共查询到20条相似文献,搜索用时 324 毫秒
1.
Trabelsi Darine M.B. Allagui M. Rouaissi A. Boudabbous 《Physiological and Molecular Plant Pathology》2007,70(4-6):142-148
Nine isolates of Phtophthora nicotianae were isolated from infected pepper plants. Their pathogenicity was studied in Capsicum annuum in comparison with P. nicotianae isolates from tomato and tobacco. The pathogenicity test showed that pepper isolates of P. nicotianae are adapted to their host. Banding patterns obtained by RAPD analysis with six oligonucleotide primers revealed polymorphism that grouped the isolates independently of the plant host. The polygenic dendrogram showed that pepper isolates were more similar to tomato isolates than to tobacco isolates. The RAPD bands of 1300 and 1500 bp, detected with primers OPD-01 and OPD-10, respectively, appeared specific to the most pathogenic pepper isolates. The OPK-08-1950 seems specific to the isolates of P. nicotianae from tomato. These results suggest that host specified might occur in P. nicotianae and that may be due to interspecific hybridization events resulting in novel pathogenic behavior. 相似文献
2.
Phytophthora root rot of sweet pepper 总被引:1,自引:0,他引:1
N. A. M. Van Steekelenburg 《European journal of plant pathology / European Foundation for Plant Pathology》1980,86(5):259-264
Phytophthora capsici proved to be the causal agent of a root and crown rot of sweet pepper in the Netherlands.P. capsici was pathogenic on sweet pepper, tomato and sometimes on eggplant but not on tobacco Xanthi. Of these test plants only tomato was infected byP. nicotianae.No different symptoms in plants infected with eitherP. capsici orP. nicotianae were found. Dipping the roots of tomato and sweet pepper plants in a suspension ofP. capsici resulted in a more severe attack than pouring the suspension on the stem base.Resistance in tomato toP. nicotianae did not include resistance toP. capsici. A method to distinguishP. capsici fromP. nicotianae after isolation from soil is described. Both species were able to infect green fruits of tomato and sweet pepper.p. capsici survived in moist soil in the absence of a host for at least 15 months.Samenvatting
Phytophthora capsici bleek de oorzaak te zijn van een voet-en wortelrot in paprika op twee bedrijven in 1977 in Nederland.P. capsici was pathogeen op paprika, tomaat en soms op aubergine maar niet op tabak Xanthi.P. nicotianae tastte van deze toetsplanten alleen tomaat aan. Verschillen in symptomen tussenP. nicotianae enP. capsici werden bij tomaat niet waargenomen.Het dompelen van de wortels in eenP. capsici suspensie gaf een ernstiger aantasting dan het begieten van de wortelhals met deze suspensie.Resistentie in tomaat tegenP. nicotianae bleek geen resistentie tegenP. capsici in te houden.
P. capsici kan in grond worden aangetoond door groene paprikavruchten als vangsubstraat te gebruiken.P. capsici enP. nicotianae kunnen beide zowel vruchten van tomaat als paprika aantasten.
P. capsici overleefde een periode van 15 maan den in vochtige grond waarop geen waardplant werd geteeld. 相似文献
3.
Acquired resistance triggered by elicitins in tobacco and other plants 总被引:17,自引:0,他引:17
Philippe Bonnet Eva Bourdon Michel Ponchet Jean -Pierre Blein Pierre Ricci 《European journal of plant pathology / European Foundation for Plant Pathology》1996,102(2):181-192
Elicitins are a family of proteins excreted byPhytophthora spp. They exhibit high sequence homology but large net charge differences. They induce necrosis in tobacco plants which then become resistant to the tobacco pathogenPhytophthora parasitica var.nicotianae. In stem-treated plants, resistance was not restricted to the site of elicitin application, but could be demonstrated by petiole inoculation at all levels on the stem. Resistance was already maximum after two days and lasted for at least two weeks. It was effective not only towardsP. p. var.nicotianae infection, but also against the unrelated pathogenSclerotinia sclerotiorum. In contrast to dichloroisonicotinic acid, an artificial inducer of systemic acquired resistance, which was increasingly effective with doses ranging from 0.25 to 5mole per plant, the basic elicitin cryptogein exhibited a threshold effect, inducing near total resistance and extensive leaf necrosis above 0.1 nmole per plant. Between 1 and 5 nmole, acidic elicitins (capsicein and parasiticein) protected tobacco plants with hardly any necrotic symptom. Elicitins exhibited similar effects in various tobacco cultivars andNicotiana species, although with quantitative differences, but induced neither necrosis nor protection in other SolanaceÆ (tomato, petunia and pepper). Among 24 additional species tested belonging to 18 botanical families, only some BrassicaceÆ, noticeably rape, exhibited symptoms in response to elicitins, in a cultivar-specific manner. Elicitins appear to be natural specific triggers for systemic acquired resistance and provide a tool for unraveling the mechanisms leading to its establishment.Abbreviations AR
acquired resistance
- HR
hypersensitive response
- INA
2,6-dichloroisonicotinic acid
- Ppn
Phytophthora parasitica var.nicotianae
- SAR
systemic acquired resistance 相似文献
4.
