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Volume 59 (1993)
- Issue 6 Pages 617-
- Issue 5 Pages 487-
- Issue 4 Pages 369-
- Issue 3 Pages 225-
- Issue 2 Pages 107-
- Issue 1 Pages 1-
Volume 59, Issue 5
Displaying 1-21 of 21 articles from this issue
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Naoto YAMAOKA1993 Volume 59 Issue 5 Pages 487-491
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSBarley coleoptiles that had been inoculated with conidia of Erysiphe graminis were immersed in 0.01M CaCl2, immediately after inoculation. Some of the immersed conidia showed normal differentiation giving rise to a haustorium, as similarly as those on coleoptiles that were not immersed. On the other hand, the percentage of elongated abnormal appressoria increased, and the penetration efficiency decreased slightly in water. However, E. graminis germlings that completed haustorium formation also elongated secondary hyphae, and eventually, sporulation occurred even in solution. The viability of the conidia and their associated structures was never affected at all while they were incubated in water without being dried. Thus, the water had no effect on the viability or on the differentiation process after formation of haustorium of E. graminis.View full abstractDownload PDF (757K) -
Mamoru SATOU, Fumiyoshi FUKUMOTO1993 Volume 59 Issue 5 Pages 492-499
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSConidia of the downy mildew fungus (Peronospora parasitica) which is an obligate parasite were well preserved by freezing at -80°C using suitable cryogenic protectants. The germination rate of the conidia which were suspended in distilled water and frozen at -20°C or -80°C was very low compared with the untreated control. However, the germination rates of the conidia suspended in 5% dimethyl sulfoxide (DMSO) and 5% skim milk were 74.8% and 32.8% of the control, respectively, even after freezing at -20°C. On the other hand, in the preparations directly frozen at -80°C, the germination rate of the conidia decreased markedly in comparison with that after freezing at -20°C. Nevertheless, in the preparations of conidia frozen by the two-step freezing method at -20°C for 24hr followed by -80°C for 24hr, the germination rate remained the same as that in the preparations frozen only at -20°C. During the storage at -20°C, the conidia suspended in 5% DMSO+5% skim milk lost their germination ability after one month. The conidia suspensions which were supplemented with 10% DMSO+5% skim milk or 10% DMSO+10% skim milk and frozen by the two-step method at -20°C and at -80°C, showed a higher germination rate at least up to a period of 12 months. Moreover, these preparations exhibited a high pathogenicity to the broccoli seedlings. Based on these results, it was suggested that the conidia of the broccoli downy mildew fungus treated with protective substances such as 10% DMSO+5% skim milk or 10% DMSO+10% skim milk which were pre-frozen at -20°C for 24hr followed by -80°C could be well preserved for a long period of time.View full abstractDownload PDF (451K) -
Kaoru HANADA, Shinya TSUDA, Mitsuro KAMEYA-IWAKI, Hiroshi TOCHIHARA1993 Volume 59 Issue 5 Pages 500-506
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSSerological and physicochemical properties of nucleocapsid of tomato spotted wilt virus (TSWV) isolated from watermelon (TSWV-W) were compared with three isolates of TSWV from dahlia (TSWV-D), green pepper (TSWV-P) and tomato (TSWV-N) in Japan. Nucleocapsid of TSWV-W also had three major RNA and one rotein. Three RNA species are tentatively called as RNA 1, RNA 2 and RNA 3, from the largest to the smallest. TSWV-W contained larger RNA 3 (Mr 1.2⁄106) and larger protein (32 K) than those of the other three isolates, although nucleocapsid of TSWV-N, -P and-D contained three major RNA species (RNAs) with Mrs of 2.7×106 (RNA 1), 2.1×106 (RNA 2) and 1.0×106 (RNA 3) and one kind of protein with Mr of 30 K. Serological relationships among the isolates were analyzed by immunodiffusion tests using antisera prepared against nucleocapsids of TSWV-W and TSWV-N. Nucleocapsid of TSWV-W and-N reacted clearly with their homologous antisera but rarely or only weakly reacted with heterologous tisera. Nucleocapsid of TSWV-P and-D was serologically closely related to that of TSWV-N but not to TSWV-W. Consequently, TSWV-W was found to be unique on the basis of properties of nucleocapsid among the four TSWV isolates compared.View full abstractDownload PDF (1269K) -
Akira SAYAMA, Yukio HARADA1993 Volume 59 Issue 5 Pages 507-513
