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Volume 44 (1999)
- Issue 4 Pages 285-
- Issue 3 Pages 163-
- Issue 2 Pages 115-
- Issue 1 Pages 1-
- Issue Suppl Pages 2-
Volume 44, Issue 4
Displaying 1-19 of 19 articles from this issue
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Katsuichiro Kobayashi, Naoko Ashida, Ie Sung Shim1999 Volume 44 Issue 4 Pages 285-292
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSThe phytotoxic activity of pretilachlor [2-chloro-2′, 6′-diethyl-N-(2-propoxyethyl) acetanilide] on transplanted rice in Utsunomiya and Yawara paddy soils under lowland condition was investigated in relation to its behavior in the soils. The inhibitory activity of pretilachlor on the growth of rice was slightly less when mixed in Utsunomiya soil than in Yawara soil. On the contrary, the growth was inhibited by pretilachlor more remarkably in the former than in the latter when the herbicide was applied into flooded water under water leakage condition. Pretilachlor concentration in soil water was higher in Yawara soil than in Utsunomiya soil by the soil-mix application. With pretilachlor application into flooded water, the herbicide-treated layer was formed in the top layer in Yawara soil but was little formed in Utsunomiya soil. Leaching of pretilachlor was greater in Utsunomiya soil than in Yawara soil, resulting in higher concentration of pretilachlor in soil water in the former. These results suggested that the higher phytotoxic activity of pretilachlor applied into flooded water on the rice transplanted in Utsunomiya soil than in Yawara soil under water leakage condition depended on its higher concentration in the water existing in the soil below the transplantation depth.View full abstractDownload PDF (1019K) -
Kim Yeong Hoo, Ie Sung Shim, Katsuichiro Kobayashi, Kenji Usui1999 Volume 44 Issue 4 Pages 293-299
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSThe relationship between Na content or K/Na ratio and the salt tolerance was investigated in several gramineous plants. Growth inhibition by NaCl treatment was greater in shoots than in roots and less in Echinochloa oryzicola Vasing (Tsukuba) than in rice (Nipponbare). Na content of roots in E. oryzicola seedlings was higher than that of leaves, whereas it was the reverse in rice seedlings under a saline condition. Rice (Nipponbare) contained more Na in their leaves than E. oryzicola (Tsukuba). These suggest that E. oryzicola might reduce the transport of Na to shoot more effectively than rice. The decrease of K uptake and the increase of Na uptake by NaCl treatment resulted in lower K/Na ratio in leaves and roots. This trend was greater in rice than E. oryzicola. Moreover, this relationship between Na content or K/Na ratio and salt tolerance was also observed in 8 gramineous species examined. Among them, foxtail and corn were comparatively salt-tolerant, and contained higher Na concentration and lower K/Na ratio in shoots, suggesting that these 2 species possess a different salt tolerance mechanism. It was suggested that the salt tolerance of the gramineous species examined in this study might be related to their different abilities in limiting Na uptake and its transport to shoot and maintaining K in shoot under a saline condition.View full abstractDownload PDF (804K) -
Yasushi Tanaka, Harutoshi Yoshikawa1999 Volume 44 Issue 4 Pages 300-308
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSVarious physiological responses were studied in Cyperus serotinus Rottb. following treatment with imazosulfuron. RNA synthesis measured by [3H] uridine incorporation and DNA synthesis measured by [3H] thymidine incorporation were inhibited to 82% and 51%, respectively, 4hr after treatment of 10ppb of imazosulfuron, while protein synthesis measured by [3H] leucine incorporation was not inhibited. Inhibition of DNA synthesis began within 1hr after treatment and reached 28% of the zero time value of radioactivity after 6hr. The amount of reversal from reduction in plant height induced by 3ppb or more of imazosulfuron increased further when valine, isoleucine and leucine were added at higher concentrations. Three amino acids at 100ppm or above alleviated DNA synthesis inhibited by 10ppb of imazosulfuron 4hr after treatment more than the control. Supplement of amino acids at 300ppm greatly alleviated the inhibition of DNA synthesis within 2hr and did the same to the control to almost the same degree 6hr following pretreatment of imazosulfuron for 24hr. The level of the soluble proteins decreased to 47% of the control 11 days after treatment with a concentration of 100ppb of imazosulfuron, while the free amino acid level increased to 354% of the control. We suggest that starvation of valine, isoleucine and leucine induced by imazosulfuron cause the inhibition of DNA synthesis in a short period of treatment and lead to protein turnover and increase in the level of amino acids over a longer period.View full abstractDownload PDF (1091K) -
