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1.
Dry mycelium (DM) of killedPenicillium chrysogenum and its water extract (DME) were used to induce resistance in cotton plants againstFusarium oxysporum f.sp.vasinfectum (Fov). Results showed that the efficacy of either DM or DME in controlling the disease depends on both the concentration and the
mode of application. DM amended to the soil at 0.25–2% (w/w) provided 32–75% protection againstFov. Soil drench with 2–5% DME (w/v) and pre-sowing seed soakage with 5–10% DME provided 51–77% and 28–35% protection against
the wilt disease, respectively, whereas no protection was obtained with foliar sprays of 1–10% DME. DM and its water extract
had no direct antifungal activity on growth ofFov in vitro, suggesting that disease control with DM or DME resulted from the induction of natural defense mechanisms in the cotton plants.
Soil drench with 5% DME was as effective as 2% DM powder in inducing resistance againstFov, implying that the resistance-inducing substances were mostly water-soluble. Four cotton cultivars with various genetic resistance
levels againstFov were tested at the seedling stage: two resistant ‘Pima’ cultivars and two susceptible ‘Acala’ cultivars. The level of protection
achieved in the two susceptible cultivars with DME was equal to, or higher than, that of the two resistant cultivars treated
with water. Innate and induced peroxidase activity in cotyledons or hypocotyls and roots coincided with the level of genetic
resistance and DME-induced resistance, respectively. Based on our results, an integrated control strategy ofFov with both genetic resistance and induced resistance is suggested. 相似文献
2.
Incorporation into soil of dry mycelium ofPenicillium chrysogenum, a waste product of the pharmacological industry, enhanced plant growth and reduced root galling caused by the root-knot
nematodeMeloidogyne javanica in cucumber and tomato plants. Incorporation into sandy loam soil in pots of dry mycelium at a concentration of 0.25% (w/w)
resulted in complete protection of cucumber plants from the nematode. The number of juveniles recovered from soils containing
dry mycelium was greatly reduced even at a concentration of 0.1% (w/w). In microplot studies conducted at two sites in two
seasons, with three or four doses, dry mycelium caused a dose-dependent reduction in root galling index (GI) and promotion
of plant growth of cucumber and tomato plants. Inin vitro studies, the water extract of dry mycelium immobilized nematode juveniles and reduced the egg hatching rate, but these effects
were partly reversible after a rinse in water. Soil-drenching of cucumber and tomato seedlings with water extract of dry mycelium
did not reduce GI or number of root-invading juveniles. The results show that dry mycelium promotes plant growth and protects
plants against nematode infection. Protection, however, does not operatevia induced resistance.
http://www.phytoparasitica.org posting April 6, 2003. 相似文献
3.
Plant resistance has become an important component of integrated pest management (IPM) for management of whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), an important pest of cotton in India. The present studies were undertaken to standardize
the plant stage and identify resistant cotton genotypes against whitefly. Nine plant stages of F846, a susceptible cotton
genotype, were exposed to whitefly for 25 days under no-choice conditions. The population buildup (eggs, nymphs, pupae and
adults) was recorded. The 12-, 14- and 16-leaf stages were suitable for plant resistance studies against whitefly, and the
14-leaf stage was taken for further studies. Ten cotton genotypes of Gossypium hirsutum and two of G. arboreum were covered with split cages in which five pairs of B. tabaci (F1) were released. The population buildup was recorded to categorize genotypes as resistant, moderately resistant, moderately
susceptible or susceptible. The experiment was repeated with F2 and F3 generation whiteflies. Based on overall average score of three experiments, LD694 was rated as resistant; LK861, Supriya,
RS2013, CNH911 and PA183 as moderately resistant; IS-376/4/1/20/72, NHH44, TxMaroon2-78, Bt 6304 and RS2098 as moderately susceptible; and F846 as susceptible. LD694 was found to be resistant in three consecutive
generations of whitefly. 相似文献
4.