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSInoculation tests were made of violet root rot fungus, Helicobasidium mompa Tanaka, using commercially sold horticultural soils as well as field soils. The mycelial growth of H. mompa on sterilized horticultural soils were superior to that on sterilized field soils, when tested in test tubes. There was little difference in mycelial growth on various sterilized horticultural soils used but was much difference among the isolates used. Isolates with fast growth in sterilized horticultural soils also showed fast growth in non-sterilized horticultural soils (Kanumatuchi and Kanumatuchi: Fuyoudo mixture (1:1, w/w)). Furthermore, mycelial growth in non-sterilized Kanumatuchi: Fuyoudo mixture (1:1, w/w) was superior to that in non-sterilized Kanumatuchi only. In inoculation tests using Kanumatuchi and Fuyoudo mixture, the isolate 475 was highly pathogenic to carrot toproots and roots of apple young trees and the isolate 827 highly pathogenic to carrot toproots, asparagus roots and roots of apple young trees. The inoculation method using horticultural soils is effective to reproduce the disease in potted plants.View full abstractDownload PDF (1105K) -
Ken'o OKAYAMA1993 Volume 59 Issue 5 Pages 514-519
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSDisease development of symptomless strawberry plants infected with G. cingulata (C. gloeosporioides) was investigated, and effects of the capillary watering and rain shelter covered with plastic film on disease spread were examined. Symptomless plants collected from previously infested fields were apparently healthy before planting in nursery beds in April. The symptoms were first appeared on petioles of mother plants and further developed on runners and daughter plants in June. Although disease development was slowed by the rain shelter covered with plastic film, the rain shelter was insufficient to control the disease because daughter plants became gradually infected from diseased mother plants. Disease development of symptomless plants was affected by watering and it was markedly suppressed by capillary watering. Disease development of daughter plants from inoculated mother plants was significantly suppressed by capillary watering and the rain shelter. The fungus was isolated frequently from necrotic runners but rarely from symptomless runners. The isolation frequency of the fungus from runners of plants watered by capillary matting was considerably lower than those watered by sprinkler. Capillary watering and rain shelter were clearly effective for controlling strawberry anthracnose in nursery beds.View full abstractDownload PDF (329K) -
Tsutae ITO, Seiji KANEMATSU, Hiroki KOGANEZAWA, Tsuneo TSUCHIZAKI, Kou ...1993 Volume 59 Issue 5 Pages 520-527
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSApple fruit crinkle (AFC) is a graft-transmissible fruit disease of apple, so far found only in Japan. A viroid-like RNA was detected in association with this disease. Its molecular size was larger than that of apple scar skin viroid (ASSVd) and it did not hybridize with ASSVd-cDNA. In addition, it was transmitted to apple seedlings when they were inoculated by razor-slash method with its electrophoretically purified preparation. These results suggest that this viroid-like RNA is a novel apple viroid and that AFC is a new viroid disease distinct from apple scar skin. We propose to call this viroid apple fruit crinkle associated viroid.View full abstractDownload PDF (2106K) -
Nobuaki MATSUYAMA, Ismail Hossain MIAN, Abdul Mannan AKANDA, Naruto FU ...1993 Volume 59 Issue 5 Pages 528-534
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSThe direct colony TLC method was applied for the comparison of chromatographic profiles of lipids from phytopathogenic bacteria. One loopful bacterial colony was pasted directly on the silica gel TLC plate and dried completely. The first development with chloroform-methanol (2:1, v/v) for short time was conducted for 10 min. After air-drying, the pasted bacterial cells were scraped out and this plate was developed at same direction with chloroform-methanol-water (60:25:4, v/v/v), secondly. The spots were visualized by spraying with ninhydrin and successive heating. The chromatograms of the bacterial isolates were different at generic level and at species level in the cases of erwinia and pseudomonad. The spots appeared at the area from Rf 0.5-0.65 were reliable benchmarks for the differentiation of bacteria. Striking difference was observed between gram positive and negative bacteria. The major spots on the chromatograms of gram negative bacteria were absent on those of gram positive bacteria, Clavibacter spp. Well reproducibility of chromatogram was observed when the culture age and conditions of TLC were kept steadfastly.View full abstractDownload PDF (1768K) -
Masao GOTO, Masahiko KOMABA, Tomohiro HORIKAWA, Noriyuki NAKAMURA1993 Volume 59 Issue 5 Pages 535-543
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSBuds and folded terminal leaves on young shoots of tea plant (Camellia sinensis (L.) Kuntze) carried gemmisphere bacteria at the median population of 2.8×106 cfu/bud or 4.8×107 cfu/g. The bacteria were detected in a log normal distribution and characterized with high population of ice nucleation-activity negative, irregularly-shaped, Gram-positive and orange colored colony formers. The ice nucleation-active (INA) bacteria, Xanthomanas campestris and Erwinia ananas, were the components of these gemmisphere bacteria. X. campestris was predominant all year round, the median population being 5.5×104 cfu/bud in contrast to 3.1×102 cfu/bud in E. ananas, although the populations varied depending on the localities, fields, growth stages of tea plants and/or neighboring plant species. No relationship was confirmed between the distribution frequency and/or population of these INA bacteria and frost damage induced under either natural conditions or artificial ones as well as freeze injuries inflicted on aseptically cultured shoots. Young leaves growing in field suffered freeze injuries at -2 to -3°C irrespective of the degree of leaf expansion, suggesting the involvement of plant intrinsic ice nuclei rather than INA bacteria in the frost damage of tea plant.View full abstractDownload PDF (438K) -
