Darimont, H.

Maixner, M.

Reinert, W.

English

JKI Open Journal Systems (Julius Kühn-Institut)

Vitis 39 (2), 8384 (2000)Research NoteTransmission of grapevine yellows byOncopsis alni (Schrank)(Auchenorrhyncha: Macropsinae)M. MAIXNER1), W. REINERT2) and H. DARIMONT1)1) Biologische Bundesanstalt für Land- und Forstwirtschaft, Institutfür Pflanzenschutz im Weinbau, Bernkastel-Kues, Deutschland2) Staatliche Lehr- und Versuchsanstalt Oppenheim, FachbereichRebenzüchtung, Alzey, DeutschlandS u m m a r y :  Oncopsis alni leafhoppers werecaptured on field-grown Alnus glutinosa that were in-fected by alder yellows phytoplasma. This pathogen isindistinguishable by RFLP of ribosomal and non-ri-bosomal DNA fragments from a phytoplasma associ-ated with grapevine yellows in the same region. PCRtests revealed that approximately 11 % of the insectscarried the pathogen. Their ability to inoculate grape-vine was studied by transmission experiments. Threeof 88 test plants developed typical symptoms of grape-vine yellows, and the respective phytoplasma could bedetected in symptomatic plants by PCR. Thus, O. alniwas identified as a vector of a grapevine yellows of theelm yellows group.K e y  w o r d s :  grapevine yellows, phytoplasma, vector,leafhopper, transmission, epidemiology, host plant.Introduction: Two types of grapevine yellows (GY)affect Vitis vinifera L. in Germany. A stolbur groupphytoplasma is associated with the widespreadVergilbungskrankheit that is present in almost allviticultural areas. A second type of GY has been reportedfrom the Palatinate region of Germany (Palatinate Grape-vine Yellows, PGY) and a phytoplasma of the elm yellowsgroup was found to be associated with this disease(MAIXNER et al. 1995 b). Serological and molecular datarevealed a close relationship of this pathogen to thephytoplasma associated with Flavescence dorée (FD)(MAIXNER et al. 1995 b), but DAIRE et al. (1997) were ableto differentiate both diseases by RFLP analysis of non-ribosomal DNA fragments. Their results were supportedby transmission experiments with Scaphoideus titanusBall, the vector of FD, that failed to inoculate grapes withPGY (BOUDON-PADIEU and MAIXNER, unpubl. data). WhilePGY could be distinguished from some other elm yellowsgroup phytoplasmas by RFLP analysis of ribosomal(REINERT and MAIXNER 1997) and non-ribosomal DNA frag-ments (DAIRE et al. 1997), no difference to the alder yel-lows phytoplasma (AGY) was found that is widespread inblack alder (Alnus glutinosa L.) in Germany.Only two vectors of grapevine yellows have been iden-tified so far. FD is transmitted by the leafhopper S. titanus,Vergilbungskrankheit and Bois noir by the planthopperHyalesthes obsoletus Sign. (MAIXNER 1994;  SFORZA et al.1998). While S. titanus is not yet present in Germany, an-other leafhopper, Oncopsis alni (Schrank), was identifiedas a vector of alder yellows (MAIXNER and REINERT 1999).We investigated the ability of this leafhopper to inoculateV. vinifera with AGY and the capability of the phytoplasmafrom alder to provoke symptoms of PGY in the inoculatedgrapes.Material and Methods: Alder trees were tested forinfection with AGY by polymerase chain reaction (PCR).Adult O. alni were collected from infected trees from Juneto August 1998 in both the Palatinate and Moselle areas ofGermany. Transmission experiments were carried out in agrowth chamber at 25 °C and a photoperiod of 16 h. Theleafhoppers were fed in groups of 2-6 individuals in cagesthat contained a potted grapevine seedling each. They wereremoved from the plants after an inoculation period of oneweek and stored at -20 °C while dead insects were removedimmediately. Grapes were grown