In four neighbouring regions of southern Italy, Basilicata, Campania, Apulia and Calabria, pepper and zucchini plants showing
Phytophthora blight symptoms, tomato plants with either late blight or buckeye rot symptoms, plants of strawberry showing
crown rot symptoms and declining clementine trees with root and fruit rot were examined for Phytophthora infections by means of polymerase chain reaction (PCR) assays, using primers directed to nuclear ribosomal DNA (rDNA) repeat
sequences. All diseased plants and trees examined tested positive. The detected fungal-like organisms were differentiated
and characterized on the basis of primer specificity as well as through extensive restriction fragment length polymorphism
(RFLP) and sequence analysis of PCR-amplified rDNA. Phytophthora capsici was identified in diseased pepper and zucchini plants, P. infestans was identified in tomato with late blight symptoms whereas buckeye rot-affected tomatoes and diseased strawberry plants proved
to be infected by P. nicotianae and P. cactorum, respectively. Declining clementine trees were infected with P. citrophthora and P. nicotianae in about the same proportion. Also, thirty-one pure culture-maintained isolates of Phytophthora which had previously been identified in southern Italy by traditional methods but were never examined molecularly, were examined
by RFLP and sequence analysis of PCR-amplified nuclear rDNA. Among these, an isolate from gerbera which had previously been
identified by traditional methods only at genus level, was assigned to P. tentaculata. For the remaining pure culture-maintained isolates examined, the molecular identification data obtained corresponded with
those delineated by traditional methods. Most of the diseases examined were already known to occur in southern Italy but the
pathogens were molecularly detected and fully characterized at nuclear rDNA repeat level only from other geographic areas,
very often outside Italy. A new disease to southern Italy was the Phytophthora blight of zucchini. This is also the first
report on the presence and molecular identification of P. tentaculata from Italy. 相似文献
5.
Hideki Watanabe Yoshihiro Taguchi Mitsuro Hyakumachi Koji Kageyama 《Journal of General Plant Pathology》2007,73(2):81-88
Pythium and Phytophthora species were isolated from kalanchoe plants with root and stem rots. Phytophthora isolates were identified as Phytophthora nicotianae on the basis of morphological characteristics and restriction fragment length polymorphism (RFLP) analysis of the rDNA-internal
transcribed spacer regions. Similarly, the Pythium isolates were identified as Pythium myriotylum and Pythium helicoides. In pathogenicity tests, isolates of the three species caused root and stem rots. Disease severity caused by the Pythium spp. and Ph. nicotianae was the greatest at 35°–40°C and 30°–40°C, respectively. Ph. nicotianae induced stem rot at two different relative humidities (60% and >95%) at 30°C. P. myriotylum and P. helicoides caused root and stem rots at high humidity (>95%), but only root rot at low humidity (60%). 相似文献
6.
Stéphane Poussier Jacques Luisetti 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(3):255-265
A sensitive and specific assay, based on a Nested-PCR-RFLP protocol, was developed for the detection of biovars of Ralstonia solanacearum, the causal agent of bacterial wilt. Oligonucleotide primer pairs were selected within the hrp gene region. Specific amplification of the hrp fragments was obtained for all R. solanacearum strains and also for two closely related species, Pseudomonas syzygii and the blood disease bacterium. No amplification was observed for a wide range of other bacterial species, including R. pickettii and Burkholderia cepacia. Digestion with HindII provided four distinct restriction profiles specific to biovars or groups of biovars of R. solanacearum: one for biovar 1 strains originating from the Southern part of Africa, one for American biovar 1 and biovars 2 and N2 strains, one for biovars 3 and 4 strains, and one for biovar 5 strains. When applied to either pure culture or infected plant tissues, Nested-PCR allowed detection as low as 103cfu ml–1, which corresponds to 1cfu per reaction. Amplification was partially or completely inhibited by compounds contained in plant extracts (potato plant and potato tuber, tomato, tobacco, eggplant, pepper and Pelargonium asperum). A combined PVPP/BSA treatment prior to amplification permitted reliable Nested-PCR detection of R. solanacearum strains in plant samples. Nested-PCR-RFLP, assessed with isolates from Reunion Island but also applicable to any R. solanacearum strain, provides a wide range of possible uses for identification, detection and epidemiological investigations. 相似文献
7.
