bluuebunny/crossref_metadata_2025 huggingface dataset:
Infections of Glomerella cingulata on olive in Italy1
Authors: GRANITI A. , FRISULLO S. , PENNISI A. M. , DI SAN LIO G. MAGNANO
Published: April 2008

Olive anthracnose, caused by strains or populations of Glomerella cingulata (anamorph Colletotrichum gloeosporioides) pathogenic for olive, was introduced into southern Italy before or during the 2nd World War presumably from Albania or Greece. In the following 20 years, severe outbreaks of fruit rot and dieback of twigs and branches were recorded in several areas of Puglia, Calabria, Sicilia and Sardegna. After the 1970s, the epidemics gradually regressed. At present, the disease is restricted to certain humid areas of southern Italy. Factors associated with this regression are discussed, including a supposed change in virulence of the fungus, possibly as a consequence of mixing of the introduced strains infecting olive trees with local, less pathogenic populations of G. cingulata. The first results of a comparison of olive isolates with isolates of the pathogen from citrus and Annona muricata in Calabria suggest that the population from olive is relatively homogeneous and can be distinguished from the population infecting other hosts by a number of morphological, pathogenic and biochemical characteristics.
Chemical control of the olive rot caused by Glomerella cingulata1
Authors: PENNISI A. M. , AGOSTEO G. E. , GRASSO S.
Published: April 2008

The effect of various fungicides on Glomerella cingulata, the causal agent of a serious rot of olive fruits, was evaluated both in vitro and in the field. The following fungicides were tested: copper oxychloride, Bordeaux mixture, ziram, myclobutanil, hexaconazole, metiram, bitertanol and benomyl. Field trials were carried out in Calabria (southern Italy) for 2 years on two olive cultivars, Ottobratica (susceptible) and Sinopolese (resistant). The minimum effective concentrations of bitertanol, hexaconazole, myclobutanil, benomyl, metiram, ziram, and copper oxychloride on mycelial growth in vitro were < 5, < 50, < 50, < 1000, < 1000, < 1000, < 1000 μg ml−1, respectively. The ED90 values for conidial germination were 0.01, 0.02, 50, 50, 1000, 1000, and 1000 μg ml−1 of benomyl, ziram, myclobutanil, copper oxychloride, bitertanol, hexaconazole and metiram, respectively. In field trials, Bordeaux mixture and copper oxychloride proved to be the most effective products; however ziram, myclobutanil, bitertanol, metiram, and hexaconazole reduced the incidence of fruit rot significantly.
Mycotoxins inAlternaria alternata‐ infected olive fruits and their possible transfer into oil1
Authors: BOTTALICO A. , LOGRIECO A.
Published: April 2008

Alternariaspecies, mostlyA. alternata, have occasionally been found in some years on olive samples collected in Puglia (southern Italy). A survey was consequently made on the occurrence of the majorAlternariamycotoxins, i.e. alternariol (AOH), alternariol methyl ether (AME), altenuene (ALT), altertoxin‐I (ATX‐I), and tenuazonic acid (TA) in olives and products of their processing (oil and husks). The toxigenicity ofAlternariastrains isolated from olives, and the possible transfer of mycotoxins into the oil, were also investigated. Four out of 13 olive samples were contaminated by 2–4Alternariamycotoxins. The highest contamination was found in a badly damaged sample containing 2.9, 2.3, 1.4 and 0.3 mg kg−1of AME, AOH, ALT and ATX‐I, respectively. No mycotoxins were detected in olive oil destined for human consumption (6 samples) or olive husks (3 samples) collected from oil‐mills after the first pressing of olives. An oil sample produced in our laboratory by processing the most contaminated olive sample, contained AOH (0.79 mg kg−1) and AME (0.29 mg kg−1). The estimated amount of mycotoxin transferred into the oil was 4%, for AME, 1.8% for AOH, and zero for ALT and TA (considering oil yield as 15%). TheA. alternatastrains isolated from olive produced much more mycotoxins when cultured on rice (up to 3 orders of magnitude for TA) than on olive.
Late frost damage to olive trees1
Authors: GRANITI A.
Published: April 2008

In southern Italy, as in other Mediterranean areas where olive is grown, it is late frosts rather than winter frosts that are harmful. Injuries produced by spring freezes and spells of low temperatures (below −5°C) are described for young leaves, adult leaves, and shoots, twigs and branches of olive.
Spread of verticillium wilt by nursery plants in olive groves in the Halkidiki area (Greece)1
Authors: Thanassoulopoulos C. C.
Published: April 2008

Olive groves have been established during the last decade in the coastal area of Halkidiki and in the northern part of the Kassandra peninsula (GR). Visual symptoms of verticillium wilt were observed recently all over this area, particularly in young trees of cv. Hondrolia Halkidikis but not in the occasional old trees already in the orchards. The symptoms appeared regardless of the previous crop (cotton or not), so the nurseries supplying the farmers with young trees were assumed to be the primary source of infection. A survey of olive nurseries in the area was conducted during 1991. Eleven out of the total 18 nurseries in the area were located in the Verticillium dahliae‐infested zone and 9 of these were sampled. Three‐year‐old olive seedlings were selected and isolations were made from the xylem onto PDA acidified with 0.25% lactic acid. V. dahliae‐infected seedlings were detected in 4 out of the 9 nurseries examined. The presence of infected young trees in nurseries covering 15.6% of the total nursery area provided strong evidence that nurseries may be responsible for the recent expansion of verticillium wilt in the area.
The solar chamber: an innovative technique for controlling verticillium wilt of olive1
Authors: AL‐AHMAD M. A.
Published: April 2008

