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Volume 63, Issue 2
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Kazuhiro KOBAYASHI, Takeshi HORIE1994 Volume 63 Issue 2 Pages 193-199
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSAn increase in rice yield in warmer areas in Japan is limited by the low number of spikelets per unit area, for which a lower efficiency in spikelet production per unit plant nitrogen (N) has been considered to be the main reason. As a basis for breaking through the lower N efficiency, differentiation of spikelets and rachis-branches and their degeneration were investigated in relation to plant N conditions for Nipponbare rice subjected to various N treatments around the reproductive stage. A total of 28 N treatments were applied at different rates and times in 2 cropping seasons in each of 1988 and 1989. The number of differentiated spikelets per square meter ranged form 17800 to 56600 of all the treatments. These differing results were highly correlated with two factors : the amount of plant N at the early stage of spikelet differentiation (ESD) and the change of plant N concentration between the panicle initiation (PI) and ESD. The increase in the N concentration between PI and ESD significantly promoted the number of differentiated spikelets through the promotion of secondary rachis-branch differentiation on a primary rachis-branch. It was suggested that, in warmer areas, luxurious dry matter production after PI rapidly lowers the plant N concentration, which results in lower efficiency in spikelet production per unit N absorbed.View full abstractDownload PDF (776K) -
Makoto TSUDA, Haruhide YAMAGUCHI, Shinichi TAKAMI, Katsuhiko IKEDA1994 Volume 63 Issue 2 Pages 200-207
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe effects of drought on the rice yield differ depending on the time when plants are subjected to the drought. It is therefore probable that water stress susceptibility, the degree of yield reduction due to drought, is also a function of plant development. Water stress susceptibility is defined as the fractional decrease of panicle weight per unit change of cumulative water stress (an integrated water stress with time). The objective of this study was to determine whether water stress susceptibility is correlated with the yield responses to drought. Wetland rice plants (cultivars Koshinishiki and Somewake) were grown in pots containing soil under polyethylene rain shelters. Water potentials of leaves and panicles, and grain yield were measured in plants subjected to short-term water deficit imposed at various stages of panicle development. Water stress susceptibility increased with panicle development prior to heading but decreased as reproduction progressed. A similar trend was also seen in the data of winnowed paddy number. Prior to heading panicle water potential under drought increased with panicle development, whereas the water potentials of panicles and leaves were similar after heading. These results indicate that changes in water stress susceptibility reflect the variability, of grain yield under drought at least partly. The greater water stress susceptibility, was due to a smaller number of winnowed paddies. In addition, the susceptibility before heading was related to the maintenance of a higher panicle water potential under drought.View full abstractDownload PDF (820K) -
Yoshitaka YAMAMOTO, Sachio KAWAGUCHI, Wataru TAKAHASHI1994 Volume 63 Issue 2 Pages 208-214
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo clarify the characteristics of rice growth, number of leaves, number of tillers and stem weight, the developmental stage estimation method (DVI method) using air temperature was applied to rice growth planted under different number of seedlings per hill conditions for the rice variety Koshihikari. The curve line models were well suited for comparison of the DVI values and the number of leaves in the different seedling groups. The number of leaves was higher at hills with a few seedlings than that of hills with many seedlings. In the main stem flag leaf number, there was a 1.5 leaf difference between 1-seedling hills and 8-seedling hills. The three-dimentional curve line models were well suited for comparison of the DVI values and the number of tillers per hill for each seedling groups. The number of tillers was higher in the hills with many seedlings than the hills with a few seedlings at every developmental stage. Both the estimated emergence stage of the last tiller and the maximum tiller number stage appeared faster in the hills with many seedlings than in the hills with a few seedlings. The maximum tiller number stages of 1-seedling and 2-seedling hills followed the