Janet E. Macdonald George P. White Marie-José Côté 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(1):67-75
Phoma foveata and P. exigua variety exigua both infect potatoes and are morphologically very similar. P. foveata produces a pigment which allows differentiation from P. exigua in culture. Discrimination of the two species based on the production of a secondary metabolite, which is dependent on the growth conditions, is not reliable. Therefore, there is a need to develop nucleic acid based identification markers. A 482bp random amplified polymorphic DNA (RAPD) fragment from P. foveata was isolated and sequenced. Polymerase chain reaction (PCR) primers, developed from the sequence of the RAPD product, amplified a 474bp fragment for P. foveata and P. exigua varieties exigua, diversispora, inoxydibilis and sambuci-nigrae. The similarity of the PCR fragments was demonstrated by sequence analysis and by using the restriction enzymes DdeI and DpnII. P. foveata was distinguished from the four varieties of P. exigua on the basis of the RFLP patterns of the PCR fragment. Ten isolates of P. foveata and nine of P. exigua var. exigua from different geographic locations were tested and all isolates but one showed the restriction digest pattern of the PCR fragment (PCR-RFLP) specific to each species. One isolate of P. foveata demonstrated a PCR-RFLP pattern similar to P. exigua var. exigua leading to the conclusion that the isolate had been previously misidentified as a strain of P. foveata lacking the ability to produce pigment. 相似文献
8.
云南魔芋新病害—疫病病原菌的鉴定 总被引:2,自引:0,他引:2
<正>魔芋为天南星科(Araceae)魔芋属(Amorphophallus Blume)植物,是富含葡甘露聚糖的经济作物。随着人们对魔芋葡甘露聚糖的进一步研究和深度开发利用,魔芋的生产越来越受到重视,种植方式也由传统的半野生零星种植转向规模化大面积种植。云南是魔芋的起源中心之一[1],其气候环境非常适宜魔芋的生长和种植,但由于规模化种植程度的扩大以及芋农较为粗放的栽培管理方式,魔芋病害日趋严重,新病害亦不断出现。20世纪90年代初,我国魔芋有3种主要病害,现已增至11种。最近在云南省魔芋不同生育期的叶片及茎杆上又发现一种新病害——魔芋疫病。该病水渍状的黑 相似文献
9.
Antonio Ippolito Leonardo Schena Franco Nigro Vincenza Soleti ligorio Thaer Yaseen 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(8):833-843
Two primers, specific for Phytophthora nicotianae (Pn6) and P. citrophthora (Pc2B), were modified to obtain Scorpion primers for real-time identification and detection of both pathogens in citrus nursery soils and roots. Multiplex PCR with dual-labelled fluorogenic probes allowed concurrent identification of both species ofPhytophthora among 150 fungal isolates, including 14 species of Phytophthora. Using P. nicotianaespecific primers a delayed and lower fluorescence increase was also obtained from P. cactorumDNA. However, in separate real-time amplifications, the aspecific increase of fluorescence from P. cactorum was avoided by increasing the annealing temperature. In multiplex PCR, with a series of 10-fold DNA dilutions, the detection limit was 10 pg l-1 for P. nicotianaeand 100 pg l–1 for P. citrophthora, whereas in separate reaction DNA up to 1 pg l-1 was detected for both pathogens.Simple and rapid procedures for direct DNA extraction from soil and roots were utilised to yield DNA whose purity and quality was suitable for PCR assays. By combining these protocols with a double amplification (nested Scorpion-PCR) using primers Ph2-ITS4 amplifying DNA from the main Phytophthora species (first round) and PnB5-Pn6 Scorpion and Pc2B Scorpion-Pc7 (second round), it was possible to achieve real-time detection of P. nicotianaeand P. citrophthora from roots and soil. The degree of sensitivity was similar to that of traditional detection methods based on the use of selective media. The analyses of artificially and naturally infested soil showed a high and significant correlation between the concentration of pathogen propagules and the real-time PCR cycle threshold. 相似文献
10.
