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1.
The biology ofLixus bardanae (F.) (Coleoptera: Curculionidae) on curly dock (Rumex crispus L.) in northeastern Anatolia (Bayburt, Erzurum and Kars Provinces), Turkey, was studied during the years 2000 and 2001.L. bardanae completes one generation in a year, overwintering as an adult. It feeds on leaves of the host plant. Females lay eggs individually into stems and the young larvae create galleries in stems while feeding. Pupation occurs inside stems in cells fashioned from frass. In late September, adults move into soil and overwinter in an upright position around the roots of the host plant. Infestation levels were found to range between 34% and 84%. Two parasitoids,Exeristes roborator F. andEndromopoda phragmitidis Perve (Hymenoptera: Ichneumonidae), were reared fromL. bardanae. http://www.phytoparasitica.org posting Dec. 21, 2003.  相似文献   

2.
Floral rot of Egyptian henbane (Hyoscyamus muticus L.) was found on potted plants in a greenhouse in Yamaguchi city, Japan, in the late summer of 2008 and 2009. The symptoms were identical to those of rots caused by Choanephora species. The pathogen was isolated and identified as C. cucurbitarum (Berkeley and Ravenel) Thaxter. This new disease was named Choanephora rot (Kougai-kabi-byo) of Egyptian henbane.  相似文献   

3.
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   

4.
The present study was conducted to determine if there is specificity in the host-pathogen relationship between the isolates of Xanthomonas oryzae pv. oryzae, the causal bacterium for rice blight and Leersia grasses, the alternative weed hosts of the disease. Plants of three species of Leersia, namely, L. sayanuka, L. oryzoides and L. japonica, were collected from various parts of Japan and were inoculated with the X. oryzae pv. oryzae isolates obtained from various locations in Japan and from 11 Asian countries. Four L. sayanuka plants were found susceptible to all Race II isolates and some Race I isolates, but were resistant to all Race III isolates. Race III is known to have a wider range pathogenicity to rice cultivar groups compared with Race I and II. Although the reactions of two L. oryzoides plants to Race I and II isolates were similar to that of L. sayanuka, the L. oryzoides plant collected from Niigata Prefecture showed a susceptible reaction to some Race III isolates. On the other hand, L. japonica plants gave reactions different those of L. sayanuka and L. oryzoides, with two plants of L. japonica found to be resistant to all test isolates collected from Japan. The Asian isolates exhibited a wide host range against the international differential rice cultivars, but almost all of them were avirulent to Leersia plants. These results indicate that the relationship between the pathogenicity of the causal bacterium and the resistance of host plants is very complex, and suggest that pathogenic diversity of X. oryzae pv. oryzae might be related to the resistance of Leersia spp.  相似文献   

5.
Sixty-nine tomato genotypes representing nine Solanum species were evaluated for resistance to Cucumber mosaic virus (CMV) subgroup IA and its aphid vector Myzus persicae. Resistance was assessed by visual scoring of symptoms in the field under natural conditions, and in the greenhouse by artificial inoculations through aphid M. persicae and mechanical transmissions in the year 2007 and 2009. Considerable variation in responses was observed among the evaluation methods used. Field evaluations were found liable to errors as different levels were observed for the same genotypes in the different years, however mechanical inoculation was found to be the most useful in identifying CMV subgroup IA resistance, in contrast aphid transmission was most useful in identifying insect transmission resistance. All genotypes observed as highly resistant to CMV subgroup IA in the field or through vector transmission became systemically infected through mechanical inoculations. Using mechanical inoculation, six genotypes (TMS-1 of S. lycopersicum, LA1963 and L06049 of S. chilense, LA1353, L06145 and L06223 of S. habrochaites) were found resistant and another six (L06188 and L06238 of S. neorickii, L06219 of S. habrochaites, L05763, L05776 and L06240 of S. pennellii) were found tolerant showing mild symptoms with severity index (SI) ranging 1-2 and with delayed disease development after a latent period (LP) of 18–30 days. However, these genotypes were found to be resistant to highly resistant in the field and through inoculation by M. persicae; and they also supported low population levels of M. persicae except TMS-1. Another nine genotypes (LA2184 of S. pimpinellifolium L., LA2727 of S. neorickii, LA0111, L06221, L06127 and L06231 of S. peruvianum L., LA1306, L06057 and L06208 of S. chmielewskii) showing a susceptible response after mechanical inoculation were highly resistant, resistant and tolerant after M. persicae transmission. The resistant genotypes, identified in the present study can be exploited in the breeding programmes aimed at developing tomato varieties resistant to CMV subgroup IA and broadening the genetic base of CMV-resistant germplasm. The differences observed between mechanical and aphid transmission suggests that one should consider both evaluation methods for tomato germplasm screening against CMV subgroup IA.  相似文献   

