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1.
The reniform nematodes of the genus Rotylenchulus are semi-endoparasites of numerous herbaceous and woody plant roots and distributed in regions with Mediterranean, subtropical and tropical climates. In this study, we provide morphological and molecular characterisation of three out of 11 valid species of the genus Rotylenchulus: R. macrodoratus, R. macrosoma, and R. reniformis from Greece (Crete), Italy and Spain. The overall prevalence of reniform nematodes in wild and cultivated olives in Greece, Italy, and Spain was 11.5%, 19.0% and 0.6%, respectively. In Greece, R. macrodoratus and R. macrosoma were detected in cultivated olive with a prevalence of 8.2% and 6.2%, respectively, but none of them were found in wild olive. This is the first report of R. macrosoma in Greece. Only one reniform nematode species was detected in olive from Italy and Spain, viz. R. macrodoratus and R. macrosoma, respectively. The parasitism of R. macrosoma on hazelnut in northern Spain was also confirmed for the first time. This study demonstrates that R. macrodoratus and R. macrosoma have two distinct rRNA gene types in their genomes, specifically the two types of D2-D3 for R. macrosoma and R. macrodoratus, the two types of ITS for R. macrodoratus and the testing of the ITS variability in other R. macrosoma populations in different countries. Rotylenchulus macrosoma from Greece and Spain showed differences in nucleotide sequences in the ITS region and D2-D3 of 28S rRNA gene.  相似文献   

2.
A survey was conducted in 16 fields cultivated with broad bean (Vicia faba L.) and garden pea (Pisum sativum L.) in nine localities of Apulia, southern Italy, to determine whether annual weeds were susceptible to the pea cyst nematode (PEACN), Heterodera goettingiana, and could therefore serve as alternate host for the nematode. The results of this study showed that black medick (Medicago lupulina L.) is a good host for the nematode increasing its population levels in the soil in the absence of the primary hosts. The identity of the PEACN was confirmed by integrative taxonomic approaches (classical, and molecular), resulting identical in all cases (broad bean and garden pea, as well as the spontaneous black medick infections). The phylogenetic analyses using ITS and coxI gene regions strongly support the identification of the populations of H. goettingiana from Italy. Also, ITS and coxI gene sequences were obtained from the same cyst, confirming the species identity in comparison to other nematodes and populations in the Goettingiana group, demonstrating that ITS and coxI gene regions of the PEACN are suitable molecular markers for accurate and unequivocal identification of the PEACN. Reproduction and histopathological analyses demonstrated a good host-suitability of black medick to the PEACN. This record enlarges the relatively narrow host-range of the pea cyst nematode and indicates the need to control M. lupulina to avoid the increase of the nematode population in the absence of the main host crop.  相似文献   

3.
Cyst nematodes obtained from commercial carrot fields in Ontario (Canada) and northern and southern Italy were subjected to morphological and molecular examination. Morphology of cyst cone tops, males and second-stage juveniles (J2) indicated the nematode species was the Carrot Cyst Nematode (CaCN), Heterodera carotae. The sequence of the Internal Transcribed Spacer (ITS), D2-D3 region of the 28S gene of ribosomal RNA, cytochrome oxidase I of mitochondrial DNA (coxI), and a heat shock protein gene (hsp90), from single cysts were also examined. Sequences of ITS and D2-D3 placed all the nematodes with Heterodera carotae and other Heterodera spp. belonging to the Goettingiana group in the same clade. The novel nine coxI sequences obtained also clustered in a well-supported phylogenetic clade for H. carotae. Similarly, the six new hsp90 sequences of H. carotae generated in this study were placed in a well-supported clade (PP = 1.00) together with other two sequences of H. carotae from Greece. Restriction Fragment Length Polymorphism (RFLP) of ITS-PCR products gave a restriction pattern for RsaI different than H. carotae but the other 6 restriction patterns were similar as described in former research. A diagnostic conventional PCR method was developed based on a primer set to be specific for H. carotae using coxI sequence. These primers were also used in real time PCR to generate a melt curve specific to H. carotae. Limit of detection for CaCN in conventional PCR reaction was a single J2.  相似文献   