The study deals with the tachinid parasitoids ofAncyrosoma leucogrammes (Gmelin) (Heteroptera: Pentatomidae):Clytiomya dupuisi Kugler,Clytiomya sola (Rondani) andGymnosoma clavatum (Rohdendorf) (Diptera: Tachinidae). All species are recorded for the first time as parasitoids ofA. leucogrammes, andC. dupuisi was reared for the first time from a host. The parasitization rates ofC. dupuisi on adults ofA. leucogrammes varied from 7% to 9% between 1994 and 1999.C. sola andG. clavatum were reared in only small numbers.
http://www.phytoparasitica.org posting July 10, 2003. 相似文献
5.
Crude ethanolic seed extracts ofAnnona muricata, A. squamosa (Annonaceae),Lansium domesticum andSandoricum koetjape (Meliaceae) collected from different locations and years in Maluku, Indonesia, were screened for inhibition of larval growth
against the polyphagous lepidopteranSpodoptera litura (Noctuidae). Extracts ofA. squamosa were significantly more active (20-fold) than those ofA. muricata. A. squamosa collected from Namlea yielded the extracts with the greatest inhibitory activity. There were significant differences among
locations for bothA. squamosa andA. muricata but not forL. domesticum andS. koetjape. Extracts ofA. squamosa, collected from Namlea, inhibited larval growth in a dose-dependent manner, with a dietary EC50 (effective concentration to inhibit growth by 50% relative to controls) of 191.7 ppm fresh weight. Extracts ofA. squamosa collected from individual trees in Namlea also varied in growth inhibitory effect againstS. litura andTrichoplusia ni larvae. This species is a candidate for development of a botanical insecticide for local use in Indonesia.
http://www.phytoparasitica.org posting Dec. 1, 2003. 相似文献
6.
Eighteen toxins produced byFusarium species were tested at different concentrations onOrobanche ramosa seeds to evaluate their effectiveness in inhibiting germination. Many of the toxins were active at the highest concentration
used. Seven of them,viz. fusarenon X, nivalenol, deoxynivalenol, T-2 toxin, HT-2 toxin, diacetoxyscirpenol and neosolaniol, were highly active at
10μM, causing 100% inhibition of germination. Many of them were still active when assayed at a concentration ten times lower,
with T-2, HT-2, nivalenol, neosolaniol and diacetoxyscirpenol still able to cause total inhibition; the last mentioned was
very active also at 0.1μM, causing more than 90% inhibition. The results show that the use of toxic secondary metabolites could represent a useful
alternative strategy in the management of parasitic weeds, by interfering with the induced germination process, and that fungal
culture extracts could be an interesting source of new compounds acting as natural and original herbicides.
http://www.phytoparasitica.org posting Sept. 18, 2002. 相似文献
7.
Essential oils extracted fromEucalyptus blakelyi (1,8-cineole, 77.5%),Melaleuca fulgens (1,8-cineole, 56.9%) and 1,8-cineole were shown to have fumigant toxicity against different development stages ofSitophilus oryzae. The eggs ofS. oryzae were the most tolerant, followed by pupae, larvae and adults in that order.M. fulgens oil,E. blakelyi oil and 1,8-cineole at 100 μl per liter of air gave, respectively, LT50 values of 16.2, 17.4 and 9.1 h for adults, 31.1, 19.3 and 17.5 h for larvae, 55.6, 75.2 and 39.7 h for pupae, and required
>7 days for eggs. Only 1,8-cineole (200 μl
−1 air) gave a significant egg kill by 7 days and the LT95 was 134.5 h. 1,8-Cineole could be a useful new fumigant.
http://www.phytoparasitica.org posting Oct. 3, 2004. 相似文献
8.
During storage studies on asparagus spears packed in plastic film and held at 15°C, a Penicillium fungus was associated with subsequent spoilage. On the basis of colony characteristics, the isolate was identified as Penicillium hirsutum Diercks. This report is the first of Penicillium hirsutum causing spoilage of asparagus spears in Japan. Inoculation tests showed that among all the Penicillium species tested in this study only the identified fungus was able to infect asparagus spears. 相似文献
9.
Tachinid parasitoids ofTraumatocampa ispartaensis Doğanlar & Avcı (Lepidoptera, Thaumetopoeidae), which was found to be a new species, were collected from the cedar forests
around Isparta-Kapıdağ. The species found wereBlondelia nigripes (Fall.),Compsilura concinnata (Meig.),Pales processioneae (Ratz.),Phryxe caudata (Rond.),Exorista segregata (Rond.) andCarcelia iliaca (Ratz.). Within the six species of Tachinidae,B. nigripes was the most common one, parasitizing up to 4.6% ofT. ispartaensis pupae.
http://www.phytoparasitica.org 相似文献
10.