panicle formation stages. A high correlation coefficient between stem weight and the number of spikelets per panicle was discovered at each developmental stage. However, it was necessary to consider the tillering dimension before the panicle formation stage. The growth curves were well suited for comparison of the DVIvralues and the stem weights of the main stem and the 4th node tiller for each seedling number per hill. The dry weight of stems decreased as the seedling number per hill increased. The growth curves were well suited for comparison of the DVIvalues and the stem weights for each number of spiklets per panicle. The dry weight of the stems decreased with the number of spiklets per panicle.View full abstractDownload PDF (783K) -
Chung Yeol LEE, Yukindo TSUNO, Junichi NAKANO, Takeshi YAMAGUCHI1994 Volume 63 Issue 2 Pages 215-222
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTwo Korean cultivars (cv. Hwangkeumkong, Danyeobkong) and one Japanese cultivar (cv. Enrei) were grown in the same pot under glasshouse conditions to investigate the influence of water deficit on the photosynthetic rate, transpiration rate and root respiratory rate. The transpiration rate and stomatal conductance rapidly decreased with decreasing of soil moisture compared to the photosynthetic rate. Net photosynthesis remained at a high constant rate (>20 mg CO2 dm-2 h-1) during 4 days after non-watering treatment (pF1.9∼3.5), but at further treatment soil moisture deficit (over pF 3.5), net photosynthesis seriously decreased. These observed results were similar for all three cultivars. Different quadratic equations were obtained between net-photosynthetic rate and stomatal conductance, and a linear equation was obtained between transpiration rate and stomatal conductance in both periods of non-watering treatment and re-watering treatment. The photosynthetic and transpiration rates recovered to less than 67% and 49% of the previous levels, respectively. At prolonged suspension of water supply (41-46 days after emergence), a positive correlation was found between the root respiratory rate (25°C) and root nitrogen content. We also recognized that the rate of photosynthesis was significantly correlated with root respiration rate under water stress condition.View full abstractDownload PDF (888K) -
Chung Yeol LEE, Yukindo TSUNO, Junichi NAKANO, Takeshi YAMAGUCHI1994 Volume 63 Issue 2 Pages 223-229
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe influence of non-watering and re-watering treatment to leaf wilting, photosynthesis, root respiration and bleeding in three cultivars (cv. Hwangkeumkong, Danyeobkong and Enrei) were investigated under glasshouse conditions in 1991 and 1992. Leaf wilting was first observed at the lower leaves of the main stem by suspending the water supply then later observed at the upper leaves. Conversely, the recovery from leaf wilting was started from the upper leaves to the lower leaves during the initial 3 hours after re-watering. In the process of soil drying, dead-leaf was observed successively from the lowest to the top leaf on main stem corresponding to soil moisture ranged pF 3.5-4.2. Recovering speed of the photosynthetic rate by re-watering seemed to be owned the both : high rate of root respiration and low ratio of leaf area/root weight. The bleeding from basal stem of each cultivar was constant rate for 2 hours after cutting the stem. It was also confirmed that the bleeding rate was significantly correlated with root respiration.View full abstractDownload PDF (798K) -
Katsuya MATSUBA1994 Volume 63 Issue 2 Pages 230-239
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIt has already shown that the main shoots of two different growth types coexist even in a precisely cultured plot. These types are : (i) N type with n leaves, (ii) N-1 type with n-1 leaves ; these types may be identified by the pattern of the length of leaves and elongated internodes, that successively develop on the main stem. In this paper, I present a comparative analysis of the growth types of tillers and their mother shoots. 1) When the number of leaves on tiller (including propyll, expressed as NLT) is equal to that of leaves in the nodes above the mother node which subtend the tiller in question (expressed as NLM), the growth type of the tiller is identical to the mother shoot. There are generally two patterns in this case : both tiller and its mother shoot represent N-1 type or N-2 type. 2) When NLT is one less than NLM, the mother shoot represents N-1 type and the tiller represents N-2 type. However ; the lower primary tillers represent N-1 type on the main shoot of N type. 3) On the main shoot of N type, the upper primary tillers represent N-2 type. 4) It is considered that the growth types, as in case 1), are fundamental ones. The growth patterns in case 1), namely mother shoot replica-tiller growth pattern shall be designated as "replicative tiller-growth".View full abstractDownload PDF (1114K) -
