of error was 2.76, 2.33, and 2.55 days for the young panicle formation stage, heading stage and maturing stage, respectively.View full abstractDownload PDF (663K) -
Kenji TERAI1993 Volume 62 Issue 4 Pages 491-495
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe relationships among branching habit, yield components, and grain yield of 37 strains of white azuki bean (Vigna angularis), collected from various parts of Akita Prefecture, were studied in field experiments in 1990 to investigate the relationship between branching habit and yield. Grain yield/plant, number of nodes/plant, number of pods/plant, and number of grains/plant significantly differed among strains, but differences were more closely associated with morphological characteristics of branch portions rather than those of the main stem. The number of branches was also significantly different among strains. Grain yield/plant was highly positively correlated with the number of pods/node and the number of grains/pod on both the main stem and branch portions, but was only slightly correlated with 100-grain weight. Correlations between the number of branches to the yield components on the main stem and branches were generally not significant, except for 100-grain weight of main stem which was slightly negative. The ratio of branch grain size (100-grain weight) to main stem grain size tended to be higher in strains having greater branch numbers. From these results, it was estimated that differences among strains in yield components were not attributed to differences in branching habit, although yielding ability was highly correlated with the branch yield components.View full abstractDownload PDF (611K) -
Toshio MABUCHI1993 Volume 62 Issue 4 Pages 496-501
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSEffects of flooding and lodging on the seed dormancy were studied in the two-rowed barley seed. Seeds were obtained from plants which were subject to the flooding treatment 4 times during the ripening period and from lodged plants which showed a lodging index of 4. Awakening from seed dormancy in this crop was closely related with the thickness of the seeds. Awakening from seed dormancy occurred earliest in seeds with a thickness over 2.8 mm, followed by seeds with thicknesses of 2.5-2.6 mm and 2.2-2.4 mm. Similarly, dormancy-awakening was clearly related to 1000 kernel weight and to germination percentage with the heavier grains awakening earlier from dormancy. When the ratio of large grain was reduced, maturation was inhibited. Analysis of the photosynthetic activity of awns during the ripening process of plants treated with flooding was based on 14CO2 levels. It was clear that the photosynthetic ability in the upper position of the ear of awns was lowered by flooding. These results suggest that flooding and lodging have an indirect effect on seed dormancy-awakening on two-rowed barley.View full abstractDownload PDF (692K) -
Shao-Hui ZHENG, Il-Doo JIN, Jun INOUYE1993 Volume 62 Issue 4 Pages 502-508
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSEight epigeal leguminous crops were used as materials : Soybean (Glycine max Merr.), kidney bean (Phaseolus vulgaris L.), hyacinth bean (Lablab purpureus Sweet.), cowpea (Vigna unguiculata Walp.), mung bean (V. radiata R. Wilczek), black gram (V. mungo Hepper), moth bean (V. aconitifolius Marechal), and peanut (Aracis hypogaea L.). When seedlings had grown to 3 cm in height in soil with 13% moisture by volume at 25°C, covering soil was removed and marks with india ink were put on the seedlings at 2-mm intervals from the top of plumular hooks downward. After the seedlings were covered with soil again up to the top of plumules, a stopper, for vertical load treatment, was placed on the top of each plumule. These procedures were performed quickly under dim green light to minimize confounding factors. Forty-eight hours after the beginning of treatment, hypocotyl length and stem thickness were measured, and the stems were examined histologically (longitudinal and cross-sectional) using a microtome technique. In all crops tested, hypocotyl elongation was inhibited by vertical load treatment, and the inhibition was the largest from the top of the plumular hook down 4 mm in each seedling. Elongation inhibition was the greatest (ca. 66%) in the cowpea and the smallest (ca. 21%) in the peanut. Furthermore, in each seedling whose elongation was inhibited, stem thickness increased. Stem thickness was found to correlate positively with elongation inhibition in each crop (r=0.621*∼0.907***). The results suggest that elongation inhibition and stem enlargement of seedlings may be caused by elongation inhibition and enlargement of cells in the cortex and in pith tissues of seedlings.View full abstractDownload PDF (867K) -