Pectinases extract (PE) from the fermentation product ofPenicillium oxalicum BZH-2002 was tested for its ability to induce protection against scab caused byCladosporium cucumerinum on cucumber (Cucumis sativus L.) plants. Seedlings with one true leaf were sprayed with various concentrations of PE (10–200 units ml−1) 3 days before inoculation withC. cucumerinum. Results showed that the induced local protection against the pathogen was dose-dependent when the concentrations of PE were
between 20 and 120 units ml−1; systemically induced resistance against the pathogen was not observed. Boiled PE had a slight effect on disease reduction.
Commercial pectinases prepared fromAspergillus niger showed lower protection against scab compared with PE when they were used at the same concentration of enzyme activity. No
inhibitory activity was observed on conidial germination or germ-tube growth ofC. cucumerinum. PE was further evaluated for its enhancement of defense-related enzymes. Peroxidase (PO), polyphenol oxidase (PPO) and phenylalanine
ammonia lyase (PAL) increased in cucumber seedlings after treatment with PE. PO and PPO remained at a higher level in PE-pretreated
seedlings throughout the experiment period whether pathogen-inoculated or non-inoculated, whereas PAL activity began to decrease
2 days after PE treatment.
http://www.phytoparasitica.org posting July 14, 2004. 相似文献
11.
Mehmet Erhan Göre 《Phytoparasitica》2007,35(3):222-231
A total of 101Verticillium dahliae isolates were recovered from cotton plants at 57 sites in the Aegean region of Turkey between 2003 and 2004. Isolates were
tested for vegetative compatibility by observing heterokaryon formation among complementary nitrate-nonutilizing (nit) mutants. Forty-six isolates were assigned to VCG 1, 12 to VCG 2A, 33 to VCG 2B and four to VCG 4B. The remaining six isolates
could not be tested for vegetative compatibility because of their inability to yieldnit mutants. All isolates recovered were tested for pathogenicity on cotton cultivars Acala SJ-1 and Deltapine 15-21 by the stem-injection
method. The isolates of VCG 2 and 4B, irrespective of their origin, induced weak to severe symptoms on cotton and were similar
to the previously described cotton non-defoliating pathotype. In contrast, all cotton isolates of VCG1 caused severe foliar
symptoms, stunting, defoliation and often death. This is the first report on VCG 1 ofV. dahliae in Turkey.
http://www.phytoparasitica.org posting May 4, 2007. 相似文献
12.
We determined the complete nucleotide sequence of RNA-1 and the 5-terminal region of RNA-2 from Broad bean wilt virus 1 (BBWV-1) isolate PV132. This report is the first analysis of the genome organization of BBWV-1. We also determined the complete nucleotide sequence of RNA-1 from Broad bean wilt virus 2 (BBWV-2) isolate IP and analyzed the genetic relations between BBWV-1 and BBWV-2. Similar to the BBWV-2 isolates, both RNAs of PV132 encoded a single large polyprotein, which was predicted to contain some functional proteins in a manner similar to those of comovirus. With respect to the deduced amino acid sequences of the mature proteins, PV132 and IP had only 20%–40% homology to comovirus. On the other hand, IP was 73%–98% homologous to BBWV-2 isolates, but PV132 was 39%–67% homologous to the isolates. Although the extent of the homologies differed, the homologies were limited between BBWV-1 and BBWV-2 not only for the coat protein but also for the other proteins. These results clearly support the placement of BBWV-1 and BBWV-2 in the genus Fabavirus as distinct species, proposed on the basis of double immunodiffusion tests.The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under the accession numbers AB084450 (RNA-1 of isolate PV132), AB084451 (RNA-2 of isolate PV132), and AB023484 (RNA-1 of isolate IP) 相似文献
13.
