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1.
Norihito Yamauchi Mamoru Satou Jyuichi Shimazu Takashi Shirakawa Seizo Horiuchi 《Journal of General Plant Pathology》2007,73(1):29-34
Race 2 isolates of Fusarium oxysporum f. sp. lactucae have been recognized as biotin auxotrophs and consequently have restricted growth on Puhalla's minimal medium (MM), which
contains no biotin. Biotin-autotrophic isolates were raised from race 2 isolates through cultural mutation that grew as well
on MM as they did on MM supplemented with biotin. These autotrophs were identical to the parental isolates in pathogenicity
on race differential cultivars of lettuce (Patriot, Banchu Red Fire, and Costa Rica No. 4), and thus were designated as race
2. A vegetative compatibility test indicated that the autotrophic isolates fell into the same vegetative compatibility group
as the parents. Culture filtrates of the autotrophs allowed abundant growth of the parental auxotroph on MM, and, through
a competitive enzyme-binding assay, biotin was detected in the culture filtrates. These results suggest that biotin auxotrophy
in the natural race 2 isolates has no direct relation to pathogenicity, qualitatively defined as physiological race, or to
vegetative compatibility. 相似文献
2.
Ayumi Notsu Norio Kondo Shohei Fujita Kippei Murata Shigeo Naito 《Journal of General Plant Pathology》2003,69(1):39-41
A new race of Phytophthora vignae f. sp. adzukicola, designated race 4, is reported from central and western Hokkaido, Japan. The isolates obtained from diseased plants of a
new cultivar, cv. Syumari, which is resistant to races 1, 2, and 3, were determined to be a new race by the pathogenic reaction
on a set of differential adzuki bean cultivars (cv. Erimo-shozu, cv. Kotobuki-shozu, cv. Noto-shozu, cv. Urasa-shimane, and
cv. Syumari).
Received: March 7, 2002 / Accepted: August 13, 2002 相似文献
3.
Norihito Yamauchi Jyuichi Shimazu Mamoru Satou Seizo Horiuchi Takashi Shirakawa 《Journal of General Plant Pathology》2004,70(6):308-313
Races were identified among butterhead lettuce isolates of Fusarium oxysporum f. sp. lactucae collected from three geographical areas of Hokkaido, Shizuoka, and Fukuoka in Japan by inoculation tests using Fujinagas race differential cultivars of lettuce (i.e., Patriot, Costa Rica No. 4, and Banchu Red Fire). Eighteen isolates from Shizuoka and Fukuoka were designated race 3, with two unknown vegetative compatibility groups (VCGs) that differed from Ogisos VCG 1 and 2. These two new VCGs were obtained from both Shizuoka and Fukuoka. On the other hand, three isolates from Hokkaido were classified as race 1 and identified as VCG 1, which represents a VCG of crisphead isolates from Nagano. 相似文献
4.
Hideki OGISO Masashi FUJINAGA Hideki SAITO Toshiaki TAKEHARA Shigeru YAMANAKA 《Journal of General Plant Pathology》2002,68(4):292-299
One hundred and sixteen isolates of Fusarium oxysporum f. sp. lactucae obtained from 85 fields in three crisphead lettuce-producing areas in Nagano Prefecture, Japan were typed for races using
differential cultivars Patriot, Banchu Red Fire and Costa Rica No. 4. They were also grouped into vegetative compatibility
groups (VCGs) using complementation tests with nitrate non-utilizing (nit) mutants. Two California strains reported as F. oxysporum f. sp. lactucum, a type culture of F. oxysporum f. sp. lactucae, and 28 avirulent isolates of F. oxysporum obtained from crisphead lettuce were included for comparison. Among Nagano isolates, 66 isolates were identified as race 1,
and 50 as race 2. Race 1 strains derived from Shiojiri and Komoro cities and race 2 from Kawakami village and Komoro city.