Control of olive tree wilt, caused by Verticillium dahliae, is not easy. A simple solar‐chamber technique has been developed to achieve effective control. The treated tree is irrigated, the soil is covered by a plastic sheet, and a chamber made of a metal framework covered with plastic sheets is placed over the tree. Trees were exposed for 10, 15 and 20 days. Using this approach the temperature in the chamber reached 55°, and soil temperatures at 5 and 15 cm depth reached 55 and 45°, respectively. It was no longer possible to isolate V. dahliae from infected trees after 15–20 days. Growth of treated trees was improved as compared with the untreated ones. Laboratory studies on the efficacy of dry heat on the survival of V. dahliae in diseased branches showed that 50–55°C was lethal after 1 h. On PDA medium, the fungus was killed in 1 h at 50°C and in 45 min at 55°C.
Evaluation of the susceptibility of olive cultivars to verticillium wilt1
Authors: PENNISI A. M. , CACCIOLA S. O. , DI SAN LIO G. MAGNANO , PERROTTA G.
Published: April 2008

In the present study, we evaluated the susceptibility of different commercial olive cultivars to verticillium wilt. Two Verticillium dahliae isolates, obtained from olive and artichoke, were used in pathogenicity tests. Two‐year‐old rooted cuttings were inoculated using either the root‐dip or the stem‐wounding method. The results were similar with both inoculation methods. Cvs Carolea and Cipressino proved to be moderately susceptible whereas Cassanese, Nocellara del Belice, Nocellara Etnea, Tonda Iblea and Uovo di Piccione were very susceptible. The response of cv. Coratina varied from susceptibility to moderate susceptibility.
Side‐effects of 107 pesticides on the whitefly parasitoid Encarsia formosa, studied and evaluated according to EPPO guideline no. 142
Authors: OOMEN P. A. , JOBSEN J. A. , ROMEIJN G. , WIEGERS G. L.
Published: April 2008

The side‐effects of plant protection products on beneficial arthropods have been studied by the Netherlands Plant Protection Service since 1974. Laboratory test methods were developed in the context of IOBC/WPRS for Encarsia formosa, a natural enemy of glasshouse whitefly, Trialeurodes vaporariorum. These methods were elaborated by EPPO into a sequential decision‐making scheme and published as an official EPPO guideline in 1989. The scheme includes a residual toxicity test on adults, a direct contact test on pupae, a persistence test on adults, all in the laboratory, and a field test. Following this guideline, the Netherlands Plant Protection Service tested and evaluated 107 pesticides at 307 concentrations over 10 years. Test details and complete test results are reported, including the risk assessments according to the EPPO scheme and according to the IOBC/WPRS conventions. These results are further summarized per type of pesticide, kind of test and risk classification. The efficiency of the scheme in classifying pesticide concentrations for risk to E. formosa is analysed. The scheme was found to be reasonably practical and efficient except for pesticides in the range between safe and hazardous. Suggestions for improvement are given. Also the possible need for changing the original IOBC/WPRS‐criterion for harmlessness (effect < 50%) is discussed. No reasons for lowering the criterion to 30% were found. The decision‐making scheme fits into the general approach for environmental risk assessment of plant protection products, developed recently by EPPO and the Council of Europe.
Bacterial leaf streak or black chaff of cereals
Authors: DUVEILLER E.
Published: April 2008

The literature related to bacterial leaf streak of cereals, due to various pathovars of Xanthomonas campestris, is confusing and dispersed. This review presents a synthesis of the knowledge that has been accumulated on the disease in cereals since the early reports on barley and wheat. The aim is to present the current status on geographical distribution of the disease, to explain possible confusions in symptoms, and to show the limited quantitative information available on losses and on host/pathogen interactions. Disease etiology and means of control are also reviewed. The objective is to define the present situation of black chaff in wheat, barley and triticale, and to delineate the major research needs in these crops. Difficulties in controlling bacterial leaf streak arise as a result of limited epidemiological knowledge and of the absence of satisfactory seed treatment permitting the eradication of the bacterium. There is an urgent need for a seed certification scheme and for more information on genetic resistance, with a view to limiting outbreaks of this sporadic but devastating disease.
European oak declines and global warming: a theoretical assessment with special reference to the activity of Phytophthora cinnamomi
Authors: BRASIER C. M. , SCOTT J. K.
Published: April 2008

Causes of current severe declines of the deciduous oaks Quercus robur and Q. petraea in northern and central Europe and of the evergreen Q. ilex, Q. suber and other Quercus spp. in the Mediterranean area are reviewed. Factors implicated include drought, pollution, winter cold, flooding, and stress‐related attacks by insects and fungi. Additional factors in Mediterranean oak declines include changing land‐use patterns and root disease caused by the aggressive, exotic oomycete root pathogen Phytophthora cinnamomi. Under conditions of global warming the survival and degree of root disease caused by this fungus seems likely to be enhanced, while the host range of the organism might also be increased. Application of the CLIMEX climate‐matching program suggests that with a mean increase in temperatures of 1.5–3°C the fungus might considerably increase its disease activity in its existing locations, and to some extent spread northwards and eastwards. However, it seems unlikely to become significantly active in areas of Europe with colder winters such as parts of Scandinavia, Russia and the central Danube. The predictive value of research on major environmental problems such as oak declines could be enhanced by more highly coordinated European forestry research programmes.
Plum pox situation in Europe
Authors: ROY A. S. , SMITH I. M.
Published: April 2008

