16 research outputs found

    The in vitro cultivation of Bursaphelenchus spp. at the reference laboratory for quarantine pests at Julius K√ľhn-Institut in Braunschweig

    Get PDF
    Das Forstquarant√§nelabor des Julius K√ľhn-Instituts in Braunschweig (Deutschland) kuratiert eine einzigartige Sammlung lebender Bursaphelenchus-Arten, zudem Dauer¬≠pr√§parate und ITS-RFLP Muster dieser Arten. Die Sammlung wurde von Dr. Helen Braasch gegr√ľndet und umfasst derzeit 48 Arten in 305 verschiedenen Isolaten. Diese Isolate wurden √ľber 30 Jahre hinweg weltweit aus verschiedenen Habitaten (B√§umen) und anderen Bezugs¬≠quellen, wie Holzimporten einschlie√ülich Holzverpackungsmaterial, gesammelt. Die Aufzucht der Nema¬≠toden auf sporulierenden und nicht sporulierenden Botrytis cinerea ‚Äď Kulturen ist anspruchsvoll, arbeitsintensiv und erfordert sowohl Erfahrung als auch Geduld.The Forest quarantine laboratory at Julius K√ľhn-Institut in Braunschweig (Germany) curates a unique collection of living Bursaphelenchus species, permanent slides and ITS-RFLP profiles. The collection was initiated by Dr. Helen Braasch and currently comprises 48 species in 308 different isolates. These isolates were collected over 30 years across the globe from various habitats and sources, like forest trees and wood imports including wooden packaging material. Cultivation of the nematodes on sporulating and non-sporulating Botrytis cinerea is sophisticated, labor-intensive and requires both, experience and patience

    Systematic Identification of the Xylophilus Group in the Genus Bursaphelenchus

    Get PDF
    The pine wood nematode (PWN) Bursaphelenchus xylophilus (Steiner & Buhrer, 1934) Nickle, 1970 is the agent responsible for pine wilt disease (PWD). This nematode has been killing native pine trees (Pinus densiflora, P. thunbergii, P. luchuensis) in Japan since the early twentieth century. It is the number one forest pest in Japan and has been spread to China, Korea, Portugal, and Spain. The nematode is native to North America (Canada, USA, Mexico) and is thought to have been carried to Japan at the beginning of the twentieth century on timber exports. Up to now, the genus Bursaphelenchus Fuchs, 1937 comprises nearly 120 species (14 groups). Around 14 species very similar to B. xylophilus are put together and named the xylophilus group. This chapter presents the grouping history, subspecies or genetic types in species of the xylophilus group, and an identification key for 14 species of the xylophilus group, ITS-RFLP identification, and other molecular identification methods are also discussed

    Identificación molecular y registro de Aphelenchoides spp. en cultivos comerciales de Hydrangea en Antioquia, Colombia

    Get PDF
    El cultivo comercial de hortensias para flor de exportaci√≥n ocupa un rengl√≥n importante en el sector econ√≥mico del oriente antioque√Īo, por ser fuente de empleo y de desarrollo en la zona. La hortensia (Hydrangea macrophylla) es afectada por numerosos organismos fitopat√≥genos, entre ellos, nematodos del g√©nero Aphelenchoides, los que ocasionan, en el follaje, lesiones necr√≥ticas angulares, malformaci√≥n de flor, enanismo y un da√Īo indirecto en la tasa fotosint√©tica, demeritando los par√°metros de calidad para exportaci√≥n. El objetivo de este estudio fue identificar, molecularmente, las especies del nematodo Aphelenchoides asociadas al cultivo de hortensias de color, en los municipios de Medell√≠n (Santa Elena), La Ceja y Rionegro, siendo este el primer reporte para Colombia, de las especies de este g√©nero. Para la ejecuci√≥n del estudio, se realizaron 10 muestreos en cultivos comerciales, distribuidos entre los tres municipios mencionados. Los nematodos extra√≠dos, se sometieron a pruebas basadas en el an√°lisis de ADN, haciendo uso del marcador ribosomal 18S. Los an√°lisis filogen√©ticos practicados mostraron la presencia de la especie Aphelenchoides ritzemabosi en cultivos de hortensias, del corregimiento de Santa Elena y, de A. fragarie, en los municipios de La Ceja y Rionegro