All isolates of race 2 were biotin auxotrophs, and the race could be distinguished based on its requirement for biotin on
minimal nitrate agar medium (MM). Pathogenic isolates were classified into two VCGs and three heterokaryon self-incompatible
isolates. Strong correlations were found between race and VCG. All the race 1 strains were assigned to VCG 1 except self-incompatible
isolates, and all the race 2 strains to VCG 2. The 28 avirulent isolates of F. oxysporum were incompatible with VCG 1 and VCG 2. California strains was vegetatively compatible with VCG 1, and they were assigned
to race 1. Based on vegetative compatibility, these two races of F. oxysporum f. sp. lactucae may be genetically distinct, and F. oxysporum f. sp. lactucae race 1 is identical to F. oxysporum f. sp. lactucum.
Received 7 May 2002/ Accepted in revised form 6 September 2002 相似文献
5.
Masashi FUJINAGA Hideki OGISO Nobuaki TSUCHIYA Hideki SAITO 《Journal of General Plant Pathology》2001,67(3):205-206
In 1995, Fusarium root rot of crisp head lettuce, caused by Fusarium oxysporum f. sp. lactucae, was simultaneously found in the Shiojiri and Kawakami areas of Nagano Prefecture, Japan. The Shiojiri and Kawakami isolates
differed in pathogenicity to lettuce cultivars. Because of this distinct physiological specialization, these Shiojiri and
Kawakami isolates should be designated as race 1 and race 2, respectively, using lines VP1010 (highly resistant to race 1),
VP1013 (highly resistant to race 2) and variety Patriot (highly susceptible to both races) as differential varieties. This
is the first report of races of Fusarium oxysporum f. sp. lactucae,
Received 21 September 2000/ Accepted in revised form 21 March 2001 相似文献
6.
Twenty-seven seed samples belonging to the lettuce cultivars most frequently grown in Lombardy (northwestern Italy), in an
area severely affected by Fusarium wilt of lettuce, were assayed for the presence ofFusarium oxysporum on a Fusarium-selective medium. Isolations were carried out on subsamples of seeds (500 to 1500) belonging to the same seed
lots used for sowing, and either unwashed or disinfected in 1% sodium hypochloride. The pathogenicity of the isolates ofF. oxysporum obtained was tested in four trials carried out on lettuce cultivars of the butterhead type, very susceptible to Fusarium
wilt. Nine of the 27 samples of seeds obtained from commercial seed lots used for sowing in fields affected by Fusarium wilt
were contaminated byF. oxysporum. Among the 16 isolates ofF. oxysporum obtained, only one was isolated from disinfected seeds. Three of the isolates were pathogenic on the tested cultivars of
lettuce, exhibiting a level of pathogenicity similar to that of the isolates ofF. oxysporum f.sp.lactucae obtained from infected wilted plants in Italy, USA and Taiwan, used as comparison. The results obtained indicate that lettuce
seeds are a potential source of inoculum for Fusarium wilt of lettuce. The possibility of isolatingF. oxysporum f.sp.lactucae, although from a low percent of seeds, supports the hypothesis that the rapid spread of Fusarium wilt of lettuce observed
recently in Italy is due to the use of infected propagation material. Measures for prevention and control of the disease are
discussed.
http://www.phytoparasitica.org posting Dec. 16, 2003. 相似文献
7.
8.