4.
A new dagger nematode, Xiphinema tica n. sp., is described and illustrated from several populations extracted from soil associated with several crops and wild plants in Costa Rica. The new dagger nematode is characterised by a moderate body size (3276–4240 μm), a rounded lip region, ca 13.5 μm wide, separated from body contour by a shallow depression, amphidial fovea large, stirrup-shaped, a moderately long odontostyle ca 135 μm long, stylet guiding ring located at ca 122 μm from anterior end, vulva almost equatorial (50–54%), well-developed Z-organ, with heavy muscularised wall containing in the most of specimens observed two moderately refractive inclusions variable in shape (from round to star-shaped), with uterine spines and crystalloid bodies; female tail short, dorsally convex-conoid, with rounded end and a small peg, with a c’ ratio ca 0.8, bearing two or three pairs of caudal pores and male absent. The unique and novel uterine differentiation based on the coexistence of a well-developed Z-organ mixed with uterine spines and crystalloid bodies in Xiphinema prompted us to update and include this combination of characters in the polytomous key of Loof and Luc (1990). Integrative diagnosis was completed with molecular data obtained, using D2-D3 expansion segments of 28S rDNA, ITS1-rDNA, partial 18S–rDNA and the partial mitochondrial gene cytochrome c oxidase subunit 1 (coxI). The phylogenetic relationships of this species with other Xiphinema spp. indicated that X. tica n. sp. was monophyletic to the other species from the morphospecies Group 4, Xiphinema oleae.  相似文献   

5.
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.
The role of the self-sown shrubsDittrichia viscosa (L.) W. Greuter andRubus ulmifolius Schott as reservoirs of aphid parasitoids was investigated. In the field studies conducted,D. viscosa grew adjacent to crops of durum wheat and barley andR. ulmifolius grew adjacent to cotton. The relative abundance of the parasitoids of(a) Capitophorus inulae (Passerini) onD. viscosa, (b) Rhopalosiphum padi (Linnaeus) on durum wheat and barley,(c) Aphis ruborum (Börner) onR. ulmifolius, and(d) Aphis gossypii Glover on cotton in various parts of Greece, was assessed during the years 1996–2000. In 2000, the fluctuation of parasitization of the above four aphid species was recorded and the action of the aphidophagous predators of the family Coccinellidae was studied. It was observed thatAphidius matricariae Haliday predominated onC. inulae andR. padi in all sampling cases. In contrast,Lysiphlebus fabarum (Marshall) was the dominant species parasitizingA. ruborum onR. ulmifolius andA. gossypii on cotton in Thessaly (central Greece) and Macedonia (northern Greece), whereasLysiphlebus confusus Tremblay et Eady andBinodoxys acalephae (Marshall) were the dominant parasitoid species in Thrace (northern Greece).Coccinella septempunctata Linnaeus was the most abundant coccinellid species on durum wheat, whereasAdonia variegata (Goeze) predominated on cotton. However, coccinellid individuals were scarce on bothD. viscosa andR. ulmifolius. The present study indicated that these two shrubs can be regarded as useful reservoirs of aphid parasitoids.  相似文献   

8.
9.
Susceptibility to the insectBactrocera oleae and the fungiSpilocaea oleagina andSphaeropsis dalmatica was investigated in four olive cultivars, two for table fruit production (Kalamon and Chondrolia Chalkidikis) and two for oil production (Lianolia and Koroneiki). Cv. Chondrolia Chalkidikis was the most susceptible to all three pathogens, followed by cv. Kalamon. Soil plowing and the organic fertilizer Bio-Trust® (10-3-6+8% MgCO3+10% CaCO8) increased the susceptibility of all four tested olive cultivars to the insect and the two fungi. Correlations were found between the attacks byB. oleae and infections byS. oleagina andS. dalmatica on the four olive cultivars.  相似文献   

10.
The plant parasitic nematode Longidorus poessneckensis found in Austria, the Czech Republic, Germany, Poland and the Slovak Republic was molecularly characterized. Mitochondrial genes encoding cytochrome c oxidase subunit I (COI) and nicotinamide dehydrogenase subunit 4 (nad4), the D2 and D3 expansion segments of 28S rRNA and Internal transcribed spacer 1 (ITS1) rRNA were sequenced for 16 L. poessneckensis populations. Six haplotypes of COI and five haplotypes of nad4 were determined. Nucleotide intraspecific variation was up to 17.1% for the partial sequenced COI gene and up to 17.7% for the partial sequenced nad4 gene, the latter being the highest up to date known intraspecific variation in this genus. The analyses of multiple amino acid sequence alignments of mitochondrial genes revealed low variability (0–2.4%) for COI gene and high divergence (0–7.6%) for nad4 gene. Intraspecific sequence diversity for the D2-D3 of 28S rRNA gene was up to 1.2% and for ITS1 rRNA gene was up to 1.6%. It has been hypothesized, that during the Last Glacial Maximum, L. poessneckensis populations probably persisted in refuge areas in the Carpathian Mountains and subsequently expanding from these areas and colonizing other European regions.  相似文献   

