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Volume 60, Issue 1
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Toshio MABUCHI1991 Volume 60 Issue 1 Pages 1-7
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe effects of different sowing and harvesting time on the seed dormancy-awakening were studied, using two-rowed barley, cv. Asahi 19, Seijyou 17 and Satsukinijyou. The experiment of sowing time was undertaken on early, optimum and late ones in Tokushima prefecture. And the experiment of harvesting time was done at early, maturing and late stages with crops of optimum sowing time also in above-mentioned area. It was cleared that the dormancy-awakening of seeds was more obtainable with the case of optimum and late sowing compared With early one. On the other hand, it was clearly observed that the dormancy-awakening of seeds harvested at early stage delayed compared with both samples of maturing and late stages. Characteristic of seed dormancy-awakening of this crop was closely related with the thickness of seeds obtained throughout two experiments; it was earliest in seed of thickness over 2.8 mm, and delayed in the order of 2.5-2.6 and 2.2-2.4 mm of thickness. However, the relationships between the dormancy-awakening and thickness in seeds which were threshed soon after early harvesting showed somewhat smaller than in those threshed after air-drying. The results may be suggested that sowing and harvesting time may be participated strongly in seed dormancy-awakening on two-rowed barley.View full abstractDownload PDF (654K) -
Kenji TERAI, Takeshi HORIE1991 Volume 60 Issue 1 Pages 8-14
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo clarify the varietal characteristics in an native variety of white azuki bean ( Vigna angularis), of endemic name "Shiro azuki", ten strains collected from various parts of Akita prefecture were cultivated, and some morphological characteristics and yield components of those strains were investigated. The results are summarized as follows : Since ten strains showed large differences in the characters of weight of 100 grains per plant, those strains were grouped into three types (Grain-Size type, Medium type and Grain-Number type) on the basis of Grain-Number·100 Grain Weight ratio proposed by Matsumoto et al. in 1987. Grain-Number types exhibited relatively large number of braches compared to the Grain-Size types. Among the strains, the periods of vegetative growth became longer in strains of Grain-Number types than in those of Grain-Size types, while with regard to the period of reproductive growth there was not such variations. The frequence of occurrence of delayed pod maturation plants was significantly higher in Grain-Number types than in Grain-Size types. The delay of such ripening in Grain-Number types brought about a great disadvantage in seed-setting. Phenotypic correlations between sunshine hours (the mean values collected from May to Nov. during the past 16 years in the native place of each strain) and number of branches and grains per plants were highly positive respectively. On the other hand, there was a negative association between accumulated temperature (the mean values collected from May to Nov. during the past 27 years) and weight of 100 grains.View full abstractDownload PDF (789K) -
Teruhisa UMEZAKI, Itaru SHIMANO, Shigeo MATSUMOTO1991 Volume 60 Issue 1 Pages 15-19
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn order to obtain fundamental information on the chemical control of plant structure in soybean (Glycine Max Merr. cv. Fukuyutaka), the effects of gibberellic acid (GA3) on the internode elongation were examined. GA3 was sprayed with different concentrations on the pot-grown plants at the different growth stages. The internode length was found to be increased by the application of (GA3 at 0.1 ppm and more concentration. The higher the GA3 concentration from 0.1 ppm to 1000 ppm was, the longer the internode elongation was (Table 1, Fig. 1) . The reduction in the diameter was observed in the internodes which were elongated by the application of the GA3 (Fig. 1) . And further, the GA3 application also promoted elongation of petioles in the similar manner (Table 1) . The promotion of internode elongation induced by the GA3 was limited for the internodes that elongated after the GA3 application and was most effective when it was given at the floral differentiation stage (Tables 2, 3, 4, Fig. 2). The GA3 application at the floral differentiation stage increased the number of nodes on the main stem (Table 2). The GA3 application increased vegetative growth, whereas seed weight per plant was not increased. From the results it appears that the GA3 treatment at optimal stage can control the plant height and plant type by increasing the length of internodes and the number of nodes on the stem.View full abstractDownload PDF (588K) -