Kunio OKANO, Kiyoshi MATSUO1994 Volume 63 Issue 2 Pages 240-246
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSWinter-depression of photosynthesis in overwintering leaves of tea (Camellia sinensis (L.) O. Kuntze) plants was investigated with special reference to cultivar and leaf age. Photosynthetic activity of the leaves was measured with an oxygen electrode. In cold-resistant cultivars 'Yamatomidori' and 'Yabukita', depression of leaf photosynthesis in winter was relatively slight and recovered of the activity in early spring progressed favorably. Conversely, winter-depression of photosynthesis was severe in the cold-sensitive cultivar 'Inzatsu-131', and the recovery in spring was slight. Less cold-sensitive cultivar 'Benihikari' showed the intermediate response to low temperature between these two groups. Thus, there was a close relationship between the degree of depression of photosynthesis during winter and the extent of cold-resistance among the four cultivars examined. As the late-sprouting immature leaves showed marked depression of photosynthesis in winter, photosynthetic activity during winter was compared among leaves with different leaf ages. Maximum activity before the winter cold was highest in the fourth crop leaves which were most recently matured, followed by the third and the second crop leaves. Under winter cold, however, photosynthetic activities were equally depressed by 40% in leaves of all ages, indicating that the depression of photosynthesis was not affected by the leaf age. These results suggest that fully mature tea leaves with different ages would have same susceptibility to low temperature stress.View full abstractDownload PDF (912K) -
Akihiro SASAKI, Masaru OHTSUKA, Tsuneo KATO, Akira KAMINAGA1994 Volume 63 Issue 2 Pages 247-253
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTwo-rowed low-protein barley Daikei HC-15, which is related to low-protein cultivar Karl, was studied to determine the changes in the percentage of nitrogen in the grain, leaf and stem during ripening period, and the grain protein fraction at maturity. As compared with commercial variety Mikamo Golden, Daikei HC-15 accumulated dry matter equally but less nitrogen in grains during the middle phase of the ripening period (3-5 weeks after heading). There was 0.5% difference in the grain nitrogen percentage between two genotypes at 5 weeks after heading, but in the last phase of the ripening period (5-7 weeks after heading), the two genotypes similarly accumulated much nitrogen in the grains. In contrast with these genotypes, Karl accumulated less nitrogen during the last phase. At maturity, the Daikei HC-15 grain nitrogen percentage was 0.37% lower than Mikamo Golden and 0.17% higher than Karl. During the middle phase of the ripening period, the nitrogen percentage of laminae decreased less in Daikei HC-15 than in Mikamo Golden, but during the last phase, it decreased considerably in Daikei HC-15. In Karl, the decrease in the nitrogen percentage of the laminae was the smallest throughout the ripening period. In the protein fraction, Karl showed a markedly lower concentration of hordein than Mikamo Golden. Though Daikei HC-15 also showed a significantly lower hordein concentration than Mikamo Golden, it had a greater proportion of hordein than Karl. It has previously been reported that hordein accumulates in grains during the later stage of the ripening period. It was concluded that the difference in hordein concentration between Daikei HC-15 and Karl was caused by the difference in grain nitrogen accumulation during the last phase of the ripening period.View full abstractDownload PDF (769K) -
Kuniyuki SAITO, Ryuzi INAMURA, Kuni ISHIHARA1994 Volume 63 Issue 2 Pages 254-260
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSWe previously reported a method for measuring trifoliolate compound leaf movement in the soybean plant. Leaflet movement was investigated by measuring the area of triangle described by the three leaflet tips (ΔT), the distance between left and right leaflet tips, and the terminal leaflet inclination angle. Diurnal changes in trifoliolate compound leaf movement were examined with reference to leaf position on the stem, growth stages, weather conditions and soil water deficit. Trifoliolate leaf in the upper layer of the canopy, inclined to the upward in the morning, and ΔT decreased remarkably. Leaflets in the lower layer of the canopy, however, inclined to the downward all day, so