This document summarizes the results of a molecular re-evaluation of Phytophthora species isolated during 30 years of vegetation health surveys in Western Australia. Several key findings are reported: 1) At least seven new Phytophthora species were identified that are genetically distinct from currently described species; 2) The molecular identification of many isolates did not match the original morphological identification; and 3) Several Phytophthora species newly recorded in Western Australia were identified, including P. inundata, P. gonapodyides, and P. sp. asparagi. The significance of identifying new Phytophthora species is discussed.

1. Molecular re-evaluation of
Phytophthora species isolated during
30 years of vegetation health
surveys in Western Australia
Mike Stukely, Giles Hardy, Dianne White, Janet Webster,
Juanita Ciampini and Treena Burgess

2. Jarrah ForestNorthern sand plain
Black gravel site
Swan Costal Plain
Fitzgerald National Park

3. Impact of Phytophthora cinnamomi on plant species
in Western Australia
Direct Impacts
• Out of 5710 described species in the South-West Botanical Province
• 2285 species susceptible (40%)
• 800 highly susceptible (14%)
Indirect Impacts
• Loss of biomass
• Loss of litter
• Loss of refugia for fauna
• Loss of food resources
• Increased exposure
• Loss of pollinators
• Loss of nesting sites
Phytophthora is listed as a
‘KEY THREATENING PROCESS’
to Australia’s Biodiversity by
Commonwealth Government

4. Dieback mapping and vegetative health surveys
•For over 30 years aerial photography has been used to map the extent
of disease in WA
•Many areas are uninterpretable aerially and ‘Dieback Interpreters’ are
sent in to ground truth
•They are trained to recognise susceptible indicator species. First
indication of the presence of P. cinnamomi is the death of susceptible
indicator species from the families Proteaceae, Epacridaceae,
Dilleniaceae, Xanthorrhoeaceae, Fabaceae.
•Usually ground truth areas of native vegetation due to be logged
•Samples are taken (usually soil from rhizosphere of dying plants) and
sent to vegetation heath service (VHS)
•Soils are baited with cotyledons of Eucalyptus sieberi
•After 5(-10) days cotyledons are examined and plated onto selective
media
•About 15% of phytophthora isolates are not P. cinnamomi

5. Phytophthora Management Map
Green = Dieback free; Purple = Uninterpretable; Red = Infested
Uninterpretable
Disease-free
Phytophthora infested

6. Phytophthora species in natural ecosystems in WA
•Until recently indentified only by morphological features
P. citricola
P. megasperma
P. cryptogea
P. drechsleri
P. nicotianae
P. boehmeriae
•Other species are found in nurseries and in horticulture
•Over the past 2 years we have been conducting a molecular re-
evaluation of Phytophthora spp. in natural ecosystems in WA
•Over 250 isolates so far examined
•Sequenced ITS region and constructed molecular phylogeny

7. P. inundata
P.sp.6 = P. sp. personii
P.sp. 10
P.sp. 7
P.sp. 3
P.sp. 8
P.sp. 11
P. megasperma
P. gonapodyides
P. sp. hungarica
P. sp. sylvatica
P. sp. asparagi
P. inflata
P. citricola
P.sp. 4
P. tropicalis
P. capsici
P. multivesiculata
P. alticola
P. bisheria
P.sp. 2
P. arecae
P. frigida
P.sp. 1
P. nicotianae
P. cactorum
P. ilicis
P. katsurae
P. cambivora
P. cinnamomi
P. melonis
P. sp. niederhauseria
P. sojae
P. ramorum
P. drechsleri
P. cryptogea
P.sp. 5 = P. cryptogea
P. kernoviae
P. boehmeriae
P. captiosa
P. fallax
P.sp. 9
5 changes
Group 6
Group 2
Group 4
Group 1
Group 3
Group 5
Group 7
Group 8
Group 9
99
100
91
100
97
100
100
100
66
77
97
100
100
100
100
97
100
56
100
67
98
95
100
96
100
98
100
100
100
100
100
100
52 100
100
100
100
100
100
100
100
53
78
87
100
100
100
85
100
100
100
100
93
100
95
71
100
100
100
98
87
100
100
100
100
100
94
93
100

8. P. humicola
P. inundata
P. sp. personii
TCH 009 - P.sp. 10
VHS 17779 - P.sp. 10
Phytophthora sp. P462 AF541911
Phytophthora sp. P532 DQ512952
Phytophthora sp. PgChlamydo
P. gonapodyides
Phytophthora sp. P1049 AF541904
Phytophthora sp. P896 AF541903
VHS 9854 - P.sp. 7
DCE 68 - P.sp. 7
DDS 3599
P.sp. 3
VHS 16108
VHS 17350
P.sp. 8
VHS 16115
P.sp. 11
VHS 5185
P. megasperma
P. hungarica
P. sylvatica
P. sp. asparagi
P. citricola
P. nicotianae
P. boehmeriae
5 changes
96
93
100
91
100
100
64
68
88
82
100
100
97
80
82
77
100
67
51
91
96
65
54
52
88
100
100
100
100
100
100

9. Often the morphological and molecular
identifications do not match
Isolates Morphology DNA
Many P. citricola P.sp.4
Many P. citricola P.sp.2
All tested P. drechsleri P.sp.3/8
Two P. megasperma P.sp.7
Many P. megasperma P.sp.9
TCH009 P. megasperma var sojae P.sp.10
VHS17183 P. megasperma P. megasperma
All tested P. nicotianae P. nicotianae
All tested P. cinnamomi P. cinnamomi
All Tested P. cryptogea P. cryptogea

10. Phytophthora species in natural ecosystems in WA
•New records for WA
P. inundata
P. gonapodyides
P. sp. asparagi
P. sp. niederhauseria
P. sp. personii
•At least seven new Phytophthora species which are genetically
distinct to currently described species

11. Phytophthora species in natural ecosystems in WA
Banksia sp., X. preissii2P. sp. 11
B. prionotes, B. grandis2P. sp. 10
B. attenuata, B. baxteri, D. cirsioides, D. falcata, A.
cuneata, Isopogon sp.; Pinus radiata (plantation)
23P. sp. 9
Soil and water baits – native forest3P. sp. 8
X. preissii; Pinus radiata (plantation)4P. sp. 7
E. marginata, B. attenuata, B. grandis, B. littoralis, B.
menziesii, B. prionotes, Conospermum sp., Leucopogon
verticillatus, X. gracilis, Podocarpus drouyniana,
Patersonia sp., Bossiaea sp., Gastrolobium spinosum;
Pinus radiata (plantation)
64P. sp. 4
E. marginata, B. attenuata,
B. grandis; Pinus radiata (plantation)
15P. sp. 3
Eucalyptus marginata, Corymbia calophylla, B. grandis,
Dryandra squarrosa, Patersonia xanthina
21P. sp. 2
B. menziesii, B. littoralis,
B. attenuata, B media
10P. sp. 1
Host speciesNo.Species

15. Significance of new phytophthora species
•Do they pose a threat to biodiversity?
•If yes, then management strategies will be developed
•Need to investigate
host range/pathogenicity
distribution
factors affecting spread
•Are these species introduced?
•Are any of these species hybrids?