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1.
James G. Menzies David L. Ehret Carol Koch Carl Bogdanoff 《European journal of plant pathology / European Foundation for Plant Pathology》1998,104(8):769-775
In 1993, a serious epidemic of a tomato root disease resembling corky root rot occurred in commercial greenhouses throughout Canada. Pyrenochaeta lycopersici could not be isolated from diseased roots, but Humicola fuscoatra was commonly isolated. The objectives of our work were to determine if H. fuscoatra is able to infect roots of tomato and cause corky root rot symptoms. Humicola fuscoatra was found to infect the roots of tomato seedlings and older plants. We concluded that H. fuscoatra is not a pathogen of tomato, however, because infection of tomato roots with the fungus did not necessarily lead to development of corky root rot or any other disease symptoms. Populations of H. fuscoatra increased greatly in sterile water or sterile nutrient solution, which would help to explain why commercial greenhouse growers can find this fungus in recirculating nutrient solutions. 相似文献
2.
In arid conditions in India,Ganoderma lucidum (Leyss: Fr.) P. Karsten was found to cause root rot diseases in jojoba (Simmondsia chinensis (Link) Schneider) plants. In the rainy season, 10–15-year-old jojoba plants growing in the proximity of aGanoderma-infectedAcacia tortilis tree, developed disease symptoms. Twigs of affected plants started drying from the top of the branch; leaves turned yellowish
brown and finally abscissed; plants dried up within 1 to 3 months. Basidiocarps developed from decaying roots near the collar
region and produced colored stalks and fruiting caps. Pathogenicity of the fungus was established by keeping the infected
root segments in direct contact with roots of healthy jojoba plants. Root rot symptoms were expressed within 5 months in inoculated
plants subjected to moisture stress. 相似文献
3.
N. Ioannou 《Phytoparasitica》2000,28(3):248-256
Preplant soil fumigation with methyl bromide (MB) is presently standard practice in greenhouse tomato production. Since this
compound is scheduled to be phased out by 2005, the possibility of using solarization as an alternative soil disinfestation
method was examined in four greenhouse tomato trials. Solarization was applied for 8 weeks in July-August, using transparent
polyethylene sheets for soil mulching, and compared with MB fumigation applied in September, before planting, at 80 g/m2. Solarization raised the maximum soil temperature by 9°C and reduced the population density ofFusarium spp. in soil by 91–98%. Similar reductions of soil inoculum (95–99%) were obtained with MB fumigation. Both methods provided
effective control of Fusarium wilt, Verticillium wilt and corky root rot on tomato plants. MB fumigation was in addition highly
effective against root-knot nematodes, whereas nematode control with solarization did not exceed 50%. Both treatments resulted
in similar fruit yield increases, ranging within 90–140% compared with plants grown in untreated soil. During the second cropping
season following soil treatment, solarization exhibited two times higher residual effectiveness against vascular wilt diseases
compared with MB fumigation. The latter treatment, however, was superior to solarization in its residual effectiveness against
root-knot nematodes and to a lesser extent against corky root rot. Fruit yields from solarized and MB-fumigated soil during
the second cropping season were higher than those obtained from untreated soil by approximately 35% and 60%, respectively.
In Cyprus, solarization appears to be an effective alternative to MB fumigation in greenhouse tomato production, especially
if integrated with other approaches enabling more effective nematode control. 相似文献
4.
Arne Hermansen Leslie Wanner Ragnhild Nærstad Sonja Sletner Klemsdal 《European journal of plant pathology / European Foundation for Plant Pathology》2012,133(1):211-228
Specific PCR primers were developed for identifying two post harvest pathogens, Mycocentrospora acerina and Fibularhizoctonia carotae, which cause liquorice rot and crater rot respectively, during prolonged low temperature storage of carrots. The methods
allow routine detection of less than 0.3 pg of M. acerina DNA and less than 0.03 pg F. carotae DNA, even in the presence of large excess of plant or soil DNA. Standard PCR and quantitative PCR gave similar results and
either method could be used in a practical situation. Experiments were carried out testing these methods on different types
of carrot tissue- and soil- samples. Soil was sampled before sowing, and soil adhering to the roots or root tissue was sampled
at different times during the growing season or at harvest. Soil adhering to the carrots at harvest had the best predictive
ability for liquorice rot development during storage (R2 predicted 74.9% using standard PCR), but samples taken during the growing season also gave reasonably good predictive ability
values. PCR data from soil samples taken in the spring were not as good as a predictor for this disease. A dense sampling
strategy using 20 m between sampling points generally gave better correlation between PCR data and disease data than using
40 m between the sampling points. Use of the developed methods in an IPM strategy for liquorice rot is discussed. For crater
rot the correlation between PCR data and disease data was generally poor for all types of samples. These results are discussed
in relation to the biology of F. carotae. 相似文献
5.