ΔT did not change greatly. In clear weather, leaflets moved actively, a great decrease in ΔT was observed in midday compared with cloudy weather, due to higher solar radiation. Hysteresis was found in the relation between solar radiation and ΔT, i.e. leaflet movement was more active in the morning than in the afternoon. Leaflet movement wad most active from the late flowering to pod growth stage, and became less active with increasing plant age. Terminal leaflets were observed to become erect or inverse in response to soil water deficit, when leaf xylem water potential decreased to nearly -1.5 MPa. These results suggest that leaflet movement is mainly affected by the intensity of solar radiation, but its diurnal changes are different with leaf position, growth stage, weather and soil water condition.View full abstractDownload PDF (766K) -
Teruhisa UMEZAKI1994 Volume 63 Issue 2 Pages 261-264
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIt is well known that there are a few turning points of leaf emergence rate on the main stem in soybean plants (Glycine max Merr.). On the other hand, it has also been reported that the leaf emergence rate was mainly controlled by temperature. On late-maturing cultivars grown in the Kyushu area, soybean plant growth is regular under high temperature, so there may be no turning points of leaf emergence rate. The present research was conducted to confirm this hypothesis, using five late-maturing cultivars from 1984 to 1991. The following results were obtained. Leaf emergence patterns in these eight years and five cultivars were nearly the same. It was found that the leaves on the main stem emerged regularly during the whole period of leaf emergence (from cotyledon emergence to terminal leaf emergence). By comparing the effects of different sowing dates and temperature conditions, it was found that leaf emergence patterns were the same in all treatments, whereas the leaf emergence rate by an earlier sowing (sown on June 18 th) or a lower temperature (20°C) treatment was slower than those of the other treatments. These results showed that there were no turning points of leaf emergence rate in late-maturing cultivars. It appears that the relationship between days after sowing and leaf order could be expressed linearly. It might simplify the growth model on synchronism in soybeans.View full abstractDownload PDF (510K) -
Gen-ichi HIRAI, Hiroyoshi CHUJO, Osamu TANAKA, Toshikatsu OKUMURA, Shi ...1994 Volume 63 Issue 2 Pages 265-270
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSRice seedlings were grown on a medium containing polyethylene glycol (PEG), which lowers the osmotic potential of the medium under high humidity, or on a medium containing no PEG under a low humidity, and their growth and partition of dry matter were compared with those of plants grown on a medium without PEG under high humidity. The growth of plant tops showed a similar tendency under both water stresses induced by a low osmotic potential and low humidity : leaf blade length, leaf area and dry weight decreased and specific leaf weight increased. In the growth of plant roots, the water stress induced by a low osmotic potential increased the total length, diameter of main roots and dry weight, while the water stress induced by a low humidity decreased these parameters. The partition of dry matter also changed in response to water stress conditions. The stress caused by low humidity increased the partition of dry matter to the top. However, the stress caused by a low osmotic potential of the medium increased the partition to the root, resulting in the decrease of the top-root ratio. These results show that the effect of water stress induced by a low osmotic potential in a medium containing PEG on the growth of rice seedlings considerably differs from that of water stress induced by low humidity.View full abstractDownload PDF (687K) -
Yuji MATSUE, Koji ODAHARA, Michikazu HIRAMATSU1994 Volume 63 Issue 2 Pages 271-277
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe protein and amylose content of milled rice grains collected from the top and base rachis branches at different positions on the panicle were measured. The palatability of the grains on primary and secondary rachis branches were also investigated. Grains on upper rachis branches had a lower protein content than those on lower rachis branches with a gradual change from the base to the top of both primary and secondary rachis branches. Grains on primary rachis branches also had lower protein content than those on secondary rachis branches at any position within the panicle. Conversely, amylose content on upper rachis branches was higher than that on lower rachis branches, and that on