The EPPO Conference on plum pox organized at Bordeaux (FR) in 1993–10 included a round‐table session at which scientists from research and plant protection services of EPPO Member Governments reviewed the current national status of the disease. These reports have been summarized and compared here. They show that plum pox is the most serious disease of stone fruit in Europe and that nearly all countries which produce stone fruits are affected to a greater or lesser extent. Broadly, Europe can be divided into three zones: (1) the central and eastern countries in which plum pox spread relatively early and levels are generally high; (2) the northern and western countries in which plum pox levels are very heterogeneous (sometimes fairly widespread as in Germany, sometimes very restricted as in France, sometimes absent as in Netherlands); (3) Mediterranean countries in which spread is relatively recent and there is high risk of further spread.
History and importance of plum pox in stone‐fruit production1
Authors: NÉMETH M.
Published: April 2008

Plum pox potyvirus (PPV), which first appeared in Bulgaria in 1915, has spread to nearly every European country, and can today also be found in various eastern Mediterranean countries. The pest is of great economic importance especially in some southern and central European countries, causing considerable losses in production of primarily plum, apricot and peach. The extent of losses varies between countries of different climates, depending on cultivars and virus strains. In joint infections with other viruses, PPV provokes synergistic effects, enhancing the economic importance of the pest. Since PPV is transmitted by insects, spread of the virus can be reduced only by eradicating sources of infection and use of virusfree propagating material. Thus introduction of more reliable detection techniques is essential, facilitating mass testing of trees. Close collaboration in studying strain‐related problems of PPV and in searching for resistant and tolerant cultivars is similarly important.
Molecular characterization of plum pox potyvirus1
Authors: GARCÍA J. A. , RIECHMANN J. L. , LAÍN S. , MARTÍN M. T. , GUO H. , SIMON L. , FERNÁNDEZ A. , DOMÍNGUEZ E. , CERVERA M. T.
Published: April 2008

In recent years, our knowledge of the molecular biology of plum pox potyvirus (PPV) and of potyviruses in general has greatly increased. The genome of PPV consists of a unique single‐strand RNA molecule with messenger polarity. A terminal protein (VPg) and a poly‐(A) tail are present at the 5’and 3’ends, respectively, of the genomic RNA. Four complete and other partial nucleotide sequences of PPV isolates have been reported. According to the levels of homology three different PPV strains can be defined. PPV RNA is translated into a unique polyprotein starting at the second AUG codon of the large open‐reading frame that covers most of the genome. The polyprotein is proteolytically processed by three virus encoded proteases (P1Pro, HCPro and NIaPro). While P1Pro and HCPro cut at their own carboxyl termini, NIaPro recognizes seven cleavage sites characterized by conserved heptapeptides. These sites differ in their susceptibility to cis and trans processing and in their reaction profiles. Immunoelectron microscopy has shown NIa and NIb proteins to form nuclear inclusions, but also dense aggregates in the cytoplasm, and CI protein to make typical pinwheel cytoplasmic inclusions. On the basis of sequence comparisons, NIb protein has been proposed to be the viral RNA replicase. CI protein has been purified from infected leaves and from Escherichia coli harbouring a plasmid that encodes it. It has nucleic acid‐stimulated NTPase and RNA helicase activities. Virus infection has been achieved by inoculation with a PPV full‐length cDNA clone and with transcripts synthesized using another one as template. These clones can be used to apply genetic engineering techniques to the in vitro manipulation of the PPV genome.
Significance of the heterologous encapsidation of zucchini yellow mosaic potyvirus in transgenic plants expressing plum pox potyvirus capsid protein1
Authors: LECOQ H. , RAVELONANDRO M. , WIPF‐SCHEIBEL C. , MONSION M. , RACCAH B. , DUNEZ J.
Published: April 2008

Transgenic Nicotiana benthamiana plants expressing the coat protein of an aphid‐transmissible strain of plum pox potyvirus (PPV‐D) were infected with an aphid non‐transmissible strain of another potyvirus, zucchini yellow mosaic potyvirus (ZYMV‐NAT). Non‐viruliferous Myzus persicae could acquire and transmit ZYMV‐NAT from these plants but not from infected N. benthamiana control plants (not transformed, or transformed by the vector alone). Immunosorbent electron microscopy experiments using the decoration technique revealed that ZYMV‐NAT virus particles in the infected transgenic plants expressing the PPV coat protein could be coated not only with ZYMV antibodies but also, on segments of the particles, with PPV antibodies. This suggests that aphid transmission of ZYMV‐NAT occurred through heterologous encapsidation, and reveals a potential risk of releasing genetically engineered plants expressing viral coat proteins into the environment.
Expression of the mature form of plum pox potyvirus helper component1
Authors: RAVELONANDRO M. , PEYRUCHAUD O. , TAVERT‐ROUDET G. , DUNEZ J.
Published: April 2008

Polyclonal antibodies raised to the plum pox potyvirus (PPV) helper component (HC) have been produced for the specific detection of HC protein in PPV‐infected plants. These experiments suggested that PPV HC is a single soluble protein of 48 kDa. The independent expression of the first two and half cistrons of the PPV genome in transgenic plants suggests that the P1 and P2 (HC‐Pro) proteases are involved in the processing of the mature form of HC.
Detection of plum pox potyvirus using monoclonal antibodies to structural and non‐structural proteins1
Authors: CAMBRA M. , ASENSIO M. , GORRIS M. T. , PÉREZ E. , CAMARASA E. , GARCIÁ J. A. , MOYA J. J. , LÓPEZ‐ABELLA D. , VELA C. , SANZ A.
Published: April 2008