Koji KAGEYAMA Tomoaki AOYAGI Rumi SUNOUCHI Hirokazu FUKUI 《Journal of General Plant Pathology》2002,68(1):15-20
Miniature roses growing in an ebb-and-flow watering system developed dieback during the summer growing season of 1996 in Gifu
Prefecture. The main diagnostic symptoms were chlorosis of leaf followed by blight, and a brown, water-soaked root rot followed
by dieback. Pythium isolates were recovered from the rotted root. The isolates form proliferous ellipsoidal papillate sporangia, spherical smooth
oogonia, elongate antheridia, and aplerotic oospores. The optimum temperature for hyphal growth was 35°C with a growth rate
of 34 mm/24 hr. Optimum temperature of zoospore formation (25-30°C) was lower than that of mycelial growth, and zoospores
were produced even at 10°C. The isolates were identified as P. helicoides on the basis of these characteristics. In pathogenicity tests disease severity was highest at the highest tested temperature
(35°C) at which the disease naturally occurred in summer. Four days after inoculation, the leaves turned yellow and the roots
had a water-soaked rot, followed by leaf blight and root dieback after 7 days. The disease transmission test showed that diseased
plants were found throughout the bench after 10 days.
Received 4 July 2001/ Accepted in revised form 10 October 2001 相似文献
6.
Susan J. Sprague Barbara J. Howlett John A. Kirkegaard 《European journal of plant pathology / European Foundation for Plant Pathology》2009,125(2):189-202
The infection of above-ground tissues of Brassica napus by Leptosphaeria maculans is well understood. However, root infection (root rot) under field conditions, the development of root rot over time and
its relationship to other disease symptoms caused by L. maculans has not been described. A survey of B. napus crops was conducted in Australia to investigate the incidence and severity of root rot. Additionally, the pathway of root
infection was examined in field experiments. Root rot was present in 95% of the 127 crops surveyed. The severity and incidence
of root rot was significantly correlated with that of crown canker; however, the strength of this relationship was dependent
on the season. Root rot symptoms appeared before flowering and increased in severity during flowering and at maturity, a pattern
similar to crown canker suggesting that the infection of the root is an extension of the crown canker phase of the L. maculans lifecycle. All isolates of L. maculans tested in glasshouse experiments caused root rot and crown canker in B. napus and Brassica juncea. In the field, the main pathway of root infection is via invasion of cotyledons or leaves by airborne ascospores, rather
than from inoculum in the soil. Root rot was present in crops in fields that had never been sown to B. napus previously, in plants grown in fumigated fields, and in glasshouse-grown plants inoculated in the hypocotyl with L. maculans. 相似文献
7.
Simon Gibert Véronique Edel-Hermann Elodie Gautheron Nadine Gautheron Eric Bernaud Jean-Marie Sol Géry Capelle Rachel Galland Arnaud Bardon-Debats Claudine Lambert Christian Steinberg 《Plant pathology》2022,71(7):1550-1569
The pea root rot complex is a major concern for green pea production worldwide. This study aimed at characterizing its composition and dynamics throughout a cropping season in northern France. To this end, fungi and oomycetes were isolated from green pea plant roots with symptoms sampled at the flowering stage in 22 fields in 2017, and at the pea emergence, elongation and flowering stages in two fields in 2018. Out of 646 isolates collected, 317 were identified using molecular markers. Fusarium oxysporum, F. solani and F. redolens were highly predominant. Pathogenicity tests separated the isolates into four aggressiveness groups. F. solani isolates were the most aggressive. Phylogenetic analysis of their TEF1 sequences showed that they mainly belonged to the F. pisi lineage, and that F. oxysporum isolates were genetically close to isolates from the UK that did not belong to the forma specialis pisi. In addition, several Clonostachys rhizophaga isolates are reported for the first time to cause pea root rot. The oomycetes were rarely found and were represented by a few Pythium spp. isolates. Lastly, this study shows that the fungal and oomycete communities associated with pea root rot change during the cropping season. The level of dissimilarity of the root-rot-associated communities decreased throughout the cropping season towards a more similar composition at the flowering stage, dominated by F. solani, F. oxysporum and F. redolens. The proportion of nonpathogenic to weakly pathogenic isolates decreased progressively during the growing season in favour of moderately to highly pathogenic isolates. 相似文献
8.
