Current threaths in Scotland

by Dr. Sarah Green, Forest Research

Transcript

1. Current threats to tree health in Scotland Sarah Green Forest Research Northern Research Station
2. 26/11/2013 2 Emerging pathogens since 2004 • Chalara fraxinia (2012) • Phytophthora austrocedrae (2011) • Phytophthora lateralis (2010) • Phytophthora ramorum on larch (2010) • Phytophthora kernoviae (2008/9) • Dothistroma septosporum (2005) • Horse chestnut bleeding canker (2004)
3. Ash dieback disease
4. 26/11/2013 4 Ash dieback disease 2012
5. 26/11/2013 5 Chalara fraxinea /Hymenoscyphus pseudoalbidus causal agent, although this wasn’t confirmed until 2010 Origin – new evidence suggests Japan Widespread throughout continental Europe Ash dieback disease
6. 26/11/2013 6 Ash dieback disease Confirmed site infections in UK as of 21 October 2013 Nurseries 24 Recent planting 343 Wider environment 234 TOTAL 601
7. 26/11/2013 7 Ash dieback disease
8. 26/11/2013 8 Ash dieback disease
9. 26/11/2013 9 • Spores are dispersed in wind and rain (spores survive a few days) • Spores produced from infected dead leaves from July to September • The disease will attack any species of ash and symptoms appear within months rather than years • Wood products will not spread the disease if treated properly • Once infected, trees can’t be cured • Not all trees die of infection, and some are likely to have genetic resistance Ash dieback disease
10. 26/11/2013 10 Look out for trees with dead tops and side shoots, or plants with tops that have wilted since the start of the growing season Lesions on stems associated with dead side shoots. Ash dieback disease
11. 26/11/2013 11 Basal stem lesions may also occur National Plan for Chalara available on FC website http://www.forestry.gov.uk/chalara Ash dieback disease
12. 26/11/2013 12 Phytophthora ramorum First reported in Britain in 2002 P. ramorum an aerial infecting pathogen, infecting leaves and shoots, as well as bark Maritime climate of western British Isles ideal for Pr Pr became widespread on Rhododendron Rhododendron is a major host – spore production and spread Commonly found on range of foliar hosts in nurseries and garden centres
13. 26/11/2013 13 Bleeding lesions on beech Inoculum from rhododendrons Pr spread to broadleaves
14. 26/11/2013 14 Pr on larch In 2009 Pr first reported on Japanese larch First finding of infections on a conifer species Spread to Wales, NI and Scotland Impact on other conifer spp. growing locally (WH, DF, GF)
15. 26/11/2013 15 Infected maturing larch commonly 20-25m tall Young larch (5-8 yr) probably infected from the mature larch
16. 26/11/2013 16 Pr produces spores on foliage – important source of inoculum allowing aerial spread of the disease – felling of infected trees essential Pr foliar symptoms on larch
17. 26/11/2013 17 Multiple stem cankers on larch
18. 26/11/2013 18 Pr spread Pr sporulates abundantly on larch needles Local splash dispersal over a few metres Sporangia can be dispersed in wind/wind-driven rain up to 4 km Dispersal over tens of kilometres due to human assisted movement
19. 26/11/2013 19 Pr persistence Pr produces chlamydospores on infected tissue These spores may persist for years Replanting must take into account this residual inoculum Use of susceptible hosts to be avoided!
20. 26/11/2013 20 Pr distribution on larch in Scotland Aerial surveys in 2013 revealed major expansion of infected larch in Dumfries and Galloway 4000-6000 Ha larch now likely to be infected in SW Scotland Wet and windy conditions in 2012 may have aided spread
21. 26/11/2013 21 How to manage Pr Rapid action of felling larch trees appears to have been effective Devon and Cornwall worst affected – over 3000 Ha of larch felled here But 75% larch stands in the West Country remain unaffected Very dry periods during spring and autumn – peak sporulation times – may help contain epidemic Surveillance will be a very important part of disease control
22. 26/11/2013 22 Phytophthora lateralis on Lawson cypress
23. 26/11/2013 23 Phytophthora lateralis outbreaks in UK
24. 26/11/2013 24 Basal lesions on Lawson cypress
25. 26/11/2013 25 P. lateralis aerial infection
26. 26/11/2013 26 P. lateralis on other species
27. Phytophthora austrocedrae – an emerging pathogen on juniper in Britain
28. 26/11/2013 28 Phytophthora austrocedrae first described in 2007 associated with widespread decline of Austrocedrus chilensis in Patagonia (mal del cipres) In Britain the pathogen was first recorded by FR on Lawson cypress and Nootka cypress in the Glasgow area in 2011 Phytophthora austrocedrae
29. 26/11/2013 29 Juniper dieback at Teesdale
30. 26/11/2013 30 First record on juniper Green, S., Hendry, S.J., MacAskill, G.A., Laue, B.E., Steele, H. 2012. Dieback and mortality of Juniperus communis in Britain associated with Phytophthora austrocedrae. New Disease Reports 26, 2.