Junji Nishikawa Takao Kobayashi Kazuto Shirata Takashi Chibana Keiko T. Natsuaki 《Journal of General Plant Pathology》2006,72(5):305-313
We isolated 629 fungi from 1296 berry seeds of solanaceous plants, including tomato (Lycopersicon esculentum), eggplant (Solanum melongena), bell pepper (Capsicum annuum), and red pepper (Capsicum annuum var. annuum) preserved for long and short terms. The isolates were classified into 22 genera excluding unidentified fungi, and the fungal
floras were divided into two types: the tomato–eggplant and pepper groups. The results of cluster analysis with unweighted
pair-group method with arithmetic average also supported these groups. Most tomato seeds infested with Geotrichum candidum germinated and grew the same as uninfested seeds. Cladosporium sphaerospermum and Arthrinium sp. isolated from eggplant seeds strongly suppressed germination, and Penicillium variabile suppressed seminal root elongation on eggplant. Alternaria alternata, Botrytis cinerea, and Myrothecium verrucaria detected from red pepper or bell pepper seeds were pathogenic to the fruits and the seedlings after artificial inoculation. 相似文献
11.
Two primer sets were designed based on the sequence of polymorphic bands that were derived from repetitive sequence-based polymerase chain reaction (rep-PCR) fingerprinting and specifically detected in Ralstonia solanacearum race 4 strains (ginger, mioga, and curcuma isolates). One primer set (AKIF-AKIR) amplified a single band (165bp) from genomic DNA obtained from all mioga and curcuma and some ginger isolates; another set (21F-21R) amplified one band (125bp) from the other ginger isolates. These primer sets did not amplify the bands from genomic DNA of other R. solanacearum strains or of other related bacteria. PCR detection limit for the pathogen was 2 × 102cfu.The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession numbers AB118756 and AB118757 相似文献
12.
Phylogenetic analyses of plant-growth-promoting rhizobacteria isolated from tomato,lettuce, and Japanese pepper plants in Hyogo Prefecture,Japan 总被引:1,自引:0,他引:1
Tomohiro Kumatani Yukihiko Yoshimi Hitoshi Nakayashiki Masataka Aino 《Journal of General Plant Pathology》2009,75(4):316-321
Approximately 30,000 fluorescent bacterial strains isolated from tomato, lettuce, eggplant, Chinese cabbage, and Japanese
pepper plants at seven different locations in Hyogo Prefecture, were screened for plant-growth-promoting (PGP) activity to
induce disease resistance against bacterial wilt in tomato. The 37 strains that had higher PGP activity were subjected to
molecular phylogenetic analyses using the sequences of the 16S rRNA, gyrB and rpoD genes. Most of the strains were identified as Pseudomonas fluorescens or its close relative, P. putida, while a few strains were grouped with more distantly related bacterial species such as Enterobacter and Stenotrophomonas. The phylogenetic relationships among tomato and lettuce isolates mostly coincided with the source locality and host plants,
with a few exceptions. In contrast, isolates from Japanese pepper plants did not form their own cluster but represented several
different bacterial species. 相似文献
13.
Jeffrey S. Batten Karen-Beth G. Scholthof Branko R. Lovic Marvin E. Miller Raymond D. Martyn 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(7):639-649
Monosporascus root rot/vine decline (MRR/VD) causes root necrosis and severe stunting of muskmelon and watermelon plants in several countries around the world. MRR/VD is caused by the soilborne ascomycete fungus, Monosporascus cannonballus. Currently, there are few options available for control of MRR/VD. This research describes experiments to test the possibility of using naturally occurring M. cannonballus isolates containing double-stranded RNA (dsRNA) for the biological control of MRR/VD. These isolates often develop a degenerate phenotype characterized by slow growth and reduced ascospore production. In addition, these degenerate isolates are hypovirulent on muskmelon. Plants co-inoculated with a hypovirulent, dsRNA+ isolate (Tx93-449+) and a virulent, dsRNA- isolate (Az90-33-) at an inoculum ratio of 10:1 (hypovirulent:virulent) were indistinguishable from the uninoculated plants in greenhouse pathogenicity trials. In vitro infection assays using fluorescence microscopy on aniline-stained muskmelon roots suggested that although the hypovirulent dsRNA+ isolate Tx93-449+ penetrated and partially colonized roots of the seedlings, it was not as efficient in colonizing the roots as the virulent, dsRNA- isolate Az90-33-. While more extensive experiments are needed, these data suggest that hypovirulent dsRNA+ isolates of M. cannonballus have potential for development as biological control agents to reduce disease pressure associated with MRR/VD. 相似文献
14.