Teruhisa UMEZAKI, Itaru SHIMANO, Shigeo MATSUMOTO1991 Volume 60 Issue 1 Pages 20-24
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn order to obtain the fundamental information on chemical control of plant structure in soybean ( Glycine max Merr. cv. Fukuyutaka), the effects of growth regulators on the internode elongation were examined. The chemicals used were the gibberellin biosynthesis inhibitors of AMO 16 18, Ancymidol, Uniconazole, Pa-clobutrazol and CCC. They were sprayed with different concentration solutions on the pot-grown plants at the different growth stages. When AMO 16 18 was sprayed at different growth stages, plant height was reduced by the application at the floral differentiation and the beginning of- flowering stages, and the former was found to be more effective (Table 1, Fig. 1 ) . Gibberellin biosynthesis inhibitor applications at floral differentiation stage inhibited the internode elongation, and Paclobutrazol and Uniconazole were most effective followed by AMO 1618and Ancymidol. However, the CCC hardly effected the vegetative growth (Table 2). When the Paclobutrazol, Uniconazole and AMO 1618 were applied, the inhibition of elongation was observed on the internodes that reached at mid-phase of elongation after treatment, whereas the inhibition was found to occur on the upper internodes when Ancymidol was used (Fig. 2) . On the other hand, the diameter of internodes was also reduced by the gibberellin biosynthesis inhibitor applications. These effects were observed on the internodes, which were lowered by 3 or 4 internodes from that reduced in length (Fig. 2). Though these growth regulators showed some disadvantages in plant growth, such as reduction of vegetative growth and pod elongation, it may become an useful tool to control internode elongation by the development of more useful chemicals applicable to soybean culture.View full abstractDownload PDF (646K) -
Toshio MABUCHI1991 Volume 60 Issue 1 Pages 25-28
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDifference of ripening and dormancy-awakening was investigated among seeds attached in different rachis positions of the ears of two-rowed barley, using cv. Satsukinijyou which has deep dormant nature as material. Samples were threshed soon after harvesting ears at yellow-, maturing-, and dead-ripe stage, respectively. After the yellow-ripe stage the ratio of seeds of thickness over 2.8 mm was high in the middle part of the ear, especially in 3/4 th rachis position from upper one. The ratio of seeds of thickness over 2.5 mm, however, was found similarly high in both upper and lower rachis position of the ear. At maturing stage the ratio of water content in seeds remarkably less in those of upper position. It may be concluded that thc fully developed seeds seemed to awake earlier from dormancy at any sampling stages after the yellow-ripe stage.View full abstractDownload PDF (528K) -
Koichi HIRAI, Seiichi FUJII, Kazuo HONJO1991 Volume 60 Issue 1 Pages 29-35
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe effect of brassinolide [ (2-alpha, 3-alpha, 22R, 23R) -tetrahydroxy-24S-methyl-B-homo-7-oxa-5-alpha-cholestan-6-one] on the ripening of rice plants under the low temperature condition was investigated. In 1985, the rice plants were transfered to a growth chamber and kept under natural day-light. The low temperature condition was set up at 22/ 17°C (day/night) for 15 days which was at early stage of ripening after heading. The foliar application with brassinolide of 1 ppm and O.O1 ppm concentration at spikelet differentiation stage, meiosis stage and heading time gave 61%, 77% and 75% ratios, on an average, of ripened grains respectively, while in control it was 57.5%. In each of the brassinolide treatments, the increasing pace of the grain weight from the early stage of the ripening till the middle stage became faster than that in the untreated control. In 1987 and 1988, the effect of brassinolide on the ripening of rice plants, set up by late seeding and late transplanting Nissan Chemical Industries, LTD., was investigated under the condition of the low temperature in natural paddy field. O.O1 ppm brassinolide was sprayed by each 2 times at the combinations of spikelet differentiation stage and meiosis stage, meiosis stage and heading time, and spikelet differentiation stage and heading time. The speed of ripening was promoted and the percentage of ripened grains was also increased. From these results, it was observed that brassinolide increased ripening under the low temperature condition of this experiment in the ripening period.View full abstractDownload PDF (697K) -