in an insect-proof green-house at 20 °C and a photoperiod of 16 h for about threemonths. They were then hibernated at 10 °C under naturallight conditions. Eighty-eight grapevine seedlings wereinoculated by a total number of 381 leafhoppers.Total DNA was extracted from leaf midribs of the in-oculated grapevine seedlings as well as from individual in-sects as described by MAIXNER et al. (1995 a). DNA wasalso extracted from a periwinkle (Catharanthus roseus(L.) G. Don) infected by an isolate of PGY, and from field-grown A. glutinosa and grapevine with symptoms of PGY.PCR and RFLP analyses were carried out as described byMAIXNER and REINERT (1999). The primers fAY/rEY wereused for the group-specific detection of elm yellowsphytoplasmas, while an unspecific amplification with prim-ers P1/P7 and subsequent digestion of the amplificationproducts by AluI allowed to compare the phytoplasmasdetected in plants and insects.Results and Discussion: O. alni is a strongly mono-phagous leafhopper on alder (OSSIANILSON 1981). We foundit frequently on A. glutinosa. However, a few specimenwere also caught on sticky traps or by sweep net in affectedvineyards adjacent to alder trees. While O. alni survivedwell on alder seedlings during previous transmission tri-als, none of the 381 leafhoppers used in our experimentssurvived the feeding period on grapevine. Four of 80 (5 %)leafhoppers from Palatinate and 17 of 113 (15 %)leafhoppers from the Moselle area tested positive withprimers fAY/rEY (Figure, A). On an average, 11 % ofO. alni were found to carry a phytoplasma of the elm yel-lows group.Only one of 88 inoculated grape seedlings developedsymptoms of grapevine yellows within three months afterinoculation. This plant ceased growing and died so fast thatit could not be used for DNA extraction. Two more seed-lings developed typical symptoms of GY after dormancy,such as rolling of leaves, lack of lignification and blackCorrespondence to: Dr. R. MAIXNER, Biologische Bundesanstalt fürLand- und Forstwirtschaft, Institut für Pflanzenschutz im Weinbau,Brüningstraße 84, D-54470 Bernkastel-Kues, Germany.Fax: +49-6531-4936. E-mail: m.maixner.bba@t-online.deNamenlos-12 30.04.02, 10:398384 M. MAIXNER, W. REINERT and H. DARIMONTpustules along the shoots. These plants were tested posi-tive in PCR with elm-yellows specific primers, however,only a faint band could be achieved with one of the sam-ples. No DNA was amplified from all other seedlings. Intotal, one of 33 seedlings (3 %) inoculated with O. alnifrom the Palatinate region and one of 55 seedlings (2 %)on which leafhoppers from the Moselle area were fed werefound positive with primers fAY/rEY.AluI digestion of DNA fragments amplified with prim-ers P1/P7 revealed identical restriction fragment patternsin samples obtained from alder, diseased grapevine fromthe field  and a PGY isolate in periwinkle as well as fromO. alni and the experimentally inoculated grapevine seed-lings (Figure, B). This profile can be distinguished fromfragment patterns obtained from other elm yellows groupphytoplasmas such as rubus stunt or elm yellows (REINERTand MAIXNER 1997).The results of the experimental inoculation of grape-vine seedlings by O. alni collected from AGY infectedA. glutinosa led to the conclusion that O. alni is not onlythe vector of alder yellows (MAIXNER and REINERT 1999)but is also able to transmit this phytoplasma to grapevine,thus inducing symptoms of grapevine yellows in the in-fected plants. In the field, PGY is normally restricted toold vines growing in vineyards along creeks or rivers whereA. glutinosa is present. This behaviour can be explained bythe strong adaptation of O. alni to alder