Eleven monoclonal antibodies specific to plum pox potyvirus (PPV) coat protein were obtained by hybridoma technology from Spanish PPV isolates. In addition, two monoclonal antibodies specific for PPV cylindrical inclusions (CIP non‐structural proteins) were obtained. The monoclonal antibodies specific for PPV coat protein were assayed by DASI ELISA against 81 PPV isolates. At least nine different epitopes were found and 21 distinct serological patterns of reaction (serogroups) were established using nine selected monoclonal antibodies against the collection of PPV isolates, indicating the high variability of coat protein among PPV isolates. Changes in epitope composition were observed after aphid and mechanical transmission, indicating the occurrence of mixtures of isolates in field trees. Monoclonal antibody 5B reacted with all PPV isolates assayed, with very high affinity, using DASI ELISA. This method was compared with immunocapture‐PCR on field samples in spring, and showed very good coincidence of results. The efficiency of PPV detection can be slightly increased using monoclonal antibodies specific to cylindrical inclusions mixed with monoclonal antibodies against structural proteins, and using mixtures of monoclonal antibodies against different epitopes of coat protein. ELISA‐I and immunoprinting‐ELISA were able to detect CIP and PPV in extracts and tissue section, respectively, of woody plants. Two monoclonal antibodies offer the possibility of distinguishing between Marcus and Dideron PPV types (M or D). These D‐specific monoclonal antibodies can be used in routine tests with high affinity.
Sensitivity of the detection of plum pox potyvirus by molecular assays1
Authors: CRESCENZI A. , NUZZACI M. , PIAZZOLLA P.
Published: April 2008

Recently, plum pox potyvirus (PPV) has been found in Basilicata, southern Italy, on plum, apricot and peach. In 1992‐09, we started a large‐scale survey to verify the effectiveness of diagnostic methods used during seasons when it is difficult to reveal any presence of the virus. The assays were carried out by dot‐blot hybridization on stone‐fruit cultivars normally planted in this area. The virus was found, by dot‐blot hybridization, to be present in seven cultivars of peach, four of apricot and one of plum. All plants were 8–10 years old and, except for two apricot cultivars, were not displaying any apparent symptoms in spring 1992. Five peach cultivars, intended for use as primary sources of propagation material, were then selected for further study, and assayed in 1992–11 by ELISA and RT‐PCR. ELISA tests on these selected peach cultivars were consistently negative, while PCR tests were consistently positive. However ELISA tests gave positive results when repeated in 1993–05. These results not only suggest that primary propagation material should be tested by techniques more sensitive than ELISA, but also question the usefulness of carrying out tests during any phenological phases of the plant.
Serological characterization of Italian isolates of plum pox potyvirus1
Authors: PASQUINI G. , BARBA M.
Published: April 2008

An Italian isolate of plum pox potyvirus (PPV) from apricot, Ispave 17, was used as antigen for production of monoclonal antibodies. Six clones secreting specific antibodies to PPV were obtained. All these monoclonal antibodies were used to test a collection of different Italian PPV isolates, collected from plum, apricot and peach orchards, and other European isolates (including PPV‐D and PPV‐M serotypes), using DAS‐ELISA, SDS‐PAGE, western blot and GIEM. In western blot analysis, the PPV‐M and PPV‐D coat protein, detected directly from crude peach GF305 extracts, showed different electrophoretic mobility, the coat protein of PPV‐M being slightly larger than that of PPV‐D. ELISA tests, performed with fixed dilutions of antibodies and limiting dilutions of clarified samples, showed with some monoclonal antibodies a marked difference between PPV‐M and PPV‐D strains, at ratios greater than 1:40 (w/v). Also in GIEM some monoclonal antibodies gave a good labelling reaction only with PPV‐D serotype. With the help of this differentiation, it was found that all Italian isolates tested were of the D serotype and none of the severe M strain of PPV, which has not been reported in Italy.
Accurate identification of plum pox potyvirus and its differentiation from Asian prunus latent potyvirus in Prunus germplasm1
Authors: HADIDI A. , LEVY L.
Published: April 2008

We have determined the accuracy of plum pox potyvirus (PPV) identification in reverse transcription‐polymerase chain reaction (RT‐PCR) assays using DNA primers for the 3’non‐coding region of PPV as compared with primers for a segment of PPV coat protein. Only primers for the 3’non‐coding region were specific for PPV identification. Primers for PPV coat protein reacted with other known potyviruses such as potato Y potyvirus and papaya ringspot potyvirus. The 3’non‐coding region sequence of PPV has great value in the specific differentiation of PPV from other potyviruses. PPV is the only potyvirus so far known to infect Prunus spp. We have now identified a latent virus, which we have named Asian prunus latent potyvirus (APLV), that infects germplasm of peach and Prunus mume. PPV can be differentiated from APLV by RT‐PCR using DNA primers specific for the 3’non‐coding region of the PPV genome. APLV, however, reacts positively with PPV coat‐protein primers in RT‐PCR assay, PPV cDNA probe of cloned PPV cDNA containing the coat protein gene in molecular hybridization assays, and PPV antiserum in serological assays.
Dissémination du plum pox potyvirus par les pucerons: analyse des vecteurs potentiels du virus dans un verger d'abricotiers1
Authors: LABONNE G. , LAURIAUT F. , WON M. , QUIOT J. B.
Published: April 2008