6.
Two hymenopteran parasitoids of the cactus scale Diaspis echinocacti (Bouché) (Hemiptera: Diaspididae) on Opuntia ficus-indica (L.) Mill. (Cactaceae) are recorded in Greece. Aphytis debachi Azim, 1963 (Aphelinidae) is first recorded for Europe and Plagiomerus diaspidis Crawford, 1910 (Encyrtidae) is first recorded for Greece. Preliminary data on phenology and natural enemies of the scale D. echinocacti on O. ficus-indica are presented. Parasitism of D. echinocacti by P. diaspidis reached 86% in southern Greece (Kalamata) and parasitism by A. debachi reached 9.3% and 12% in Kalamata and Athens, respectively. Two predators, Cybocephalus fodori Endrödy-Youga (Coleoptera: Nitidulidae) and a mite species (Prostigmata: Bdellidae), were found to be associated with D. echinocacti.  相似文献   

7.
Susceptibility of eggs of Tribolium confusum du Val. (Coleoptera: Tenebrionidae), Ephestia kuehniella (Zell.) (Lepidoptera: Phycitidae) and Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) to vapors of essential oil from garlic (Allium sativum L.), birch (Betula lenta L.), cinnamon (Cinnamonum zeylanicum (Blume)) and aniseed (Pimpinella anisum L.) was studied. Preliminary bioassay tests indicated that vapors of the essential oils had a significant effect on the eggs of tested insect species when exposed to a concentration of 20 μl l −1 air for 24 h. Generally, garlic and birch essential oils were more toxic to the eggs of tested insect species than cinnamon and aniseed essential oils (except for eggs of T. confusum). There was also a significant difference between susceptibility of eggs of T. confusum, E. kuehniella and P. interpunctella to tested essential oils. Toxicity data indicated that eggs of T. confusum were more susceptible to tested essential oils, with LC90 values ranging from 3.11 to 33.49 μl l −1 air, than those of E. kuehniella and P. interpunctella; eggs of P. interpunctella were the most tolerant to the essential oils, with LC90 values ranging from 22.02 to 72.42 μl l −1 air. Concentration × time (Ct) products of 0.29, 0.22, 0.13 and 1.37 mg h l −1 for garlic, birch, cinnamon and aniseed essential oil, respectively, were required to obtain 90% kill of T. confusum eggs. Although cinnamon essential oil had a much closer Ct product value to methyl bromide, garlic and birch essential oils were found to be the most promising ones since they had also high fumigant toxicity on eggs of both E. kuehniella and P. interpunctella.  相似文献   

8.
Populations of pear psylla,Cacopsylla pyri (L.) (Rhynchota: Psyllidae), and its natural enemies were sampled on pears in Antalya province during the years 2000–2002. Thirty-two species of predators and three species of parasitoids were detected to be associated withC. pyri in Antalya province. The heteropterans (especially anthocorid species) were the most abundant predator group. Among the anthocorids,Anthocoris nemoralis (Fabricius) (Heteroptera: Anthocoridae), whose population was closely related to the dynamics of the pear psylla population, was generally the principal antagonist ofC. pyri. Other species recorded during the study were the miridDeraeocoris spp., the chrysopidChrysoperla carnea L., and many coccinellid species. Although these predators are polyphagous, as are theOrius species, their populations were related to the psylla fluctuations. Among the parasitoid complex belonging to the order Hymenoptera, the encyrtidTrechnites psyllae (Ruschka) was the only primary parasitoid. Two hyperparasites,viz., Syrphophagus mamitus (Walker) andPachyneuron aphidis (Bouché) (Encyrtidae and Pteromalidae, respectively), were detected in the surveys. Also, this study revealed new information concerning the pear psylla parasitoid complex in Turkey. WhileT. psyllae andS. mamitus are new records to Turkish parasitoid fauna,C. pyri is a new host record forP. aphidis. The population development and abundance of pear psylla and its natural enemies, as well as the parasitization rates in treated and untreated pear orchards, are presented here. http://www.phytoparasitica.org posting May 6, 2004.  相似文献   

9.
Cucumber mosaic virus (CMV) was isolated from a mosaic diseased plant of Eucharis grandiflora. The virus caused mosaic symptoms on leaves and slight distortion of flower petals in E. grandiflora by either mechanical or aphid inoculation. The virus was identified as a strain of CMV subgroup I from its biological and serological characteristics.  相似文献   