D. Louro G.P. Accotto A.M. Vaira 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(6):589-592
Tomato chlorosis virus (ToCV), a new whitefly-transmitted and phloem-limited Crinivirus infecting tomatoes in Europe, is reported for the first time in Portugal. Tomato plants with symptoms of interveinal chlorosis, collected during autumn 1998 and summer and autumn 1999 in Algarve, southern Portugal, were positive in RT-PCR assays using ToCV-specific primers. The amplified 439bp fragment was sequenced and showed 99% homology with the ToCV sequence in the GenBank database. A digoxigenin–DNA probe was produced and tested in dot-blot with total RNAs extracted from tomato samples. Both the RT-PCR and dot-blot hybridisation procedures enabled rapid and reliable detection of ToCV from field samples. 相似文献
15.
为探讨枯草芽胞杆菌Bacillus subtilis菌株B1409对番茄早疫病和辣椒疫霉病的防效和生防机制,采用平板对峙法和盆栽法测定了该菌株对番茄早疫病菌和辣椒疫霉病菌菌丝生长的抑制作用、对2种病害的盆栽防效以及对番茄和辣椒植株促生长效果和防御酶活性的影响。结果表明:菌株B1409能明显抑制番茄早疫病菌和辣椒疫霉病菌菌丝生长,且导致菌丝发生畸变。10~8CFU/mL菌株B1409菌液对番茄早疫病和辣椒疫霉病的预防效果分别为67.82%和61.22%,治疗效果分别为41.22%和56.43%。不同浓度B1409菌液均能促进番茄和辣椒植株生长,并能增强其体内超氧化物歧化酶、过氧化物酶和过氧化氢酶活性,且浓度越高促进效果越明显。番茄和辣椒植株的平均干重分别在10~2CFU/mL和10~4CFU/mL B1409菌液处理后显著高于对照,增长率分别为42.35%和4.87%。番茄和辣椒植株经10~2CFU/mL B1409菌液处理后,体内超氧化物歧化酶活性比对照显著增加,增长率分别为91.23%和19.58%。研究表明枯草芽胞杆菌B1409菌株可通过直接抑制菌丝生长及诱导植物体自身抗病性等方式来有效防治番茄早疫病和辣椒疫霉病。 相似文献
16.
Classification of 32 Verticillium dahliae isolates originating from 19 plant species in eight different botanical families to races and determination of host range pathogenicity were carried out. The physiological races of isolates were identified using the two differential tomato cultivars ??Belladonna?? (susceptible to both races 1 and 2 of V. dahliae) and ??Ace 55VF?? (resistant to race 1, susceptible to race 2 of V. dahliae). Among these isolates, 14 were race 2 (43.8%), 12 race 1 (37.5%) and six nonpathogenic (18.7%) on tomato. The host range pathogenicity of isolates was determined using four differential hosts (eggplant, turnip, tomato (Ve ? ) and sweet pepper). Among isolates, five were pathogenic to both eggplant and turnip (15.6%), 21 to eggplant, turnip and tomato (65.6%), five to eggplant, turnip, tomato and sweet pepper (15.6%) and one was pathogenic to eggplant, turnip and sweet pepper (3.2%). The pathogenicity of isolates on the aforementioned five hosts was investigated on the basis of external symptoms and by calculating the relative areas under disease progress curves (relative AUDPC). Results showed that eggplant was the most susceptible, followed by turnip and tomato cv. Belladonna, while sweet pepper and tomato cv. Ace 55VF were less susceptible to all the isolates used. The pathogenicity of isolates varied from highly to mildly virulent on eggplant and turnip while on Belladonna, Ace 55VF and sweet pepper it varied from highly virulent to nonpathogenic. Belladonna exhibited a similar level of susceptibility to races 1 and 2 of V. dahliae, but was more susceptible than Ace 55VF to race 2. Interestingly, the isolates originating from eggplant were clearly more virulent than those originating from tomato and black nightshade on all solanaceous plants tested. 相似文献
17.