Le plum pox potyvirus (PPV) est dissémine selon le mode non persistant par plusieurs espèces de pucerons, mais moins d'une dizaine d'espèces ont été deérites comme vecteurs de ce virus. Pour savoir si le PPV était préférentiellement dissemine par des espèces particulières dans le sud‐est de la France, nous avons cherchéà connaître la diversité et l'abondance des espèces de pucerons dans un verger d'abricotiers. Des pièges à fils englués que nous avions mis au point pour le piégeage des pucerons ailés vecteurs de virus de type non persistant dans d'autres cultures ont été utilisés pendant 6 années consécutives dans le même verger. L'analyse des captures montre une espèce prédominante (Aphis spiraecola, 15% des effectifs), ainsi qu'une forte diversité des autres espèces et la concentration des vols de pucerons de mars à juin (80% des captures). La corrélation démontrée entre les pucerons capturés et les pucerons qui se posent sur les feuilles permet de donner une estimation du nombre de pucerons qui se posent sur un arbre en une saison. La transmission du PPV par les espèces les plus abondantes a été testée en utilisant une technique adaptée aux virus transmis difficilement. Aphis gossypii, A. hederae et Rhopalosiphum padi sont ainsi apparus comme vecteurs du PPV.
Résistance des Prunusà la sharka1
Authors: DOSBA F. , LANSAC M. , EYQUARD J. P.
Published: April 2008

Après un rappel des travaux conduits depuis plusieurs années sur l'évaluation de la resistance au plum pox potyvirus (PPV) des Prunus, la méthodologie mise au point en France pour apprécier ce comportement en conditions contrôlées est présentée. Les difficultés de standardisation de la méthode sont liées à la réponse différée à l'inoculation, la variabililé du parasite, l'état physiologique du matériel végétal et le type d'inoculation. Le comportement des principales espèces de Prunus, hôles du PPV, est analysé. Des perspectives en matière de lulle génélique sont présentées.
Utilisation de la transgénose pour l'obtention de pruniers et d'abricotiers exprimant le gène de la protéine capside du plum pox potyvirus1
Authors: ESCALETTES V. , DAHURON F. , RAVELONANDRO M. , DOSBA F.
Published: April 2008

L'intégration du gène codant pour la protéine capside du plum pox potyvirus (PPV) dans les Prunus offre un grand intérêt pour l'induction de la résistance à cet agent pathogéne si la transformation via Agrobacterium est réalisée sur tissus adultes. L'inoculation de plusieurs clones de Prunus par A. rhizogenes a permis d'obtenir quelques clones de racines, en particulier dans le cas d'un hybride P. salicina×P. cerasifera cv. Burbank clone P(16‐5 × 2128)2. Ces clones contiennent et expriment le gène de capside du PPV mais aucune régénération de plante entière n'a pu être obtenue. L'utilisation d'A. tumefaciens, malgré la faible efficacité de la transformation, a en revanche permis l'obtention de plantes du prunier Marianna et de deux hybrides d'abricotier présentant des zones de transformation. La présence du géne de capside et son expression est à l'étude dans ces plantes.
Amélioration de l'abricotier pour la résistance à la sharka1
Authors: AUDERGON J. M. , DOSBA F. , KARAYIANNIS I. , DICENTA F.
Published: April 2008

Depuis 1985, sur la base de données obtenues en verger en Grèce, un programme d'hybridation a été engagé afin d'exploiter la résistance contre le plum pox potyvirus chez l'abricotier. Un test a été développé pour caractériser la résistance. L'evaluation des ressources génétiques ainsi que le déterminisme de la résistance sont en cours d'étude. Divers mécanismes de résistance peuvent être exploités, notamment au niveau de la sensibilité tissulaire et de l'aptitude à la transmission par les pucerons. La sélection pour la résistance doit se situer dans un programme général d'amélioration des caractéres agronomiques de l'espèce.
Resistance to plum pox potyvirus in apricots1
Authors: KARAYIANNIS I. , MAINOU A.
Published: April 2008

The susceptibility of 115 apricot cultivars to plum pox potyvirus (PPV) has been examined, since 1981, in the experimental plots of the Pomology Institute at Naoussa and Skydra, Makedonia (GR). Inoculation was assured by aphids, transmitting strain PPV‐M (Marcus) from naturally infected trees in adjacent peach orchards. For each cultivar, four to six trees were examined for at least 4 years. Observations on symptoms were made on leaves early in May and on fruits at maturity. Most cultivars expressed severe disease symptoms. Those without symptoms were inoculated by grafting onto heavily infected old apricot trees. The grafted shoots were tested for PPV in the following year by ELISA and on the woody indicator GF305. The cultivars which were rated as resistant after artificial inoculation and ELISA came from North America: Early Orange, Stella, NJA2, Sunglo, Veecot, Harlayne, Goldrich and Henderson. Most of these have been crossed with quality cultivars for the creation of resistant hybrids. The PPV resistance of large numbers of these apricot hybrids is now under investigation.
Susceptibility of apricot cultivars to artificial inoculation with plum pox potyvirus and use of ELISA for its evaluation1
Authors: SEDLAKOVA E. , GALLO J.
Published: April 2008

The susceptibility to plum pox potyvirus (PPV) of 13 apricot cultivars and two hybrids was studied under isolated conditions in the experimental orchard of the Research Breeding Station at Vesele from 1989 to 1993 after artificial inoculation of the trees. The plants were inoculated in the nursery in 1988 by chip‐budding with a local source of virus and then planted into the field trial. First symptoms of plum pox appeared on the leaves in 1990. Reinoculation of symptomless trees was done in summer 1991. By 1993, plum pox had totally invaded some apricot trees of the most susceptible cultivars (Madarska, Velkopavlovicka, Kisinevskij rannij, Ligeti orias, Bergeron, Vesna and Vestar). Uninoculated control trees remained symptomless despite the proximity of diseased trees and the fact that the orchard was not sprayed with insecticides during the period of experiment. Cvs Julskij, Veecot, Vegama and Veharda remained free from plum pox symptoms on leaves and fruits. In 1993‐05/06, the trees were assayed for the presence of the PPV antigen by ELISA. Leaf samples from 33 trees showing symptoms were positive. Samples prepared from the healthy tissues of leaves with symptoms were negative. Other trees (indexed by ELISA) growing in the neighbourhood of diseased trees in the period of 5 years were visually and ELISA negative.
Pathotypes of Synchytrium endobioticum in Germany
Authors: LANGERFELD E. , STACHEWICZ H. , RINTELEN J.
Published: April 2008