Black root rot disease of cotton seedlings caused by Thielavioposis basicola was first reported in New South Wales (NSW), Australia in 1990. In 2018, T. basicola was reclassified into a new genus Berkeleyomyces, accommodating two closely related species: B. basicola and B. rouxiae. However, species status of cotton-T. basicola in NSW remains unsolved. Ninety-five isolates recovered from black root rot diseased cotton seedlings sampled across NSW in 2017/18 season was subjected to morphological, multigene sequencing (ITS, MCM7, RPB2), and pathogenicity assessments for their species identification. Berkeleyomyces rouxiae was accurately identified as the causal agent of black root rot of cotton.
相似文献9.
Black rot, caused by Xanthomonas campestris pv. campestris, (Xcc), is one of the most serious diseases of crucifers world-wide. Forty-nine genotypes were evaluated for resistance under field
conditions in Tanzania after artificial inoculation with Xcc race 1. Open pollinated white cabbage cultivars were generally susceptible, while Portuguese and pointed cabbages exhibited
partial resistance. Some F1 white cabbage cultivars were highly susceptible, whereas others exhibited a high level of partial
resistance. The most promising of the hybrid cultivars were T-689 F1, Gianty F1, No. 9690 F1, N 66 F1, and SWR-02 F1. Breeding
line Badger I-16 exhibited the highest level of resistance of all genotypes. The genotypes accounted for 72.9–75.5% of the
variation of the disease severity when assessed on the leaves, and 71.4% of the variation when assessed as internal black
rot in heads at harvest. High correlations (equal to or above 0.7) were found between disease severities assessed on leaves
three times during the growing season and also with the amount of internal black rot in heads. Leaf loss also was correlated
with disease severity. The high genetic determination of the trait and the high correlations between disease assessments indicate
that selection for resistance to black rot will be efficient when field screenings are carried out. Evaluation of genotypes
for disease severity on leaves during the growing season combined with evaluations of head resistance in the most promising
genotypes may be a simple method to select resistant cultivars. 相似文献
10.
Mariana Nakova 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(4):517-525
Disease on fruit trees in Bulgaria caused by Phytopthora cactorum and P. citrophthora was found in the period 1998–1999. Leaves of some trees become reddish during July, and later in the season fall off. Infected
trees die during the same season, or the next season. Observations on symptom development and spread of Phytophthora root and crown rot of fruit trees was undertaken from 1999 to 2009. Disease incidence is between 2% and 14% in some gardens
and nurseries. The disease was registered in the regions of Plovdiv, Kjustendil, Sliven, Yambol, Karnobat, Bourgas and Svishtov.
Samples from infected plant tissues were taken and isolations were done on selective PARP media, or by applying a baiting
bioassay. Based on morphological and cultural characteristics and temperature requirements the following Phytophthora species have been identified: Phytophthora cactorum, P. citrophthora, P. drechsleri, P. cryptogea, hybrid and Pythium. Pathogenicity of the isolates was tested on green apple fruits or one-year-old apple rootstocks. Laboratory studies of the
effect of temperature on mycelia growth showed that most isolates can grow from 5° up to 30°C, with an optimum from 18° to
25°C. Only three strains grew at 35–36°C, two developed slowly, one grew well. The optimal pH for mycelia development was
tested. Aiming at control of disease, in vivo pot trials have been carried out for studying resistance of rootstocks to P. cactorum. At the end of the growing season a good level of resistance has been shown in the rootstocks M29C, Gizela 6, and MAXMA 14. 相似文献
11.
Kentaro Ikeda 《Journal of General Plant Pathology》2010,76(4):241-246
Pepper (Piper nigrum L.) root rot caused by Fusarium solani f. sp. piperis (FSP; teleomorph: Nectria haematococca f. sp. piperis) includes two symptom types called root rot (RR) type and stem rot (SR) type. In this study, the temporal and spatial associations
between perithecial formation of FSP and development of SR were investigated in naturally infested fields to verify the hypothesis
that ascospores from the perithecia are the major inoculum source of the SR type on vines in the field. In surveys of all
vines in two neighboring pepper fields every month from December 2005 to November 2006, I mapped the locations of all vines
with perithecia and all vines the SR type. The frequency of vines with perithecia increased during April and May, the late
rainy season. In June, the early dry season, the number of vines with SR type greatly increased. The vertical range of perithecial
formation on the vines extended to 200 cm in height, but was restricted to 30 cm in the dry season in both fields. The join-count
statistics showed a significant spatial association between vines with perithecia and vines with SR type in one field (P = 0.042), while no significant spatial association was recognized in another field. The results suggested that ascospores
from perithecia of FSP on pepper vines are likely to be one of the main inoculum sources of the SR type of the disease on
adjacent vines, but they may not be the exclusive source. 相似文献
12.