Norio KONDO Yuki KOBAYASHI Futoshi SAKUMA Shohei FUJITA Kippei MURATA 《Journal of General Plant Pathology》2002,68(4):284-291
The distribution of two races (1 and 2) of Phialophora gregata f. sp. adzukicola, the causal agent of brown stem rot of adzuki bean, was examined using a total of 483 isolates obtained from 39 fields in
19 locations on Hokkaido, Japan between 1997 and 1999. Race 1 was predominant (416 isolates or 86.1%) in the commercial fields
tested. Race 2 was found in 25 fields (64.1%), including two fields of cultivar Kita-no-otome (resistant to race 1, but susceptible
to race 2), indicating that race 2 was widely distributed in most of the production areas in Hokkaido. Using amplified fragment
length polymorphisms (AFLP), a total of 67 polymorphic AFLP markers was recorded among 72 representative isolates (37 and
35 isolates of races 1 and 2, respectively), and 57 distinct haplotypes were detected. Cluster analysis revealed no close
correlation between races and AFLP groups. Thus, no difference was observed between values of gene diversity in each race
(0.253 and 0.284 in races 1 and 2, respectively), and the coefficient of gene differentiation was very low (G
ST
=0.015). Gene differentiation between both races by analysis of molecular variance was not significantly different from zero
(Φ=−0.001; p=0.403). However, the results of gene differentiation among regional populations (G
ST
=0.290, Φ=0.292; p<0.001) are not necessarily consistent with the result that isolates from the same district were generally not tightly clustered.
Received 15 April 2002/ Accepted in revised form 6 September 2002 相似文献
9.
Two diseases of adzuki bean, brown stem rot (BSR, caused by Cadophora gregata f. sp. adzukicola) and adzuki bean Fusarium wilt (AFW, caused by Fusarium oxysporum f. sp. adzukicola), are serious problems in Hokkaido and have been controlled using cultivars with multiple resistance. However, because a
new race of BSR, designated race 3, was identified, sources of parental adzuki bean for resistance to race 3 were needed.
Therefore, we examined 67 cultivars and lines of cultivated and wild adzuki bean maintained at the Tokachi Agricultural Experiment
Station using a root-dip inoculation method. Consequently, nine adzuki bean cultivars, one wild adzuki bean accession and
30 lines (including two lines resistant to all the three races of BSR and AFW) were confirmed to be resistant or tolerant
to race 3 of BSR, and we found a cultivar Akamame as well as a wild adzuki bean Acc2515 to be a new source for a resistance
gene to the race 3. This cultivar also holds promise as a source of resistance against other races of BSR and AFW. 相似文献
10.
Norihito Yamauchi Hayato Horinouchi Kazuhiko Sakai Kengo Yonemoto Mamoru Satou Takashi Shirakawa 《Journal of General Plant Pathology》2011,77(4):260-262
The race of field isolates of Peronospora farinosa f. sp. spinaciae (Pfs), causal agent of spinach downy mildew, were identified using race-differential cultivars. One isolate was similar to
race Pfs:6. Three isolates were identified as race Pfs:8, the first time the race has been reported in Japan as far as we
know. The differential reaction caused by the other two isolates did not match any known to be caused by races Pfs:1 through
Pfs:11; thus, this strain appears to a new pathogenic strain in Japan. 相似文献
11.
Takashi OKU Kotaro SATO Masaki KURAO Shohei MATSUURA Yasufumi SAKAI Takao TSUCHIYA 《Journal of General Plant Pathology》2000,66(4):332-334
The pathogenic race of 59 cultures of Xanthomonas oryzae pv. oryzae, a pathogen of bacterial leaf blight of rice, isolated from six locations in the inland mountainous area of Hiroshima Prefecture
in 1999, were determined by a set of traditional differentials. Four races—I, II, V and VII—were found across the area; however,
we noticed the composition of the races as well as the dominant race in each location different. All races were avirulent
on differential cultivar Te-tep. Races V and VII were new to Hiroshima. The rice cultivars infected with bacterial leaf blight
in Hiroshima are thought to be grouped into the Kinmaze group, which does not have any resistance genes. Apparently, a variety
of races occurred unexpectedly on the cultivars contrary to stabilizing selection theory.
Received 25 February 2000/ Accepted in revised form 13 July 2000 相似文献
12.