Results are given of a survey on the occurrence of pathotypes (races) of Synchytrium endobioticum (potato wart) in both parts of re‐unified Germany. An assortment of six differential cultivars appears to be sufficient to distinguish between the seven presently important German wart pathotypes. A total of ten pathotypes was recorded. Two West and two East German pathotypes seem to be identical, based on the results obtained with presently available cultivars. In contrast to pathotype 1 (common race) which prior to 1945 was distributed over the whole German territory, the ‘new’ pathotypes seem to prefer the central and south German mountain areas.
Evaluation of a Swedish steam‐dryer for treatment of Bursaphelenchus xylophilus in pine chips
Authors: DWINELL L. D. , MAGNUSSON C. , TOMMINEN J.
Published: April 2008

A steam‐dryer, designed and manufactured in Sweden, was evaluated for destroying Bursaphelenchus xylophilus in pine chips from southern USA. In a trial, pine chips were treated at different temperature and pressure regimes for 5 or 10min. The lowest time/temperature/pressure combination was to increase the vessel temperature from 85 to 104°C in 5 min at low pressure. Samples of pine chips were assayed for nematodes in laboratories in USA, Sweden, and Finland. No nematodes of any species were recovered from any of the treated pine‐chip samples. Large and heterogeneous pieces of wood in the treated samples were also nematode‐free. The apparatus was a prototype capable of handling about 400 kg h‐1. The final version would have to be able to process 100‐200 th‐1.
Plant‐parasitic nematodes of Croatia1
Authors: IVEZIC M. , SAMOTA D. , RASPUDIC E.
Published: April 2008

Investigations on the distribution of nematodes were carried out mostly in the northern and eastern parts of Croatia up to 1991. Sampling was performed in the following crops: maize, wheat, barley, sugarbeet, soybean, sunflower, rape, tobacco, potato, alfalfa, blackberry, onion, carrot, cucumber, lettuce, tomato, capsicum, oak, chrysanthemum, tulip, rose, grapevine, peach, apple, plum, pear, cherry, poplar, willow, clover, nettle, grass, meadow, woodland, many species of weeds, various glasshouse crops and vegetation in a nature reserve. 63 genera of nematodes with 81 species were detected. The most numerous representatives of plant parasitic nematodes were: Anguina, Aphelenchoides, Aphelenchus, Criconemoides, Ditylenchus, Gracilacus, Helicotylenchus, Hemicycliophora, Heterodera, Longidorus, Macroposthonia, Meloidogyne, Paratylenchus, Pratylenchus, Rotylenchulus, Rotylenchus, Trichodorus, Tylenchorhynchus, Tylenchus and Xiphinema.
Pratylenchus species of soybean in Croatia1
Authors: RASPUDIC E. , IVEZIC M. , SAMOTA D.
Published: April 2008

The numbers and species of phytoparasitic nematodes on soybean were studied over several years in Croatia, especially in the regions of Slavonija and Baranja. 19 phytoparasitic species were found, and of these Pratylenchus spp. predominated. These nematodes were found in mixed populations and their numbers were, at times, enormous. The average number per 100 ml of soil was about 100 individuals, with a maximum of 3348. The relationship between the number of nematodes and yield of soybean was calculated by a single regression equation. The soybean cultivars Sava and OS‐88 apparently possess tolerance to relatively high numbers of Pratylenchus spp. in the rhizosphere.
Agroecological characterization of Xiphinema index in Spain1
Authors: ARIAS M. , FRESNO J.
Published: April 2008

The agroecological characteristics of Xiphinema index were determined by studying its spatial and temporal distribution in different environmental conditions in Spain. The host range, life cycle in the Mediterranean continental climate and its relationships with grapevine fanleaf nepovirus are also reported. X. index is widespread in grape‐growing areas in a wide range of soil textures and pH, even at high percentage of carbonates. However, it seems to prefer sandy‐loam and sandy‐clay loam soils, and populations decrease when soil carbonates increase. Its spatial distribution is random but it has a tendency to be found in the deepest clay horizons, where soil moisture is retained. Availability of moisture seems to be the limiting factor for nematode development. Grapevine and fig are the main host plants but X. index is also associated with fruit trees, ornamental crops, vegetable crops, woodlands and other uncultivated soils. Its life cycle in central Spain, where temperature ranges from <0°C until March to above 40°C from May—June until September, takes 6–8 weeks to complete. X. index was found in 14% of all vineyards sampled and in 50% of the fanleaf virus‐infected vineyards. Transmission tests using bait plants were successful and the detection of the virus by means of ELISA test in a mimimun of five nematodes was achieved. Fanleaf‐like symptoms often occurred in the absence of the virus, as demonstrated by ELISA.
A scheme of plant certification for production of nematode‐free stocks1
Authors: TACCONI R. , LAMBERTI F.
Published: April 2008