Makoto Kitou1999 Volume 44 Issue 4 Pages 309-315
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSWater extract of Acacia pubescens leaves inhibited the germination of lettuce seeds. The effect of the water extract disappeared during a shorter period of incubation of the soil-leaf powder mixture (sample) under 60% MWHC (maximum waterholding capacity) at 25°C. Further incubation of the samples led to a stimulation of root elongation. The stimulatory effect of the water extract on root elongation thereafter gradually decreased and disappeared by the 35th day of incubation. Water extracts of samples incubated under 60% MWHC but at 5°C continued to display an inhibitory effect on germination up to 35 days of incubation and did not show any stimulatory effect on root elongation. The stimulatory effect on root elongation was not distinct in the samples incubated under 120% MWHC at 25°C. Samples incubated under 30% and 60 MWHC at 25°C showed similar characteristic effects, but a longer period was required for the disappearance of the inhibitory effect on germination in the samples incubated under 30% MWHC. The soil temperature thus appeared to have a stronger influence than the soil water content on allelopathic effect of soil mixed with leaf powder of A. pubescens. The variations in the characteristic allelopathic effects of water extracts in relation to the incubation period of the mixture of soil and leaf powder were related to the pH and EC values of water extracts.View full abstractDownload PDF (758K) -
Tomio Itani, Takuya Fujita, Masahiko Tamaki, Masanori Kuroyanagi, Yosh ...1999 Volume 44 Issue 4 Pages 316-323
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSThe allelopathic activity of the exudate of dry leaf from 53 species known to be rich in oxalates, including the families Polygonaceae, Oxalidaceae, Chenopodiaceae, Begoniaceae and Musaceae was assayed by the “Sandwich Method” (S W Method) using lettuce (Lactuca sativa L. var. Great Lakes 366) as a receptor plant. A wide interspecific variation in the allelopathic activity was recognized in these species (Tables 1, 2). Particularly, Oxalis corniculata L. and Begonia spp. inhibited the elongation of the lettuce radicle and hypocotyl at less than about 10% of the control (Fig. 1). The total oxalate contents (including soluble and non-soluble types) in dry leaf were determined for 18 species (Table 3). The total oxalate contents obtained were negatively and significantly associated with the radicle elongation of lettuce (% of control) in the SW method (Figs. 2, 3), suggesting that the oxalates in the dry leaf of oxalate-rich plants contributed, at least partly, to their allelopathic effect. Since several species, on the other hand, deviated from this relationship of oxalate contents and allelopathic activity, the chemical forms of oxalates and/or other unknown inhibitory substances might also be involved in the allelopathic activity of these oxalate-rich plants.View full abstractDownload PDF (832K) -
Kazuhito Matsuo, Masayuki Nemoto, Isamu Nouchi1999 Volume 44 Issue 4 Pages 324-328
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSWe compared the growth and phenology of four annual weed species (Chenopodium album, Commelina communis, Digitaria ciliaris, Persicaria vulgaris) grown under artificial UV-B radiation system using fluorescent sunlamps wrapped in cellulose diacetate film for the UV-B treatment and Lumirror film for the control (Fig. 1). The intensity of the artificial UV-B radiation was regulated so as to become 1.7 times as high as the value obtained in measurements performed at Tsukuba in winter. In four annual species all the plants grew less rigorously under high intensity UV-B treatment than the control, showing that the effect of UV-B significantly reduced the weight of plants. Visible foliar injury caused by UV-B radiation did not occur in any of the plants examined. C. album, P. vulgaris, D. ciliaris, which are short-day plants, did not exhibit so delayed flowering after UV-B treatment. However, C. communis, a day-neutral plant, exhibited a obvious delay in flowering after UV-B treatment (Fig. 2).View full abstractDownload PDF (634K) -