11.
Ditylenchus dipsaci is a species complex including diploid and polyploid individuals. The onion race of D. dipsaci is a sensu stricto group and has a wide range of host spectrum. Identification of the D. dipsaci onion race is difficult using morphological and morphometrical methods. Species specific primers are mostly used in molecular approaches for identification of D. dipsaci populations. Fifty one morphologically selected Ditylenchus spp. populations from onion production areas in Turkey were subjected to molecular identification using four D. dipsaci species specific primer sets (PF1-PR1, PF2-PR2, DdpS1-rDNA2, DitNF1- rDNA2, H05-H06) targeting 5.8S and 18S rDNA, ITS1 and flanking ITS regions. Thirty nine percent of the nematode samples were positive with four primers tested, while four of the nematode samples gave specific bands with H05-H06 primers. Ditylenchus dipsaci sensu stricto was identified with specific primer sets in Adana, Hatay, Tekirdag, Bursa, Aksaray, Karaman, Eskisehir and Ankara provinces in Mediterranean, Trace, Aegean and Central Regions in Turkey.  相似文献   

12.
The nematicidal effect of a formulated product containing extract from Quillaja saponaria was evaluated against the root-knot nematodes. The product QL Agri® 35 (QL) was tested to record the effect on second stage juveniles motility, egg hatch and also against field populations in greenhouse experiments contacted in three different locations of Greece. Convulsive movement of second stage juveniles of Meloidogyne incognita was recorded after exposure for 8 days at a series of doses, while the most paralyzed juveniles were counted at the dose of 8 mg l?1. There was also a gradual decrease in the number of juveniles emerging from egg masses of the same nematode species when the dose of Q. saponaria was increased from 0 to 8 mg l?1. In greenhouse experiments, the use of Q. saponaria could control root-knot nematodes and prevent nematodes increase in soil. The present study demonstrates that the use of Q. saponaria extract has the ability to control root-knot nematodes. Control given by Q. saponaria in field populations infecting cucumber was similar to that of cadusafos (Rugby®) and oxamyl (Vydate®) under the tested dosages and the specific conditions of the experiments.  相似文献   

13.
Laimaphelenchus suberensis sp. nov. obtained from declining Quercus suber trees of Herdade da Gouveia de Baixo, Alentejo, Portugal, is described and illustrated based on morphological, biometrical and molecular characters. The diagnosis of Laimaphelenchus species has been commonly based on the presence or absence of a vulval flap and on the shape structure of the tail tip. The species described here has been included in the Laimaphelenchus group without vulval flap, and can be distinguished from morphologically similar species by its tail tip shape structure that has a stalk-like terminus and three diffuse tubercles with 4–6 finger-like protrusions. For the molecular analyses, the mitochondrial DNA region from the cytochrome oxidase subunit I (mtCOI), the D2-D3 expansion segments of the large subunit (LSU) and small subunit (SSU) of rRNA gene were amplified and sequenced. Sequences of L. suberensis sp. nov. clustered separately from all Laimaphelenchus spp. with available sequences in Genbank, confirming its identification as a new species. This is the second report of the genus Laimaphelenchus in Portugal, associated with Q. suber: L. heidelbergi and L. suberensis sp. nov.  相似文献   

14.
The occurrence and geographic distribution of longidorid nematode species inhabiting the rhizosphere of cultivated olive (cvs. Chemlali and Chétoui) in Tunisia were investigated. Morphological and morphometrical studies identified three Longidorus and six Xiphinema species, with frequencies of prevalence as following: Longidorus africanus (23.0 %), L. euonymus (4.5 %), L. glycines (13.7 %), Xiphinema conurum (13.7 %), X. italiae (36.4 %), X. meridianum (13.7 %), X. pachtaicum (18.2 %), X. robbinsi (9.1 %), and Xiphinema sp. (4.5 %). The three Longidorus species were reported for the first time in Tunisia, in addition to two species of Xiphinema (viz. X. meridianum and X. robbinsi). Molecular characterisation using D2-D3 expansion regions of 28S rRNA and ITS1-rRNA was carried out and Bayesian inference analysis was used to reconstruct phylogenetic relationships among these species and with other longidorids. Twenty-five new D2-D3 of 28S rRNA gene sequences were obtained in the present study, seven for Longidorus and 18 for Xiphinema spp., as well as 14 new ITS1 rRNA gene sequences (seven for Longidorus and seven for Xiphinema spp.).  相似文献   