31. 26/11/2013 31 P. austrocedrae in England Results of FERA survey of juniper in England and Wales 10 (?) sites in Lake District confirmed as infected so far Upper Teesdale and Yorkshire Dales Found in three nurseries Isolated from J. horizontalis
32. 26/11/2013 32 P. austrocedrae in Scotland Infected juniper sites in Scotland (so far) Add to this findings of the pathogen on Lawson and Nootka cypress in Glasgow Also findings on juniper planted in 3 private gardens in Glasgow area Is the pathogen native or introduced to Britain ?, and how has it spread from site to site ? Look to DNA sequence data for clues
33. 26/11/2013 33 P. austrocedrae diagnostic test Isolates of P. austrocedrae from Britain are genetically uniform but distinct from the Argentinian isolates (which are almost clonal) Probably introduced to Britain and Argentina from an unknown origin DNA sequence data used to design real-time PCR detection assay for tracking pathways of spread within Britain/Argentina Paus-481-F Paus-554-R Paus-507-TM TGTGGCGGTACGAACTGGTGAACCGTAGCTGTATTTAAGCTTGGCATTTGAACCGGCGATGTGGTGCGAAGTAGAGTGGCGGTTGTTCCGGCGCAAGCTG P. austrocedrae TDJ3 (JQ346527) TGTGGCGGTACGAACTGGTGAACCGTAGCTGTATTTAAGCTTGGCATTTGAACCGGCGATGTGGTGCGAAGTAGAGTGGCGGTTGTTCCGGCGCAAGCTG P. austrocedrae RG04 (JQ346530) TGTGGCGGTACGAACTGGTGAACCGTAGCTGTATTTAAGCTTGGCATTTGAACCGGCGATGTGGTGCGAAGTAGAGTGGCGGTTGTTCCGGCGCAAGCTG P. austrocedrae 10 113 100 (JQ346531) TGTGGCGGTACGAACTGGTGAACCGTAGCTGTATTTAAGCTTGGCATTTGAACCGACGATGTGGTGCGAAGTAGAGTGGCGGTTGTTCCGGCGCAAGCTG P. austrocedrae AG203 (DQ995184) TGTGGCGGTACGAACTGGTGAACCGTAGCTGTATTTAAGCTTGGCATTTGAACCGACGATGTGGTGCGAAGTAGAGTGGCGGTTGTTCCGGCGCAAGCTG P. austrocedrae AG195 (DQ995185) TGTGGCGGTACGAACTGGTGAACCGTAGCTGTATTTAAGCTTGGCATTTGAACCGACGATGTGGTGCGAAGTAGAGTGGCGGTTGTTCCGGCGCAAGCTG P. austrocedrae P15132 (HQ261500) TGTGGCGGTACGAACTGGTGAACCGTAGCTGTATTTAAGCTTGGCATTTGAACCGACGATGTGGTGCGAAGTAGAGTGGCGGTTGTTCCGGCGCAAGCTG P. austrocedrae P16040 (HQ261499) TGTGGTGGTACGAACTGGTGAACCGTAGCTGTGTTTG-GCTTGGCTTTTGAACTGGCGATGTGGTGCGAAGTAGAGTGACGGTTGTTCCGGCGCAAGCTG P. syringae 8919 (EU000103) TGTGGCGGTACGAACTGGTGAACCGTAGCTGTGTTTG-GCTTGGCTTTTGAACTGGCGATGTGGTGCGAAGTAGAGTGACGGTTGTTCCGGCGCAAGCTG P. syringae AG5 (AY787034) TGTGGTGGTACGAACTGGTGAACCGTAGCTGTGTTTG-GCTTGGCTTTTGAACTGGCGATGTGGTGCGAAGTAGAGTGACGGTTGTTCCGGCGCAAGCTG P. primulae CBS 275.74 (DQ335635) TGTGGCGGTACGGACTGGTGAACCGTAGCTGTGCGAG-GCTTGGCTTTTGAATCGGCGATGTGGTGCGAAGTAGAGTGGCTGTT----CGGCGCAAGCTG P. foliorum P10970 (HQ261560) TGTGGTGGGACGGACTGGTGAACCGTAGCTGTACTAG-GCTTGGCGTTTGAACTGGCGGTGTGGTGCGAAGTAGGGTGTCTGTT---CCGGCGCAAGCTG P. megasperma BR331 (DQ831524) TGTGGCGGGACGGACTGGTGAACCGTAGCTGTGCTAG-GCTTGGCGTTTGAACCGGCGGTGTGGTGCGAAGTAGGGTGTCTGTT---CCGGCGCAAGCTG P. medicaginis x cryptogea (AY995389) TGTGGCGGGACGGACTGGTGAACCGTAGCTGTGCTAG-GCTTGGCGTTTGAACCGGCGGTGTGGTGCGAAGTAGGGTGTCTGTT---CCGGCGCAAGCTG P. sansomea CBS 117692 (DQ275186) TGTGGCGGGACGGACTGGTGAACCGTAGCTGTGCTAG-GCTTGGCGTTTGAACCGGCGGTGTGGTGCGAAGTAGGGTGTCTGTT---CCGGCGCWAGCTG P. trifolii BR530 (DQ821183) TGTGGCTGGATGGACTGGTGAACCGTAGCTGTGCTAG-GCTTGGCGTTTGAACCGGCGGTGTGGTGCGAAGTAGGGTGTCTGTT---CCGGCGTAAGCTG P. erythroseptica BR664 (HQ643226) TGTGGCTGGATGGACTGGTGAACCGTAGCTGTGCTAG-GCTTGGCGTTTGAACCGGCGGTGTGGTGCGAAGTAGGGTGTCTGTT---CCGGCGCAAGCTG P. andina P13780 (FJ801754) TGTGGCTGGATGGACTGGTGAACCGTAGCTGTGCTAG-GCTTGGCGTTTGAACCGGCGGTGTGGTGCGAAGTAGGGTGTCTGTT---CCGGCGTAAGCTG P. richardiae P10811 (FJ801518) V. Mulholland, A. Schlenzig, G.A. MacAskill, S. Green. 2013. Development of a quantitative real-time PCR assay for the detection of Phytophthora austrocedrae, an emerging pathogen in Britain. Forest Pathology doi:10.1111/efp.12058.
