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41.
Burkholderia plantarii , the pathogen of bacterial seedling blight of rice, was detected in paddy water. Its concentration rose in July and August.
The bacterial concentration in the paddy water was always higher along levees than at distances more than 5 m from levees.
Confirmed to be released into water when graminaceous weeds were immersed, B. plantarii survived for at least 4 days at 30°C. B. plantarii was splashed at least 30 cm upward by rain splash in the field. Harvested seeds, which had been sprayed with B. plantarii released from graminaceous weeds at the flowering stage, retained the bacteria. Bacterial seedling blight occurred when the
seeds were then sown in nursery boxes. These results indicated that graminaceous weeds growing on levees of paddy fields are
a source of infection of the disease and that rice seeds are infected through the paddy water.
Received 23 May 2002/ Accepted in revised form 1 September 2002 相似文献
42.
Minimal Set of Metabolic Pathways Suggested from the Genome of Onion Yellows Phytoplasma 总被引:1,自引:0,他引:1
43.
Achmadi PRIYATMOJO Ryo YAMAUCHI Koji KAGEYAMA Mitsuro HYAKUMACHI 《Journal of General Plant Pathology》2002,68(1):1-7
Cellular fatty acids were analyzed to characterize and differentiate 34 isolates of Rhizoctonia species representing binucleate Rhizoctonia AG-D (I), AG-D (II), R. solani AG 2-2 IIIB, AG 2-2 LP, R. circinata var. circinata and var. oryzae associated with turfgrass diseases in Japan. Myristic, pentadecanoic, palmitic, palmitoleic, stearic, oleic, linoleic and
linolenic acids were consistently present in varying quantities in all isolates. Heptadecanoic and 9-heptadecenoic acids were
present in isolates of Rhizoctonia AG-D (I), AG-D (II), R. solani AG 2-2 IIIB and AG 2-2 LP but not in isolates of R. circinata var. circinata and var. oryzae. Palmitic, oleic and linoleic acids were the major fatty acids found, constituting 88.30-98.37% of the whole-cell fatty acid
content. The remaining fatty acids were present in smaller amounts. Isolates within a single group were closely clustered,
whereas isolates from different groups were clearly distinguishable based on average linkage cluster analysis of cellular
fatty acids. Principal component analysis, based on all fatty acids detected, confirmed the distinct separation of isolates
representing the six groups of Rhizoctonia species obtained from turfgrasses. These results suggested that fatty acid analysis is useful for the characterization and
differentiation of isolates of Rhizoctonia species associated with turfgrass diseases.
Received 21 May 2001/ Accepted in revised form 28 September 2001 相似文献
44.
Motoo KOITABASHI Masataka IWANO Seiya TSUSHIMA 《Journal of General Plant Pathology》2002,68(2):183-188
Microorganisms isolated from wheat leaf surfaces were screened for inhibition of wheat powdery mildew. A new screening method,
in which wheat leaves were inoculated with Blumeria graminis f. sp. tritici and incubated with the cultured microorganisms under non-contact conditions, was developed in the present study. Using this
method, 10 phylloplane fungi that inhibited wheat powdery mildew were selected from 408 microorganisms isolated from wheat
leaf surfaces. Among these 10 strains, a fungus designated as Kyu-W63 had an especially strong inhibitory effect. Kyu-W63
produced white colonies without spores when cultivated on PDA. Kyu-W63 had a strong aromatic odor when being cultured. Wheat
powdery mildew was suppressed even though a membrane filter with a pore size of 0.45 μm was placed between the mycelial colony
and wheat leaf segment. However, when activated charcoal was introduced, Kyu-W63 did not inhibit growth of B. graminis. It was presumed that volatile substances were involved in the inhibitory effect of Kyu-W63. GC-MS analysis was used to identify
two substances produced by Kyu-W63 with molecular weights of 164 and 166. Kyu-W63 also inhibited the in vitro growth of four plant pathogenic fungi other than B. graminis.
Received 19 September 2001/ Accepted in revised form 7 February 2002 相似文献
45.