that prevents a fre-quent inoculation of grapevine even if  the infestation ofthe leafhopper population is fairly high. However, moredetailed investigations are required to understand the epi-demiology of PGY. It will be necessary to search for PGYin other viticultural areas where infected alders are grow-ing. Furthermore, the ability of other vectors of elm yel-lows group phytoplasmas  to transmit PGY has to be inves-tigated. Macropsis fuscula (Zetterstedt), for example, thevector of rubus stunt disease, is also present in the areasaffected by PGY.As long as O. alni remains the only vector of PGY, theeconomic risk of this disease seems to be low. The situa-tion would change, however, if a transmission cycle fromgrape to grape by another, ampelophagous vector could beestablished. Therefore, care has to be taken to avoid theintroduction of potential vector species and known vec-tors of elm yellows group phytoplasmas into areas wherePGY occurs.This work was supported by grants of the Forschungsring desDeutschen Weinbaues. We thank YVONNE GERHARD for her excel-lent technical assistance.DAIRE, X.; CLAIR, D.; REINERT, W.; BOUDON-PADIEU, E.; 1997: Detection anddifferentiation of grapevine yellows phytoplasmas belonging to theelm yellow group and to the stolbur subgroup by PCR amplification ofnon-ribosomal DNA. European Journal of Plant Pathology 103,507-514.MAIXNER, M.; 1994: Transmission of German grapevine yellows(Vergilbungskrankheit) by the planthopper Hyalesthes obsoletus(Auchenorrhyncha: Cixiidae). Vitis 33, 103-104.- -; AHRENS, U.; SEEMÜLLER, E.; 1995 a: Detection of the German grapevineyellows (Vergilbungskrankheit) MLO in grapevine, alternative hostsand a vector by a specific PCR procedure. European Journal of PlantPathology 101, 241-250.- -; REINERT, W.; 1999: Oncopsis alni (Schrank) (Auchenorrhyncha:Cicadellidae) as a vector of the alder yellows phytoplasma of Alnusglutinosa (L.) Gaertn. European Journal of Plant Pathology 105, 87-94.- -; RÜDEL, M.; DAIRE, X.; BOUDON-PADIEU, E.; 1995 b: Diversity of grapevineyellows in Germany. Vitis 34, 235-236.OSSIANILSON, F.; 1981: The Auchenorrhyncha (Homoptera) of Fennoscandiaand Denmark. Part 2: The families Cicadidae, Cercopidae, Membracidae,and Cicadellidae (excl. Deltocephalinae). In: Fauna Entomologica Scan-dinavia Vol. 7 (2), 223-593. Scandinavian Science Press Ltd.,Klampenborg, Denmark.REINERT, W.; MAIXNER, M.; 1997:  Epidemiological studies on a new grape-vine yellows in Germany. Extended Abstracts 12th Meeting ICVG,Lisboa, Portugal, 29 Sep - 2 Oct 1997, 65-66.SFORZA, R.; CLAIR, D.; DAIRE, X.; LARRUE, J.; BOUDON-PADIEU, E.; 1998: Therole of Hyalesthes obsoletus (Hemiptera: Cixiidae) on the occurrenceof bois noir of grapevines in France. Journal of Phytopathology 146,549-556.Figure: Specific detection of elm yellows group phytoplasmas byPCR with primers fAY/rEY (A); AluI restriction profiles of a DNAfragment that had been amplified with primers P1/P7 (B).1 = Periwinkle isolate of PGY; 2 = Healthy Alnus glutinosa seed-ling; 3 = Infected A. glutinosa on which Oncopsis alni was cap-tured; 4 = O. alni used to inoculate grapevine; 5 = Healthy seedlingof V. vinifera; 6 = Seedling of V. vinifera inoculated by O. alni;7 = Infected V. vinifera cv. Scheurebe from a Palatinate vineyard.Namenlos-12 30.04.02, 10:4084

Transmission of grapevine yellows by Oncopsis alni (Schrank) (Auchenorrhyncha: Macropsinae)

https://ojs.openagrar.de/index.php/VITIS/article/download/4612/4490

Transmission of grapevine yellows by Oncopsis alni (Schrank) (Auchenorrhyncha: Macropsinae)

Abstract

Similar works

Full text

Available Versions

JKI Open Journal Systems (Julius Kühn-Institut)