Bao-sen XIA, Kiichi HANADA, Fumio KIKUCHI1991 Volume 60 Issue 1 Pages 36-41
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTwo experiments were carried out to analyze the expression of some agronomic characteristics by semidwarfing gene sd-1, which has played an important role in improvement of rice productivity per area. A Japonica variety Norin 29, its semidwarf near-isogenic line SC-TN 1 and an Indica variety Taichung Native l were used as materials. SC-TN 1 was obtained by transfering the semidwarfing gene sd- 1 from Taichung Native 1 into a Japonica tall variety Norin 29. The results were as follows : (1) The culm length of Norin 29 was reduced by introducing semidwarfing gene sd-1. The elongation of lower internodes was promoted by high nitrogen level, depending on the variety : scarecely in the two semidwarf varieties, but substantially in Norin 29. The high lodging resistance of the semidwarf varieties seemed to be caused by the low response of lower internodes to nitrogen. (2) Semidwarfing of some agronomic characteristics. Bao-sen XIA., warfing gene sd-1 was found to have small negative pleiotropic effects for panicle length and l000 kernel weight. The negative effects may be recovered by genetic improvement. (3) The number of tillers and panicles of the two semidwarf varieties were larger than those of Norin 29 under high nitrogen level. The sd-1 gene was found to have positive pleiotropic effect on tillering ability.View full abstractDownload PDF (734K) -
Fumitake KUBOTA, Noriyuki TANAKA, Susumu ARIMA, Sigeo MAKIYAMA1991 Volume 60 Issue 1 Pages 42-46
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSRockwool pot water culture system was devised as an experimental techunique to observe and measure the growth responses of plants to various treatments imposed on the roots. This system is composed of the steel pot in which rockwool block is placed and the culture solution container. The pot can be readily attached to and detached from the solution container, and it is easy to move plants grown in the pot. In this experiment, corn plant cultivation was tested using the Kimura's A solution. The leaf began to etiolate about ten days after the germination. However, by keeping Mn concetration in the solution at 50 mg/l and pH at 5.5, the rapid recovery was found in the leaf color and photosynthetic rate, thereafter plants grew normally to the maturation stage. Abnormality of plant grown caused by O2 deficits in the solution was not found because O2 was adequately supplied to the roots through the aerial space made in the rockwool pot. The rockwool pot water culture system can be readily applied to the cultivation of many other crops and become a useful and covenient expermental technique to examine the functional interrelationship between root and shoot growth under various expermental conditions.View full abstractDownload PDF (609K) -
Daiyu ITO1991 Volume 60 Issue 1 Pages 47-56
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSSprouting dates of potted mulberry trees were examined by applying high temperature treatment at various times of the year. Multiple regression analysis was also carried out using mulberry sprouting dates collected over 21 areas of Japan as independent variable, while local temperature every ten days as explanation variable. High temperature treatment in November, December and January corresponded with a slight delay in sprouting, while treatment in February and March corresponded with slight to extreme promotion of sprouting. Additionally, the partial regression coefficient which was positive through December turned negative in January, and then continuously declined through March. So, thermosensitivity through January was thought to be different from that after February, and this might be due to an insufficient dormancy awakening. Next, time-dependent models with five and seven parameters were constructed based on the above information. To determine the best model and to select optimum values for parameters, each model was examined by calculating the sprouting dates over Japan under various temporal values for parameters. The best model obtained here consisted of three reactions : one for dormancy awakening and two for sprouting. Three reactions proceed every day and sprouting occurs when the product of the last reaction accumulates to a threshold point. Temperature dependency of these reactions was determined as being similar to Arrhenius'equation. Making allowance of ±3 days, 87 to 92% of estimated dates accorded with actual sprouting dates under the determined optimum parameters.View full abstractDownload PDF (996K) -