Chunyu Li Shi Chen Cunwu Zuo Qingming Sun Qian Ye Ganjun Yi Bingzhi Huang 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(2):327-340
Fusarium oxysporum f. sp. cubense (Foc) is the causal pathogen of Fusarium wilt of banana. To understand infection of banana roots by Foc race 4, we developed a green fluorescent protein (GFP)-tagged transformant and studied pathogenesis using fluorescence microscopy
and confocal laser scanning microscopy. The transformation was efficient, and GFP expression was stable for at least six subcultures
with fluorescence clearly visible in both hyphae and spores. The transformed Foc isolate also retained its pathogenicity and growth pattern, which was similar to that of the wild type. The study showed
that: (i) Foc race 4 was capable of invading the epidermal cells of banana roots directly; (ii) potential invasion sites include epidermal
cells of root caps and elongation zone, and natural wounds in the lateral root base; (iii) in banana roots, fungal hyphae
were able to penetrate cell walls directly to grow inside and outside cells; and (iv) fungal spores were produced in the root
system and rhizome. To better understand the interaction between Foc race 4 and bananas, nine banana cultivars were inoculated with the GFP-transformed pathogen. Root exudates from these cultivars
were collected and their effect on conidia of the GFP-tagged Foc race 4 was determined. Our results showed that roots of the Foc race 4-susceptible banana plants were well colonized with the pathogen, but not those of the Foc race 4-resistant cultivars. Root exudates from highly resistant cultivars inhibited the germination and growth of the Fusarium
wilt pathogen; those of moderately resistant cultivars reduced spore germination and hyphal growth, whereas the susceptible
cultivars did not affect fungal germination and growth. The results of this work demonstrated that GFP-tagged Foc race 4 isolates are an effective tool to study plant–fungus interactions that could potentially be used for evaluating resistance
in banana to Foc race 4 by means of root colonization studies. Banana root exudates could potentially also be used to identify cultivars in
the Chinese Banana Germplasm Collection with resistance to the Fusarium wilt pathogen. 相似文献
13.
Antonín Dreiseitl Junmei Wang 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(4):357-368
Four hundred and sixty-one isolates of Blumeria
graminis f.sp. hordei were obtained from eight populations occurring on cultivated barley (Hordeum
vulgare) at four geographically distant locations in China during 2003 and 2004. Their virulence frequency was determined on 30 differential
lines. No isolate was virulent on differential lines possessing the resistance genes Mla1, Mla3, Mla6, Mla7, Mla9, Mla12, Mla13, Mlat, Mlg, Mla10, Mla22, Mla23, Mlp1, Ml(N81) and Mlmw. Virulences to the first nine resistance genes are prevalent in Europe and constitute the main part of genetic distance between
Chinese and European populations. Conversely, no isolate was avirulent on the differential lines possessing the genes Mla8 and Ml(Ch). The frequencies of isolates overcoming the genes Mla2, Mla11, Mlk1 and Mlk2 were .4–9.3%, and frequencies of isolates overcoming the genes Mlh, MlLa, Ml(Bw), Mlra, Ml(Ru2), mlw, MlGa, MlWo and Mlnn ranged from 18.2% to 98.7%. Based on reactions of differential lines possessing the genes Mlk1, Mlh, MlLa, Ml(Bw), Mlra and Ml(Ru2), pathotypes were identified and diversity parameters calculated. Eleven of 22 detected pathotypes were found in both years
and comprised 94.6% of isolates. Generally, the populations from different locations in 1 year were more closely related than
populations collected from the same locations in different years. Complete effectiveness of the resistance genes, for which
no corresponding virulences were found, will allow Chinese breeders to access many modern European barley cultivars that are
fully resistant to powdery mildew in China, including those possessing the non-host resistance gene mlo. 相似文献
14.
Sara Fondevilla José I. Cubero Diego Rubiales 《European journal of plant pathology / European Foundation for Plant Pathology》2007,119(1):53-58
Mycosphaerella pinodes is one of the most devastating pea pathogens. Pea cultivars with adequate levels of resistance to control the disease are
not so far available. However, promising levels of resistance have been identified in wild accessions of pea. In the present
investigation the inheritance of resistance to M. pinodes was studied in two crosses between the susceptible pea cv. ‘Ballet’ and the partially wild resistant accessions P665 (Pisum sativum subsp. syriacum) and P42 (P. sativum subsp. sativum var. arvense). Both additive and dominant effects were important in control of resistance and susceptibility dominated over resistance. 相似文献
15.