primary rachis branches was higher than that on secondary rachis branches. Protein content and amylose content varied widely within the panicle with 1.2% and 3.3%, respectively, range at maximum. Grain weight was negatively correlated with protein content and positively correlated with amylose content. Grains which originated from early flowering spikelets generally had low protein content and high amylose content. The palatability of the grains on primary rachis branches was superior to grains on secondary rachis branches, both in Koshihikari and Nipponbare. It was concluded that the variations in protein content and amylose content, and differences in palatability within a rice panicle were caused by the differences in the extent of grain filling, which was closely related to the flowering order of spikelets. This leads us to suppose the varieties with high and stable palatability in any growth environment could be raised from genetic resources which have more grains on primary rachis branches in the ear or on the secondry rachis branches in the upper position of the ear.View full abstractDownload PDF (718K) -
Kana NAKAHISA, Eiji TSUZUKI, Hiroyuki TERAO, Seiji KOSEMURA1994 Volume 63 Issue 2 Pages 278-284
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSAllelopathic substances in alfalfa plants (Medicago sativa L.) were purified from methanol extracts of alfalfa shoots. The methanol extracts were fractionated into an acidic fraction, and the sample was divided into 10 fractions by thinlayer chromatography (TLC). Growth of radish seedlings was inhibited by the substances obtained from Rf values of 0.5∼0.6 and 0.6∼0.7. These fractions were eluted with distilled water, and the eluates were analyzed by high-performance liquid chromatography (HPLC). Six peaks were detected on the chromatogram. Growth of radish seedlings was inhibited on three peaks. Of these peaks, two were identified using HPLC, a mass-spectrometer, IR, and 1NMR as follows : peak b, ferulic acid and peak f, salicylic acid. The growth of alfalfa and radish seedlings was inhibited at lower concentrations of these substances.View full abstractDownload PDF (636K) -
Hisashi KATO, Eiji SHIOTA1994 Volume 63 Issue 2 Pages 285-288
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo clarify the role of endogenous inhibitors of growth in dwarf and tall bean plants, a search for specific inhibitors of growth was undertaken using the acidic substances of acetone extracts from the hypocotyls of dwarf (cv. Morocco) and tall (cv. Kentucky Wonder) bean seedlings (Phaseolus vulgaris L.). Two inhibitors were isolated from both cultivars and named A-1 and A-2, respectively, based on the order of their elution from a silica-gel column. Variations in the activity of the inhibitors in hypocotyls of both cultivars after the onset of red-light irradiation were determined using a bean bioassay, and the results were compared with those of red light-induced inhibition of growth. The difference in the activity of A-1 and A-2 between the two cultivars was not great, and the changes with time in activity of A-1 and A-2 in hypocotyls of each cultivar did not reflect the light-induced inhibition of growth of hypocotyls of the same cultivar. These results suggest that acidic inhibitors, A-1 and A-2, are not involved in light-induced growth inhibition of the bean.View full abstractDownload PDF (529K) -
Lawrence Misa ABOAGYE, Akihiro ISODA, Hiroshi NOJIMA, Yasuo TAKASAKI, ...1994 Volume 63 Issue 2 Pages 289-297
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSVarietal differences in growth, dry matter production and solar radiation interception among 11 peanut cultivars were studied under field conditions for 2 years to elucidate the salient features augmenting productivity. The cultivars used were Chiba 43, Chibahandachi (Virginia types) ; Kintoki, Hakuyu 7-3, (Spanish types) ; Valencia, Hotakuchuryu, Tarapoto (Valencia types) ; and Nakateyutaka, Kanto 56, Tachimasari and 334A (crossing types derived from crossing Spanish with Virginia types). The crossing types had early onset of pod formation with greater dry matter in the pods. Valencia, Chiba 43 and Tarapoto had late pod formation with most assimilates in their vegetative parts. In the initial growth period, the crop growth rate (CGR) was dependent on the leaf area index (LAI) ; in the late growth period the CGR was dependent on the net assimilation rate (NAR) and the pod growth rate (PGR) depended on the NAR. There was a highly negative correlation between the NAR and the LAI indicating the existence of severe mutual shading. The optimum LAIs ranged from 3.2 to 4.0. Intercepted radiation per unit LAI was higher in Tachimasari and Kanto 56 and lower in Chiba 43. From these results, the early development of larger leaf areas as in the Virginia types ; early sink development, higher percentage of pod dry weight and interception efficiency in the crossing types ensured higher dry matter production.View full abstractDownload PDF (878K) -