Kuniyuki SAITOH, Hiroyuki SHIMODA, Kuni ISHIHARA1993 Volume 62 Issue 4 Pages 509-517
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDifferences in yield, dry matter production, and harvest index between new (registered after 1955) and old (before 1940) Japanese rice varieties were examined with reference to light-intercepting characteristics, single-leaf photosynthesis, and dry matter accumulation in the panicle. The average yield of new varieties (586g/m2) was higher than that of old varieties (483g/m2) owing to higher dry matter production during the ripening period. This difference was caused by a smaller decline in the leaf photosynthetic rate and by the lower canopy light extinction coefficient observed in the new varieties, as compared with the old varieties, during the ripening period. The new varieties had a higher harvest index as compared with the old varieties, but there were no differences in sink size between them. The higher dry matter production in the new varieties resulted in the accumulation of assimilate in the culm at the late ripening stage. Clearly, the sink size was not enough in the new varieties, i.e. the sink size should be enlarged by using the Indica or Indica/Japonica hybrid varieties (Nanjing 11, Milyang 23) in the breeding program.View full abstractDownload PDF (1046K) -
Jian-min LI, Koou YAMAZAKI1993 Volume 62 Issue 4 Pages 518-524
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSWheat (Triticum aestivum L.) yields often are closely related to the sowing rate and the number of tillers on a plant. This study was conducted to examine the morphological features of whole plant and main stem, their relationships with the number of tillers, and the effects of environmental conditions. Winter wheat plants, cv. Norin 61 grown on dry (D, notirrigated), wet (W, irrigated) conditions in a vinyl-house and under field (F) conditions were sampled at maturity. The number of tillers per plant and 11 characteristics about ear, stem, rooting nodes, and roots were measured. The data was analysed by principal component analysis (PCA) and correlation analysis (CA). The results are as follows. (1) The results of PCA of whole plants showed that the first component, which was interpreted as a "size" factor, explained 94.4% of the observed variations. This indicated that the morphological feature of whole plant could be represented by the "size" factor. The results of CA showed that the "size" ot whole plant was determined primarily by the number of tillers. (2) The results of PCA of main stems showed that the morphological features of a main stem could be represented by the factors of "size" (53.2%), "ratio of aerial parts to subterranean parts" (17.1%), and "shape of stem axis" (10.1%). The subsequent CA suggested a positive correlation between the "size" of the main stem and the number of tillers. (3) The relationships between the "size" of main stem and the number of tillers were different amont the three experimental plots. This result indicated that environmental conditions exerted a direct effects on tiller formation in addition to those affecting the "size" of the main stem.View full abstractDownload PDF (793K) -
Taiichiro OOKAWA, Yasuhiro TODOKORO, Kuni ISHIHARA1993 Volume 62 Issue 4 Pages 525-533
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe present investigation was undertaken to examine which physical and chemical characteristics of the culm associated with lodging resistance changed under different growth conditions using three varieties. Three different conditions were prepared : (1) "Border" (Border of the rice population was made by reaping several rows in the south side at the maximum tiller number stage, and rice plants were grown under strong light intensity and low humidity compared with "Control".), (2) "Shade" (50% Shade of the population was treated from the maximum tiller number stage to heading time) and (3) "Control" (Untreated rice population). Change in the degree of lodging and the lodging index was largely dependent on variation in the breaking strength of the basal internode. The breaking strength was much larger in "Border" and much smaller in "Shade" than that in "Control" for all varieties. The