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61.
62.
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
63.
Minimal Set of Metabolic Pathways Suggested from the Genome of Onion Yellows Phytoplasma 总被引:1,自引:0,他引:1
64.
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
65.
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
66.
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
67.
68.
Kazuhiko Narisawa Hitoshi Kawamata Randolph S. Currah Teruyoshi Hashiba 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(2):103-109
One hundred and twenty-three fungal isolates were obtained from 225 root segments of eggplants, melon, tomato, strawberry and Chinese cabbage, grown as bait plants in a mixed soil made up of samples from different fields in Shizuoka, Japan. Isolates belonging to Mycelium radicis atrovirens (MRA), including Phialocephala fortinii, were the most prevalent in all the five bait plants. Eleven of the 123 isolates, after being inoculated onto axenically reared eggplant seedlings, almost completely suppressed the pathogenic effects of a post-inoculated, virulent strain of Verticillium dahliae. Seven of these 11 isolates had come from the roots of eggplant and included Heteroconium chaetospira,
P. fortinii, and unidentified species of Fusarium, Penicillium, Trichoderma and MRA. P. fortinii, H. chaetospira, a non-sporulating isolate with white mycelium (SWM) and MRA were easily reisolated from root segments. Hyphae of H. chaetospira, P. fortinii and SWM colonized the root tissues of eggplant without causing apparent pathogenic symptoms. The mechanisms by which these endophytes confer resistance to infection by V. dahliae are unknown but the effectiveness of these fungi in a laboratory setting indicates that they have potential as biocontrol agents and merit further investigation. 相似文献
69.
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
70.
甘薯根腐病抗性在不同环境条件下的表现及遗传趋势 总被引:1,自引:0,他引:1
结果表明,甘薯根腐病发病轻重与环境条件有很大关系,表现为干旱少雨的年份发病较重,降雨量较多的年份发病较轻;土壤瘠薄的发病较重,肥力条件较好的则发病较轻;通常情况下,年份间品种的抗性表现较为一致,但遇特殊气候则年份间品种的抗性有一定的差异。对1150份甘薯品种资源及育种材料的根腐病抗性鉴定结果表明,高抗型材料占14.6%,抗病型占15.7%,感病型占26.0%,高感型占43.7%。对754份材料及亲本的抗性分析表明,不同的抗性组合后代中均可分离出高抗至高感类型的材料,杂交后代的抗性强弱随双亲抗性水平的提高而提高。中国自1970年以来采用品种间杂交和种间杂交育种技术,先后育成了一批高产、优质的高抗型优良品种。 相似文献