Akihiro ISODA, Takao YOSHIMURA, Toshio ISHIKAWA, Hiroshi NOJIMA, Yasuo ...1994 Volume 63 Issue 2 Pages 298-304
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDetailed features of solar radiation distribution and penetration in soybean communities were examined using integrated solarimeter films for 2 days. Five cultivars (c.v. Tsurukogane, Nanbushirome, Enrei, Tachinagaha and Miyagishirome) were grown under field conditions and in pots for comparison. All of these cultivars except Tsurukogane had leaf concentration in the upper layers of the canopy. Tsurukogane and Nanbushirome had smaller leaflet areas in the upper of the canopy, whereas Enrei, Tachinagaha and Miyagishirome had larger leaflets in the upper layer. The higher the intercepted radiation and the smaller the leaflet size, the larger the difference in intercepted radiation between the edge and the center of the leaflet. The mean radiation penetrating leaflet was around 1 MJ m-2 2 days-1 and penetrated radiation against intercepted radiation on the leaf adaxial surface ranged from 13 to 27%. The differences were larger in the cultivars with larger leaflets and smaller in the cultivars with smaller leaflets. A canopy structure with smaller leaflets and smaller leaf area in the upper layer of the canopy may be advantageous for radiation transmission and distribution.View full abstractDownload PDF (717K) -
Makie KOKUBUN, Shinji SHIMADA1994 Volume 63 Issue 2 Pages 305-312
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSApparent photosynthetic rates (AP) of plant leaves often decline in midday even when solar radiation is adequate. The objective of this study was to determine whether this phenomenon is responsible for the cultivar differences in growth and yield of soybean (Glycine max (L.) Merr.). In a 3 year experiment using nine (1990) or ten (1991, 1992) cultivars, the association of the following parameters with growth and yield of cultivars was examined : APam (AP measured about 10h), APpm (AP measured about 14h), daily mean AP ([APam+APpm]/2) or APdec (APpm/APam, %) during flowering to early pod-filling. Cultivar differences in these parameters were observed and the ranking among cultivars tended to be consistent, although the significance varied with the day or year. None of the parameters were consistently correlated with growth rates or yields across cultivars. For each cultivar, however, yearly variation in yield closely corresponded to variation in APdec. The results suggest that less decline of midday photosynthesis contributes to yield stability in soybean cultivars.View full abstractDownload PDF (875K) -
Tadashi TAKAHASHI, Naoyuki TSUCHIHASHI, Toshihiro TAKAKU, Kimio NAKASE ...1994 Volume 63 Issue 2 Pages 313-319
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo determine the effects of assimilate shortage to grain filling mechanisms in spring wheat canopy (cv. Haruyutaka), we examined the accumulation and translocation of dry matter in grain, along with water soluble sugar content (WSC) and structural material in culm under shading conditions during grain filling phases. Shading treatments were conducted using 95% shading cloth from -2 to 7 days after anthesis (DAA) (initial shading), 7 to 14 DAA (early shading) and 14 to 21 DAA (late shading). These shadings prevented the wheat canopy from producing any assimilate. However rates of increase in grain dry weights for all the shadings were 50-60% of the control (no shading), while the WSC in culm was used for the grain growth. During the initial grain filling phase, the WSC in culm for the initial shading decreased (-15 mg pl-1day-1), whereas that for the control increased (20 mg pl-1day-1). The grain dry weight showed a high rate of increase (11 mg pl-1day-1) for the initial shading, being about 50% of the control (19 mg pl-1day-1). During the early phase, the WSC in culm for the early shading decreased (-15 mg pl-1day-1), although that for the control increased (12 mg pl-1day-1). The rate of grain weight increase for the early shading (24 mg pl-1dayl-1). During the late phase, the WSC in culm for the late shading decreased (-33 mg pl-1day-1) five times as much as the control (-7 mg pl-1day-1). The rate of grain weight increase for the late shading (34 mg pl-1day-1) was 60% of that for the control (55 mg pl-1day-1). Although the culm lengths at harvest were no different between the initial shading and the control, the dry weight of culm structural material for the initial shading was lower than that for the control. The difference between the cases in which the partitioning rate to grain did or did not increase is discussed herein.View full abstractDownload PDF (772K) -