degree of change in the breaking strength was more pronounced in Koshihikari which has a small breaking strength, however, the change was smaller in Taichung 189 or Milyang 23 which have large breaking strength. With the exception of "Shade" in Milyang 23 with a large section modulus, these changes in the breaking strength were not due to the section modulus but rather to the bending stress. The density of glucose, xylose and lignin were correlated with the bending stress in each variety, and their correlations were the closest on Taichung 189. The degree of the increase in bending stress accompanied by a concomitant increase in the densities of xylose and lignin was much larger in Taichung 189 and Koshihikari than in Milyang 23, and the efficiency of the increase in bending stress to the increase in density of lignin was the highest in Taichung 189.View full abstractDownload PDF (1000K) -
Jian-min LI, Jiro HARADA, Koou YAMAZAKI1993 Volume 62 Issue 4 Pages 534-539
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn this study, the relationships between the emergence of tillers and the plant development, the emergence of leaves and roots were examined. Winter wheat (Triticum aestivum L.) plants, cv. Norin 61 grown under dry (D, notirrigated), wet (W, irrigated) conditions in a vinyl-house and under field (F) conditions were sampled at intervals of 10-14 days from seedling stage to maturity. The emergence and the numbers of leaves, roots, and tillers were observed and their relationships were examined and compared. The results are as follows. (1) Number of tillers per plant increased until the stem elongation stage, and the environmental conditions affected both the period of tillering and the emergence of tillers from the leaf axils at higher positions and orders. (2) Linear relationships were found between the number of leaves and roots on the main stem and the tillers. However, the tillers produced a smaller number of roots per phyllochron than main stems, as did the tillers at higher positions and orders compared to those at lower positions and orders, although the tillers at higher positions and orders produced root earlier. (3) Similar differences were also found in the main stems or primary tillers grown under different conditions. However, there were no differences among the individual plants grown under different conditions, because the differences in main stems and primary tillers were balanced by the differences caused by the number of tillers per plant. This result suggested that the emergence of tillers was connected with the developmental relationships of leaves and roots.View full abstractDownload PDF (752K) -
Masahiko TAMAKI, Toru TASHIRO, Masashi ISHIKAWA, Morie EBATA1993 Volume 62 Issue 4 Pages 540-546
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSWe examined the effects of short and long-term storage on the eating quality of rice. The texture of cooked rice became harder and less sticky after being stored at higher temperatures and moisture contents for 90 days. The texture of rice stored under excessively dry conditions deteriorated only during the early stages of storage, and became better than rice stored under normal moisture conditions with prolonged storage. The eating quality of rice stored for 6 years was also analyzed. Most of the change in texture occurred during the first 1 to 2 years, and very little change was observed thereafter. Water-insoluble protein and amylose contents showed no significant changes. Fat-by-hydrolysis content, however, increased ; this may be a contributing factor in the deterioration of cooked rice texture during storage. A reduction was also observed in the amount of glutamic acid in milled rice as well as a decrease in the ratio of glutamic acid both in milled rice and in the exterior of cooked rice. The pH in the cooking liquid also decreased. These seemed related to the deterioration of the taste of rice.View full abstractDownload PDF (750K) -
Yoshiharu WADA, Kunio MIURA, Kazuyuki WATANABE1993 Volume 62 Issue 4 Pages 547-553