Takanobu Ito, Yuichiro Nakayama, Hirofumi Yamaguchi1999 Volume 44 Issue 4 Pages 329-340
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSIn order to analyze the effect of paddy field reconstruction on the biological environment, the vegetation on four kinds of levees surrounding different types of paddy fields, namely traditionally managed levees, levees of paddy fields reconstructed 10 years ago, levees of paddy fields reconstructed 6 years ago, and levees of paddy fields reconstructed in the previous year was investigated in Sakai city, Osaka. The composition of the plant species in the vegetation on the flat and sloping parts of the levees was monitored by the total estimation method 8 times with one month intervals from April to December in 1997. On the flat part of the levees the average number of species per levee ranged from 35 to 36 in four kinds of levees. However species composition was different among the levee types (Table 2). On the sloping part of the levees, the average number of species per levee ranged from 29 to 38 and the species composition was different in the four levees (Table 3). On traditionally managed levees, domestic perennial species dominated, and annual and alien species were seldom observed. On the levees of the paddy fields reconstructed 10 years ago and 6 years ago, alien perennial species such as Solidago altissima became dominant with the lapse of time from paddy field reconstruction.
The plant diversity on the traditionally managed levees was stable (Fig. 1) though that of the levees of the paddy fields reconstructed 10- and 6-years ago declined remarkably when mowing was practiced (Fig. 2, 3). On the traditionally managed levees, the complex plant-community structure may be maintained with a high plant diversity. On the levees of the paddy field reconstructed 10- and 6-years ago, a simple plant-community structure resulted in a lower plant diversity when mowing was practiced.
It is suggested that the vegetation on the levees of the paddy fields reconstructed 10- and 6-years ago may undergo a successional process different from the usual process in the vegetation of traditionally managed levees (Fig. 5, 6).View full abstractDownload PDF (1436K) -
Min Soo Yun, Fan Deng, Kenji Usui1999 Volume 44 Issue 4 Pages 341-348
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSThe O-dealkylating activities in rice were investigated to obtain fundamental information relating to the selectivity and safening action of sulfonylurea herbicides by measuring 7-ethoxycoumarin O-deethylase (ECOD) and 7-methoxycoumarin O-demethylase (MCOD) activities in microsomes taken from rice shoots. NADPH cytochrome P-450 (c) reductase (NADPH cyt. c red.) activity was measured to confirm the effect of electron transfer system on cytochrome P-450 reaction. Cytochrome P-450 dependence of the reactions was demonstrated by use of safeners: 1, 8-naphthalic anhydride (NA) and ethanol; inhibitors: 1-aminobenzotriazole (1-ABT) and piperonyl butoxide (PBO); herbicides: dimepiperate, dymron, pyrazosulfuron ethyl (PSE) and bensulfuron methyl (BSM). The O-dealkylation was induced by the treatment of not only safeners (NA, ethanol) but also herbicides (dimepiperate, dymron, PSE, BSM). Furthermore, it was inhibited to varying degrees by both inhibitors (1-ABT, PBO) of induced cytochrome P-450 enzymes and by sulfonylurea herbicides (PSE, BSM). In contrast, NADPH cyt. c red. activity was not significantly changed by either induction or inhibition. These results suggest that cytochrome P-450 is involved in the oxidative detoxifying metabolism of sulfonylurea herbicides like PSE and BSM, so that these herbicides may be a substrate or competitive inhibitor of microsomal oxygenases.View full abstractDownload PDF (983K) -
Makoto Kitou, Satoko Okuno1999 Volume 44 Issue 4 Pages 349-352
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
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Shun Kawaguchi, Masaru Ogasawara, Kohichi Yoneyama, Yasutomo Takeuchi1999 Volume 44 Issue 4 Pages 353-355
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
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Tomoko Nishida, Norihisa Kitahara, Norikazu Harashima, Osamu Watanabe, ...1999 Volume 44 Issue 4 Pages 356-360
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
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Seiko Imaizumi, Minoru Honda, Kenji Morita, Atsushi Tateno, Takane Fuj ...1999 Volume 44 Issue 4 Pages 361-369