Hitoshi NAITO, Mikio TSUCHIYA, Seiichi KUMANO1994 Volume 63 Issue 2 Pages 320-325
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn order to clarify the relationships of sodium exclusion to transpiration and root-respiration rates in 100 mmol 1-1 NaCl-treated rice plant, transpiration stream concentration factor of Na+ (TSCFNa+) was measured at different oxygen concentrations, pH and temperatures of root medium under different humidity conditions. It was confirmed that TSCFNa+ decreased hyperbolically with the increase of the transpiration rate, namely, sodium-exclusion efficiency increased with transpiration rate. However, TSCFNa+ and top-Na content were not clearly related to root-respiration. Neither was a difference found in the relationship between TSCFNa+ and transpiration rate measured at 20°C and 32°C, and at pH 4.0 and 7.0 of culture solution. These results imply that root respiration is not directly related to the sodium exclusion mechanism. It was shown that the sodium-exclusion mechanism also works for chlorine because of a positive correlation between TSCFNa+ and TSCFCl-. These results suggest that ion exclusion in rice plants may be based on a non-metabolic process and it is important to maintain a high transpiration rate for exclusion and growth under saline conditions.View full abstractDownload PDF (662K) -
Mikio TSUCHIYA, Miyuki MIYAKE, Hitoshi NAITO1994 Volume 63 Issue 2 Pages 326-332
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe mechanism and varietal difference of Na+ exclusion in rice roots exposed to NaCl stress was studied in relation to reverse osmosis as the principle of ion exclusion. Exudates from the cut-surface of a root exposed to 20 mmoll-1 NaCl solution with hydrostatic pressure of 294 and 686 kPa were sampled. Na+ concentration of the exudate from the whole cut-surface was at most 60% lower than that of the root medium. However, Na+ concentration of the exudate from the cut-surface of the stele was about 85% lower than that of the root medium. These results indicated that Na+ exclusion might occur at the exodermis and endodermis. The decrease of Na+ concentration of the exudate with hydrostatic pressure indicated that Na+ exclusion might be a non-metabolic process which could be driven by negative pressure induced by transpiration, and seemed to be based on reverse osmosis. From the results of X-ray micro-analysis, Na+ movement across the endodermis was less in IR28 than in Kala-Rata 1-24 (KR1). However, transpiration rate under saline conditions was higher in KR1, and it was considered to be supported by morphological characteristics of KR1 root, i.e. more roots per plant, longer and thicker roots, high ratio of stele area to the area of cross-section and more vessels per cross-section. It is concluded that the varietal difference in salt tolerance between KR1 and IR28 is related to the difference in the ability to maintain the negative pressure for ion exclusion by keeping the transpiration rate under saline conditions.View full abstractDownload PDF (728K) -
Yasunori KODA, Kiyoshi TAKAHASHI, Yoshio KIKUTA1994 Volume 63 Issue 2 Pages 333-338
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSUsing a bioassay for tuber-inducing activity, which was carried out with cultures of single-node segments of potato stems in vitro, jasmonic acid (JA) was isolated from the leaves of Jerusalem artichoke (Helianthus tuberosus L.), and identified by both HPLC and mass spectrometry. The level of endogenous JA in the leaves of young plants was very high (4.0×10-6gt; mol·kg<-1) but decreased sharply with the growth of the plants. By contrast, the level of water-soluble derivatives of JA increased with the growth of plants and reached a maximum near the time at which tuberization was initiated. The effect of exogenous JA on the tuberization of Jerusalem artichoke plants was examined in vitro, and JA was found to have strong tuber-inducing activity. These results suggest that tuberization of Jerusalem artichoke plants is controlled by JA and related compounds.View full abstractDownload PDF (675K) -
Michihiro WADA, Luiz J.C.B. CARVALHO, Gustavo C. RODRIGUES, Ryuichi IS ...1994 Volume 63 Issue 2 Pages 339-344