Mitsuo WATABE, Masaki YAMAGUCHI, Iwao FURUSAWA, Osamu HORINO1993 Volume 59 Issue 5 Pages 544-550
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSA series of mutants impaired in productivity of extracellular polysaccharide (EPS) were generated by transposon Tn4431 mutagenesis in Xanthomonas campestris pv. oryzae. EPS production in the mutants on potato semisynthetic agar medium ranged from 2 to 41% of that in their parent strain T7174R. Disease index number of the mutants on rice plants (Oryza sativa cv. IR24) ranged from 0.4 to 3.2 28 days after inoculation, which were significantly lower than that of T7174R (5.4). Furthermore, chemical composition of EPS from the mutants was altered by the mutation. However, any mutants with reduced productivity of EPS did not completely lose their virulence. Although the mutants multi-plied almost to the same level of T7174R in area close to the inoculation point, distribution of the mutants tended to be restricted in the area. Our results suggest that EPS productivity is not an essential factor for multiplication of X. c. pv. oryzae in rice plants but is related with movement of bacteria in infected xylem vessels. The reduced movement of the mutants may reflect the reduced virulence of the mutants.View full abstractDownload PDF (1906K) -
Hideaki NEGISHI, Hiroshi TANAKA, Hatsue MAEDA, Tetsuji YAMADA1993 Volume 59 Issue 5 Pages 551-554
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
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Akemi TANAKA, Hiroyuki YAMAMOTO, Toshikazu TANI1993 Volume 59 Issue 5 Pages 555-558
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
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Takahide SASAYA, Mabito IWASAKI, Takashi YAMAMOTO1993 Volume 59 Issue 5 Pages 559-562
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
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Norihiro SHIMOMURA, Pyoyun PARK, Hiroshi OTANI, Motoichiro KODAMA, Kei ...1993 Volume 59 Issue 5 Pages 563-567
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
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Norio SATO, Masayasu KATO1993 Volume 59 Issue 5 Pages 568-571
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
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Masahiro YOSHIDA, Kenzo KOBAYASHI1993 Volume 59 Issue 5 Pages 573-580
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSA method of intensive isolation for the pathogenic Streptomyces sp. causing root tumor of melon was investigated to reduce contaminative bacteria in dilution plate technique from the diseased tissues. Pre-treatment of isolating samples with phenol in 140-fold dilution for 10 minutes became extremely effective to decrease the bacterial population but efficacy of alkaline treatment with 0.01 N-NaOH was low. In tested 15 inhibitors added to culture medium, 50 ppm of kanamycin had the most effect for reducing of the bacteria, and 25 ppm of kanamycin and 500 ppm of dehydroacetic acid sodium salt were secondary effective ones. The best medium for the isolation in tested 12 media was the basal medium for rhizosphere microorganisms by Lochhead and Chase (medium B), and this incubation period was 5 days at 28°C. In the isolation tests with these results from natural diseased melon, especially incorporating 50 ppm kanamycin into medium B caused the effects that not only reduced contaminative bacteria but also increased appearance of the pathogenic Streptomyces sp. in total actinomycetes. As the results, the isolation on medium B containing kanamycin (50 ppm) by incubation at 28°C for 5 days from pre-treated isolating sample with phenol dilution (×140) was best method. This constructed isolation procedure for the pathogenic Streptomyces sp. was able to enhance values of its isolation ratio (number of successful isolation tests/number of isolation tests×100) from diseased root tumor, percentage in total actinomycetes and mean number of isolates per isolating plate in comparison with non-treated isolation on medium B: from 42.9% to 100%, from 12.5% to 71.2% and from 0.3 isolate to 80.6 isolates respectively.View full abstractDownload PDF (502K) -
Yoshiyuki TAKAHARA, Tetsuya IWABUCHI, Masayuki SHIOTA, Toshio KIMURA, ...1993 Volume 59 Issue 5 Pages 581-586