Ednar G. Wulff Cames M. Mguni Carmen N. Mortensen Chandroo L. Keswani John Hockenhull 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(4):317-325
Biological control efficiency of an antagonistic, endophytic strain of Bacillus subtilis (strain BB) was evaluated against three strains of the black rot pathogen, Xanthomonas campestris pv. campestris (Xcc), in four Brassica crops (cabbage, cauliflower, rape and broccoli) grown during three consecutive growing seasons and on two soil types, in two different areas in Zimbabwe. Strain BB controlled the disease caused by strain Xcc B-147 in all Brassica crops during the dry and short rainy seasons. A similar effect was observed in cabbage using the strain Xcc 33908. Biological control was effective in broccoli, but not in cabbage and rape during the main rainy season in clay loam soil and limited biological control effect was still observed when these crops were grown in sandy loam soil. The endophytic colonisation of cabbage roots by strain BB was confirmed by immuno-blotting during the whole growing season. Biological control of black rot with strain BB is discussed in relation to its effect on Xcc strains, Brassica crops and to the effect of weather and soil conditions. 相似文献
13.
M. Castejón-Muñoz P. J. Oyarzun 《European journal of plant pathology / European Foundation for Plant Pathology》1995,101(1):35-49
Potential antagonists ofFusarium solani f. sp.pisi (Fsp) were selected from soil samples with varying degrees of receptivity to this pathogen. They were tested against Fsp isolate 48 (Fs48), in increasingly complex systems. Most species testedin vitro were able to antagonize Fs48. No relation could be establishedin vitro between the receptivity of the soil from which an isolate originated and its antagonism to Fs48. In soils naturally infested with pea root rot pathogens, which were stored humid at 4°C for a period longer than a year, various isolates ofFusarium, Gliocladium andPenicillium spp. were able to reduce root rot. After sterilization of these soils, onlyGliocladium roseum isolates, added at 105 conidia g–1 dry soil, significantly reduced disease severity and prevented root weight losses caused by Fs48 at 104 conidia g–1 dry soil. In soils in which the biota were activated by growing peas before the assays, doses of 106 and 107 ofG. roseum were required to reduce root rot. In these soils, the antagonistic effects of fluorescent pseudomonad strains from soil of low receptivity to Fsp were variable. Some strains of fluorescent pseudomonads, from soil moderately receptive to Fsp and from highly infested soils, were also able to reduce root rot. Disease suppression by pseudomonad strains was more evident in the absence than in the presence ofAphanomyces euteiches in the root rot pathogen complex. The role of receptiveness of the soil with regard to potential antagonists is discussed. 相似文献
14.
J. M. DUNCAN 《EPPO Bulletin》1990,20(1):107-115
Phytophthora frugariae causes red core root rot of strawberries. Although the disease is probably most acute in northern Europe, serious outbreaks have been reported from a number of Mediterranean countries, especially France and Italy. Leather rot of fruit and crown rot, which are caused by P. cuctorum, can also be severe problems in warmer climates. Both fungi survive in soil for long periods, but the most common form of spread is in diseased planting material. Sensitive tests have been developed to detect red core in planting material, and been used to effect in certification schemes. Root rot of raspberry has gained prominence in the last 10 years in Europe as raspberry growing has expanded, but the disease has been known for many years in France. Nine species of Phyfophthora have been recovered from affected plants, but two of these, one with affinities with P. megasperma, and P. cumbiuora, are responsible for most major outbreaks. The other species are only troublesome where drainage is poor. Again, spread is mainly in infected material. Few raspberries are resistant to root rot, but some wild RubuP spp., blackberries and raspberry x blackberry hybrids are resistant and may be useful in breeding programmes. 相似文献
15.