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSPartial removal of spikelets and partial defoliation were conducted in rice at anthesis to evaluate the effects of the source-to-sink ratio (ratio of leaf area to grain number). The ratio was 0.75 in the control plants and ranged from 0.24 to 1.53 for the various treatments. The apparent photosynthetic rate was not influenced significantly by the treatments 12 days after anthesis. Contents of chlorophyll and Rubisco decreased substantially 3 weeks after anthesis, but remained relatively high when the sink size was reduced. Three weeks after anthesis, both the chlorophyll and Rubisco contents were positively correlated with the source-to-sink ratio (P<0.01). Therefore, it appears that a large sink size (i.e., smaller source-to-sink ratio) promotes flag leaf senescence. However, no significant differences in the enzyme activities related to sucrose synthesis were observed among the treatments. In spite of the large differences in sucrose and starch contents in leaf sheath and culm among the treatments, the trends of change in sucrose and starch contents in the flag leaf blades during the ripening period were similar. Thus, the ability of the flag leaves to synthesize sucrose was not greatly reduced during senescence. The nitrogen content of flag leaf blade was negatively correlated with sink size. These results suggest that the difference in leaf senescence under various source-to-sink ratios may be associated with the different rates of nitrogen withdrawal from leaf blades to grains.View full abstractDownload PDF (762K) -
Tadashi TAKAHASHI, Kimio NAKASEKO1993 Volume 62 Issue 4 Pages 554-559
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIt has been generally believed that the crop ideotype canopy has an erect small leaves to allow the photosynthetically active radiation (PAR) to penetrate deeply. In wheat, this might be not always applied to high-yielding varieties. We investigated the morphology and the PAR distribution in canopy (400 plants m-2) for three varieties with different canopy structures at early and late sowing times (April 13 and May 10, respectively). These three varieties, semi-dwarf early Norin 61 bred in Kyushu Japan, semi-dwarf early Haruyutaka bred in Hokkaido Japan, and tall late Selpek bred in Germany, differ from each other in canopy structure. Surface areas of ears and lower leaves were larger in early sowing than in late sowing for the three varieties, while those of flag leaves were larger in late sowing. Surface area of ears was larger for long-awned Haruyutaka than for short-awned Norin 61 and awnless Selpek, so that PAR penetration under the ears was lower for Haruyutaka. Surface area of flag leaves was larger for Haruyutaka and Selpek than for Norin 61, so that PAR penetration under flag leaves was lower for these varieties. However Haruyutaka and Selpek yielded their biomass higher than Norin 61. PAR penetration under lower leaves was higher in late sowing, and was especially high for Norin 61 and Selpek. On the other hand, there were significant negative relations between surface areas and PAR penetrations within layers of ears, flag leaves and lower leaves. Regression analysis showed that the horizontal flag leaf intercepted the PAR more effectively than the erect lower leaves. Culm surface areas seemed to intercept 27% of PAR within the flag leaf layer and 51% of PAR within the lower leaf layer.View full abstractDownload PDF (651K) -
Tadashi TAKAHASHI, Naoyuki TSUCHIHASHI, Kimio NAKASEKO1993 Volume 62 Issue 4 Pages 560-564
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo define the growth phases for analyzing the physiological and morphological mechanisms of grain filling in a spring wheat canopy, the dry weight of the grains and the water soluble sugar content (WSC) and structural weight of the culm were measured for the variety Haruyutaka everyday during the grain-filling period. The grain-filling period was divided into four phases ; (1) Initial grain filling (from anthesis to cessation of culm elongation) where assimilate is used mainly for culm elongation and the dry weight of the grains increase slightly ; (2) Early grain filling (from cessation of culm elongation to the milk ripe stage) where assimilate is used for both grain growth and culm reserve. (3) Late grain filling (from the milk ripe stage to termination of photosynthesis) where assimilate is used entirely for grain growth and the culm reserve is also translocated to the grain ; and, (4) Final grain filling (from the end of photosynthesis to maturity) where grain growth is supported only by translocation of the culm reserve because assimiltate is no longer being actively produced. In the early and late grain-filling phases, the increase rate of the WSC in the culm was related linearly to radiation (r=0.616***), while grain weight increased linearly with time (r=0.992***), independent of radiation.View full abstractDownload PDF (618K) -