15.
A new longidorid nematode, Longidorus persicus n. sp., is described and illustrated from a population extracted from soil associated with wild rose (Rosa sp.) naturally growing in the mountains close to the village of Cheshmeh-e-Nezamei near the city of Gilan-e-Gharb, Kermanshah province, western Iran. The new needle nematode is characterised by a large body size (6550–7763 μm), an anteriorly flattened lip region, ca 13 μm wide, distinctly set off from body contour by a depression, amphidial fovea large, pocket shaped, slightly asymmetrically bilobed, a moderately long and flexible odontostyle ca 86 μm long, stylet guiding ring located at ca 25 μm from anterior end, posterior arrangement of the pharyngeal gland nuclei, vulva almost equatorial (49–54 %), tail short, about 3/4 of its width, dorsally convex-conoid, with rounded terminus, with a c’ ratio ca 1.3, bearing three pairs of caudal pores and male rare (ratio 1:10 females) with spicules ca 46 μm long. Integrative diagnosis was completed with molecular data obtained using D2-D3 expansion segments of 28S rDNA, ITS1-rDNA, and partial 18S-rDNA. The phylogenetic relationships of this species with other Longidorus spp. using D2-D3 expansion segments and partial 18S-rDNA indicated that L. persicus n. sp. clustered together with L. perangustus and L. euonymus: both of them sharing an anteriorly flattened lip region and distinctly set off from body contour by a depression.  相似文献   

16.
Pinewood nematode (PWN), Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD), was detected in Spain in 2008. This gives rise to serious concern, as the disease has caused severe environmental and economic losses in Portugal and in Asian countries. We studied interspecific variation in susceptibility to pine wilt disease and differences in constitutive chemical compounds in the xylem tissue of the seven pine species -P. canariensis, P. halepensis, P. pinaster, P. pinea, P. sylvestris, P. radiata and P. taeda. Two-year-old trees were inoculated with B. xylophilus. Water potential and nematode densities were measured for each species on specific dates; whereas, wilting symptoms were recorded weekly until the end of the assay. Chemical compounds in the xylem were determined prior to inoculation. Three different resistance groups can be established in terms of the pine species susceptibility to PWN: non- to slightly-susceptible (P. canariensis, P. halepensis, P. taeda and P. pinea), susceptible (P. pinaster and P. radiata), and highly-susceptible (P. sylvestris). Nematodes migrated downward to the roots in all seven species. Constitutive xylem nitrogen, total polyphenols, and marginally phosphorus were negatively correlated with mortality caused by PWN. The most susceptible species, Pinus sylvestris, presented high levels of constitutive lipid-soluble substances and low levels of manganese, pointing to a possible relation between these components and PWN susceptibility. The results suggest P. sylvestris, P. pinaster and P. radiata forests could be severely damaged by PWN in Spain and highlight how constitutive chemical compounds such as nitrogen might play a role in resistance mechanisms against PWN.  相似文献   

17.
Hibiscus syriacus, as a national flower of Korea, is most popularly used for ornamental purposes and includes numerous cultivars, and it is widely planted in temperate zones that feature hot summers. We investigated Choanephora flower rot on H. syriacus from 2012 to 2014 in Korea and Japan and confirmed Choanephora infection in several localities in both countries. Here, our objectives were to identify the main causal agent of Choanephora flower rot on H. syriacus and describe its morphological and molecular characteristics. We identified 44 out of 50 isolates as Choanephora cucurbitarum and the remainder as C. infundibulifera based on morphological characterization and phylogenetic analysis. The sequences of the internal transcribed spacer region (ITS) of ribosomal DNA and the D1/D2 region of the large subunit (LSU) rDNA of examined isolates were compared with sequences obtained from GenBank, and the analysis of the results revealed 100 % identity with the corresponding sequences of C. cucurbitarum and C. infundibulifera strains. Classification of the Choanephora species performed here according to the key described by Kirk (1984) corresponded with the results of the phylogenetic analysis of this study. Through intraspecific and interspecific mating tests, the characteristics of zygospore were described in details. Pathogenicity tests using both species showed the same symptoms, causing blossom blight and soft rot on the flowers, which were identical to those observed in the field. All identified causal agents of Choanephora rot were indeed Choanephora species, where C. cucurbitarum was identified in the majority, while the others were in the minority of examined samples.  相似文献   