Jing-WANG Wei, Katsuyuki KATAYAMA, Tomoshiro TAKEDA1991 Volume 60 Issue 1 Pages 57-64
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSAn applicability of nitrogen-deep placement culture (NDPC) in warmer area suffered from poor number of spikelets and low sink-source ratio, and responsibilities of NDPC for not only japonica rice cultivars (Tsukushibare, Hiyokumochi), but also japonica-indica rice hybrids (Milyang 23, Suweon 258) and indica rice cultivar (IR 661) were studied. Results were as follows : 1) The ratio of ear culm length of rice cultivars was not significant between NDPC and ordinary culture (OC) . 2) All cultivars on NDPC enlarged leaf area index due to increase of tiller numbers and leaf elongation. 3) Dry matter production during 30 days after heading of japonica-indica rice hybrids increased, but that of the others decreased on NDPC. Canopy of japonica-indica rice hybrids didn't reach rank growth. 4) All cultivars on NDPC increased spikelet numbers, but decreased ripened grains. Therefore, yield was not significant between NDPC and OC. But the yield of Japonica-indica rice hybrids increased. 5) The sink-source ratio of rice cultivars was not significant between NDPC and OC. 6) It was concluded that the rice cultivar with high fertilizer responsiveness like japonica-indica hybrid was suitable to increasing the yield on NDPC in warmer area.View full abstractDownload PDF (792K) -
Kuniyuki SAITOH, Hiroyuki SHIMODA, Kuni ISHIHARA1991 Volume 60 Issue 1 Pages 65-74
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe difference of dry matter production process among the rice cultivars was previously reported with reference to light intercepting characteristics. This study was conducted to determine if the single leaf photosynthetic characteristics, which affect the dry matter production, were different among the rice cultivars. Leaf apparent photosynthetic rate (APR), diffusive conductance, nitrogen content and chlorophyll content were monitored every ten days from the maximum tillering stage to the harvesting time in the uppermost five leaves on the main stem of two early varieties ; Akihikari (Japanese cultivar) and Nanjing 11 (Chinese cultivar, Indica), and three medium varieties ; Nipponbare, Musasikogane Japanese cultivars) and Milyang 23 (Korean cultivar, Japonica/Indica hybrid). The results obtained were as follows. The maximum APR of the uppermost two leaves in the early varieties was higher than that in the medium varieties. Maximum APR in Akihikari and Milyang 23 was higher as compared with that in Nanjing 11 and that in Nipponbare and Musasikogane, respectively. APR decreased with getting lower in position of leaf on the stem and with increasing in leaf age. Decreasing degree of APR was greater in Nanjing 11 and Milyang 23 than in Akihikari, Nipponbare and Musasikogane, respectively. APR was significantly correlated with nitrogen content (correlation coefficient, r = 0.84), chlorophyll content (r = 0.68) and diffusive conductance (r = 0.90) in the leaves of various positions on the stem and of various ages. However, there was no significant correlation between APR and chlorophyll content above 4 mg dm-2. These relationships were different among the varieties. These results suggested that the lower canopy net assimilation rate in Nanjing 11 as compared with that in Akihikari was mainly owing to the lower leaf photosynthetic rate, but photosynthetic rate hardly affected the difference of canopy dry matter production among the medium varieties.View full abstractDownload PDF (1056K) -
Hui-lian Xu, Ryuichi ISHII1991 Volume 60 Issue 1 Pages 75-81
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn order to explore the physiological basis for the difference among plant parts in photosynthetic depression by soil water dieficit, the tissue water status was examined by using an electric circuit analogue. It was found that the tissue water storage capacity per unit volume was larger in the leaf blades than in the ear, and larger in the lower leaves than in the upper ones. In reverse, the tissue water storage resistance was larger in the ear than in the leaf blades, and in the upper leaves than in the lower ones. This suggests that the water loss is easier in the lower parts of a plant than in the upper ones. Furthermore, the percentage change of stomatal resistance per unit leaf water potential decrease was larger in the lower leaves than in the upper ones, and larger in the leaf blades than in the ear, suggesting that stomata close earlier in the lower plant parts as water stress develops. These results account for the difference among plant parts in photosynthetic depression by soil water deficit.View full abstractDownload PDF (699K) -
Yosei KAKIZAKI1991 Volume 60 Issue 1 Pages 82-90