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
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Naohiko Kondo, Tetsuo Matsumoto, Kuni Matsuya, Yasufumi Imai1999 Volume 44 Issue 4 Pages 370-376
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
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Masayuki Hamada, Kenji Wakayama, Naoki Matsumoto, Hirokazu Kamatani, T ...1999 Volume 44 Issue 4 Pages 377-382
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
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Fan Deng1999 Volume 44 Issue 4 Pages 383-390
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
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Je Cheon Chae, Ja Ock Guh1999 Volume 44 Issue 4 Pages 391-404
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSThe planted area of direct-seeding rice cultivation in Korea, which began in 1991, increased remarkably up to 117, 500 ha in 1995, but decreased to 63, 900 ha in 1998 and then rose to 71, 700 ha in 1999. Farmers preferred dry paddies to flooded paddies at first for direct-seeding, but in recent years this has changed due to frequent rainfalls at seeding time. The number of weed species occurring in paddy fields in Korea was 23 in direct seeding on dry paddy and 18 in direct-seeding on flooded paddy. Echinochloa crus-galli was the most dominant weed species in direct-seeding on dry paddy and was followed by Cyperus difformis, Cyperus serotinus, Ludwigia prostrata and Aneilema japonica. The dominant weed species in direct-seeding on flooded paddy were Echinochloa crusgalli, Eleocharis kuroguwai, Scirpus hotarui, Monochoria vaginalis and cyperus difformis. On the contrary, Eleocharis kuroguwai, Sagittaria pygmaea, Sagittaria trifolia, Echinochloa crus-galli and Monochoria vaginalis were dominant weeds in machine transplanted paddy fields. Occurrence of weedy rice, especially red rice, was also increased greatly in directly-seeded rice fields, although effective herbicides or other practical control methods are not yet developed. The recommended herbicide application for controlling weeds in direct seeded dry paddies and flooded paddies in Korea is the systemic application of two time points: before and after water logging, in case of medium weed occurrence. Additional application is recommended for heavy weed occurrence. It seems that direct seeding is one of the most attractive rice cultivation techniques for labor and cost saving. However, it is still an unstable technique because of poor seedling establishment, more occurrence of weedy rice, lodging problem and lack of satisfactory seeding machines. Direct-seeding rice cultivation is expected to increase in future by farmers in Korea who understand the technique better.View full abstractDownload PDF (1538K) -
Dale L. Shaner1999 Volume 44 Issue 4 Pages 405-411
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSAcetolactate synthase (ALS) inhibitors are highly potent herbicides that include the sulfonylureas, imidazolinones, triazolopyrimidine sulfonamides and pyrimidyl salicylates. Currently there are ALS-inhibiting herbicides for use in all major crops including maize, soybeans, rice, and cereals. These herbicides kill plants by inhibiting the first enzyme in the biosynthetic pathway of the branched chain amino acids. Resistance to ALS inhibitors can be conferred by single mutations at multiple sites within the ALS gene. The first case of resistance to ALS inhibitors was discovered in 1987 in a wild lettuce (Lactuca serriola) population in Idaho, U. S. Resistance to ALS inhibitors in the U. S. is now found in populations of 26 species in all of the major crops. In all the cases studied, the mechanism of resistance has been due to selection of an altered form of the ALS enzyme. Detection of resistance to ALS inhibitors can be done through whole plant screening, in vitro and in vivo enzyme assays. ALS resistance can be managed through the by using ALS inhibitors in an integrated system which utilizes other herbicides as well as mechanical, cultural and biological weed control methods.View full abstractDownload PDF (873K) -
1999 Volume 44 Issue 4 Pages 412-419
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
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Akira Koarai, Akihide Fushimi, Hiroshi Tsuyuzaki, Shinichi Shirakura1999 Volume 44 Issue 4 Pages 420-423
Published: December 28, 1999
Released on J-STAGE: December 17, 2009
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