Biosecurity model for exotic and non-exotic plant ... · Plant parasitic nematodes cause documented losses of over $600 million/yr in Australia Australia currently lacks many damaging

biosecurity built on science Cooperative Research Centre for National Plant Biosecurity

S.K. Singh1,2,3, M. Hodda1,2,3, G.J. Ash 1,3 & D. Paini 2

1Cooperative Research Centre for National Plant Biosecurity 2CSIRO Ecosystem Sciences

3Charles Sturt University

Biosecurity model for exotic and non-exotic plant parasitic

nematodes

http://commons.wikimedia.org/wiki/File:Soybean_cyst_nematode_and_egg_SEM.jpg#file

biosecurity built on science

Plant parasitic nematodes

Majority are microscopic in size

Occupy various different niches

Variable life cycle and survival strategies

~ 2800 named plant parasitic nematode spp

Nearly 600 nematode spp cause economic damage to plants

- 200 spp listed as quarantinable by at least one country

- Approx. 50 genera


Biosecurity perspective

Plant parasitic nematodes cause documented losses of over $600 million/yr in Australia

Australia currently lacks many damaging nematode species

Increased trade volume and diversity increases risks of invasive species gaining entry

Quarantine measures prevent entry and spread of damaging nematode species

Market access


Objective

To determine nematode species which are likely to become pests in Australia

To establish a methodology for assessing biosecurity risks


Methods Nematode distribution data sources

- CABI crop protection compendium (2010)

- CABI pest distribution maps

- EPPO pest distribution maps

- Peer reviewed publications

- Australian nematodes List (Nobbs, 2003 and McLeod et al. 1994)

Stage 1: SOM analysis using SOM toolbox for MATLAB (Paini et al. 2010)

- 220 species

- 356 regions

- 11x 9 map with 99 neurons (5√n)


Results: SOM regional associations

Aust, Qld, S.Afr, China,

India, Pakistan

NT, Samoa, Tonga,

Mozambique, Sudan,

Brunei, Oman, Panama

11

4

3

2

1

10

9

7

8

6

5

13

12 67

14 25

23

24

18

22

20

16

17

19

15

21

78

26

29

27

33

31

32

89

30

28

40

42

44

43

41

36

34

38

35

37

39

46

48

45

50

49

47

51

52

66

53

55

54

59

57

58

60

61

62

63

64

65

56

90 79 68

69 80 91

71

92 81 70

72

93 82

73

94 83

74

95 84

96 85

97 86 75

98 87 76

77 99 88

NSW, USA,

Florida

SA, Vic, Uzbekistan,

Chile, Peru WA, Japan,

Korea, California

TAS,

Armenia,

Tajikistan

Key

Australian states

Other countries

Empty neurons


Top 10 A1 species

Nematode species SOM Risk index

Hirschmanniella oryzae 0.70498 Heterodera glycines 0.48359 Bursaphelenchus xylophilus 0.43284

Meloidogyne graminicola 0.4088 Ditylenchus destructor 0.35678 Zygotylenchus guevarai 0.35215 Bursaphelenchus mucronatus 0.34025 Globodera pallida 0.32358 Nacobbus aberrans 0.30883 Hoplolaimus (B.) indicus 0.30659


Top 10 A2 species

Nematode species SOM risk index

Present states

Aphelenchoides besseyi 0.68383 NT, Q Trichodorus sp. 0.654493 Q, V, WA Helicotylenchus pseudorobustus 0.60567 S, V, WA Criconemella sp. 0.603433 NSW Rotylenchulus reniformis 0.56097 NT, Q, WA Tylenchorhynchus claytoni 0.558895 Q Globodera rostochiensis 0.51113 V Xiphinema index 0.504903 V Longidorus sp. 0.498932 NSW, Q, V Scutellonema brachyurus 0.4678 NT, NSW, Q, S


Discussion

SOM can be used to determine regions with similar nematode assemblages hence identify potential source of invasive species

The risk levels of internal quarantine species are often greater than the external threats

Internal quarantine can be justified since the nematode species assemblages varied between the states


Nematode - Levels of threat

1. Species causing damage elsewhere and not present in Australia eg. Pale cyst nematode, Soybean cyst nematode

2. Species causing damage but with restricted distribution and under internal quarantine eg. Golden cyst nematode

3. Species emerging as a result of changing crops, practices or climate eg. Root lesion nematode after Cereal cyst nematode

4. Species damaging only under certain circumstances or in restricted areas eg. Pine wilt nematode


Nematode - Levels of threat

5. Pathotypes or races, which differ in host relations and pathogenicity eg. Stem and bulb nematode

6. Poorly known threat from species closely related to known pathogenic species eg. Corn cyst nematode related to Potato cyst nematode

7. Unknown threat from recently-described and currently undescribed species eg. Paradolichodera tenuissima, Pea root-knot nematode, Carrot root-knot nematode


Future work

Detailed analysis of selected species based on

Host availability

Climatic suitability

Biological characteristics

Pathways, trade and interception records

Detection and diagnostic capability


Thank you For more information,

Email: [email protected]

Phone: 02 6246 4417

CRC National Plant Biosecurity for PhD scholarship and travel grant

Acknowledgements

References McLeod R. et al. 1994. Plant nematodes of Australia. 3rd edition,

Department of Primary Industries, Canberra.

Nobbs, J. M. 2003. Plant parasitic nematodes of Australia.

SARDI, Adelaide South Australia.

Paini, D.R. et al. 2010.Threat of invasive pests from within

national borders. Nat. Commun. 1:115 doi: 10.1038/ncomms1118.

mailto:[email protected]

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Biosecurity model for exotic and non-exotic plant ... · Plant parasitic nematodes cause documented losses of over $600 million/yr in Australia Australia currently lacks many damaging