18.
Meloidogyne enterolobii (syn. M. mayaguensis) has been reported to cause severe damage in commercial guava orchards and other plants in Central and South American countries. Considering the risk of introduction and dissemination of this pest in the European region, M. enterolobii was placed on the EPPO A2 list in 2010. The use of non-host fruit species is a recommended strategy to manage root-knot nematodes in infested guava orchards. This study screened 89 plant genotypes from 25 fruit plants of economic importance, plus two susceptible controls (guava and tomato) for its host status to M. enterolobii. Three to eight months after inoculation, nematode reproduction factor (RF) was used to characterize host suitability of fruit crops to this nematode. Ten banana genotypes, six Barbados cherries, one fig, two grape rootstocks and six melons were rated as good hosts for this nematode. Sixteen fruit plants behaved either as non-hosts or poor hosts to M. enterolobii, including assaí, atemoya, avocado, cashew nut, citrus, coconut, grape, jabuticaba, mango, mulberry, papaya, passion fruit, sapodilla, soursop, starfruit and strawberry. For the future, field experiments in areas infested by this nematode are essential to confirm the greenhouse results. These non-host fruit species can replace in the future eradicated guava trees in fields severely infested by this nematode and become an economic option for growers where M. enterolobii is considered a serious problem.  相似文献   

19.
Pratylenchus zeae parasitizes various crops and damages the host roots, resulting in decreased yield and quality of the host plants. Alignments of mitochondrial DNA (mtDNA) Cytochrome Oxidase I (COΙ) sequences revealed the genetic variation among Pratylenchus species. The results indicated 0.2–2.4% intraspecific variations for mtDNA COI sequences among eight P. zeae populations, and 25.4–35.1% interspecific variations between P. zeae and other Pratylenchus species. Based on the mtDNA COΙ region, a loop-mediated isothermal amplification (LAMP) assay was developed for the rapid and specific detection of P. zeae. The optimal conditions for the LAMP assay were 64 °C for 40 min. The LAMP products were confirmed using conventional polymerase chain reaction (PCR), analysis with the restriction enzyme Bam HI and visual inspection by adding SYBR Green I to the products. The LAMP assay could detect P. zeae populations from different hosts and different geographical origins specifically. The LAMP assay was also sensitive, detecting 0.1 individual P. zeae, which was 10 times more sensitive than conventional PCR. This is the first report of the detection of Pratylenchus spp. using LAMP. In addition, the results also suggested that use of the COI gene might allow for good resolution at the Pratylenchus species level.  相似文献   

20.
Psytallia concolor (Szépligeti) is a koinobiont endoparasitoid of many Tephritidae larvae, including Bactrocera oleae (Rossi), and has been used in Mediterranean areas for biological control of olive fruit fly by inundative release. The present study evaluates the influence of olive fruit variety (Amfissis, Arbequina, Branquita de Elvas, Carolea, Kalamon, Koroneiki, Leccino, Manzanilla, Mastoidis, Moroccan Picholine and Picholine) on P. concolor parasitism efficiency and performance in the field during two successive years. The results showed that the percentage of parasitism was significantly higher (>30%) in Mastoidis and Koroneiki (light-weight varieties <1.5 g) than Leccino which has a medium fruit weight, followed by Amfissis, Moroccan Picholine, Picholine and Branquita de Elvas. Only Manzanilla among large weight varieties, exhibited high percentage of parasitization (42.72%) during 2013. The mean weight of the pupae (>4.21 mg) as well as the length of the developed adult parasitoids (>3.5 cm) in Mastoidis and Manzanilla were significantly higher than these individuals developed from other varieties such as Koroneiki and Kalamon. Finally, the optimal host fruit for P. concolor development seems to be Mastoidis variety with great biological parameters and percentage of parasitism.  相似文献   

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