    Identification, systematics and phylogeny of the genera in the family Aphelenchoididae (Nematoda: Tylenchomorpha)

    Get PDF

    Control biológico del vector del nematodo de la madera del pino Monochamus galloprovincialis Olivier mediante autoinfección con el hongo entomopatógeno Beauveria pseudobassiana S.A. Rehner & Humber

    Get PDF
    Bursaphelenchus xylophilus, cuyo vector es Monochamus galloprovincialis, provoca la enfermedad del marchitamiento del pino. Las estrategias de control se centran en el manejo del vector. Se desarrolla un método de autodiseminación de Beuaveria pseudobassiana, hongo entomopatógeno con elevada mortalidad, que permita la infección sobre el vector, consistente en un sistema de autoliberación, adaptado para autoinfección, de los insectos vectores capturados en el bote colector de las trampas multiembudos. Se intenta reducir las capturas de especies de xilófagos no objetivo mediante modificaciones en el sistema. Se determina la dosis del hongo entomopatógeno que autoinfecte y pueda transmitir inóculo, mediante distintos dispositivos. El sistema de autoliberación-infección, tubo enroscado externamente al bote colector de las trampas y el de escape de insectos no objetivo, mediante mallas de 6,0 mm de luz han resultado exitosos. Se han determinado las características del dispositivo de infección y la concentración del hongo entomopatógeno que pueden resultar adecuadas.Máster en Ingeniería de Montes2020-01-302020-01-3

    The early stage of wood decay : wood/fungus interaction and its attraction to xylophagous coleoptera, especially cerambycids and their hymenopteran parasitoids

    No full text
    Loss of dead wood habitat and biodiversity has led to numerous excellent conservation based ecological and management studies. However, the structure of the xylophagous food web remains unclear for saproxylic xylophagous beetles and their parasitoid wasps, but fungi are believed to play an important role, both in direct and indirect nutritional acquisition and production of volatile chemicals. In the first study of its kind this thesis explores the importance of volatiles in host-searching behaviour and role of fungi in oviposition choice and larval nutrition, using three endophytic fungi, Stereum hirsutum, Stereum gausapatum and Eutypa spinosa, and two tree species Fagus sylvatica and Quercus robur, in early stage decay. Newly designed traps, excluding wood visual stimuli, provided the first evidence of wood-fungal volatile attraction by saproxylic wood-boring beetles, including primary and secondary xylophages, and their parasitoid wasps. Expanding on these results, the importance of fungi was further demonstrated through oviposition choice in field logs by two polyphagous cerambycid species. Ovipositing within or 20 mm from their preferred fungal species plug, females chose abiotic conditions suitable for sustaining fungal growth, suggesting a larval nutritional benefit. Further investigation, using one of the cerambycid species above, corroborated, via olfactometry, that volatiles from the preferred wood-fungal combination were attractants to gravid females, and induced ovipositor probing within the olfactometer. In addition, GC-EAG found six volatile compounds provoked an antennal response, including a monoterpene, two sesquiterpenes, an alkane and a ketone. Most importantly olfactometry and GC-EAG showed gravid females were unresponsive to wood or favored fungus presented singly. The result are discussed herein. In conjunction with the volatile only field trap experiment, a novel method to promote fungal only volatiles, by autoclaving the wood prior to sub-culturing, was trialed. GC-MS comparative analysis showed disparity between agar sub-cultured, autoclaved wood and natural wood with fungi, volatiles. This suggests that genes encoding cellulases and hemicellulases are regulated according to carbohydrate source, nutritional availability, oxygen and metal ions, supporting the variations observed. These results are discussed herein with regard to xylophagous beetles and their parasitoid wasps. The principal findings of this thesis are that wood-fungal interaction volatiles of the ephemeral early decay stage provide important olfactory host resource cues for saproxylic xylophagous beetles and their parasitoid wasps. Fungi, and particular, endophytic fungi, were shown to be a key component of the early stage xylophagous food web through volatile production, and as nutritional support evidenced by oviposition choice, olfactometry, GC-EAG and GC-MS analysis. This thesis has opened a new, exciting and important area of research with the potential to radically improve conservation management and employ a more holistic approach. These insights bring together the disparate research conducted individually on wood decay fungi, saproxylic xylophagous beetles and their parasitoid wasp