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe emergence and elongation of the tiller buds of rice plants are greatly affected by the environmental temperature, especially by the temperature around the culm-bases where the tillers differentiate. Temperature switching from low to high and vice versa was carried out and varieties used were Norin 1 and Zosan 1. The experiments were conducted in growth cabinets at 25°C (light) and 18°C (dark). The results : (1) Compared with those given no temperature treatment, tillers increased in number in low temperature treatment (15°C) . On the contrary, emergence was inhibited in the high temperature treatment (33°C). (2) In Zosan 1, the emergence of secondary tillers ceased completely, while in Norin 1, there were six secondary tillers in the high temperature treatment. (3) In the temperature switching treatments in the 8th leaf stage of the main stems, the tillers which were inhibited in growth during the supply of high temperature water emerged after switching in the former treatment, and, synchronous regularity was disturbed in this case. In the inhibited in growth after switching to high temperature. The inhibition of emergence by high temperature was more conspicuous in Zosan 1 of the heavy panicle type.View full abstractDownload PDF (899K) -
Makoto NAKATANI, Michitaka KOMEICHI1991 Volume 60 Issue 1 Pages 91-100
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSChanges in zeatin riboside (ZR), abscisic acid (ABA) and indole acetic acid (IAA) contents of roots in sweet potato (Ipomoea batatas) during their development were investigated by using two cultivars which differed in the thickening potential of tuberous roots and a related wild species, I.trifida, which formed no tuberous roots. Although ZR contents of fibrous roots did not differ among the materials, it apparently increased at the formation of tuberous roots in the cultivars. In the wild species, ZR content slightly increased later when root diameter exceeded 2mm. ZR contents of tuberous roots was a little higher in one cultivar, which had more tuberous roots but of smaller weight of tuberous roots than the other. ABA contents of fibrous roots did not differ between two cultivars and was smaller in the wild species. ABA contents of tuberous roots in the cultivars increased after the time of increase in ZR contents. In the wild species, it was almost steady. Remarkable difference in ABA contents of tuberous roots was found between two cultivars ; it was higher in the cultivar which had higher weight of tuberous roots. Regarding IAA contents of roots, no tendencies were found in the cultivars after fluctuation. From these results with the results of anatomical observations of roots, the differential roles of these plant hormones on the formation and thickening of tuberous roots was suggested.View full abstractDownload PDF (1284K) -
Genshichi WADA, Rowena C. ARAGONES, Ho ANDO1991 Volume 60 Issue 1 Pages 101-106
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSField experiments on the response of rice plants to slow release fertilizer (Meister 10, MS10) were conducted from the 1986 wet season (WS) to the 1987 WS at IRRI, with ammonium sulfate (AS) as control. IR64 and IR36892-163-1-2-2-1 were planted under two N levels and three spacings. In all experimental plots regardless of season, the amount of N in the plants increased exponentially at the early growth stage (y = abx) and linearly at the middle and late growth stages (y = a + bx), as previously reported. MS10 lengthened the exponential phase and increased parameter 'b' during the linear phase. The amount of N in the plants was higher in AS than in MS10 plots up to 5 weeks after transplanting. Comparing narrow and wide spacing, the difference in the amount of N in the plants was greater in the MS10 plots. At flowering and maturity, the amount of N in the plants was higher in the MS10 plots due to the higher percentage recovery of basal N and the higher rate of N absorption during the linear phase. The amount of N in the plants grown under MS10 was almost equivalent to those in the plants grown under a double dose of basal AS. Tillering pattern and achievement of the maximum tiller number stage varied with spacing and fertilizer types, as reflected in the N absorption pattern of the plants. Yield, sink size and potential sink size of the plants reflected the N absorption pattern and the amount of N in the plants. The yield of 6g N-MS10 was almost equivalent to the yield of 12g N-AS. The yield of MS10 plots was especially higher, with narrow spacing due to N absorption during the early growth stage.View full abstractDownload PDF (689K) -
Mineo MINAMI, Akio UJIHARA1991 Volume 60 Issue 1 Pages 107-115