Comparative effect of root-knot nematode on severity of verticillium and fusarium wilt in cotton 总被引:1,自引:0,他引:1
The effect of root-knot nematode (RKN) (Meloidogyne incognita) onVerticillium dahliae andFusarium oxysporum f.sp.vasinfectum in cotton (Gossypium hirsutum) was investigated. Two different inoculation methods were used, one in which inoculum was added to the soil, so that nematode
and fungal inoculum were in close proximity; the other, inoculation into the stem, whereby the two inocula were spatially
separated. Invasion of the roots by RKN enhanced disease severity, as measured by the height of vascular browning in the stem,
following inoculation with either wilt pathogen. The effect of RKN on Fusarium wilt was more pronounced than that on Verticillium
wilt. Nematode-enhanced infection byF. oxysporum is a well known effect but there are few reports of enhanced infection byVerticillium due to RKN. Relative resistance of a number of cotton cultivars to both wilt diseases, as measured by height of vascular
browning, was similar to the known field performance of the cultivars. The use of vascular browning as an estimate of disease
severity was therefore validated.
http://www.phytoparasitica.org posting Feb. 3, 2003. 相似文献
14.
Guillermo A. Galván Carole F. S. Koning-Boucoiran Wim J. M. Koopman Karin Burger-Meijer Pablo H. González Cees Waalwijk Chris Kik Olga E. Scholten 《European journal of plant pathology / European Foundation for Plant Pathology》2008,121(4):499-512
The aim of this research was to study levels of resistance to Fusarium basal rot in onion cultivars and related Allium species, by using genetically different Fusarium isolates. In order to select genetically different isolates for disease testing, a collection of 61 Fusarium isolates, 43 of them from onion (Allium cepa), was analysed using amplified fragment length polymorphism (AFLP) markers. Onion isolates were collected in The Netherlands
(15 isolates) and Uruguay (9 isolates), and received from other countries and fungal collections (19 isolates). From these
isolates, 29 were identified as F. oxysporum, 10 as F. proliferatum, whereas the remaining four isolates belonged to F. avenaceum and F. culmorum. The taxonomic status of the species was confirmed by morphological examination, by DNA sequencing of the elongation factor
1-α gene, and by the use of species-specific primers for Fusarium oxysporum, F. proliferatum, and F. culmorum. Within F. oxysporum, isolates clustered in two clades suggesting different origins of F. oxysporum forms pathogenic to onion. These clades were present in each sampled region. Onion and six related Allium species were screened for resistance to Fusarium basal rot using one F. oxysporum isolate from each clade, and one F. proliferatum isolate. High levels of resistance to each isolate were found in Allium fistulosum and A. schoenoprasum accessions, whereas A. pskemense, A. roylei and A. galanthum showed intermediate levels of resistance. Among five A. cepa cultivars, ‘Rossa Savonese’ was also intermediately resistant. Regarding the current feasibility for introgression, A. fistulosum, A. roylei and A. galanthum were identified as potential sources for the transfer of resistance to Fusarium into onion. 相似文献
15.
The clustered hrp genes encoding the type III secretion system in the Japanese strains MAFF301237 and MAFF311018 of Xanthomonas oryzae pv. oryzae were sequenced and compared. The strains differ in their pathogenicity, location, and year of isolation. A 30-kbp sequence comprising 29 open reading frames (ORFs) was identical in its structural arrangement in both strains but differed from X. campestris pv. campestris, X. axonopodis pv. citri, and X. axonopodis pv. glycines in certain genes located between the hpaB-hrpF interspace region. The DNA sequence and the putative amino acid sequence in each ORF was also identical in both X. oryzae pv. oryzae strains as were the PIP boxes and the relative sequences. These facts clearly showed that the structure of the hrp gene cluster in X. oryzae pv. oryzae is unique. 相似文献
16.
Mikiko Harada Satoshi Ishikawa Tadaaki Hibi Kyoko Watanabe 《Journal of General Plant Pathology》2008,74(4):341-343
In 2003–2004, anthracnoses of Enkianthus campanulatus and Rhynchosia acuminatifolia were found for the first time in Kanagawa Prefecture and Tokyo in Japan. These pathogens were identified as Colletotrichum gloeosporioides based on their pathogenicity, morphology and ribosomal DNA spacer sequences.
Results were presented at the annual meeting of The Phytopathological Society of Japan in 2004. 相似文献
17.