Phytophthora clandestina is a causal agent of root rot disease of subterranean clover in Western Australia (W.A). As a significant number of isolates
of P. clandestina from W.A. could not previously be designated using existing differentials, a comprehensive set of subterranean clover (Trifolium subterraneum) cultivars was used as differentials to delineate a broader range of races of the pathogen. One hundred and one isolates
of the pathogen collected from W.A. were screened on nine subterranean clover cultivars, of which seven were found to be useful
as host differentials. A total of 10 races (in contrast to the five recognized previously) were defined and differentiated
using octal nomenclature, presenting a clearer picture of the racial distribution of P. clandestina among W.A. isolates. Differences were found in the race populations between Australian states and are therefore important
to the selection/breeding of cultivars for specific regions of Australia to counter the predominant race populations and for
enforcing quarantine measures in relation to seed movements within and outside Australia. The octal nomenclature used provides
a sound basis for follow-up studies and future race designations. Races 173 and 177 in this study were widely distributed
and were the most common races in W.A., and together constitute 80% of the isolates characterized. While six of the seven
host differentials were resistant to isolates belonging to race 001 and all were resistant to 000, it is of concern that only
one differential was resistant to 157 and 173 and that none of the host differentials were resistant to 177. Our approach
to P. clandestina race delineation is clearly conservative and is different from previous studies. The octal nomenclature we applied in this
study is not only scientifically sound but also will facilitate rapid recognition and characterization of the races. 相似文献
16.
Joana G. Vicente Steven J. Roberts 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(4):383-392
Bacterial canker is one of the most important diseases of cherry (Prunus avium). This disease can be caused by two pathovars of Pseudomonas syringae: pv. morsprunorum and pv. syringae. Repetitive DNA polymerase chain reaction-based fingerprinting (rep-PCR) was investigated as a method to distinguish pathovars,
races and isolates of P. syringae from sweet and wild cherry. After amplification of total genomic DNA from 87 isolates using the REP (repetitive extragenic
palindromic), ERIC (enterobacterial repetitive intergenic consensus) and BOX primers, followed by agarose gel electrophoresis,
groups of isolates showed specific patterns of PCR products. Pseudomonas syringae pv. syringae isolates were highly variable. The differences amongst the fingerprints of P. syringae pv. morsprunorum race 1 isolates were small. The patterns of P. syringae pv. morsprunorum race 2 isolates were also very uniform, with one exception, and distinct from the race 1 isolates. rep-PCR is a rapid and
simple method to identify isolates of the two races of P. syringae pv. morsprunorum; this method can also assist in the identification of P. syringae pv. syringae isolates, although it cannot replace inoculation on susceptible hosts such as cherry and lilac. 相似文献
17.
Margarita Lema María Elena Cartea Tamara Sotelo Pablo Velasco Pilar Soengas 《European journal of plant pathology / European Foundation for Plant Pathology》2012,133(1):159-169
Black rot, caused by Xanthomonas campestris pv. campestris (Xcc) is a severe seedborne disease of Brassica crops around the world. Nine races are recognized, being races 1 and 4 the
most aggressive and widespread. The identification of Xcc races affecting Brassica crops in a target area is necessary to
establish adequate control measures and breeding strategies. The objectives of this study were to isolate and identify Xcc
strains from northwestern Spain by using semi-selective medium and pathogenicity tests, determine the existing races of Xcc
in this area by differential series of Brassica spp., and evaluate the use of repetitive DNA polymerase chain reaction-based fingerprinting (rep-PCR) to differentiate among
the nine existing Xcc races. Seventy five isolates recovered from infected fields were identified as Xcc. Race-typing tests
determined the presence of the following seven pathogen races: 1, 4, 5, 6, 7, 8 and 9. Race 4 was the most frequent in Brassica oleracea and race 6 in Brassica rapa crops, therefore breeding should be focussed in obtaining resistant varieties to both races. Cluster analysis derived from
the combined fingerprints showed four groups, but no clear relationship to race, crop or geographical origin was found. Rep-PCR
analysis was found not to be a reliable method to discriminate among Xcc races, therefore race typing of Xcc isolates should
be done by using the differential series of Brassica spp. genotypes or another alternative approach. 相似文献
18.