10.
In some areas of Japan, yellow spots with white pustules on leaves, stems, petioles, peduncles and calyces were found on Ipomoea nil, I. triloba, I. lacunosa and I. hederacea var. integriuscula. We demonstrated that the diseases on I. nil, I. triloba and I. lacunosa were caused by host-specific strains of Albugo ipomoeae-panduratae and defined three forma speciales of the fungus, respectively, for the three Ipomoea species: “f. sp. nile”, “f. sp. trilobae” and “f. sp. lacunosae”. Because the diseases were new to Japan, we coined the Japanese name “shirosabi-byo”, which means white rust. We also showed that the disease on I. hederacea var. integriuscula was caused by A. ipomoeae-hardwickii. We named this new disease “white rust (shirosabi-byo in Japanese)”.  相似文献   

11.
Fourteen species in two families of the order Hymenoptera: Ichneumonidae (1 sp.) and Eulophidae (13 spp.), were recorded during the study ofCameraria ohridella parasitoids at eight localities in Serbia. Among the observed parasitoids, the most significant species wereMinotetrastichus frontalis, Pediobius saulius, Pnigalio agraules andClosterocerus trifasciatus. In addition, at some localities the speciesMinotetrastichus platanellus andCirrospilus talitzkii were also significant. The parasitoids do not have a significant effect on the abundance ofC. ohridella because in the majority of study samples parasitism levels did not exceed 20%. http://www.phytoparasitica.org posting Feb. 23, 2004.  相似文献   

12.
From the genome of a Japanese field isolate of the rice blast fungus, Magnaporthe oryzae, we newly identified Inago1 and Inago2 LTR retrotransposons. Both elements were found to be Ty3/gypsy-like elements whose copies were dispersed within the genome of Magnaporthe spp. isolates infecting rice and other monocot plants. Southern hybridization patterns of nine re-isolates derived from conidia of the strain Ina168 produced after a methyl viologen treatment were not changed, indicating that the insertion pattern of Inago elements is relatively stable.  相似文献   

13.
Root-knot nematodes (RKN) are obligate parasite species of the genus Meloidogyne that cause great losses in Arabica coffee (Coffea arabica L.) plantations. Identification of resistant genotypes would facilitate the improvement of coffee varieties aiming at an environmental friendly and costless nematode control. In this work, the C. arabica genotype ‘UFV 408-28’ was found to be resistant to the most destructive RKN species M. incognita. Pathogenicity assays indicated that the highly aggressive populations of M. incognita races 1, 2 and 3 were not able to successfully reproduce on ‘UFV 408-28’ roots and displayed a low gall index (GI = 2). An average reduction of 87% reduction of the M. incognita population was observed on ‘UFV 408-28’ when compared to the susceptible cultivar ‘IAC 15’. By contrast, ‘UFV 408-28’ was susceptible to the related species M. exigua and M. paranaensis (GI = 5 and 4, respectively). Histological observations performed on sections of UFV408-28 roots infected with M. incognita race 1 showed that nematode infection could be blocked right after penetration or during migration and establishment stages, at 6 days, 7 days and 8 days after infection (DAI). Fluorescence and bright field microscopy observations showed that root cells surrounding the nematodes exhibited HR-like features such as accumulation of phenolic compounds and a necrotic cell aspect. In the susceptible ‘IAC 15’ roots, 6 DAI, feeding sites contained giant cells with a dense cytoplasm. Necrotic cells were never observed throughout the entire infection cycle. The HR-like phenotype observed in the ‘UFV 408-28’—M. incognita interaction suggests that the coffee resistance may be mediated by a R-gene based immunity system and may therefore provide new insights for understanding the molecular basis of RKN resistance in perennial crops.  相似文献   

14.
The effect of food plants [Acacia elatior Brenan, A. tortilis (Forssk.) and A. nilotica (L.) Del.] on the development time of Gonometa postica Walker (Lepidoptera: Lasiocampidae) larvae and the quality of their cocoons was studied in the Imba and Mumoni forests of Mwingi, Eastern Kenya, during the long (March-May) and short (October-December) rainy seasons of 2006 and 2007. Larvae were reared in semi-captivity in net sleeves attached to branches of the plants. The period between hatching of eggs and spinning of cocoons, as well as their weight, as determinants of cocoon quality were recorded. In addition, collections of cocoons from the wild were done in the two forests from the same host plants for assessment of their quality. In the cage experiment, larval development period and quality of cocoons differed according to food plants, seasons and sites, whereas quality of cocoons sampled from the wild habitat was similar for all food plants and seasons but varied according to site. Generally, there was a positive correlation between weight of cocoon, its length and width for the two seasons for both the semi-captive population and those from the wild. Larvae reared on A. elatior had a shorter development period and higher cocoon quality than those raised on A. tortilis and A. nilotica. Generally, temperature and relative humidity significantly influenced larval development time and the effect was both positive and negative. Rainfall was generally higher in Mumoni than in Imba. The implications of the above findings for the semi-captive rearing of G. postica to increase the quality of cocoons are discussed.  相似文献   