34. 26/11/2013 34 Current research Morphological and genetic comparison of British and Argentinian isolates Distribution of P. austrocedrae in Britain and elsewhere (Europe and North America) Host range testing – results Resistance in juniper population ?
35. 26/11/2013 35 Current research Epidemiology - spread and survival in soil – detection in water, including rainwater - using real-time PCR
36. 26/11/2013 36 Range of field symptoms
37. 26/11/2013 37 Range of field symptoms
38. 26/11/2013 38 P. austrocedrae aerial lesion on juniper
39. 26/11/2013 39 Range of field symptoms
40. 26/11/2013 40 Range of field symptoms
41. 26/11/2013 41 Dothistroma needle blight Dothistroma needle blight (Dothistroma septosporum) Infects Corsican pine, lodgepole pine and Scots pine (80+ Pinus hosts) Notifiable disease if found in nursery
42. 26/11/2013 42 Dothistroma needle blight Infection occurs June/July: wetter, warmer springs aid spore dispersal and infection Symptoms first appear on needles in late autumn: bands and spots Diagnosis can be confirmed in May-July the following year as pycnidia become visible, discharge conidia Infected older needles are shed in late summer
43. 26/11/2013 43 DNB on Corsican pine On CP, disease starts in the lower crown Premature defoliation Decreased yield Mortality occurs in severe cases
44. 26/11/2013 44 DNB on lodgepole pine Damage can be very severe on inland provenance LP stands over 40 years old Red banding may be weak or absent on needles of LP
45. 26/11/2013 45 DNB on Scots pine
46. 26/11/2013 46 2013 Survey results District CP LP SP Total Cowal & Trossachs 2 1 3 Dumfries and Borders 1 2 3 Galloway 10 4 14 Inverness, Ross & Skye 28 13 41 Lochaber 3 1 4 Moray and Aberdeenshire 31 19 50 North Highland 15 14 29 Scottish Lowlands 1 5 12 18 Tay 3 6 9 West Argyll 7 1 8 Total 1 105 73 169 FES 27/08/2013 - 533 samples received Private sector/FR Scotland 27/08/2013 - 364 samples received; 6 LP, 59 SP and 1 Cedrus alantica glauca
47. 26/11/2013 47 Caledonian Pine survey 2013 Hosts and impact Sites selected based on; 1. Distance to nearest known DNB 2. Native woodland area in the site 3. Geographic coverage Within each of the selected CPI; 1. Visible Regeneration (VR), Established Regeneration (ER) and Immature Pole (IP) stages previously identified in the NWSS survey 2. Planted pine stands of all species (i.e. including LP) under 30 ys old
48. 26/11/2013 48 Caledonian pinewood survey 2013 Crathie YES Abernethy YES Torphantrick YES Strath Oykel YES Rothiemurchus YES Glen Affric and Glengarry YES Ben Mallie No Coille Coire No Ballochbuie (Creag Clunie) No Creag Ghiubhas No All DNB positives on established regeneration
49. 26/11/2013 49 Management – Resistance/ breeding • Some disease resistance reported within species Varieties of P. nigra from Serbia and Bosnia Herzegovina and P. ponderosa from the Rocky Mountains • P. radiata breeding programme in New Zealand Families and hybrids of radiata pine that incorporate Dothistroma resistance predicted to have a 12% reduction in crown infection • Two students are currently looking at the genetic and phenotypic variability in populations of SP and LP • Initial results suggest that some populations of SP may be more susceptible than others.
50. 26/11/2013 50 Management options for DNB • Control on movement of plants from infected nurseries • No chemicals permitted for disease control in forestry situations • Thinning can help reduce disease impact and mortality • Re-spacing trials currently underway
51. 26/11/2013 51 Summary • Increasing number of newly emerging diseases over the last ten years • New Phytophthora diseases present a huge risk to amenity and forest trees in Scotland • International trade in live plant material plays a role in disease spread • Attempts to eradicate Phytophthora spp., but Chalara and DNB will have to be lived with