We examined the response of adzuki bean leaves to infection by Phytophthora vignae f. sp. adzukicola and determined whether inoculated leaves can be used to evaluate cultivar resistance. Detached adzuki bean leaves were inoculated
with zoospores, and the resulting symptoms were diagnosed. Resistant reactions were characterized by dark brown, speckled
lesions or a lack of symptoms, while susceptible reactions were characterized by water-soaked spreading lesions. In an inoculation
experiment using a combination of three differential cultivars and three races, the response of 10-day-old primary leaves
accurately differentiate between race-specific resistance and susceptibility of adzuki cultivars. 相似文献
19.
Y. L. Wu G. J. Yi X. X. Peng 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(3):409-415
In order to accelerate breeding and selection for disease resistance to Fusarium wilt, it is important to develop bioassays
which can differentiate between resistant and susceptible cultivars efficiently. Currently, the most commonly used early bioassay
for screening Musa genotypes against Fusarium oxysporum f. sp. cubense (Foc) is a pot system, followed by a hydroponic system. This paper investigated the utility of in vitro inoculation of rooted banana plantlets grown on modified medium as a reliable and rapid bioassay for resistance to Foc. Using a scale of 0 to 6 for disease severity measurement, the mean final disease severities of cultivars expressing different
levels of disease reaction were significantly different (P ≤ 0.05). Twenty-four days after inoculation with Foc tropical race 4 at 106 conidia ml−1, the plantlets of two susceptible cultivars had higher final disease severities than that of four resistant cultivars. Compared
with ‘Guangfen No.1’, ‘Brazil Xiangjiao’ is highly susceptible to tropical race 4 and its mean final disease severity was
the highest (5.27). The plantlets of moderately resistant cultivar ‘Formosana’ had a mean final disease severity (3.53) lower
than that of ‘Guangfen No.1’ (4.33) but higher than that of resistant cultivars: ‘Nongke No.1’, GCTCV-119, and ‘Dongguan Dajiao’
(1.87, 1.73, and1.53, respectively). Promising resistant clones acquired through non-conventional breeding techniques such
as in vitro selection, genetic transformation, and protoplast fusion could be screened by the in vitro bioassay directly. Since there is no acclimatization stage for plantlets used in the bioassay, it helps to improve banana
breeding efficiency. 相似文献
20.
The development time and parasitization rate ofDiaeretiella rapae (M’Intosh) onBrevicoryne brassicae (L.) feeding on differentBrassica cultivars was studied in the laboratory at 20°C. The shortest development time from egg to adult parasitoid was 11.6 days
on cabbage cv. ‘Yalova 1’ and the longest was 12.1 days on turnip cv. ‘Antep’ and rapeseed cv. local variety. Females lived
significantly longer than males on the host plants used in the study. Females and males had the shortest longevity on rapeseed
at 11.1 and 5.1 days, respectively. The highest percent parasitism ofB. brassicae byD. rapae was found on cabbage (40.20%), and the lowest was recorded on turnip (32.64%). Our results demonstrate that parasitism rate
could be influenced by the plant quality, probably due to the nutritional status of the aphids or to toxic compounds ingested
through the plant. Cabbage, cauliflower and broccoli were found to be suitable plants for the parasitoid, considering the
development time of pre-adults, and the parasitization rate ofD. rapae onB. brassicae.
http://www.phytoparasitica.org posting Jan. 23, 2007. 相似文献