Elm Wood Nematode as the potential threat to the urban woodlands in the Russian North‐West Kristina POLYANINA, BSc (Forestry), Forestry & Technical University, St Petersburg (in coauthorsip with Alexander Ryss, ZIN RAS, St Petersburg ) Lammi‐Finland ‐ 2016
RESEARCH SUPPORT: GRANT 14‐14‐00621 OF THE RUSSIAN SCIENCE FOUNDATION PINE WOOD DISEASE (PWD) – how a model study
PWD Association:
‐ fungus Ophiostoma, vectored by ‐ beetles from the family Cerambycidae ‐ nematode Bursaphelenchus xylophilus Nematode life cycle THREE HOSTS, TWO GENERATION TYPES JJ – larvae R – resistant stage II: T – dauer juvenile TRANSMISSIVE GENERATION TYPE
I: PROPOGATIVE GENERATION TYPE Dutch elm disease( DED): origin & historic spread
The DED has been firstly detected in The Netherlands; the Ophiostoma ulmi pathogen imported from China to Europe during the First World War. And later spread to America. DED was detected in the Russian NW since 1990‐thies. Dutch Elm Disease (DED) caused devastation of the Ulmus spp.
• Association for DED: - Ophiostoma novo-ulmi, vectored by - Scolytus scolytus & Scolytus multistriatus ???but it is also possible??? ‐ nematodes of the genus Bursaphelenchus The symptoms of Dutch elm disease
• symptom "yellow flag" ‐ a wilting tree crown • Bark beetle galleries in sapwood • Beetle outlets in bark • wood color change (blue stain fungi) • Bore meal below the trunk RESEARCH GOAL To list the nematode biota of DED infected elm trees (Ulmus glabra and U. laevis), and to evaluate the pathogenicity expression the elm nematode pathogens to tree species parks in St. Petersburg RESEARCH TASKS
• to monitor the presence of wood nematodes and their beetle vectors in the DED detection points in St. Petersburg
• To conduct the phyto‐tests for specificity and pathogenicity to the elm wood nematodes on the local experimental woody plant hosts DED survey: detection Extraction of nematodes culturing Results DED sumptoms: Ulmus laevis trunk & bark, SPb, Krestovsky isl. New records of Dutch Elm Disease with the nematode detection (Bursaphelenchus) The vector beetle, larvae (visual detection) The Scolytus sp. beetle pupa under LM Biota of nematodes
SUBORDER FAMILY SPECIES 1 RHABDITINA RHABDITIDAE Protorhabditi sp. 2 DIPLOSCAPTERIDIDAE Diploscapter coronata (Cobb, 1893) 3 DIPLOGASTEROIDIDAE Rhabditolaimus ulmi (T.Goodey, 1930) 4 TYLENCHINA CEPHALOBIDAE Chiloplacus sp. 5 PANAGROLAIMIDAE Panagrolaimus rigidus (Schneider, 1866) 6 APHELENCHIDAE Aphelenchus avenae Bastian, 1865 7 APHELENCHOIDIDAE Ektaphelenchus scolyti Rühm, 1956 8 Bursaphelenchus ulmophilus Ryss, Polyanina, Popovichev et Subbotin, 2015, n. sp. Protorhabditis sp.
vulva Diploscapter coronata (Cobb, 1893) Rhabditolaimus ulmi (T.Goodey, 1930) Susoy et Herrmann 2012 Chiloplacus sp. Panagrolaimus rigidus (Schneider, 1866) Thorne, 1937:female Panagrolaimus rigidus (Schneider, 1866) Thorne, 1937:male Aphelenchus avenae Bastian, 1865 Ektaphelenchus scolyti Rühm, 1956 Ektaphelenchus scolyti Rühm, 1956 Bursaphelenchus ulmophilus Ryss, Polyanina, Popovichev et Subbotin, 2015, n. sp. Bursaphelenchus ulmophilus n.sp. female Key character of the genus Bursaphelenchus: BURSA at the end of male tail
BURSA B. ulmophilus, COPULATION (male uses BURSA to attach to female Phyto-tests. Methods. Rooted cuttings (left) & inoculation points (arrows) Table host plants
Name Oder Family Origin
Ulmus glabra Huds. ROSALES ULMACEAE St. Petersburg, parks
Rosa canina L. ROSALES ROSACEAE St. Petersburg, parks
Populus nigra L. MALPIGHIALES SALICACEAE St. Petersburg, parks
Salix sp. MALPIGHIALES SALICACEAE St. Petersburg, parks
Quercus robur L. FAGALES FAGACEAE St. Petersburg, parks
Betula pubescens Ehrh. FAGALES BETULACEAE St. Petersburg, parks
Acer platanoides L. SAPINDALES SAPINDACEAE St. Petersburg, parks
Pinus sylvestris L. PINALES PINACEAE St. Petersburg, parks
Larix decidua Mill. PINALES PINACEAE St. Petersburg, parks
Abies sibirica Ledeb. PINALES PINACEAE Leningrad region
Picea abies (L.) H.Karst. PINALES PINACEAE Leningrad region CONCLUSIONS: MONITORING
• Nematode biota of the DED‐ infected elm trees (Ulmus glabra & U. laevis) has been listed for the Russian NW • New records of Dutch elm disease in St. Petersburg parks have been mapped, with 100% detection of the beetle vectors Scolytus scolytus and S. multistriatus, and the new nematode pathogen BURSAPHELENCHUS ULMOPHILUS N.SP. associated with DED and vectored by Scolytus spp. was descrided CONCLUSIONS: laboratory tests: B. ulmophilus ‐ 11 woody plant species • B. ulmophilus - Ulmus glabra tests showed 100% wilt and lack of immune response of elm • NATIVE HOSTS: Ulmus glabra and Quercus robur ensured increase of a nematode number but the final density/control difference was not confirmed by statistical post-hoc analysis • ASYMPTOMATIC CARRIER: Populus nigra showed no wilt symptoms neither immune response to nematode infection, combining with high nematode population growth,. • SUSCEPTIBLE HOSTS: Plant hosts combining the strong immune response & high wilt expression, with a significant nematode population growth: Pinus sylvestris, Larix decidua, Abies sibirica. • POOR HOSTS: Hosts showing the nematode number reduction comparing to inoculum: conifers - Picea abies; deciduous - Acer platanoides, Betula pubescens, Salix sp, Rosa canina. Acknowlegement
• RESEARCH SUPPORT: GRANT 14‐14‐00621 OF THE RUSSIAN SCIENCE FOUNDATION • Participation in the Dead Wood Meeting‐ 2016: Lammi Biological station, Finland, and Dr Dmitry Shchigel Thank you for attention!