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo analyze the mechanism of damage to yield of maize by lodging, root lodging(RL) and stalk lodging(SL) were mechanically induced at four growth stages, and their effects on canopy architecture, dry matter and grain yield, and nutritional composition were investigated. Except for RL 15 days before silking, a decrease of dry matter and grain yield by treatment was observed. An uneven distribution of leaves in the narrow spaces of lodged canopy reduced the net assimilation rate (NAR). Increased reduction of the NAR occurred as the treatment stage advanced, more so by SL than by RL. Crop growth rate(CGR) correlated closely with the NAR. These results indicated that due to lodging, a reduction of the NAR was correspondingly the primary cause of a reduction of the CGR, and of subsequent yield reductions. Reduction of leaf area also decreased the CGR. Translocation of assimilates from foliage to ear was not inhibited by lodging. Being lowest by SL at silking, grain yield correlated with the number of grains per ear. It was concluded that lodging at silking decreased the number of grains per ear and caused the most serious damage to grain yield. All treatments caused a change in the nutritional composition of ear and foliage.View full abstractDownload PDF (878K) -
Toru TASHIRO, Yasuko FUKUDA, Toshihiko OSAWA1991 Volume 60 Issue 1 Pages 116-121
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSField trials were conducted at the Experimental Station of Nagoya University from May to September 1986 to study within-plant variations in seed weight, hull percentage and the seed oil content and its minor components as affected by different capsule locations on individual sesame plants. Seven capsule positions, five on the main stem and two on the branches, were selected. Seed weight and hull percentage decreased with capsule position from the bottom to the top of the main stem and branches. The oil content of the seed was greatest at positions on the top part of the branches and smallest at the position on the lower bottom part of the main stem. The capsules on the lower bottom part of the main stem had the lowest sesamin and sesamolin contents, but the capsules on the upper central part had the highest sesamin content and those on the Lower central part had the highest sesamolin content. The difference in sesamin and sesamolin contents from the time when the lower bottom part capsules turned light yellow to the time of rupture showed a marked decrease at the central position. The evidence suggests that conversion of sesamin and sesamolin to other substances takes place prior to full maturity.View full abstractDownload PDF (696K) -
Nobuhiro HIGUCHI, Eizo MAEDA1991 Volume 60 Issue 1 Pages 122-129
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe formation of white and compact rice callus cultures was promoted by preculturing mature seed -derived celli on the medium containing a high concentration of sucrose. The obtained white and compact callus had a high regenerating ability on the regeneration medium containing 5 × 10-5M kinetin. When mannitol was added to the medium at the same osmotic level as excess sucrose treatment, it offered the intermediate effect between 3% (control) sucrose and 69L (high concentration) sucrose. Scanning electron microscopic examination revealed that the calli which retained the high regenerating ability had a tendency to show a smooth-surfaced appearance.View full abstractDownload PDF (981K) -
Morio IIJIMA, Yasuhiro KONO1991 Volume 60 Issue 1 Pages 130-145
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSComparison of the root system structures of four cereal species as affected by soil compaction was conducted morphometrically. Plants were grown under two different soil bulk densities of 1.33g/cm3 (control)and 1.50g/cm3 (compact) for two weeks in the root box, and measurements were made on the number, length and diameter of all the roots from every component of the root system. Promoted or less restricted growth was recognized in the mean length and number of higher order laterals in every species under compact treatments. The increased occurrence of L-type lateral roots in the compact treatment contributed to the promoted growth of higher order laterals. Compared to upland rice and Job's tears, sorghum and maize showed higher restriction in both shoot and root growth. As for the occurrence ratio of L-type laterals in the compact treatment, the former two species had 1.5 to 3 times that of the latter two species. Regardless of root diameter, the species with longer root length showed higher restriction of total root length in both 1st and 2nd order laterals. It was suggested that the ability to produce L-type laterals and extension rate of each order lateral roots were closely related to root growth responses under mechanically impeded soil conditions.View full abstractDownload PDF (860K) -