A scheme for the control of plant‐parasitic nematodes in the production of planting stocks of garlic (Allium sativum) and strawberry (Fragaria × ananassa) is described. Nematodes controlled are Ditylenchus dipsaci on garlic and D. dipsaci, Aphelenchoides ritzema‐bosi, A. fragariae and Meloidogyne spp. on strawberry. The scheme gave very satisfactory results in the protection of garlic cultivations for over 10 years and strawberry plantations for at least 8 years.
First record of aBursaphelenchusspecies fromPinus pinasterin Italy1
Authors: PALMISANO A. MARINARI , AMBROGIONI L. , CAROPPO S.
Published: April 2008

Until now, no research has been performed in Italy on the nematodes of the aerial parts of forest trees and it is not known whetherBursaphelenchus xylophilusor other species of the genus are present. Information on this point is important to assess the risk of a possible introduction of the pine wood nematode. Therefore, a survey forBursaphelenchusspp. throughout northern, central and a part of southern Italy was initiated in 1992, choosing, in the first instance, areas whereMonochamusbeetles, possible vectors of the nematode, had been recorded. In samples taken from recently dead trees ofPinus pinasterin three localities of Liguria, nematodes belonging to the genusBursaphelenchuswere found associated withMonochamus galloprovincialisand inside the wood. The nematodes were propagated on fungal cultures ofCeratocystissp. and identified asBursaphelenchus mucronatus.Morphometric characters of the Italian specimens are reported. A distinct morphological difference in comparison with the original description ofB. mucronatuslies in the shape of the male bursa.
Control of food legume nematodes in the Mediterranean Basin1
Authors: DI VITO M. , GRECO N.
Published: April 2008

Control of food legume nematodes should consider the nematode species, type of crops, whether for grain or fresh pod production, environmental conditions and the economics of the crops. In general, 3–4‐year crop rotations could provide sufficient control of Heterodera goettingiana and H. ciceri and to a lesser extent also of Meloidogyne artiellia. Soil solarization has shown promise in controlling Pratylenchus thornei and H. ciceri on chickpea and has also been reported to be effective against Meloidogyne spp. The use of fumigants such as 1,3‐dichloropropene or 1,3‐dichloropropene + methylisothiocyanate and also of non‐volatile nematicides (aldicarb, oxamyl, carbofuran, thionazin and fenamiphos) gives good control of these nematodes resulting in impressive yield increases in heavily infested soil. However, both nematicides and soil solarization are expensive and their use may not be economic in most cases. The use of resistant cultivars is, so far, of little importance due to very limited number of those with good agronomic characteristics. To ensure good yield of faba bean, attention must also be paid to producing seed stocks free from Ditylenchus dipsaci. In addition, quarantine regulations must avoid spread of this nematode among different countries.
Biological control of Meloidogyne spp. with Pasteuria penetrans1
Authors: GOWEN S. R. , TZORTZAKAKIS E.
Published: April 2008

Pasteuria penetrans, an endospore‐forming obligate parasite of root‐knot nematodes, can be an effective biological control agent, particularly when used in pots, small plots or container‐grown crops. The absence of adequate mass‐production techniques prevents its deployment on a field scale. The spores are not mobile and their concentration and distribution influence parasitism since attachment of spores to free‐living juvenile root‐knot nematodes depends upon chance contact. Efficacy can also be influenced by the specificity of the population of P. penetrans to the root‐knot nematode population. If these problems can be overcome, the use of P. penetrans in integrated management systems developed over several crop cycles would appear to have good prospects for decreasing root‐knot nematodes in intensively cultivated soils.
Pest risk analysis of Meloidogyne chitwoodi for Finland
Authors: TIILIKKALA K. , CARTER T. , HEIKINHEIMO M. , VENÄLÄINEN A.
Published: April 2008

There is a an ever‐present risk of Meloidogyne chitwoodi extending its range to Finland because of the active import of plant material to the country. If the nematode becomes established in Finland, two factors may limit its pest potential: low temperature accumulation during the growing season and low winter temperatures. On average, the effective temperature accumulation may enable development of 1.5 generations yearly. In warm years, development of two generations is possible in the southern parts of the country. Hatching of the second generation, and infection of potato tubers, is possible in most potato‐growing areas. Low soil temperatures during the winter reduce population densities but may not prevent the nematode from becoming established in Finland. If M. chitwoodi were to extend its range to Finland, it could become a pest of potatoes, especially seed potatoes. For other crops, such as cereals and vegetables, population densities of M. chitwoodi would probably remain at such low levels that yield losses would not occur under current climatic conditions. Scientific information concerning M. chitwoodi populations in Europe is insufficient for a fully reliable pest risk analysis. This will not be possible until the effect of abiotic and biotic factors on the nematode are well known. A data base of the distribution of the nematode, based on a geographical information system, is urgently needed for the whole of Europe. Soil temperature maps interpolated from direct measurements, or derived from air temperatures, should also be constructed because soil temperature accumulation is one of the most important factors which may limit the distribution of this polyphagous nematode.
Testing for Pseudomonas syringae pv. atrofaciens and Xanthomonas campestris pathovars on cereals in Italy
Authors: ALEXANDROVA M. , ZACCARDELLI M. , STEFANI E. , BAZZI C.
Published: April 2008

During recent years, recurrent attacks of basal glume rot/leaf blight attributed to Pseudomonas syringae pv. atrofaciens have been observed on cultivars of durum wheat grown in the Po valley (IT). The main aim of this study was to test for this pathogen and Xanthomonas campestris pathovars in commercial seed lots of cereals produced in different regions of Italy, as well as in symptomatic plants collected in the field. None of the analyses led to the detection of xanthomonads. In testing for P.s. atrofaciens, representative bacterial isolates were selected and characterized; this was done by combining conventional identification tests and computerized densitometric analysis of electrophoretic patterns of cell proteins obtained using the SDS‐PAGE technique. P.s. atrofaciens was detected in seed samples (barley, wheat and durum wheat) and symptomatic plants (durum wheat) grown in northern and central Italy. The possible pathogenic role of other unrelated fluorescent pseudomonads in this interaction was also examined. Difficulties in discriminating pvs syringae and atrofaciens of P. syringae are discussed and the uncertain taxonomic relationship between these two pathovars is emphasized.
The use of polymerase chain reaction to detect latent infection of Clavibacter michiganensis subsp. michiganensis in tomato seedlings
Authors: GHEDINI R. , FIORE N.
Published: April 2008