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSCultivar differences in leaf photosynthesis (LPS) and grain yield of wheat [Triticum aestivum L.] were examined under irrigated and non irrigated conditions in Cerrados, a semi-arid region in Brazil. Twelve Brazilian, five Mexican and two Japanese cultivars were used in this project. The plants were grown under low planting density to elucidate the relationship between LPS and the potential yield of an individual plant. Brazilian cultivars ranked high in LPS, followed by Mexican and Japanese cultivars under non-irrigated conditions, although there were practically no differences in LPS among these three groups of cultivars in irrigated conditions. The LPS showed a significant positive correlation with grain yield (r=0.63) and dry matter yield (r=0.73) per plant in non-irrigated conditions. However, LPS showed neither correlation with grain yield nor dry matter yield per plant in irrigated conditions. The present results suggests that PLS could be a breeding criteria to increase the yield per plant under soil water deficit conditions.View full abstractDownload PDF (608K) -
Katsu IMAI, Kiyoshi SHIMABE, Kenichi TANAKA, Takeo KAWANA1994 Volume 63 Issue 2 Pages 345-351
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSEdible canna is a highly productive crop in temperate to tropical regions. To clarify ontogenetic changes of structure which contribute to its high yield capacity, edible canna was grown from late April to mid-November in 1-m rows with spacing of 0.5 m between plants in the row at the experimental field of the University of Tsukuba. During the growth period, light transmittance into the canopy was measured and the aerial allocatons of dry weight and leaf area were determined by stratified clipping. The plants reached maximum height by mid-September, at which time the leaf area index (LAI) exceeded 10 and reached a maximun of 11.2 before declining as the plant matured. The light extinction coefficient (K) changed from 1.34 (typical of broad-leaf plants) in early growth to 0.4-0.5 (typical of grasses) in the latter growth stages. This indicated that in the early growth, this crop developed planophyll leaves which maximized light interception under low LAI but with growth, the upper leaves became more upright, which enabled light to penetrate deep into the tall canopy. The initiation of shoots and the azimuth angles of leaves as the plants grew appeared to be such that light interception by the crop canopy was maximized.View full abstractDownload PDF (708K) -
Katsumi SUZUKI, Hiroshi MIYAKE, Takeshi TANIGUCHI, Eizo MAEDA1994 Volume 63 Issue 2 Pages 352-361
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTransmission electron microscopy revealed that a shoot apical meristem showed the first sign of organization at 3.5 DAA (days after anthesis), soon after an indentation by an incipient coleoptile on the upper ventral surface of the rice embryo. The demarcation of the meristem was terminated by a small depression on the lower surface at 4 DAA and then by periclinal divisions at 4.5 DAA. After that, the tip of the coleoptile gradually covered the apical meristem, making a notch of great depth, and the edges of the coleoptile rose along the periphery of the meristem, As a result, these events were conducive to the bilateral symmetry of the embryo. At 5 DAA, the coleoptile was overarching the apical meristem. At 8 DAA, the meristem was completely enveloped by the coleoptile and the first and second leaves, resulting in the formation of a plumule. The ventral organization of the shoot apical meristem is discussed in relation to somatic embryogenesis of rice as it is currently mentioned.View full abstractDownload PDF (2619K) -
Nisyawati, Hiroshi MIYAKE, Takeshi TANIGUCHI1994 Volume 63 Issue 2 Pages 362-367
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSHigh yields of viable protoplasts were obtained from leaf mesophyll of 10-day-old peanut seedlings (Arachis hypogaea L. var. Lokal). An enzyme solution containing 1% Cellulase YC, 2% Meicelase P-1, 0.15% Pectolyase Y-23 and 0.5% Macerozyme R-10 was found to be the best for protoplast isolation. The protoplasts were then cultured in liquid or in agarose-gel modified KM8P medium. Cultured protoplasts divided 2 days after culture. In solidified media, protoplasts divided continually and formed many colonies 1 month after culture. The best viability and colony formation was obtained in a culture medium solidified with 1.2% agarose.View full abstractDownload PDF (1268K) -
Kazutoshi YAMAGISHI, Koh NAGATANI, Takako TUKASE, Cristina MITSUMORI, ...1994 Volume 63 Issue 2 Pages 368-369
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (358K) -
[in Japanese]1994 Volume 63 Issue 2 Pages 370-376
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (764K) -
[in Japanese]1994 Volume 63 Issue 2 Pages 377-382
Published: June 05, 1994
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (858K)
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