Katsu IMAI, Manami OKAMOTO-SATO1991 Volume 60 Issue 1 Pages 139-145
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe effects of elevated CO2 in the atmosphere and the accompanied temperature rise predicted for the future on gas exchanges of two summer C3 (rice, soybean) and two C4 Japanese millet, finger millet) crop plants were examined. Plants were grown in artificially illuminated growth cabinets under 350 and 500μ mol mol-1 ambient CO2 (Ca) and were measured for rates of CO2 exchange (CER) and transpiration (E) of leaves at 23, 28 and 33°C in terms of Ca (0-500μ mol mol-1). The responses of CER to Ca were slightly lower in plants grown in high Ca than those in normal Ca and were largely influenced by temperature. The promotive effect of elevating Ca on CER was larger at higher temperatures, especially in C4 crop plants. With the rise of Ca, the E in C4 crop plants decreased more than in C3 crop plants and it was correlated with the decrease in stomatal conductance to CO2 transfer. The water use efficiency (WUE) of leaves increased with the rise in Ca but the effect of temperature on WUE was unclear. It is concluded that, whthin limits, under high Ca, C4 crop plants expand their photosynthetic capacity in an environment of high temperature.View full abstractDownload PDF (759K) -
Kazuyuki SAITOU, Yasunori NAKAMURA, Yosinobu KAWAMITSU, Makoto MATSUOK ...1991 Volume 60 Issue 1 Pages 146-152
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn Mesembryanthetnum crystallinum L.leaves exhibiting C3 photosynthesis, Crassulacean acid metabolism (CAM), as characterized by CO2 uptake during the dark period, was induced by exposing the plant roots to high NaCl concentration over a week. The increase in malate content in the leaves at the end of the dark period correlated with the increases in the activities of phosphoenolpyruvate carboxylase (PEPCase), NADP malic enzyme (NADP-ME) and pyruvate, orthophosphate dikinase (PPDK) which exhibited a maximum about a week after NaCl treatment. It was found that PPDK existed in C3-M. ctystallinum and the increases in the activities of PEPCase and PPDK were accompanied by the de novo synthesis of these proteinsView full abstractDownload PDF (840K) -
Kiyosada HIROI, Abdullah Al MAMUN, Tomikichi WADA, Yoji TAKEOKA1991 Volume 60 Issue 1 Pages 153-160
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe objectives of this study were to clarify the interspecific variation on (i) the structure of spikelet and reproductive organs, (ii) the relationship between the size of spikelets and the reproductive organs, and (iii)the surface structure of anther. Oryza breviligulata had the longest spikelet and O. sativa had the shortest. O.sativa had the broadest spikelet and 0. meridionalis had the narrowest. 0. longistaminata had the longest anther while 0.breviligulata had the smallest. O. longistamenata had the longest stigma and 0. sativa had the smallest. The spikelet length had a significant positive correlation with the stigma, but it had almost no correlation with the anther length. The anther length and the stigma length had a positive significant correlation. The spikelet width and stigma length had a negative significant correlation. A difference in the degree of development of cuticular ridges on the anther surface was observed according to species, position of spikelet on a panicle and region in an anther. It was more dense on the surface of the upper region of an anther than on the lower one, and in the spikelets of higher position on a panicle than in those of lower position. The difference in the development of cuticular ridges on the anther surface due to spikelets position on a panicle was more conspicuous in wild species than in cultivated species.View full abstractDownload PDF (861K) -
Katsumi SUZUKI, Takeshi TANIGUCHI, Eizo MAEDA1991 Volume 60 Issue 1 Pages 161-173