Atsushi OYANAGI, Tomomi NAKAMOTO, Michihiro WADA1993 Volume 62 Issue 4 Pages 565-570
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSVertical distribution of roots is known to influence environmental stress tolerance of crops. To estimate the genotypic characteristic on the vertical distribution of roots in the field, the growth angle of seminal roots of 7-day-old seedlings of 12 Japanese winter wheat cultivars was measured using the basket method in a pot experiment. For comparison, the same cultivars were grown in an upland field and monolith samples of the top 30 cm soil layer were taken at the stem elongation stage. Root length was measured in every 5 cm horizontal soil layer. Root growth angle showed negative correlation with root length percentage in the top 10 cm soil layers, but the angle showed positive correlation with the percentage in 10-30 cm depth layers. The root depth index (RDI) was calculated to characterize the root vertical distribution of the cultivars. The RDI was closely related to the growth angle of the seminal roots of the cultivars (r=0.779 ; P<0.01). It was, therefore, assumed that the determination of the growth angle of seminal roots in a pot experiment could be useful to estimate genotypic differences in the root vertical distribution at the stem elongation stage in the field.View full abstractDownload PDF (581K) -
Yoshie S. MOMONOKI, Tokuhiro MOMONOKI1993 Volume 62 Issue 4 Pages 571-576
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSAcetylcholine (ACh) and acetylcholinesterase (AChE) have previously been demonstrated to occur in leguminous plant, Siratro (Macroptilium atropurpureum). In the present work, the localizatiion of acetylcholinesterase (AChE) within selected organs of Siratro is described. Histochemical techniques have been employed to show the presence of acetylcholinesterase activity in petiole, stem, root and the primary and secondary pulvini. No histochemical evidence was observed in petiole, stem and root segments. The enzyme was only present in the primary and secondary pulvini. The AChE in tissues of the primary and secondary pulvini appeared to be in the endodermal cells around the vascular system. Particularly, after the cytochemical reaction dark spots of copper sulfide strongly stained the endodermal cells that circled around the vascular system in the primary pulvinus. The results confirmed a high ACh content and a hige enzyme activity was present in the primary and secondary pulvini of Siratro. In addition, it is demonstrated that the primary pulvinus is associated with ACh function in Siratro plants.View full abstractDownload PDF (1416K) -
Kunio OKANO, Yasuhiro KONO1993 Volume 62 Issue 4 Pages 577-584
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSHydroponically-grown rice (Oryza sativa L.) plants were pulse-labelled with 15N-ammonium sulphate at various stages of reproductive growth, and partitioning of 15N among grains or grain tissues were examined at full maturity for a better understanding of the ripening process of rice panicle, which consisted of a large number of grains. Labelled nitrogen applied before heading was equally distributed to all grains. 15N applied at heading or the milk-ripe stage was mainly distributed to the early developing grains located on the upper part of the panicle, while that administered at a later period of ripening was principally transported to the later developing grains on the basal part. Thus, the position of grains actively accumulating nitrogen moved down from the upper to the basal part of the panicle with ripening. Active incorporation of 15N into husk continued up to the milk-ripe stage. At the later stages of grain filling, 15N uptake in the embryo became lower than that in the endosperm, indicating the formation of embryo preceded the endosperm. 15N levels incorporated into the inner parts of the endosperm decreased earlier than the outer parts ; this suggested that the deposition of nitrogen in the endosperm was first completed at the central part then extended to the peripheral layer. Based on these results, it could be concluded that the increase in the source-sink ratio is not sufficient to improve grain filling in the rice plants. It is also very important to maintain the physiological activities of leaves and roots until the later stages of ripening when the inferior spikelets continue to accumulate materials.View full abstractDownload PDF (892K) -