15.
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   

16.
Sequence analysis of hrp loci and effector genes in the flanking regions showed significantly high similarities between two phylotype I strains of Ralstonia solanacearum, GMI1000 and Japanese strain OE1-1. Further sequence analysis of the distribution of avrA and popP1, known as determinants of a hypersensitive response (HR) induction on Nicotiana tabacum (tobacco), in 22 Japanese phylotype I strains revealed that all strains had one of the two distinct avrA alleles and that 10 strains had an identical popP1 but the other 12 did not. After infiltration of tobacco leaves, more than half of these 22 strains elicited HR. In combination with the ability to induce HR, avrA and popP1 are thus not likely to be the sole determinants of HR in Japanese phylotype I strains.  相似文献   

17.
A disease on parthenium weed (Parthenium hysterophorus L.) was observed in June 2008 in Danzhou of Hainan Province. Infected weeds showed phytoplasma-like associated symptoms such as severe stunting, excessive proliferation of shoots, inflorescence-clustering, green petal, small leaves and witches’-broom. The original cause of phytoplasma was further confirmed by polymerase chain reaction (PCR). PCR products of 1.8 kb were obtained using the universal primers pair (P1/P7) designed to amplify the entire 16S rDNA and the 16/23S intergenic spacer region in a direct PCR assay. The primers pair R16F2n/R2 was used to amplify a PCR product of 1.2 kb. Restriction fragment length polymorphism (RFLP) was used to analyze the partial 16S rDNA sequences (1.2 kb) of all phytoplasma DNA digested with five endonucleases (Kpn I, Hpa II, Taq I, Rsa I, EcoR I). The RFLP patterns of the strain were found to be identical with that of the reference peanut witches’-broom phytoplasma. Based on the RFLP data, it is suggested that the phytoplasma strain belongs to subgroup 16SrII-A. This is the first demonstration of a 16SrII-A group phytoplasma associated with parthenium weed.  相似文献   

18.
Transmission of three strains of OMMV by an Olpidium sp. was evaluated and compared. The three strains were 1) an OMMV wild type (WT) recovered from olive trees, 2) an OMMV variant (L11) obtained after 15 serial passages of single local lesions induced in Chenopodium murale plants, and 3) a construct OMMV/OMMVL11 in which the coat protein (CP) gene replaced that of the wild type. A single-sporangial culture derived from Chinese cabbage (Brassica pekinensis) used as a bait plant grown in soil of an olive orchard, was identified as Olpidium brassicae based on the size and sequence of the generated amplicon in PCR specific tests. Each of the three virus strains was soil transmitted to cabbage roots in the absence of the fungus at similar rates of 30 to 40%. Separate plant inoculation by O. brassicae zoospores incubated with each viral strain resulted in enhanced transmission of OMMV, reaching 86% of infection whereas that of the other two strains remained practically unaffected at ca. 34%. Binding assays showed that the amount of virus bound to zoospores, estimated spectrophotometrically, was 7% in the case of OMMV, and practically nil in the case of the other two viral strains. Substitution of the coat protein (CP) gene of OMMV by that of the OMMV L11 strain, drastically reduced viral transmissibility in the presence of zoospores to the level of that observed in their absence. Our data shows that OMMV soil transmission is greatly enhanced by O. brassicae zoospores and that the viral CP plays a significant role in this process, most likely by facilitating virus binding and later entrance into the host plant roots.  相似文献   

19.
Mycosphaerella leaf disease (MLD) is caused by species of Mycosphaerella and several anamorphic form genera that have been connected to Mycosphaerella. Until recently, MLD of eucalypts was largely ignored in Portugal. However, serious damage to Eucalyptus globulus has been reported since 1999 when frequent and severe defoliation of young trees was observed. The severity of this disease prompted a preliminary study of the Mycosphaerella species associated with major symptoms of a leaf blotch disease in commercial plantations of E. globulus in Portugal, which is presented here. The species were identified by molecular methods based on the ITS1-5.8S-ITS2 cluster, together with morphological characters. In addition to confirming the species previously recorded, Mycosphaerella vespa is reported for the first time from Portugal, while the status of Mycosphaerella grandis remains to be resolved.  相似文献   

20.
An outbreak of black mottle and dieback on basil (Ocimum basilicum L.; Lamiaceae) was recorded in a greenhouse in Okinawa Prefecture, Japan during 2004. The causal agent was identified as Alternaria alternata (Fr.) Keissler based on morphological characters and growth temperature. This report is the first of Alternaria leaf spot of basil caused by A. alternata.  相似文献   

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