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe whole surface of rice embryo was continuously covered with a cuticular layer until 4 days after anthesis. The cuticular layer became intermittent at only the abaxial side of scutellum at 5 days and disappeared completely up at 7 days. By the extinction of this cuticular layer, it was possible to distinguish scutellar epithelial cells from epidermal cells on the other side of the embryo. Therefore, scutellar epithelial cells began to establish a peculiar nature from about 5 days. Epithelial cells, in this time, were still rich in cytoplasm and showed anticlinal divisions. At the end of the anticlinal divisions, epithelial cells gradually altered to an elongated profile in shape. Tiny ingrowths of cell walls were often observed at the surface of cell walls. The walls of epithelial cells were lengthened at a right angle to the outer surface and thickened about half the length inward from the surface, showing unique characteristic of scutellar epithelial cells. Thereafter, the number of lipid bodies and amyloplasts increased in the cells and vacuoles accumulated their contents and transformed to protein bodies. As the embryo developed into the dormant stage, lipid bodies were displaced near the cell walls. By using freeze-substitution method, it was noticed that membrane systems are smooth and the inside of mitochondria or plastids is more electron-dense in comparison with chemical fixation. The presence of tiny ingrowth and thickening of cell walls was also observed by freeze-substitution method.View full abstractDownload PDF (3244K) -
Tadashi HIRASAWA, Kuni ISHIHARA1991 Volume 60 Issue 1 Pages 174-183
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSRoot water uptake ability is supposed to greatly affect the degree of midday depression in the photosynthetic rate of crop plants. However, there is no useful indicator for estimating it quantitatively despite necessity. This study investigated whether resistance to water transport calculated according to Ohm's law can be adopted in estimating water uptake ability by using rice, corn and soybean plants. The resistance to water transport from soil through root to leaf decreased markedly as the transpiration rate increased, especially at low transpiration rates, but became constant at high transpiration rates where there were close linear correlations between transpiration rate and leaf xylem water potential and the linear extrapolation of the regression lines down to zero transpiration rate gave the water potentials quite near to thc origin. By measuring transpiration rate and leaf xylem water potential for the leaves on the intact stem and the excised stem with its cut end kept under water, it was supposed that root have a relatively high resistance in the water pathway of plants and this resistance could be attributed to the variable resistance of whole plants. Water uptake decreased and the resistance to water transport increased significantly when the root system was partly excised and when treated with NaN3. On the other hand, the resistance was not affected by lowering the water potential of the culture solution, although water uptake of the plants decreased markedly. Our conclusions are that resistance to water transport in crop plants under intense transpiration could be adopted in estimating water uptake and transport ability of plants and that the differences in root water uptake abilities among plants could be compared by calculating the resistance, since the root water uptake ability very much affects whole plant resistance.View full abstractDownload PDF (1092K) -
Teresita O. GALAMAY, Yasuhiro KONO, Akira YAMAUCHI, Mitsuru SHIMIZU1991 Volume 60 Issue 1 Pages 184-190
Published: March 05, 1991
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSSeminal and nodal root axes play an important role as conducting pathways for transporting substances into and out of roots. The anatomical feature of the tissue at the basal portion of these axes in nine species of cereals was examined with emphasis on the hypodermis and the cortical sclerenchyma. In the seminal root axes, none of the species examined developed cortical sclerenchyma except rice. In contrast, all the species developed the cortical sclerenchyma in the nodal root axes. This phenomenon was regarded as a type of heterorhizy. The hypodermis consisted of more regularly arranged cells in the nodal root axes than in seminal root axes in all the species. The marked wall thickening of the hypodermal cells in the nodal root axes was observed in Japanese barnyard millet, pearl millet and foxtail millet but not in the other species. Some specimens of Japanese barnyard millet showed wall thickening also in the epidermis. The number of cortical scleren-chymatous layers varied with the species. The cortical disintegration was observed in the nodal root axes of all the species. However, in the seminal root axes, among the species examined, only finger millet, pearl millet, and foxtail millet did not show cortical disintegration. In these three species, the tissues external to endodermis tended to be deformed and sloughed off in the seminal root axes. Finger millet developed a thickened-wall cortical layer encircling the endodermis.View full abstractDownload PDF (1032K)
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