Yoichi TORIGOE, Takahiro INOUE, Tetsuro AMANO, Kei OGAWA, Michikazu FU ...1993 Volume 62 Issue 4 Pages 585-594
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe objectives of our study were : (1) To investigate the feasibility of using the digital KFA 1000 imagery analysis as a means of accurately describing and quantifying soil properties of Andosols, and (2) to reveal the relationship between the soil properties and the extent of clubroot disease incidence in cabbage. The film (Sojuzkarta #25253, scale 1 : 250, 000), acquired on June 7, 1988, was used to examine the approach in the entire area of Tsumakoi-mura of Gunma Prefecture. The film is sensitive in the red (570-680 nm) and near infrared (680-810 nm) regions. The scanner data were converted from analog to digital from by a drum scanner with a 25-μm sampling pitch. This method provided data with a pixel size of approximately 6 m×6 m. The near infrared reflectance was a better indicator for delineating five soil series than the red reflectance, indicating the differences of soil color, organic matter content, and water regime among the five soil series. The large variations in the red reflectance within a single soil series may be influenced by different soil moisture conditions ; five soil series and three drainage classes were identified. The effect of soil series on the retardation of the disease incidence was much greater in Light-colored Andosols than in other types. The disease was more severe in the poorly drained class. A season of abundant rainfall was shown to increase the incidence of the disease. Sojuzkarta KFA 1000 imagery provides good information on soil properties of Andosols for the assessment of the incidence of clubroot disease.View full abstractDownload PDF (998K) -
Hiroshi SUGE, Hajime IWAMURA1993 Volume 62 Issue 4 Pages 595-600
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSCytokinin, N-[2-isopentenyl] adenine (2iP), increased and anticytokinin, 4-chloro-2-cyclobutylamino-6-ethylamino-s-triazine (CCET), retards tillering of barley. Tillering was also shown to be retarded by auxin, α-naphthalene acetic acid (NAA) and promoted by antiauxin, 2, 3, 5-triiodobenzoic acid (TIBA). TIBA and 2iP treatment promoted tillering by altering the parallelism of leaf emergence between main stem and tiller ; and the tillering itself, including secondary or tertiary tillers, was hastened which resulted in more tillers being produced at high leaf positions where the untreated control plants had not produced any tillers. Conversely anticytokinin CEET and auxin NAA inhibited or delayed the release of tiller buds even when corresponding leaves on the main stem had already developed to the point where tiller buds normally occur.View full abstractDownload PDF (738K) -
Katsu IMAI, Takeo KAWANA, Kiyoshi SHIMABE, Keo INTABON, Kenichi TANAKA1993 Volume 62 Issue 4 Pages 601-608
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSEdible canna was grown for three successive seasons from late April to early to mid-November under field conditions to clarify the basis of its productivity in the temperate climate of Japan. The growth of the aerial part of the plant was substantially accelerated by the hot weather from mid-July to late August, and the plant grew up to 2.7∼2.8 m in height. It grew 20∼22 leaves on its main stem, and 9∼19 shoots with 29∼35 newly formed rhizomes. Edible canna maintained a high leaf area index (LAI, ca. >9) for about 2 months from late August to early November with a maximum of 11.5∼12.7. Accumulation of dry matter to newly formed rhizomes began in mid-August and continued until the final harvest in November, when frost damage occurred. The final dry weight of the whole plant was 2578∼3968 gm-2 and that of rhizome was 954∼1644 gm-2 so that the harvest index range was as low as 0.37∼0.43. The mean crop growth rate (CGR) was 12.7∼19.3 gm-2 d-1 and interestingly, the maximum CGR (35.3∼43.6 gm-2 d-1) occurred from mid-September to early October in 2 of the 3 years. A tall stand of edible canna population has a high potential productivity based on its high LAI during the latter half of ontogenesis.View full abstractDownload PDF (827K) -
Motoyuki HAGIWARA, Mitsuo IMURA1993 Volume 62 Issue 4 Pages 609-613