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSAvirulent strains of Erwinia carotovora subsp. carotovora CGE234M403 and CGE10M2 obtained by mutagenesis using ethylmethanesulfonate, suppressed soft rot of cabbage leaf efficiently. The degree of soft rot suppression correlated with the ratio of the cell concentration of avirulent strain to virulent strain. Only living cell of avirulent strains showed soft rot suppressiveness. Whereas heat-killed bacteria and supernatant broth excluding bacteria did not show soft rot suppresiveness. The strain CGE10M2 suppressed the growth of wild strains of Erwinia which were susceptible to the bacteriocin produced by CGE10M2. On the other hand, the strain CGE234M403 showed strong suppression activity to even some virulent strains which were resistant to the bacteriocin. Therefore, although antibacterial activity of bacteriocins may contribute to disease suppression, other factor(s) may play a part in the soft rot suppression mechanisms.View full abstractDownload PDF (336K) -
Nobukazu TANAKA, Misato TAKAO, Takeshi MATSUMOTO, Yasunori MACHIDA1993 Volume 59 Issue 5 Pages 587-593
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSAgrobacterium rhizogenes MAFF03-01724 (mikimopine type), isolated in Japan, showed resistance to ampicillin, carbenicillin, chloramphenicol, kanamycin, rifampicin, streptomycin, tetracycline and vancomycin. Two kanamycin sensitive mutants (Kms) and two chloramphenicol sensitive ones (Cm3) were obtained from strain 1724 by treatment with N-metyl-N'-nitro-N-nitrosoguanidine (NTG) for transformation by transfer of foreign genes possessing antibiotic selection markers. Transformants were obtained from the Kms mutant by electroporation with binary vector, pBIN19, and/or pF 11 constructed by cloning of Bam HI fragment (8.5 kb) of pRi1724 into pHSG298 vector. To improve transformation frequency, strain 1724 was cultured in a flask with baffles and cells washed with 10% glycerol by repeated pipetting in extrusion. By this modified preparation, transformation frequency of pBIN19 increased fifty times.View full abstractDownload PDF (1040K) -
Nobukazu TANAKA, Takeshi MATSUMOTO, Yasunori MACHIDA1993 Volume 59 Issue 5 Pages 594-600
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSA root-inducing plasmid, pRi1724, in Agrobacterium rhizogenes strain MAFF03-01724 (mikimopine type) isolated in Japan, was combined with a kanamycin resistant gene. The resulting plasmid called pRi1724:: kan was transferred from strain 1724 to other Agrobacterium strains by bacterial transconjugation or electroporation. A. tumefaciens strain C58C1 harboring pRi1724:: kan had abilities such as induction of hairy roots, biosynthesis of mikimopine in infected cells and degradation of mikimopine. We could deduce that the size of pRi 1724 ranged from 205 to 210 kb from results of electrophoresis of fragments from pRi1724:: kan digested by restriction enzymes.View full abstractDownload PDF (1622K) -
Takashi OKU, Mami ARIE, Hideo KISHIRA1993 Volume 59 Issue 5 Pages 601-606
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSPowdery mildew of wasabi (Eutrema wasabi Maxim.) has been found to occur in a green house in Toda city, Saitama Prefecture since 1990. The fungus was identified as an imperfect stage of Erysiphe cruciferarum Opiz ex Junell (Oidium sp.) on the basis of following obsevations, amphigenous, and thin mycelium covered the whole surface of diseased leaves. Formation of conidia was normally low, but occassionally abundant. Conidia were cylindric, 32.0-51.6×13.6-23.2μm, and contained no fibrosin body. Conidia were borne singly on straight erect conidiophores with cylindric foot-cells. Lobed appressoria were formed on short germ tubes at the end of conidia. No cleistothecium was observed. The mildew was pathogenic also on other species of Cruciferae.View full abstractDownload PDF (883K) -
Motoaki TOJO, Takio ICHITANI1993 Volume 59 Issue 5 Pages 607-609
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSTo prepare an field soil modeled for ecological study of Pythium spp., the field soil was heat-treated with water vapor-saturated air for eliminating native populations of Pythium spp. without disturbing physical and chemical properties of the soil. Oospores of P. spinosum or P. aphanidermatum were then introduced to the treated soil and the untreated soil to observe their germination patterns. These patterns varied with species and seasons, but there was few difference between the soils.View full abstractDownload PDF (164K) -
Michiyoshi ARAI1993 Volume 59 Issue 5 Pages 610-613
Published: October 25, 1993
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSIn the fall of 1989, a new disease was found on Sesbania, tropical leguminous manure crops, in Niigata, Japan. Dark green to grayish brown lesions appeared on the stems, petioles, leaf blades and pods of the plants. A species of Botrytis was isolated from those lesions. The fungus isolated was pathogenic to fruits of eggplant, cucumber and green pepper. Conidia were obovoid to ellipsoid, 1-celled, hyaline or pale brown. The optimum temperature for mycelial growth was 20-25°C on PSA medium. The causal agent was identified as Botrytis cinerea Persoon. “Gray mold of Sesbania” was proposed to the disease.View full abstractDownload PDF (512K)
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