A method was developed for routine analysis to detect latent infection of Clavibacter michiganensis subsp. michiganensis in samples from tomato seedling lots, before transplant, using polymerase chain reaction. In samples of 300 stem segments 1 cm long, the sensitivity threshold of the method was estimated at around 1.1 × 103 corynebacteria or 0.33% of latently infected stems. This method was shown to have a good specificity.
Main tree pathogens of western Himalayan forests in Nepal: description and risk of introduction
Authors: VANNINI A. , CECCA D. , MONACI L. , ANSELMI N.
Published: April 2008

The presence of some tree pathogens in natural forests in Nepal in western Himalaya is reported. Among them Melampsora ciliata on Populus ciliata and Arceuthobium minutissimum on Pinus wallichiana are described and considered for their risk of introduction into Europe.
Decline of a swarm of Schistocerca gregaria in a marginal invasion area
Authors: TUNÇ I. , INCI A.
Published: April 2008

Observations were made on a caged batch of Schistocerca gregaria from a swarm which invaded Antalya (TR) on 1988‐12‐03. Females did not change their colour, and this might be a sign of lack of sexual maturity. Only 1.5% of the eggs deposited were viable. Mortality, apparently due to exhaustion during the crossing of the Mediterranean sea and unfavourable local winter conditions, and inviability of the eggs produced are proposed as detectable causes of the decline of S. gregaria in Antalya.
Situation of Lymantria dispar in Europe
Authors: ROY A. S. , MCNAMARA D. G. , SMITH I. M.
Published: April 2008

The situation of Lymantria dispar in Europe and Russia was reviewed at an EPPO meeting held in Poznan (PL) in 1995‐03. The introduction of an Asian form of L. dispar, with flying females and a wider host range, from the Far East of Russia across the Pacific Ocean into North America had led to concerns that such a form might be present elsewhere in the EPPO region and might be introduced into North America across the Atlantic Ocean. Outbreaks of L. dispar were observed in many parts of Western Europe in the early 1990s, but were not considered exceptional compared with earlier outbreaks. Flying females were, however, seen in Germany. Preliminary results obtained with DNA markers suggested that the ‘Asian genes’ which they identify occur at low density in Western Europe, and that there is a progressive eastwards increase in their frequency. It is concluded that the presence of ‘Asian genes’ and of flying females, at low density, is a normal feature of European populations of L. dispar, and that European countries do not need to take special measures against the introduction of an ‘Asian form’.
The recent situation of the gypsy moth (Lymantria dispar) and other Lymantriids in Poland
Authors: LIPA J. J. , KOLK A.
Published: April 2008

Data is given on occurrence of Lymantria dispar in Poland, and on infested forest areas, over the period 1945/1994. Outbreaks occurred in 1952/1956, 1966/1971, 1980/1986 and 1992/1994, which corresponded with other outbreaks of this pest in Central Europe. A breeding area of L. dispar has been recognized in marshes and forests in north‐eastern Poland, adjoining Belarus. Information is also provided on the pest status of six other Lymantriidae: Dasychira pudibunda, Euproctis chrysorrhoea, E. similis, Leucoma salicis, Lymantria monacha and Orgyia antiqua. A list of pathogens and parasitoids recorded in larvae and pupae of L. dispar in Poland is given.
The use of monoclonal antibodies for the detection of fungi 1
Authors: BURNS R. , GEORGE E.
Published: April 2008

Monoclonal antibody‐secreting cell lines were generated against Pyrenophora graminea and Phylophthora fragariae by various immunization techniques. The specificity of each antibody was investigated by DAS ELISA, membrane ELISA and IF. Antibodies generated against P. fragariae were found to be genus‐specific and could be used to detect P. fragariae‐infected strawberry roots. Antibodies developed against P. graminea showed marked isolate variability in two Pyrenophora spp. The differences in isolate specificity were not consistent in all the assays investigated: antibodies reacted to some isolates by ELISA but did not detect them in other assays. An attempt was made to develop a membrane ELISA for detection of the fungi in seed material using the monoclonal antibodies that had been developed.
Identification of Fusarium avenaceum strains by isozymes analysis 1
Authors: YLI‐MATTILA T. , PAAVANEN S. , HANNUKKALA A. , PARIKKA P. , TAHVONEN R.
Published: April 2008

Differences in isozyme polymorphisms between 33 isolates of Fusarium avenaceum were compared using the native polyacrylamide gel electrophoresis technique. The isolates were collected from different regions of Finland. Of eight enzymes analysed, five showed clear isozyme polymorphism. By using these five enzymes, the isolates could be grouped into 20 different electrophoretic phenotypes. One of them was specific for oats, five for wheat and six for barley. Two further phenotypes were isolated from each of these crop species. In addition, two phenotypes were isolated from strawberry, one from both rye and cotoneaster, while the electrophoretic phenotypes from thuja, apple and hawthorn were specific for each. The phenotypes could be classified into five main groups. The extent of isozyme polymorphisms found in F. avenaceum provides a useful method for studying the identification and evolution of F. avenaceum strains.