Takeshi SHINOGI Tomoko SUZUKI Yoshihiro NARUSAKA Pyoyun PARK 《Journal of General Plant Pathology》2002,68(1):38-45
The rapid generation of reactive oxygen species (ROS), called the oxidative burst, is one of the earliest host responses to
pathogen infection or elicitor treatments. Therefore, we looked for the induction of ROS generation in Japanese pear leaves
by the host-specific toxin, AK-toxin I using a cytochemical method for detecting H2O2. A small amount of non-specific generation of H2O2 was found in the cell walls in toxin- and water-treated susceptible and resistant leaves. Thus, the generation of H2O2 at cell walls appears to be caused by wounding stress during sampling. Specific generation of ROS, however, was found only
in the membrane fragments and extended desmotubules characteristic of modified sites of the plasma membrane in the toxin-treated
susceptible leaves. In addition, generation of H2O2 at plasma membranes was observed with higher frequency in toxin-treated susceptible leaves. This result indicates that the
H2O2 generation was associated with damaged sites in the plasmalemma after toxin treatment and perhaps with the formation of membrane
fragments from altered portions of the invaginated plasma membrane.
Received 21 September 2001/ Accepted in revised form 25 October 2001 相似文献
46.
47.
Hitomi NAKABAYASHI Yasuyuki YAMAJI Satoshi KAGIWADA Masashi UGAKI Shigetou NAMBA 《Journal of General Plant Pathology》2002,68(2):173-176
The complete nucleotide sequence was determined for genomic RNA of White clover mosaic virus (WClMV-RC) isolated from red clover (Trifolium pratense) in Japan, It is 5843 nucleotides in length, excluding the poly(A) tail at the 3' terminus. Similar to other potexviruses,
it contains five open reading frames (ORFs 1 through 5), which putatively encode an RNA-dependent RNA polymerase (RdRp) (147
kDa), a triple gene block (TGB) (26 kDa/13 kDa/7 kDa), and a coat protein (CP) (22 kDa), respectively. The deduced amino acid
sequence of the WClMV-RC CP was identical to that of WClMV-O, one of two New Zealand isolates, but only 85% identical to that
of WClMV-M, the other New Zealand isolate, because of heterogeneity in the C-termini of CP amino acid sequences. The implication
of this CP heterogeneity is discussed.
Received 30 August 2001/ Accepted in revised form 11 January 2002 相似文献
48.
49.
辣椒疫病发病主导因素及综合防治技术研究 总被引:2,自引:0,他引:2
通过3a在多年辣椒重茬地的田间试验及调查研究,基本明确了辣椒疫病发生与灌水方法、栽培方式、降水、中心病株的出现等主导因素的关系。提出了栽培防病、化学治疗的综防技术,达到控病增产的目的。 相似文献
50.
J Petersen 《Weed Research》2003,43(1):33-39
Summary The experiments were carried out in the two spring barley fields of the organic six-course cattle:crop rotation at Foulumgaard, Denmark. The weed density was 300 and 1800 plants m−2 respectively. Pig slurry was applied by hand in microplots by four methods: broadcasting followed by incorporation, or injected in bands to depths of 5, 10 or 15 cm. Spring barley and weeds were sampled separately six times during the tillering and elongation phase of the spring barley. The effect of application method on dry-matter (d.m.) production, nitrogen uptake and recovery of applied nitrogen in the spring barley and the weeds is reported. Slurry banding halved the weed d.m. and weed N uptake compared with broadcasting, irrespective of weed density. Weeds recovered up to 12% of the applied nitrogen, which made them a significant competitor when the slurry was broadcast and incorporated. Banding by direct injection reduced the slurry:soil contact and the weed:crop competition balance for applied nitrogen moved in favour of the crop. Thus, the crop recovery of applied nitrogen at the end of the sampling period was increased from approximately 45% for broadcast and incorporated to approximately 50% for injected slurry, and coincidental weed recovery was reduced to a maximum of 5%. As the nitrogen supply normally affects plant d.m. production, banding of slurry might well improve crop competitiveness and its tolerance to mechanical weed control. 相似文献