    Re-establishment of Devibursaphelenchus Kakuliya, 1967 (Nematoda, Aphelenchoididae) and proposal for a new combination of several Bursaphelenchus species

    No full text
    Among theca 100 known species of Bursaphelenchus, there are a few questionable taxa which share some morphological characters with this genus and other characters with the genera of the subfamily Ektaphelenchinae. B. lini and B. eproctatus are characterized, amongst other features, by having bursa, wide-lumened stylet, well developed oblong median bulb with posterior valve plates, and obscure/non-functional rectum and anus, that is, the same combination of diagnostic characters as B. typographi (syn. Devibursaphelenchus typographi). In this context, Devibursaphelenchus Kakuliya, 1967, for a long time regarded as a junior synonym of Bursaphelenchus, is re-established as a genus belonging to Ektaphelenchinae, and its generic definition is expanded. It is characterized by its lip region offset; V > 75; male tail conoid and curved ventrad, with terminal bursa, as in Bursaphelenchus; strong spicules with high condylus and, sometimes, hook-like distal terminus; absence of vulval flap; obscure rectum and anus in females, strongly sclerotized vagina, posterior placement of valve plates in metacorpus, lip region slightly trapezoid, and widelumened stylet ca 20 őľm long in common with Ektaphelenchus. Devibursaphelenchus lini (Braasch, 2004) comb. n. is proposed for Bursaphelenchus lini, D. eproctatus (Sriwati, Kanzaki, Phan & Futai, 2008) comb. n. for B. eproctatus, D. teratospicularis (Kakuliya & Devdariani, 1965) recomb. n. for B. teratospicularis and D. hunanensis (Yin, Fang & Tarjan, 1988) comb. n. for B. hunanensis. The taxonomic position of B. abruptus Giblin-Davis, Mundo-Ocampo, Baldwin, Norden & Batra, 1993 and B. minutus Walia, Negi, Bajaj & Kalia, 2003 is discussed

    Revised intra-generic grouping of Bursaphelenchus Fuchs, 1937 (Nematoda: Aphelenchoididae)

    No full text
    Based on a complex of characters, in particular the number of incisures in the lateral field, arrangement ofmale caudal papillae, presence or absence of vulval flap, spicule shape, position of excretory pore and length of postvulval uterus branch, the taxonomic grouping of Bursaphelenchus is revised. The genus is divided into seven groups with four incisures in the lateral field (xylophilus, okinawaensis, africanus, fungivorus, cocophilus, kevini and sexdentati groups), four groups with three incisures (eggersi, eremus, hofmanni and leoni groups) and two groups with two incisures (abietinus and sinensis groups). This system is supported by phylogenetic trees based on rDNA partial sequences (SSU, ITS1/2, LSU D2/D3). Several species could not be grouped and require further investigation. The four-incisure groups cluster together in a big clade in molecular trees, with the exception of the scolytid-vectored sexdentati group, which shares a big clade with the species having reduced number of incisures. Bursaphelenchus abruptus usually clusters outside the genus in molecular trees, as also do Devibursaphelenchus lini (syn. B. lini) and D. hunanensis (syn. B. hunanensis). Bursaphelenchus digitulus Loof, 1964 is newly combined to Parasitaphelenchus digitulus Loof, 1964. The groups are morphologically characterized, and a dichotomous key for their identification is given

    On the vulval morphology of some species of Bursaphelenchus (Nematoda: Parasitaphelenchinae)

    Get PDF
    The vulval pattern of six species of the genus Bursaphelenchus (B. abruptus, B. conicaudatus, B. fraudulentus, B. luxuriosae, B. mucronatus and B. xylophilus) was studied using scanning electron microscopy. A terminology for the vulval region structures observed is proposed herein and illustrated by micrographs and line drawings. It was shown that, of the studied species, only B. mucronatus and B. xylophilus share an identical morphology of the vulval region, all other species differing significantly from each other and from both B. mucronatus and B. xylophilus. This study indicates the diagnostic potential for variation in vulval morphology within Bursaphelenchus and it is recommended that such features are recorded in all future descriptions
    corecore