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSAlthough seedling emergence and establishment is inhibited by soil reduction in the direct sowing of paddy rice into puddled and leveled soil, the reasons for this are not clearly understood. This experiment was carried out to clarify whether substances produced in reductive flooded paddy soil could be inimical to seedling emergence and establishment of paddy rice seed sown into flooded soil. As typical substances produced in reductive soil, sulfide, acetic acid, and ferrous iron were added to flooded soil before sowing. Seedling emergence and establishment was poor when the amount of addition was large in all substances. Thus, it seemed that substances produced in reductive soil could be one of the direct causes of seedling emergence and establishment inhibition. Ferrous iron seemed to be the most harmful among the substances tested. But inhibition of seedling emergence and establishment by the substances was attenuated when the seeds were coated with calcium peroxide.View full abstractDownload PDF (589K) -
Zheng-Jun XU, Kaien FUJINO, Yoshio KIKUTA1993 Volume 62 Issue 4 Pages 614-620
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSCallus was initiated from mature seeds without the rinds of barnyard grass, Echinochloa oryzicola Vasing, on a modified Murashige and Skoog (MS) medium containing 2.0∼20.0 mgl-1 2, 4-D. The rate of callus formation was greatly improved with the addition of 4 mgl-1 tryptophan. Upon transfer to MS medium containing 6.0 mgl-1 of 2, 4-D, the calli were sustained in subcultures. The plantlets were regenerated under light on MS medium involving various hormone combinations of 2, 4-D and cytokinins. In the regenerated plantlets 55% were normal plants and 45% abnormal plants including albinos. The processes of plantlet regeneration were observed after the plantlets were embedded in paraffin. The ratio of embryogenesis to organogenesis was found to be 25 : 75 and this ratio could not be effectively controlled by media using varying concentration of 2, 4-D, BA, kinetin, and zeatin.View full abstractDownload PDF (780K) -
Daisuke NISHIOKA, Ebiamadon Andi BRISIBE, Hiroshi MIYAKE, Takeshi TANI ...1993 Volume 62 Issue 4 Pages 621-627
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSWe examined chloroplast development with respect to the stacking of grana in Zea mays L., an NADP-ME type C4 monocot, and in Portulaca grandiflora, an NADP-ME type C4 dicot species. In both species, mean numbers of thylakoids per granum in bundle sheath chloroplasts were suppressed less than 3 throughout chloroplast development while they were increased gradually in mesophyll chloroplasts. It was concluded that in both phylogenetically distinct NADP-ME type C4 plants the stacking of grana was suppressed in bundle sheath chloroplasts from early developmental stages.View full abstractDownload PDF (1565K) -
Kazuto IWAMA, Toshie HUKUSHIMA, Tohru YOSHIMURA, Kimio NAKASEKO1993 Volume 62 Issue 4 Pages 628-635
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe influence of planting density on root growth and its relationship to leaf and tuber growth were investigated with two maincrop varieties in the potato. Three levels of planting density were examined ; 23810, 47620 and 95240 hills ha-1. The root length (RL) was investigated to a depth of 1 m at 90 days after emergence (DAE). The root length density (RLD) to a depth of 30 cm was also investigated at 30 DAE. The leaf area and tuber dry weight were measured at several stages. Total RL to a depth of 1 m at 90 DAE in the sparse, intermediate and dense plots was 12.5, 15.9 and 24.1 km m-2 in Norin 1 and 6.4, 7.0 and 10.4 km m-2 in Konafubuki, respectively. These differences were mainly due to those in RL at a depth of 0-30 cm. RL below a depth of 30 cm did not increase in Norin 1, or decreased in Konafubuki in the dense plot. The similar differences were also seen in RLD at 30 DAE. Total RL at 90 DAE showed significant positive correlations with leaf area index (LAI, r=0.929**) and tuber growth rate (GR, r=0.913**) at the late stage. These results confirmed the importance of longer RL to maintain larger LAI and tuber GR at the late stage. They also suggested that poorer deep roots at the dense plot might cause severe drought in dry soil conditions.View full abstractDownload PDF (844K) -
Tsuneo KATO, Kazuyoshi TAKEDA1993 Volume 62 Issue 4 Pages 636-637
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (345K) -
Yoshio INOUE, Shinsuke MORINAGA, Michio SHIBAYAMA1993 Volume 62 Issue 4 Pages 638-640
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (393K) -
[in Japanese]1993 Volume 62 Issue 4 Pages 641-646
Published: December 05, 1993
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (648K)
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