White top strain (WT strain) of Pseudomonas syringae pv. pisi (Ppi) is a variant strain causing white top disease of peas. The WT strain is distinguishable from common Ppi strains only by symptom expression chlorosis and whitening of apical shoots. To develop a specific detection method for the WT strain, we cloned a specific DNA region of the WT strain using transposon tagging. Five mutants defective in white top symptom expression were obtained. A part of the Tn5-flanking region was cloned and labeled as a hybridization probe. One clone, pAY3, gave two signal bands, one of which was detected from the genomic DNA of all the WT and the common Ppi strains; another was specific to WT strains. A restriction map of pAY3 showed that it contains two BamHI fragments; one is 5.0kb in length involving a part of Tn5, and the other is 1.5kb, did not carry Tn5, and may have been accidentally ligated into pAY3. The 1.5-kb band was subcloned as pAY13 and was used as a probe. It hybridized specifically to WT strains. These results suggested that the WT strains have a specific DNA region and that part of the region was successfully cloned. Sequence analysis of pAY13 showed that it is similar to part of nonribosomal peptide synthetases (NRPSs) genes. The deduced amino acid sequence of pAY13 suggested the existence of eight conserved motifs of NRPSs. WT strain-specific PCR primers, PS1 and PS2, were designed from the DNA sequence. These primers gave a specific amplification product of 981bp from both the genomic DNA and a direct cell preparation of WT strains. No specific amplicon was produced from Ppi strains that caused only water-soaked lesions or from strains of other P. syringae pathovars. A specific amplicon was not produced from four strains of the pea pathogen: P. marginalis pv. marginalis, P. viridiflava, Erwinia carotovora ssp. carotovora, Xanthomonas campestris pv. pisi. Using the primers, WT strain was detected from water-soaked lesions and green and white tissues without water soaking.The sequence reported in this paper has been deposited in the DDBJ database under accession no. AB117755 相似文献
18.
A severe crown rot of pear trees of cultivar ‘Kondoula’ grafted on quince rootstock was observed in Greece. Isolations from
the affected tissues repeatadly yielded aPhytophthora sp. that was determined by morphological and physiological characteristics to beP. citrophthora. The pathogenicity of two of theP. citrophthora isolates was tested by inoculating trunks of 2-year-old pear trees by mycelial agar disks. Thirty-two days after inoculation
all inoculated trees were infected. Although the pear isolates could not be differentiated from isolates ofP. palmivora orP. nicotianae based on isozyme profiles of α-esterase or lactate dehydrogenase, RAPD profiles with one selected primer differentiated the
pear isolates from the other species and revealed an electrophoretic banding pattern similar to that of aP. citrophthora standard. This is the first report ofP. citrophthora on pear trees in Greece. 相似文献
19.
Suppressive effect of potassium silicate on powdery mildew of strawberry in hydroponics 总被引:1,自引:0,他引:1
From 1996 to 1997, potassium silicate (SiO2) was tested at 0, 25, 50, and 100mgl–1 in hydroponics to control powdery mildew. Other elements were added in the usual amounts, and the strawberries were cultivated hydroponically in a greenhouse for 4 months (from October to January). The powdery mildew spread in the control plot, but little mildew developed in the plot with 25mgl–1 silicate, and none in plots with more than 50mgl–1 silicate. The suppressive effect lasted for about 4 months on fruits and even longer on leaves. On analysis of mineral content in the leaves, only the silicate content differed markedly between the control and treated plants. Nitrogen, phosphate, potassium, and calcium contents did not differ greatly. The maximum silicate content was about 24 times that of the control, and disease severity decreased significantly when the content was more than 1.5% in the leaves. The hardness of the strawberry leaves, measured by a creep meter, was increased by the silicate treatment. 相似文献
20.
E. Ilieva F. X. Arulappan R. Pieters 《European journal of plant pathology / European Foundation for Plant Pathology》1995,101(6):623-626
Root and crown rot of raspberry (Rubus idaeus L.) was observed in a plantation at the experimental station of small fruits in Kostinbrod, Bulgaria. Isolates ofPhytophthora spp. were obtained from diseased plants. Colony morphology, growth rates, features of asexual and sexual structures were studied and as a result twoPhytophthora species were identified:Phytophthora citricola Saw. andPhytophora citrophthora (R.E. Sm. & E.H. Sm.) Leonian. Their pathogenicity was confirmed in artificial inoculation experiments. The isozyme (-esterase) patterns ofP. citrophthora andP. citricola isolates from raspberry and from the collection of the CBS, Baarn the Netherlands were compared, using micro-gel electrophoresis. Both species are reported for the first time as pathogens of raspberry in Bulgaria. This is only the second report in phytopathological literature ofP. citrophthora on raspberry, the first being from Chile [Latorre and Munoz, 1993]. 相似文献