A weed survey conducted in 2004 and 2005 in Aydin province of Turkey showed that Solanum nigrum, Xanthium strumarium, Amaranthus retroflexus, Portulaca oleracea, Sonchus oleraceus and Datura stramonium were the most prevalent weeds in the cotton fields exhibiting Verticillium wilt. Verticillium dahliae Kleb. was recovered from A. retroflexus and X. strumarium in those cotton fields. This is the first report of V. dahliae occurring naturally in A. retroflexus in Turkey. Pathogenicity tests on cotton and weeds showed that the virulence of V. dahliae isolates from weeds was higher on cotton plants than on weeds, with the disease severity ranging from 31.7% to 98.0%. Disease
severity of V. dahliae isolates was 54.7–93.9% on eggplant, 23.7–51.6% on cucumber and 11.0–16.4% on tomato, whereas it did not cause any disease
symptoms, or only low levels, on pepper and bell pepper. Two vegetative compatibility groups (VCGs) were identified among
seven tested weed isolates: VCG2A (two isolates) and VCG2B (three isolates) using international reference strains. 相似文献
18.
Shigemitsu Kimura Susumu Tokumaru Kazuhiko Kuge 《Journal of General Plant Pathology》2009,75(4):322-324
Yeast-like fungi were isolated from lesions on azuki bean (cv. Shin-Kyotodainagon) seeds that had been sucked by bean bugs
in Kyoto Prefecture, Japan. On the basis of morphological and physiological characteristics and sequence data of the internal
transcribed spacer (ITS) regions including the 5.8S rDNA, these yeasts were identified as Eremothecium coryli and E. ashbyi. Pathogenicity of those yeasts was confirmed by a reinoculation test. To our knowledge, this is the first report of the occurrence
of yeast spot in azuki bean in Japan.
The nucleotide sequence data reported are available in the GeneBank/EMBL/DDBJ database as accessions AB478291–AB478309 for
E. coryli AZC1–19 and AB478310–AB478317 for E. ashbyi AZA1–8. 相似文献
19.
Five accessions ofArabidopsis thaliana, Ws-3, Nd-1, Ler, Col-5 and Oy-0, were inoculated withPeronospora parasitica isolate Emoy2 and the accumulation of camalexin within infected tissues was measured. The variations in camalexin accumulation
in various accessions ofA. thaliana induced by a specific (P. parasitica isolate Emoy2) and a non-specific elicitor (UV-B irradiation) were investigated. Phenotypic examination of Emoy2/Oy-0 revealed
that susceptibility was characterized by extensive asexual sporulation of the pathogen, whereas early restriction of the pathogen
in infected plant tissues, accompanied by chlorosis and necrosis — which are associated with the hypersensitive response —
was observed in Nd-1, Ws-3 and Ler. Partial resistance detected in Col-0 was characterized by low to medium sporulation of
the pathogen. Camalexin was monitored by high pressure liquid chromatography (HPLC) and found to accumulate during both compatible
and incompatible interactions and also following treatment with the abiotic inducer, UV-B. Among the accessions tested, Ws-3
yielded significantly more camalexin than the other accessions, regardless of which inducers (biotic or abiotic) were used.
There was no significant correlation between resistance and camalexin accumulation in theA. thaliana/P. parasitica interaction. The results suggest that there is genetic variation in camalexin biosynthesis among accessions ofA. thaliana, rather than variation in types of induction.
http://www.phytoparasitica.org posting Dec. 16, 2002. 相似文献
20.
Significant antibacterial activity was observed in the essential oil (E.O.) ofRosa damascena Mill. and the Minimum Bactericidal Concentration (MBC) of the E.O. was determined as 1386.5 μg ml−1 forErwinia amylovora, the causal agent of fire blight disease. Ooze formation on immature pears and lesion formation in artificially inoculated
shoots were completely (100%) prevented by the essential oil ofR. damascena (1500 μg ml−1), essential oil ofThymbra spicata var.spicata (500 μg ml−1) and streptomycin (100 μg ml−1). Copper oxychloride plus maneb significantly reduced ooze formation and lesion formation, but the control was less than
that obtained with the essential oils or streptomycin. The essential oil ofR. damascena may be a useful natural bactericide for the control of the fire blight pathogen,E. amylovora.
http://www.phytoparasitica.org posting July 14, 2004. 相似文献