Jonathan Scauflaire Olivier Mahieu Julien Louvieaux Guy Foucart Fabien Renard Fran?oise Munaut 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(1):59-66
In order to investigate the pre-harvest contamination of maize plants by Fusarium species in Belgium, a three-year survey has been performed in five fields in which three hybrids differing in susceptibility
to maize stalk rot were sampled at four different physiological stages. An extensive collection of 5,659 Fusarium isolates characterized at the species level was established during the 2005, 2006, and 2007 growing seasons, with a total
of 23 different Fusarium species identified to occur on ears and stalks. A high number of plants was already contaminated by Fusarium spp. at the anthesis stage, although no symptoms were visible on ears or on stalks. As the season progressed, the incidence
of Fusarium-infected maize plants reached 100% in several fields. At the end of the growing season, the most frequently isolated species
in maize ears were F. graminearum, sometimes associated with F. avenaceum, F. crookwellense, F. culmorum, F. poae, and F. temperatum, a new species recently described on maize. The predominant Fusarium species detected in stalks at the end of the growing season were F. graminearum and F. crookwellense, often associated with F. culmorum and F. temperatum. Year-to-year variability observed for the incidence of F. graminearum can most likely be associated with differences in climatic conditions among the three years. 相似文献
16.
黑龙江省大豆疫霉根腐病调查与病原分离 总被引:10,自引:0,他引:10
1996年对黑龙江省东部和中部大豆产区23个市、县的大豆苗期疫霉根腐病进行了调查、研究,应用PBNIC疫霉选择性培养基分离大豆疫霉根腐病病原菌,从牡丹江、穆棱、林口和佳木斯豆田具疫霉根腐症状的大豆植株上分离到大豆疫霉根腐病菌,并从根腐病株上单独或与大豆疫霉菌同时分离到终极腐霉菌,研究进一步证实我国黑龙江省有大豆疫霉根腐病。调查发现,大豆疫霉根腐病和终极腐霉根腐病主要发生在土质粘重、土壤含水量高或易积水的田块。 相似文献
17.
18.
A study was conducted in two greenhouses with a history of Fusarium crown and root rot (Fusarium oxysporum f.sp.radicis-lycopersici, Forl) and root-knot nematodes (Meloidogyne javanica andM. incognita). During the 2005–06 growing season, the effectiveness of soil disinfestation by solarization in combination with low doses
of metham-sodium (500, 750, 1000 and 1250l ha−1) or dazomet (400 g ha−1), was tested against soilborne pathogens and nematodes in an attempt to find a suitable alternative to methyl bromide, which
is soon to be phased out. Solarization alone was not effective in the greenhouse with a high incidence ofForl. In the greenhouse with a low level ofForl, all the treatments tested reduced disease incidence, and were therefore considered to be applicable for soil disinfestation.
In addition, root-knot nematode density decreased with all the treatments tested in both of the greenhouses. 相似文献
19.
Poinsettia plants growing in ebb-and-flow irrigation systems developed wilting and root rot during the summer growing seasons of 2010 in Gifu Prefecture and 2011 in Aichi Prefecture. Pythium species were isolated from roots with rot symptoms. The isolates were identified as P. helicoides and P. myriotylum on the basis of morphological characteristics and sequence homologies in the rDNA internal transcribed spacer regions. In pathogenicity tests, these isolates caused severe wilting and root rot. This is the first report of poinsettia root rot disease caused by P. helicoides and P. myriotylum, although P. aphanidermatum was reported as a pathogen of poinsettia root rot. To better understand these diseases, we performed an epidemiological study of three high-temperature-tolerant Pythium species, P. aphanidermatum, P. helicoides and P. myriotylum. Disease incidence as a percentage of diseased plants was greatest at 35 °C for all three species. Disease severity using the rating scale of root rot was also highest at 35 °C, particularly with high zoospore inoculum densities (100.0 zoospores/mL). Although the disease incidence and severity were reduced at lower temperatures, the three Pythium species were able to cause disease at temperatures as low as 20 °C. 相似文献
20.
Root‐knot nematodes do not affect black root rot disease severity on watermelon and bottle gourd
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The effects of root‐knot nematodes on black root rot of watermelon and bottle gourd were studied using field surveys and co‐inoculation tests with Meloidogyne incognita (southern root‐knot nematode) and Diaporthe sclerotioides. The results of the field survey suggested that root‐knot nematodes had little effect on either the severity of black root rot or infection with D. sclerotioides. None of the three fields showed a significant positive correlation between disease severity and nematode gall index, with low correlation coefficients. Co‐inoculation experiments under controlled conditions found no significant effect of root‐knot nematodes on black root rot of watermelon and bottle gourd based on area under disease progress curves (AUDPC). These results were supported by the quantities of DNA of the two agents in root tissues because no significant difference was found between dual‐ and single‐inoculation treatments with M. incognita and/or D. sclerotioides. These findings suggest that root‐knot nematodes probably do not affect the infection of watermelon or bottle gourd roots by D. sclerotioides or the incidence of black root rot in these crops caused by this fungus. 相似文献